Patent Application
20150056193
This disclosure relates generally to proteins and genes involved in cancer (e.g., human cancer), and to the detection, diagnosis and treatment of cancer.
Many cancers are characterized by disruptions in cellular signaling pathways that lead to aberrant control of cellular processes including growth and proliferation. These disruptions are often caused by changes in the activity of particular signaling proteins, such as kinases.
In some cases, aberrant expression or activity of protein kinase proteins can be a causative agent of (and a driver of) cancer. Aberrant expression or activity can be caused, e.g., by activating mutations that increase kinase activity of the protein, fusion of the protein (or kinase portion thereof) with a secondary protein (or portion there), expression of a truncated portion of the protein, or by abnormal regulation of expression of the full-length protein.
The oncogenic role of receptor tyrosine kinases (RTKs) have been implicated in blood cancers such as lymphoma and leukemia, as well as many types of solid tumor cancers including, lung cancer, colon cancer, liver cancer, brain cancer, and breast cancer. Unfortunately solid tumors cancer is often not diagnosed at an early stage, and it often does not respond completely to surgery even when combined with chemotherapy or radiotherapy. For example, non-small cell lung carcinoma NSCLC is the leading cause of cancer death in the United States, and accounts for about 87% of all lung cancers. See “Cancer Facts and Figures 2005,” American Cancer Society.
Thus, it would be useful to discover new ways to identify cancer at an early stage, and new ways (and new reagents) to treat cancer.
This disclosure is based, at least in part, upon the discovery that epidermal growth factor receptor (EGFR) mutations and c-ros oncogene 1 (ROS1) fusions may be co-expressed in tumors. This discovery can allow for identification of patients whose tumors can benefit from therapy with one or both of an EGFR-inhibiting therapeutic or a ROS1-inhibiting therapeutic.
Accordingly, in one aspect the disclosure features methods that include detecting in a biological sample from a patient having or suspected of having cancer the presence of a polypeptide having ROS1 kinase activity or a polynucleotide encoding the same and detecting in the biological sample the presence of a mutant EGFR polypeptide or a polynucleotide encoding the same. In some embodiments, the sample is from a tumor. In some embodiments, the sample is from the lung of the patient. The sample may be from a cancer or carcinoma, e.g., a lung cancer (e.g., a non-small cell lung cancer).
The polypeptide having ROS1 kinase activity can be, e.g., a ROS1 fusion. Exemplary ROS1 fusions include SLC34A2-ROS1 fusion proteins, CD74-ROS1 fusion proteins, and FIG-ROS1 fusion proteins, TPM3-ROS1 fusion proteins (Takeuchi et al., 2012, Nat. Med., 18:378-381), SDC4-ROS1 fusion proteins (Id.), EZR-ROS1 fusion proteins (Id.), and LRIG3-ROS1 fusion proteins (Id.).
The mutant EGFR polypeptide can include a mutation in the kinase domain of EGFR. Exemplary mutations include deletions in exon 19 and the mutation of leucine at residue 858 to arginine (L858R).
One or both of detecting the presence of a polypeptide having ROS1 kinase activity and detecting the presence of a mutant EGFR polypeptide can include, e.g., the use of an antibody (e.g., a ROS1 fusion or EGFR mutant specific antibody) and/or the use of mass spectrometry. One or both of detecting the presence of a polynucleotide encoding a polypeptide having ROS1 kinase activity and detecting the presence of a polynucleotide encoding a mutant EGFR polypeptide can include, e.g., the use of one or more of in situ hybridization, nucleic acid amplification, and nucleic acid sequencing.
In some embodiments, the methods further include treating the patient with one or both of an inhibitor of ROS1 kinase activity and an EGFR inhibitor. In some embodiments, the patient is treated with one compound that inhibits ROS1 kinase activity and EGFR, e.g., AP26113.
In another aspect, the disclosure features methods of treating a patient for cancer that include determining that a biological sample from a tumor in the patient includes a polypeptide having ROS1 kinase activity or a polynucleotide encoding the same and a mutant EGFR polypeptide or a polynucleotide encoding the same and administering to the patient a therapeutically effective amount of a ROS1 inhibitor (e.g., crizotinib, ASP3026, NVP TAE-684, CH5424802, and AP26113) and an EGFR inhibitor (e.g., gefitinib, erlotinib, cetuximab, afatinib, necitumumab, nimotuzumab, PF299804, RO5083945, ABT-806, and AP26113), thereby treating the patient for cancer.
In some embodiments, the tumor is a lung cancer, e.g., a carcinoma or non-small cell lung cancer.
The polypeptide having ROS1 kinase activity can be, e.g., a ROS1 fusion. Exemplary ROS1 fusions include SLC34A2-ROS1 fusion proteins, CD74-ROS1 fusion proteins, and FIG-ROS1 fusion proteins.
The mutant EGFR polypeptide can include a mutation in the kinase domain of EGFR. Exemplary mutations include deletions in exon 19 and the mutation of leucine at residue 858 to arginine (L858R).
In another aspect, the disclosure provides methods of treating a patient for cancer, that include: detecting the presence in a biological sample from a patient having or suspected of having cancer of one or more polypeptides selected from the group consisting of a polypeptide having ROS1 kinase activity, a polypeptide having anaplastic lymphoma kinase (ALK) kinase activity, and a mutant EGFR polypeptide; and administering a therapeutically effective amount of one or more of an ALK/ROS1-inhibiting therapeutic and an EGFR-inhibiting therapeutic to the patient, thereby treating the patient for cancer. In some embodiments, the detecting step is performed by using a reagent that specifically binds to a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, or a mutant EGFR polypeptide.
In some embodiments, the detecting step is performed by using a reagent that specifically binds to a polynucleotide encoding a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, or a mutant EGFR polypeptide.
In a further aspect, the disclosure provides methods for identifying a patient with cancer or suspected of having cancer as a patient likely to respond to an ALK-inhibiting therapeutic that include: contacting a biological sample from a patient with a first reagent that specifically binds a polypeptide having ROS1 kinase activity and a second reagent that specifically binds to a polypeptide having ALK kinase activity and detecting whether the first reagent or the second reagent specifically binds to the biological sample, wherein detection of binding of either the first reagent or the second reagent to the biological sample identifies the patient as a patient likely to respond to an ALK-inhibiting therapeutic.
In a further aspect, the disclosure provides methods for identifying a patient with cancer or suspected of having cancer as a patient likely to respond to an ALK-inhibiting therapeutic, that include: contacting a biological sample from a patient with a first reagent that specifically binds a polypeptide having ROS1 kinase activity or specifically binds to a polynucleotide encoding a polypeptide having ROS1 kinase activity and a second reagent that specifically binds to a polypeptide having ALK kinase activity or specifically binds to a polynucleotide encoding a polypeptide having ALK kinase activity and detecting whether the first reagent or the second reagent specifically binds to the biological sample, wherein detection of binding of either the first reagent or the second reagent to the biological sample identifies the patient as a patient likely to respond to an ALK-inhibiting therapeutic.
In various embodiments, the first reagent specifically binds to full length ROS1 kinase protein. In various embodiments, the second reagent specifically binds to full length ALK kinase protein. In various embodiments, the first reagent specifically binds to the kinase domain of ROS1 kinase protein. In various embodiments, the second reagent specifically binds to the kinase domain of ALK kinase protein. In some embodiments, the first reagent is an antibody. In some embodiments, the second reagent is an antibody.
In various embodiments of the above methods, the patient is a human patient and the cancer (or suspected cancer) is from a human. In some embodiments, the ROS1-inhibiting therapeutic or the ALK-inhibiting therapeutic is PF-02341066, NVP TAE-684, or AP26113. In some embodiments, the ROS1-inhibiting therapeutic or ALK-inhibiting therapeutic is AP26113, CEP-14083, CEP-14513, CEP11988, CH5424802, WHI-P131 and WHI-P154.
In various embodiments of the above methods, the biological sample is from the cancer or suspected cancer of the patient. In some embodiments, the cancer is a solid tumor cancer. In some embodiments, the cancer is leukemia. In some embodiments, the cancer is lymphoma. In some embodiments, the cancer is a lung cancer (e.g., a non-small cell lung carcinoma or a small cell lung carcinoma). In some embodiments, the cancer is a brain cancer (e.g., glioblastoma). In some embodiments, the cancer is a liver cancer (e.g., cholangiocarcinoma). In some embodiments, the cancer is colon cancer. In some embodiments, the cancer is breast cancer. In some embodiments, the cancer is ovarian cancer.
In further embodiments of the above methods, the biological sample is selected from the group consisting of a tumor biopsy, a bronchoalveolar lavage, a circulating tumor cell, a tumor resection, a fine needle aspirate, a lymph node, a bone marrow sample, and an effusion (e.g., pleural effusion).
In some embodiments of the above methods, the detection reagents (e.g., antibodies) are detectably labeled. In another embodiment, a reagent (or first reagent) specifically binds to a full length ROS1 polypeptide. In another embodiment, a reagent (or first reagent) specifically binds to a ROS1 kinase domain. In another embodiment, a reagent (or first reagent) specifically binds to a ROS1 fusion polypeptide (e.g., specifically binds to a CD74-ROS1 fusion polypeptide, an SLC34A2-ROS1(S) polypeptide, an SLC34A2-ROS1(L) polypeptide, an SLC34A2-ROS1(VS) polypeptide, a FIG-ROS1 (L) polypeptide, a FIG-ROS1(S) polypeptide, or a FIG-ROS1(VL) polypeptide. In various embodiments, the polypeptide having ROS1 kinase activity (to which a detection reagent specifically binds) includes the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 27, SEQ ID NO: 24, SEQ ID NO: 22, SEQ ID NO: 26, SEQ ID NO: 13, SEQ ID NO: 7, SEQ ID NO: 5, or SEQ ID NO: 11. These ROS1 fusions have been previously described (see U.S. Patent Publication Nos. 20100221737 and 20100143918, and PCT Publication No, WO2010/093928, all of which are hereby incorporated by reference in their entirety).
In some embodiments of the above methods, a reagent (e.g., or first reagent) specifically binds to full length ALK polypeptide. In some embodiments, the reagent specifically binds to an ALK kinase domain. In some embodiments, the reagent (or second reagent) specifically binds to an ALK fusion polypeptide selected from the group consisting of NPM-ALK, ALO17-ALK, TFG-ALK, MSN-ALK, TPM3-ALK, TPM4-ALK, ATIC-ALK, MYH9-ALK, CLTC-ALK, SEC31L1-ALK, RANBP2-ALK, CARS-ALK, EML4-ALK, KIF5B-ALK, and TFG-ALK.
In various embodiments of the above methods, the polypeptide having ROS1 kinase activity is a full-length ROS1 polypeptide. In another embodiment, the polypeptide is a ROS1 fusion polypeptide. In another embodiment, the ROS1 fusion polypeptide is selected from the group consisting of a CD74-ROS1 fusion polypeptide, an SLC34A2-ROS1(S) polypeptide, an SLC34A2-ROS1(L) polypeptide, an SLC34A2-ROS1(VS) polypeptide, a FIG-ROS1 (L) polypeptide, a FIG-ROS1(L) polypeptide, and a FIG-ROS1(VL) polypeptide. In various embodiments, the polypeptide having ROS1 kinase activity includes the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 27, SEQ ID NO: 24, SEQ ID NO: 22, SEQ ID NO: 26, SEQ ID NO: 13, SEQ ID NO: 7, SEQ ID NO: 5, or SEQ ID NO: 11.
In various embodiments of the above methods, the polypeptide having ALK kinase activity is full length ALK polypeptide. In another embodiment, the polypeptide is an ALK fusion polypeptide. In another embodiment, the ALK fusion polypeptide is selected from the group consisting of NPM-ALK, ALO17-ALK, TFG-ALK, MSN-ALK, TPM3-ALK, TPM4-ALK, ATIC-ALK, MYH9-ALK, CLTC-ALK, SEC31L1-ALK, RANBP2-ALK, CARS-ALK, EML4-ALK, KIF5B-ALK, and TFG-ALK.
In some embodiments, the above methods are implemented in a format selected from the group consisting of a flow cytometry assay, an in vitro kinase assay, an immunohistochemistry (IHC) assay, an immunofluorescence (IF) assay, an Enzyme-linked immunosorbent assay (ELISA) assay, and a western blotting analysis assay.
In some embodiments of the above methods, the kinase activity of a polypeptide (e.g., a polypeptide having ALK kinase activity, a polypeptide having ROS1 kinase activity, or a mutant EGFR polypeptide) is detected. In further embodiments, a detection reagent is a heavy-isotope labeled (AQUA) peptide. In another embodiment, the heavy-isotope labeled (AQUA) peptide includes an amino acid sequence that includes a fusion junction of an ROS1 fusion polypeptide, a fusion junction of an ALK fusion polypeptide, or a fragment of a mutant EGFR polypeptide that includes a mutant amino acid sequence. In another embodiment, the method is implemented using mass spectrometry analysis.
In some embodiments, where the polynucleotide is detected, a detection reagent (e.g., or the first reagent and second reagent) is a nucleic acid probe. In some embodiments, the reagent is detectably labeled. In another embodiment, the nucleic acid probe is a fluorescence in-situ hybridization (FISH) probe and said method is implemented in a FISH assay. In another embodiment, the nucleic acid probe is a polymerase chain reaction (PCR) probe and said method is implemented in a PCR assay.
In another aspect, the disclosure provides methods for inhibiting the progression of a mammalian cancer or suspected mammalian cancer that expresses one or more of a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, and a mutant EGFR polypeptide, said methods including the step of inhibiting the expression and/or activity of one or more of the polypeptide having ROS1 kinase activity, the polypeptide having ALK kinase activity, and the mutant EGFR polypeptide in said mammalian cancer or suspected mammalian cancer.
In another aspect, the disclosure provides methods for inhibiting the progression of a mammalian cancer or suspected mammalian cancer that expresses one or more polynucleotides encoding a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, and a mutant EGFR polypeptide that include a step of inhibiting the expression of one or more of the polynucleotides in said mammalian cancer or suspected mammalian cancer.
In further aspects, the disclosure provides methods for determining whether a compound inhibits the progression of a mammalian lung cancer or suspected mammalian lung cancer characterized by the expression of a first polypeptide with ROS1 activity, a second polypeptide with ALK activity, and/or a third polypeptide with EGFR activity that include a step of determining whether said compound inhibits the expression of said first, second, or third polypeptide in said cancer. In some embodiments, the cancer is from a human.
This disclosure is based, at least in part, upon the discovery that EGFR mutations and ROS1 fusions may be co-expressed in tumors. This discovery can allow for identification of patients whose tumors can benefit from therapy with one or both of an EGFR pathway-inhibiting therapeutic or a ROS1 pathway-inhibiting therapeutic.
The published patents, patent applications, websites, company names, and scientific literature referred to herein establish the knowledge that is available to those with skill in the art and are hereby incorporated by reference in their entirety to the same extent as if each was specifically and individually indicated to be incorporated by reference. Any conflict between any reference cited herein and the specific teachings of this specification shall be resolved in favor of the latter.
Further aspects, advantages, and embodiments are described in more detail below. The patents, published applications, and scientific literature referred to herein establish the knowledge of those with skill in the art and are hereby incorporated by reference in their entirety to the same extent as if each was specifically and individually indicated to be incorporated by reference. Any conflict between any reference cited herein and the specific teachings of this specification shall be resolved in favor of the latter. Likewise, any conflict between an art-understood definition of a word or phrase and a definition of the word or phrase as specifically taught in this specification shall be resolved in favor of the latter. As used herein, the following terms have the meanings indicated. As used in this specification, the singular forms “a,” “an” and “the” specifically also encompass the plural forms of the terms to which they refer, unless the content clearly dictates otherwise. The term “about” is used herein to mean approximately, in the region of, roughly, or around. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20%.
Technical and scientific terms used herein have the meaning commonly understood by one of skill in the art to which the present disclosure pertains, unless otherwise defined. Reference is made herein to various methodologies and materials known to those of skill in the art. Standard reference works setting forth the general principles of antibody and recombinant DNA technology, all of which are incorporated herein by reference in their entirety, include Harlow and Lane, Antibodies, a Laboratory Manual, Cold Spring Harbor Laboratory Press, New York (1988), Ausubel et al. Current Protocols in Molecular Biology, John Wiley & Sons, New York, N.Y. (1989 and updates through September 2010), Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor Laboratory Press, New York (1989); Kaufman et al., Eds., Handbook of Molecular and Cellular Methods in Biology in Medicine, CRC Press, Boca Raton (1995); McPherson, Ed., Directed Mutagenesis: A Practical Approach, IRL Press, Oxford (1991). Standard reference works setting forth the general principles of pharmacology, all of which are incorporated herein by reference in their entirety, include Goodman and Gilman's The Pharmacological Basis of Therapeutics, 11th Ed., McGraw Hill Companies Inc., New York (2006).
Accordingly, in a first aspect, the disclosure provides methods of treating a patient for cancer that include: detecting in a biological sample from a patient having or suspected of having cancer the presence of one or both of a polypeptide selected from the group consisting of a polypeptide having ROS1 kinase activity and an mutant EGFR polypeptide; and administering a therapeutically effective amount of one or both of an EGFR pathway-inhibiting therapeutic or a ROS1 pathway-inhibiting therapeutic, thereby treating the patient for cancer. In some embodiments, the detecting step is performed by using a reagent that specifically binds to either a polypeptide having ROS1 kinase activity or a mutant EGFR polypeptide.
Human ROS1 kinase protein (encoded by the ROS1 gene) is a 2347 amino acid long receptor tyrosine kinase that is prone to aberrant expression leading to cancer. A description of full length human ROS1 kinase (with the amino acid sequence of the human ROS1 protein) can be found at UniProt Accession No. P08922. As shown in Table 1, the signal peptide, extracellular, transmembrane, and kinase domains of ROS1 are found at the following amino acid residues in SEQ ID NO: 1:
The coding DNA sequence of human ROS1 is provided herein as SEQ ID NO: 2.
Additionally, there are multiple known naturally-occurring variants of ROS1 (see, e.g., Greenman et al., Nature 446: 153-158, 2007). The nucleotide and amino acid sequences of murine full-length ROS1 are known (see, e.g., UniProt Accession No. Q78DX7). Using routine experimentation, the ordinarily skilled biologist would be readily able to determine corresponding sequences in non-human mammalian ROS1 homologues.
By “wild-type” ROS1 is meant the expression and/or activation of full length ROS1 kinase (i.e., for human ROS1, the 2347 amino acid long polypeptide or 2320 amino acid long polypeptide following removal of the signal peptide sequence) in healthy (or normal) tissue (e.g., non-cancerous tissue) of a normal individual (e.g., a normal individual who is not suffering from cancer). ROS1 kinase (full length or truncated) does not appear to be expressed in normal lung tissue in humans (e.g., see below in the Examples). However, using the methods described in the below Examples, the inventors have made the surprising discovery of ROS1 kinase expression in lung cancer. Such expression in an atypical cell (in this case a cancerous cell) where no expression is seen in a typical cell (e.g., a non-cancerous lung cell) is aberrant.
Aberrantly expressed ROS1 kinase, in the form of a fusion with another protein, namely FIG, has been reported in a glioblastoma cell line (see Charest et al., Genes Chromosomes Cancer 37: 58-71, 2003; Charest et al., Proc. Natl. Acad. Sci. USA 100: 916-921, 2003) and in liver cancer (see, e.g., PCT Publication No. WO2010/093928).
As used herein, the term “ROS1 fusion” refers to a portion of the ROS1 polypeptide that includes the kinase domain of the ROS1 protein (or polynucleotide encoding the same) fused to all or a portion of another polypeptide (or polynucleotide encoding the same), where the name of that second polypeptide or polynucleotide is named in the fusion. (The term “fusion” simply means all or a portion of a polypeptide or polynucleotide from first gene fused to all or a portion of a polypeptide or a polynucleotide from a second gene). For example, an SLC34A2-ROS1 fusion is a fusion between a portion of the SLC34A2 polypeptide (or polynucleotide encoding the same) and a portion of the ROS1 polypeptide (or polynucleotide encoding the same) that includes the kinase domain ROS1. An ROS1 fusion often results from a chromosomal translocation or inversion. There are numerous known ROS1 fusions, all of which are ROS1 fusions are useful herein, and include, without limitation, the SLC34A2-ROS1 fusion proteins whose members include SLC34A2-ROS1(VS), SLC34A2-ROS1(S), SLC34A2-ROS1(L) (see U.S. Patent Publication No. 20100143918), CD74-ROS1 (see U.S. Patent Publication No. 20100221737), the FIG-ROS1 fusion proteins whose members include FIG-ROS1(S), FIG-ROS1(L), and FIG-ROS1(XL) (see PCT Publication No. WO2010/093928), TPM3-ROS1 fusion proteins (Takeuchi et al., 2012, Nat. Med., 18:378-381), SDC4-ROS1 fusion proteins (Id.), EZR-ROS1 fusion proteins (Id.), and LRIG3-ROS1 fusion proteins (Id.). See also WO 2011/0162295.
All of the known ROS1 fusion proteins include the full kinase domain of full length ROS1. Thus, as used herein, by a “polypeptide with ROS1 kinase activity” (or “polypeptide having ROS1 kinase activity”) is meant a protein (or polypeptide) that includes the full kinase domain of full length ROS1 protein and, thus, retains ROS1 kinase activity. Non-limiting examples of proteins with ROS1 kinase activity include, without limitation, full length ROS1 protein, the SLC34A2-ROS1 fusion proteins, whose members include SLC34A2-ROS1(VS), SLC34A2-ROS1(S), SLC34A2-ROS1(L) (see U.S. Patent Publication No. 20100143918), CD74-ROS1 (see U.S. Patent Publication No. 20100221737) and the FIG-ROS1 fusion proteins whose members include FIG-ROS1(S), FIG-ROS1(L), and FIG-ROS1(XL) (see PCT Publication No. WO2010/093928), and any truncated or mutated form of ROS1 kinase that retains the kinase domain of full-length ROS1 kinase protein. As the kinase domain of ROS1 is set forth in SEQ ID NO: 27, a “polypeptide with ROS1 kinase activity” is one whose amino acid sequence includes SEQ ID NO: 27 or a sequence at least 95% identical to SEQ ID NO: 27.
ALK (anaplastic lymphoma kinase) is a 1620 amino acid long receptor tyrosine kinase that is prone to aberrant expression leading to cancer. A description of full-length human ALK kinase (with the amino acid sequence of the human ALK protein) can be found at UniProt Accession No. Q9UM73 (see also U.S. Pat. No. 5,770,421, entitled “Human ALK Protein Tyrosine Kinase”). As shown in Table 2, the signal peptide, extracellular, transmembrane, and kinase domains of ALK are found at the following amino acid residues in SEQ ID NO: 35:
Additionally, there are multiple known naturally-occurring variants of ALK (see, e.g., Greenman et al., Nature 446: 153-158, 2007). The nucleotide and amino acid sequences of murine full-length ALK are known (see Iawahara et al., Oncogene 14: 439-449, 1997). Using routine experimentation, the ordinarily skilled biologist would be readily able to determine corresponding sequences in non-human mammalian ALK homologues.
By “wild-type” ALK is meant the expression and/or activation of full length ALK kinase (i.e., 1620 amino acid long polypeptide or 1602 amino acid long polypeptide following removal of the signal peptide sequence) in healthy (or normal) tissue (e.g., non-cancerous tissue) of a normal individual (e.g., a normal individual who is not suffering from cancer). Pulford et al., J. Cell. Physiol., 199:330-358, 2004 provides a comprehensive review relating to ALK and fusion polypeptides that include portions of the full length ALK polypeptide. In normal humans, full-length ALK expression has been detected in the brain and central nervous system, and has been reported in the small intestine and testis (see, e.g., Morris et al., Oncogene 14:2175-88, 1997). However, ALK kinase (full length or truncated) does not appear to be expressed in normal ovarian tissue in humans, a finding which the inventors have confirmed using various commercially available ALK-specific antibodies (e.g., Catalog Nos. 3791, 3633, and 3333 from Cell Signaling Technology, Inc., Danvers, Mass.). However, using the methods described in the below Examples, the inventors have made the surprising discovery of ALK kinase expression in ovarian cancer. Such expression in an atypical cell (in this case a cancerous cell) where no expression is seen in a typical cell (e.g., a non-cancerous ovarian cell) is aberrant.
Numerous examples of aberrantly expressed ALK kinase have been found in other cancers. For example, point mutations within the kinase domain have been found in neuroblastoma, overexpression of ALK has been found in numerous cancers (including, e.g., retinoblastoma, breast cancer, and melanoma), and fusion proteins that include the kinase domain (but not the transmembrane domain) of ALK fused to all or a portion of a second protein have been discovered in various cancers including non-small cell lung cancer (NSCLC) in inflammatory myofibroblastic tumor. See review in Palmer et al., Biochem. J. 420: 345-361 (2009), herein incorporated by reference in its entirety.
Accordingly, as used herein, the term “ALK fusion” refers to a portion of the ALK polypeptide that includes the kinase domain of ALK (polynucleotide encoding the same) fused to all or a portion of another polypeptide (or polynucleotide encoding the same), where the name of that second polypeptide or polynucleotide is named in the fusion. (The term “fusion” simply means all or a portion of a polypeptide or polynucleotide from first gene fused to all or a portion of a polypeptide or a polynucleotide from a second gene). For example, an NPM-ALK fusion is a fusion between a portion of the NPM polypeptide or polynucleotide and a portion of the ALK polypeptide (or polynucleotide encoding the same) that includes the kinase domain of ALK. An ALK fusion often results from a chromosomal translocation or inversion. There are numerous known ALK fusions, all of which are ALK fusions useful herein, and include, without limitation, NPM-ALK, ALO17-ALK, TFG-ALK, MSN-ALK, TPM3-ALK, TPM4-ALK, ATIC-ALK, MYH9-ALK, CLTC-ALK, SEC31L1-ALK, RANBP2-ALK, CARS-ALK, EML4-ALK, KIF5B-ALK, and TFG-ALK (see, e.g., Palmer et al., Biochem. J. 420: 345-361, 2009 (and the articles cited therein), U.S. Pat. No. 5,770,421; Rikova et al., Cell 131: 1190-1203, 2007; Soda et al., Nature 448: 561-566, 2007; Morris et al., Science 263: 1281-84, 1994; Du et al., J. Mol. Med. 84: 863-875, 2007; Panagopoulos et al., Int. J. Cancer 118: 1181-86, 2006; Cools et al., Genes Chromosomes Cancer 34: 354-362, 2002; Debelenko et al., Lab. Invest. 83: 1255-65, 2003; Ma et al., Genes Chromosomes Cancer 37: 98-105, 2003; Lawrence et al., Am. J. Pathol. 157: 377-384, 1995; Hernandez et al., Blood 94: 3265-68, 1999; Takeuchi K., Clin Cancer Res. 15:3143-49, 2009; Tort et al., Lab. Invest. 81: 419-426, 2001; Trinei et al., Cancer Res. 60: 793-798, 2000; and Touriol et al., Blood 95: 3204-07, 2000, all hereby incorporated by reference in their entirety. Some of these ALK fusions have multiple variants, all of which are considered ALK fusions and, thus, are included in the definition of ALK fusion. For example, there are multiple variants of TFG-ALK (see, e.g., Hernandez et al., Amer. J. Pathol. 160: 1487-94, 2002) and at least nine known variants of EML4-ALK (see, e.g., Horn et al., J. of Clinical Oncology 27(26): 4232-35, 2009, U.S. Pat. Nos. 7,700,339 and 7,728,120 and EP Patent No. 1 914 240, all hereby incorporated by reference in their entirety).
As used herein, by the term “polypeptide with ALK kinase activity” is meant any polypeptide that retains the full kinase domain of ALK and thus, has ALK kinase activity. Non-limiting polypeptides with ALK kinase activity include full length ALK, ALK fusion polypeptides (e.g., NPM-ALK fusion, various EML4-ALK fusions, ATIC-ALK fusion, CARS-ALK fusion, ALO17-ALK fusion, TFG-ALK fusion, MSN-ALK fusion, TPM3-ALK fusion, TPM4-ALK fusion, MYH9-ALK fusion, CLTC-ALK fusion, SEC31L1-ALK fusion, RANBP2-ALK fusion, KIF5B-ALK fusion, and TFG-ALK fusion).
The epidermal growth factor receptor (EGFR; also known as ErbB-1 and HER1 in humans) is the cell-surface receptor for members of the epidermal growth factor family (EGF-family) of extracellular protein ligands. The amino acid sequence of an exemplary wild-type human EGFR (including the signal sequence) is provided herein as SEQ ID NO: 3; the amino acid sequence of wild-type human EGFR (minus the signal sequence) is provided herein as SEQ ID NO: 4. The nucleotide sequence of an exemplary wild-type human EGFR mRNA is provided herein as SEQ ID NO: 9. Patients having a non-small cell lung cancer (NSCLC) carrying a somatic mutation of epidermal growth factor receptor (EGFR) have been shown to be hyperresponsive to the EGFR tyrosine kinase inhibitors Gefitinib [Lynch, T. J., et al., N Engl J Med, 2004. 350(21): p. 2129-39, and Paez, J. G., et al., Science, 2004. 304(5676): p. 1497-500] and Erlotinib [Pao, W., et al., Proc Natl Acad Sci USA, 2004. 101(36): p. 13306-11].
Mutations are known to arise in the EGFR molecule. As used herein, the term “mutant” or “mutation” refers to a molecule (e.g., a polypeptide or a polynucleotide) that has a different structure than the wild-type molecule. That difference in structure from the wild-type molecule includes, without limitation, a different sequence (e.g., a different amino acid or nucleotide sequence), additional sequences, missing sequences (i.e., a portion of the sequence is missing), changes in modification (methylation, phosphorylation, etc.), and/or fusion of all or part of the wild-type molecule with another molecule. By “wild-type” is meant that form of the molecule that naturally occurs in the majority of individuals of the species from which the mutant molecule is derived, and/or the form of the molecule that naturally occurs in an healthy individual (e.g., noncancerous) individual of a species from which the mutant molecule is derived. The sequence of the wild-type molecule is that typically provided in the GenBank database. For example, an amino acid sequence of wild-type human EGFR is provided in SEQ ID NO: 3 (without the 24 amino acid long signal sequence) and SEQ ID NO: 4 (with the signal sequence).
As used herein, an “EGFR mutant” includes any type of mutation (i.e., change) in an EGFR molecule that renders the EGFR mutant different than wildtype EGFR. In some embodiments, the mutation increases the kinase activity of the EGFR molecule and/or renders a tumor cell sensitive to one or more EGFR inhibitors. In some embodiments, the mutation is in the kinase domain of EGFR. In some embodiments, the mutation is in one of exons 18 to 21 of the human EGFR gene. The most common EGFR mutations are deletions within exon 19 (e.g., a 15-bp nucleotide in-frame deletion in exon 19 (Del E746-A750) and a point mutation replacing leucine with arginine at codon 858 in exon 21 (L858R). These two classes of EGFR mutants account for 85-90% of activating EGFR mutations [Riely, G. J., et al, Clin Cancer Res, 2006. 12:7232-41]. Exon 19 deletions include Del E746_A750; Del E746_S752>V; Del E746_T751>A; Del E746_T751; Del L747_A750>P; Del L747_E749; Del L747_P753>Q; Del L747_P753>S; Del L747_S752; Del L747_T751>P; Del L747_T751, and Del S752_I759. Other mutations include T790M, S768I, L861Q, 2240del12, G719C (Lynch et al., supra), G791A and G719S (Paez et al., 2004, Science, 304:1497-1500), and insertions in exon 19 (He et al., 2011, Clin. Cancer Res., 18:1790-97). The ability to detect mutated gene products in cancer cells can identify patients most likely benefit from such therapies, and make clinical trials more efficient and informative.
EGFR mutants can be detected by standard means known in the art. For example, mutants can be detected at the nucleotide level by sequencing, nucleic acid amplification using primers and/or probes specific for the wild-type or mutant sequence, and amplification and length analysis to detect deletional mutants. Exemplary methods to determine EGFR mutational status are disclosed in Rosell et al., 2009, N. Engl. J. Med., 361:958-967 and Li et al., 2011, PLoS ONE, 6: e28204. Kits for nucleic acid analysis are commercially available, e.g., EGFR Pyro Kit (QIAGEN), EGFR PCR Kit (QIAGEN), and EGFR RGQ PCR Kit (QIAGEN). The EGFR RGQ PCR Kit is capable of detecting 29 mutations in the EGFR gene, including 19 deletions in exon 19, T790M, L858R, L861A, S768I, and G719X (detects the presence of G719S, G719A, or G719C but does not distinguish among them).
Specific EGFR mutants can be detected at the polypeptide level (e.g., by western blot or immunohistochemistry) using mutant-specific antibodies, e.g., EGF Receptor (E746-A750del Specific) (6B6) XP® Rabbit mAb or EGF Receptor (L858R Mutant Specific) (43B2) Rabbit mAb, both from Cell Signaling Technology, Inc. (Danvers, Mass.) or mutation-specific AQUA peptides (Stemmann et al., 2001, Cell, 107: 715-726). Mutant-specific antibodies can be prepared that bind specifically to other identified mutant EGFR polypeptides. Exemplary mutant specific antibodies are disclosed in WO 2009/126306.
As used herein, by “polypeptide” (or “amino acid sequence” or “protein”) refers to a polymer formed from the linking, in a defined order, of preferably, α-amino acids, D-, L-amino acids, and combinations thereof. The link between one amino acid residue and the next is referred to as an amide bond or a peptide bond. Non-limiting examples of polypeptides include refers to an oligopeptide, peptide, polypeptide, or protein sequence, and fragments or portions thereof, and to naturally occurring or synthetic molecules. Polypeptides also include derivatized molecules such as glycoproteins and lipoproteins as well as lower molecular weight polypeptides. “Amino acid sequence” and like terms, such as “polypeptide” or “protein”, are not meant to limit the indicated amino acid sequence to the complete, native amino acid sequence associated with the recited protein molecule.
It will be recognized in the art that some amino acid sequences of an indicated polypeptide (e.g., a FIG-ROS1(S) polypeptide) can be varied without significant effect of the structure or function of the mutant protein. If such differences in sequence are contemplated, it should be remembered that there will be critical areas on the protein that determine activity (e.g. the kinase domain of ROS1). In general, it is possible to replace residues that form the tertiary structure, provided that residues performing a similar function are used. In other instances, the type of residue may be completely unimportant if the alteration occurs at a non-critical region of the protein.
Thus, a polypeptide with ROS1 activity or a polypeptide with ALK activity further includes variants of the polypeptides described herein that shows substantial ROS1 kinase activity or ALK kinase activity. Some non-limiting conservative substitutions include the exchange, one for another, among the aliphatic amino acids Ala, Val, Leu and Ile; exchange of the hydroxyl residues Ser and Thr; exchange of the acidic residues Asp and Glu; exchange of the amide residues Asn and Gln; exchange of the basic residues Lys and Arg; and exchange of the aromatic residues Phe and Tyr. Further examples of conservative amino acid substitutions known to those skilled in the art are: Aromatic: phenylalanine tryptophan tyrosine (e.g., a tryptophan residue is replaced with a phenylalanine); Hydrophobic: leucine isoleucine valine; Polar: glutamine asparagines; Basic: arginine lysine histidine; Acidic: aspartic acid glutamic acid; Small: alanine serine threonine methionine glycine. As indicated in detail above, further guidance concerning which amino acid changes are likely to be phenotypically silent (i.e., are not likely to have a significant deleterious effect on a function) can be found in Bowie et al., Science 247, supra.
In some embodiments, a variant may have “nonconservative” changes, e.g., replacement of a glycine with a tryptophan. Similar variants may also include amino acid deletions or insertions, or both. Guidance in determining which amino acid residues may be substituted, inserted, or deleted without abolishing biological or immunological activity may be found using computer programs well known in the art, for example, DNASTAR software.
The polypeptides having ROS1 kinase activity can include the full length human ROS1 protein (having an amino acid sequence set forth in SEQ ID NO: 1) and the ROS1 fusion polypeptides having the amino sequences set forth in SEQ ID NOs: 5, 7, 11, 13, 22, 24, and 26 (whether or not including a leader sequence), an amino acid sequence encoding a polypeptide that includes at least six contiguous amino acids encompassing the fusion junction (i.e., the sequences at the junction between the non-ROS1 partner protein and the ROS1 protein; see Table 3, as well as polypeptides that have at least 90% similarity, more preferably at least 95% similarity, and still more preferably at least 96%, 97%, 98% or 99% similarity to those described above.
The polypeptides having ALK kinase activity include the full length human ALK protein (having an amino acid sequence set forth in SEQ ID NO: 35) and the various ALK fusion polypeptides described herein, an amino acid sequence encoding a polypeptide that includes at least six contiguous amino acids encompassing the fusion junction (i.e., the sequences at the junction between the non-ALK partner protein and the ALK protein, as well as polypeptides that have at least 90% similarity, more preferably at least 95% similarity, and still more preferably at least 96%, 97%, 98% or 99% similarity to those described above.
Full length ROS1-specific reagents and the ROS1 fusion polypeptide specific reagents (such as polyclonal and monoclonal antibodies) or full length ALK-specific reagents and the ALK fusion polypeptide specific reagents (such as polyclonal and monoclonal antibodies) which are useful in assays for detecting ROS1 or ALK polypeptide expression and/or ROS1 or ALK kinase activity as described below or as ROS1-inhibiting therapeutics or ALK-inhibiting therapeutics capable of inhibiting ROS1 protein function/activity and/or ALK protein function/activity. Further, such polypeptides can be used in the yeast two-hybrid system to “capture” binding proteins, which are also candidate ROS1-inhibiting therapeutics or ALK-inhibiting therapeutics according to the present disclosure. The yeast two hybrid system is described in Fields and Song, Nature 340: 245-246 (1989).
In some embodiments, a detection reagent may further include a detectable label (e.g., a fluorescent label or an infrared label). By “detectable label” with respect to a polypeptide, polynucleotide, or reagent (e.g., antibody or FISH probe) disclosed herein means a chemical, biological, or other modification of or to the polypeptide, polynucleotide, or antibody, including but not limited to fluorescence (e.g., FITC or phycoerythrin), infrared, mass (e.g., an isobaric tag), residue, dye (chromophoric dye), radioisotope (e.g., 32P), label, or tag (myc tag or GST tag) modifications, etc., by which the presence of the molecule of interest may be detected. Such a polypeptide, polynucleotide, or reagent thus called “detectably labeled.” The detectable label may be attached to the polypeptide, polynucleotide, or binding agent by a covalent (e.g., peptide bond or phosphodiester bond) or non-covalent chemical bond (e.g., an ionic bond).
Reagents useful in the methods disclosed herein include, without limitation, reagents such as antibodies or binding fractions thereof, that specifically bind to full length ROS1 protein or one of the many ROS1 fusion proteins, or to full length ROS1 protein or one of the many ROS1 fusion proteins expressed in cancer, or to an EGFR mutant polypeptide. By “specifically binding” or “specifically binds” means that a reagent or binding agent (e.g., a nucleic acid probe, an antibody) interacts with its target molecule where the interaction is dependent upon the presence of a particular structure (e.g., the antigenic determinant or epitope on the polypeptide or the nucleotide sequence of the polynucleotide); in other words, the reagent is recognizing and binding to a specific polypeptide or polynucleotide structure rather than to all polypeptides or polynucleotides in general. By “binding fragment thereof” means a fragment or portion of a reagent that specifically binds the target molecule (e.g., an Fab fragment of an antibody).
A reagent that specifically binds to the target molecule may be referred to as a target-specific reagent or an anti-target reagent. For example, an antibody that specifically binds to a FIG-ROS1(L) polypeptide may be referred to as a FIG-ROS1(L)-specific antibody or an anti-FIG-ROS1(L) antibody. Similarly, a nucleic acid probe that specifically binds to a FIG-ROS1(L) polynucleotide may be referred to as a FIG-ROS1(L)-specific nucleic acid probe or an anti-FIG-ROS1(L) nucleic acid probe.
In some embodiments, where the target molecule is a polypeptide, a reagent that specifically binds a target molecule has a binding affinity (KD) for its target molecule of 1×10−6 M or less. In some embodiments, a reagent that specifically binds to a target molecule has for its target molecule a KD of 1×10−7 M or less, or a KD of 1×10−8 M or less, or a KD of 1×10−9 M or less, or a KD of 1×10−10 M or less, of a KD of 1×10−11 M or less, of a KD of 1×10−12M or less. In certain embodiments, the KD of a reagent that specifically binds to a target molecule is 1 pM to 500 pM, or between 500 pM to 1 μM, or between 1 μM to 100 nM, or between 100 mM to 10 nM for its target molecule. Non-limiting examples of a target molecule to which a reagent specifically binds to include full length ROS1 polypeptide, the full length ALK polypeptide, one of the many ALK fusion proteins and/or the ROS1 fusion polypeptides described herein, or an EGFR mutant polypeptide.
In some embodiments, where the target molecule is a polynucleotide, a reagent that specifically binds its target molecule is a reagent that hybridizes under stringent conditions to it target polynucleotide. The term “stringent conditions” with respect to nucleotide sequence or nucleotide probe hybridization conditions is the “stringency” that occurs within a range from about Tm minus 5° C. (i.e., 5° C. below the melting temperature (Tm) of the reagent or nucleic acid probe) to about 20° C. to 25° C. below Tm. Typical stringent conditions are: overnight incubation at 42° C. in a solution comprising: 50% formamide, 5×SSC (750 mM NaCl, 75 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 micrograms/ml denatured, sheared salmon sperm DNA, followed by washing the filters in 0.1×SSC at about 65° C. As will be understood by those of skill in the art, the stringency of hybridization may be altered in order to identify or detect identical or related polynucleotide sequences. By a “reagent (e.g., a polynucleotide or nucleotide probe) that hybridizes under stringent conditions to a target polynucleotide (e.g., a full length ROS1 polynucleotide)” is intended that the reagent (e.g., the polynucleotide or nucleotide probe (e.g., DNA, RNA, or a DNA-RNA hybrid)) hybridizes along the entire length of the reference polynucleotide or hybridizes to a portion of the reference polynucleotide that is at least about 15 nucleotides (nt), or to at least about 20 nt, or to at least about 30 nt, or to about 30-70 nt of the reference polynucleotide. These nucleotide probes are useful as diagnostic probes (e.g., for FISH) and primers (e.g., for PCR) as discussed herein.
The reagents useful in the practice of the disclosed methods, include, among others, full length ROS1-specific and ROS1 fusion polypeptide-specific antibodies, full length ALK-specific and ALK fusion polypeptide-specific antibodies, EGFR mutant-specific antibodies, and AQUA peptides (heavy-isotope labeled peptides) corresponding to, and suitable for detection and quantification of, the indicated polypeptide's expression in a biological sample. Thus, a “ROS1 polypeptide-specific reagent” is any reagent, biological or chemical, capable of specifically binding to, detecting and/or quantifying the presence/level of expressed ROS1 polypeptide in a biological sample. Likewise, an “ALK polypeptide-specific reagent” is any reagent, biological or chemical, capable of specifically binding to, detecting and/or quantifying the presence/level of expressed ALK polypeptide in a biological sample. An “EGFR mutant polypeptide-specific reagent” is any reagent, biological or chemical, capable of specifically binding to, detecting and/or quantifying the presence/level of expressed EGFR mutant polypeptide in a biological sample. The terms include, but are not limited to, the antibodies and AQUA peptide reagents discussed below, and equivalent binding agents are within the scope of the present disclosure.
The antibodies that specifically bind to full length ROS1 protein, to one of the ROS1 fusion polypeptides, to full length ALK protein, to one of the ALK fusion polypeptides, or to a mutant EGFR polypeptide in cancer may also bind to highly homologous and equivalent epitopic peptide sequences in other mammalian species, for example murine or rabbit, and vice versa. Antibodies useful in practicing the methods disclosed herein include (a) monoclonal antibodies, (b) purified polyclonal antibodies that specifically bind to the target polypeptide (e.g., the fusion junction of the fusion polypeptide, (c) antibodies as described in (a)-(b) above that specifically bind equivalent and highly homologous epitopes or phosphorylation sites in other non-human species (e.g., mouse, rat), and (d) fragments of (a)-(c) above that specifically bind to the antigen (or more preferably the epitope) bound by the exemplary antibodies disclosed herein.
The term “antibody” or “antibodies” refers to all types of immunoglobulins, including IgG, IgM, IgA, IgD, and IgE, including binding fragments thereof (i.e., fragments of an antibody that are capable of specifically binding to the antibody's target molecule, such as Fab, and F(ab′)2 fragments), as well as recombinant, humanized, polyclonal, and monoclonal antibodies and/or binding fragments thereof. Antibodies can be derived from any species of animal, such as from a mammal. Non-limiting exemplary natural antibodies include antibodies derived from human, chicken, goats, and rodents (e.g., rats, mice, hamsters and rabbits), including transgenic rodents genetically engineered to produce human antibodies (see, e.g., Lonberg et al., WO93/12227; U.S. Pat. No. 5,545,806; and Kucherlapati, et al., WO91/10741; U.S. Pat. No. 6,150,584, which are herein incorporated by reference in their entirety). Antibodies may be also be chimeric antibodies. See, e.g., M. Wroser et al., Molec. Immunol. 26: 403-11 (1989); Morrision et al., Proc. Nat'l. Acad. Sci. 81: 6851 (1984); Neuberger et al., Nature 312: 604 (1984)). The antibodies may be recombinant monoclonal antibodies produced according to the methods disclosed in U.S. Pat. No. 4,474,893 (Reading) or U.S. Pat. No. 4,816,567 (Cabilly et al.). The antibodies may also be chemically constructed specific antibodies made according to the method disclosed in U.S. Pat. No. 4,676,980 (Segel et al.).
Natural antibodies are the antibodies produced by a host animal, however the disclosure also contemplates genetically altered antibodies wherein the amino acid sequence has been varied from that of a native antibody. Because of the relevance of recombinant DNA techniques to this application, one need not be confined to the sequences of amino acids found in natural antibodies; antibodies can be redesigned to obtain desired characteristics. The possible variations are many and range from the changing of just one or a few amino acids to the complete redesign of, for example, the variable or constant region. Changes in the constant region will, in general, be made in order to improve or alter characteristics, such as complement fixation, interaction with membranes and other effector functions. Changes in the variable region will be made in order to improve the antigen binding characteristics. The term “humanized antibody”, as used herein, refers to antibody molecules in which amino acids have been replaced in the non-antigen binding regions in order to more closely resemble a human antibody, while still retaining the original binding ability. Other antibodies specifically contemplated are oligoclonal antibodies. As used herein, the phrase “oligoclonal antibodies” refers to a predetermined mixture of distinct monoclonal antibodies. See, e.g., PCT publication WO 95/20401; U.S. Pat. Nos. 5,789,208 and 6,335,163. In one embodiment, oligoclonal antibodies consisting of a predetermined mixture of antibodies against one or more epitopes are generated in a single cell. In other embodiments, oligoclonal antibodies include a plurality of heavy chains capable of pairing with a common light chain to generate antibodies with multiple specificities (e.g., PCT publication WO 04/009618). Oligoclonal antibodies are particularly useful when it is desired to target multiple epitopes on a single target molecule. In view of the assays and epitopes disclosed herein, those skilled in the art can generate or select antibodies or mixtures of antibodies that are applicable for an intended purpose and desired need.
Recombinant antibodies are also included in the present disclosure. These recombinant antibodies have the same amino acid sequence as the natural antibodies or have altered amino acid sequences of the natural antibodies. They can be made in any expression systems including both prokaryotic and eukaryotic expression systems or using phage display methods (see, e.g., Dower et al., WO91/17271 and McCafferty et al., WO92/01047; U.S. Pat. No. 5,969,108, which are herein incorporated by reference in their entirety). Antibodies can be engineered in numerous ways. They can be made as single-chain antibodies (including small modular immunopharmaceuticals or SMIPs™), Fab and F(ab′)2 fragments, etc. Antibodies can be humanized, chimerized, deimmunized, or fully human. Numerous publications set forth the many types of antibodies and the methods of engineering such antibodies. For example, see U.S. Pat. Nos. 6,355,245; 6,180,370; 5,693,762; 6,407,213; 6,548,640; 5,565,332; 5,225,539; 6,103,889; and 5,260,203. The genetically altered antibodies may be functionally equivalent to the above-mentioned natural antibodies. In certain embodiments, modified antibodies can provide improved stability or/and therapeutic efficacy.
Non-limiting examples of modified antibodies include those with conservative substitutions of amino acid residues, and one or more deletions or additions of amino acids that do not significantly deleteriously alter the antigen binding utility. Substitutions can range from changing or modifying one or more amino acid residues to complete redesign of a region as long as the therapeutic utility is maintained. Antibodies can be modified post-translationally (e.g., acetylation, and/or phosphorylation) or can be modified synthetically (e.g., the attachment of a labeling group). Antibodies with engineered or variant constant or Fc regions can be useful in modulating effector functions, such as, for example, antigen-dependent cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Such antibodies with engineered or variant constant or Fc regions may be useful in instances where a parent singling protein is expressed in normal tissue; variant antibodies without effector function in these instances may elicit the desired therapeutic response while not damaging normal tissue. Accordingly, certain aspects and methods of the present disclosure relate to antibodies with altered effector functions that include one or more amino acid substitutions, insertions, and/or deletions. The term “biologically active” refers to a protein having structural, regulatory, or biochemical functions of a naturally occurring molecule. Likewise, “immunologically active” refers to the capability of the natural, recombinant, or synthetic polypeptide (e.g., one of the ROS1 or ALK fusion polypeptides described herein), or any oligopeptide thereof, to induce a specific immune response in appropriate animals or cells and to bind with specific antibodies.
Also within the present disclosure are antibody molecules with fewer than 4 chains, including single chain antibodies, Camelid antibodies and the like and components of an antibody, including a heavy chain or a light chain. In some embodiments an immunoglobulin chain may include in order from 5′ to 3′, a variable region and a constant region. The variable region may include three complementarity determining regions (CDRs), with interspersed framework (FR) regions for a structure FR1, CDR1, FR2, CDR2, FR3, CDR3 and FR4. Also within the disclosure are heavy or light chain variable regions, framework regions and CDRs. An antibody may include a heavy chain constant region that includes some or all of a CH1 region, hinge, CH2 and CH3 region.
One non-limiting epitopic site of a fusion polypeptide-specific antibody is a peptide fragment consisting essentially of about 11 to 17 amino acids of a fusion polypeptide sequence, which fragment encompasses the fusion junction between the ROS1 or ALK portion of the molecule and the portion of the molecule from the non-ROS1 or -ALK fusion partner. It will be appreciated that antibodies that specifically binding shorter or longer peptides/epitopes encompassing the fusion junction of a ROS1 or ALK fusion polypeptide are within the scope of the present disclosure.
The disclosure is not limited to use of antibodies, but includes equivalent molecules, such as protein binding domains or nucleic acid aptamers, which bind, in a ROS1 or ALK protein-specific or ROS1 or ALK fusion protein-specific or EGFR mutant-specific manner, to essentially the same epitope to which an antibody useful in the disclosed methods binds. See, e.g., Neuberger et al., Nature 312: 604 (1984). Such equivalent non-antibody reagents may be suitably employed in the methods disclosed herein.
Polyclonal antibodies useful in practicing the methods disclosed herein may be produced according to standard techniques by immunizing a suitable animal (e.g., rabbit, goat, etc.) with an antigen encompassing a desired fusion-protein or mutant protein specific epitope (e.g. the fusion junction between the non-ROS1 or ALK protein partner and the ROS1 or ALK protein partner in a ROS1 or ALK fusion polypeptide or a fragment of a mutant EGFR polypeptide that includes one or more mutant residues), collecting immune serum from the animal, and separating the polyclonal antibodies from the immune serum, and purifying polyclonal antibodies having the desired specificity, in accordance with known procedures. The antigen may be a synthetic peptide antigen that includes the desired epitopic sequence, selected and constructed in accordance with well-known techniques. See, e.g., A
Monoclonal antibodies may also be beneficially employed in the methods disclosed herein, and may be produced in hybridoma cell lines according to the well-known technique of Kohler and Milstein. Nature 265: 495-97 (1975); Kohler and Milstein, Eur. J. Immunol. 6: 511 (1976); see also, C
Monoclonal Fab fragments may also be produced in Escherichia coli by recombinant techniques known to those skilled in the art. See, e.g., W. Huse, Science 246: 1275-81 (1989); Mullinax et al., Proc. Nat'l Acad. Sci. 87: 8095 (1990). If monoclonal antibodies of one isotype are desired for a particular application, particular isotypes can be prepared directly, by selecting from the initial fusion, or prepared secondarily, from a parental hybridoma secreting a monoclonal antibody of different isotype by using the sib selection technique to isolate class-switch variants (Steplewski, et al., Proc. Nat'l. Acad. Sci., 82: 8653 (1985); Spira et al., J. Immunol. Methods, 74: 307 (1984)). The antigen combining site of the monoclonal antibody can be cloned by PCR and single-chain antibodies produced as phage-displayed recombinant antibodies or soluble antibodies in E. coli (see, e.g., A
Further still, U.S. Pat. No. 5,194,392, Geysen (1990) describes a general method of detecting or determining the sequence of monomers (amino acids or other compounds) which is a topological equivalent of the epitope (i.e., a “mimotope”) which is complementary to a particular paratope (antigen binding site) of an antibody of interest. More generally, this method involves detecting or determining a sequence of monomers which is a topographical equivalent of a ligand which is complementary to the ligand binding site of a particular receptor of interest. Similarly, U.S. Pat. No. 5,480,971, Houghten et al. (1996) discloses linear C1-C-rosyl perrosylated oligopeptides and sets and libraries of such peptides, as well as methods for using such oligopeptide sets and libraries for determining the sequence of a perrosylated oligopeptide that preferentially binds to an acceptor molecule of interest. Thus, non-peptide analogs of the epitope-bearing peptides also can be made routinely by these methods.
Antibodies useful in the methods disclosed herein, whether polyclonal or monoclonal, may be screened for epitope and fusion protein specificity according to standard techniques. See, e.g., Czernik et al., Methods in Enzymology, 201: 264-283 (1991). For example, the antibodies may be screened against a peptide library by ELISA to ensure specificity for both the desired antigen and, if desired, for reactivity only with the full-length ROS1 or ALK protein, a particular ROS1 or ALK fusion polypeptide (e.g., an SLC34A2-ROS1(S) polypeptide), a particular EGFR mutant polypeptide, or fragments thereof. The antibodies may also be tested by western blotting against cell preparations containing target protein to confirm reactivity with the only the desired target and to ensure no appreciable binding to other proteins. The production, screening, and use of fusion protein-specific antibodies are known to those of skill in the art, and have been described. See, e.g., U.S. Patent Publication No. 20050214301.
Antibodies useful in the methods disclosed herein may exhibit some limited cross-reactivity with similar epitopes in other proteins or polypeptides, such as similar fusion polypeptides. This is not unexpected as most antibodies exhibit some degree of cross-reactivity, and anti-peptide antibodies will often cross-react with epitopes having high homology or identity to the immunizing peptide. See, e.g., Czernik, supra. Cross-reactivity with other fusion proteins is readily characterized by western blotting alongside markers of known molecular weight. Undesirable cross-reactivity can be removed by negative selection using antibody purification on peptide columns.
ROS1-specific antibodies and ROS1 fusion polypeptide-specific antibodies that are useful in practicing the methods disclosed herein are ideally specific for human fusion polypeptide, but are not limited only to binding the human species, per se. The disclosure includes the production and use of antibodies that also bind conserved and highly homologous or identical epitopes in other mammalian species (e.g., mouse, rat, monkey). Highly homologous or identical sequences in other species can readily be identified by standard sequence comparisons, such as using BLAST, with the human ROS1 protein sequence (SEQ ID NO: 1), and the human ROS1 fusion polypeptide sequences disclosed herein (SEQ ID NOs: 5, 7, 11, 13, 22, 24, and 26).
ALK-specific antibodies and ALK fusion polypeptide-specific antibodies that are useful in practicing the methods disclosed herein are ideally specific for human fusion polypeptide, but are not limited only to binding the human species, per se. The disclosure includes the production and use of antibodies that also bind conserved and highly homologous or identical epitopes in other mammalian species (e.g., mouse, rat, monkey). Highly homologous or identical sequences in other species can readily be identified by standard sequence comparisons, such as using BLAST, with the human ALK protein sequence (SEQ ID NO: 35), and the human ALK fusion polypeptide sequences previously described.
EGFR mutant polypeptide-specific antibodies of the disclosure that are useful in practicing the methods disclosed herein are ideally specific for human fusion polypeptide, but are not limited only to binding the human species, per se. The disclosure includes the production and use of antibodies that also bind conserved and highly homologous or identical epitopes in other mammalian species (e.g., mouse, rat, monkey). Highly homologous or identical sequences in other species can readily be identified by standard sequence comparisons, such as using BLAST, with the human EGFR protein sequence (SEQ ID NO: 3), and the human EGFR mutant polypeptide sequences previously described.
Antibodies employed in the methods disclosed herein may be further characterized by, and validated for, use in a particular assay format, for example FC, IHC, and/or ICC. The use of full-length ROS1 protein-specific and/or ROS1 fusion polypeptide-specific antibodies and/or EGFR mutant polypeptide-specific antibodies in such methods is further described herein. The antibodies described herein, used alone or in the below-described assays, may also be advantageously conjugated to fluorescent dyes (e.g. ALEXA FLUOR 488, phycoerythrin), or labels such as quantum dots, for use in multi-parametric analyses along with other signal transduction (phospho-AKT, phospho-Erk 1/2) and/or cell marker (cytokeratin) antibodies, as further described below.
In practicing the methods disclosed herein, the expression and/or activity of a ROS1 fusion polypeptide and/or of full-length ROS1 in a given biological sample may also be advantageously examined using antibodies specific for (i.e., that specifically bind to) full length ROS1 protein or antibodies specific for ROS1 fusion polypeptides. For example, ROS1-specific antibodies (i.e., antibodies that specifically bind full-length ROS1) are commercially available (see Santa Cruz Biotech., Inc. (Santa Cruz, Calif.) Catalog No. sc-6347; Cell Signaling Technology, Inc. (Danvers, Mass.), Catalog Nos. 3078, 3266, and 3287); and Abcam (Cambridge, Mass.), Catalog Nos. ab5512 and ab108492, for example). In some embodiments, ROS1-specific antibodies used in the methods disclosed herein specifically bind the kinase domain of ROS1 and, thus, will detect full-length ROS1 and all of the ROS1 fusion polypeptides described herein. In some embodiments, ROS1-specific antibodies used in the methods disclosed herein specifically bind a region on the ROS1 protein that is C-terminal to the kinase domain of ROS1 and, thus, will detect full-length ROS1 and all of the ROS1 fusion polypeptides described herein. Such antibodies may also be produced according to standard methods.
Likewise, the expression and/or activity of an ALK fusion polypeptide and/or of full-length ALK in a given biological sample may also be advantageously examined using antibodies specific for (i.e., that specifically bind to) full length ALK protein or antibodies specific for ALK fusion polypeptides. For example, ALK-specific antibodies (i.e., antibodies that specifically bind full-length ALK) are commercially available (see C
Detection of expression and/or activity of full-length ROS1 and/or a ROS1 fusion polypeptide expression or a mutant EGFR polypeptide expression, in a biological sample (e.g. a tumor sample) can provide information on whether the kinase protein alone is driving the tumor, or whether aberrantly expressed full length ROS1 or mutant EGFR is also present and driving the tumor. Such information is clinically useful in assessing whether targeting the fusion protein or the full-length protein(s), or both, or is likely to be most beneficial in inhibiting progression of the tumor, and in selecting an appropriate therapeutic or combination thereof.
In some embodiments, a reagent that can be used to detect full length ROS1 or a ROS1 fusion polypeptide, full length ALK or an ALK fusion polypeptide, or a mutant EGFR polypeptide is a heavy-isotope labeled peptide (i.e., an AQUA peptide) that, for example, corresponds to a peptide sequence that includes the fusion junction of a ROS1 or an ALK fusion polypeptide or a mutant-specific sequence of a mutant EGFR polypeptide. Such an AQUA peptide may be suitable for the absolute quantification of an expressed ROS1 or ALK fusion polypeptide or mutant EGFR polypeptide in a biological sample. As used herein, the term “heavy-isotope labeled peptide” is used interchangeably with “AQUA peptide”. The production and use of AQUA peptides for the absolute quantification or detection of proteins (AQUA) in complex mixtures has been described. See WO/03016861, “Absolute Quantification of Proteins and Modified Forms Thereof by Multistage Mass Spectrometry,” Gygi et al. and also Gerber et al., Proc. Natl. Acad. Sci. U.S.A. 100: 6940-45 (2003) (the teachings of which are hereby incorporated herein by reference, in their entirety). The term “specifically detects” with respect to such an AQUA peptide means the peptide will only detect and quantify polypeptides and proteins that contain the AQUA peptide sequence and will not substantially detect polypeptides and proteins that do not contain the AQUA peptide sequence.
The AQUA methodology employs the introduction of a known quantity of at least one heavy-isotope labeled peptide standard (which has a unique signature detectable by LC-SRM chromatography) into a digested biological sample in order to determine, by comparison to the peptide standard, the absolute quantity of a peptide with the same sequence and protein modification in the biological sample. Briefly, the AQUA methodology has two stages: peptide internal standard selection and validation and method development; and implementation using validated peptide internal standards to detect and quantify a target protein in sample. The method is a powerful technique for detecting and quantifying a given peptide/protein within a complex biological mixture, such as a cell lysate, and may be employed, e.g., to quantify change in protein phosphorylation as a result of drug treatment, or to quantify differences in the level of a protein in different biological states.
Generally, to develop a suitable internal standard, a particular peptide (or modified peptide) within a target protein sequence is chosen based on its amino acid sequence and the particular protease to be used to digest. The peptide is then generated by solid-phase peptide synthesis such that one residue is replaced with that same residue containing stable isotopes (13C, 15N). The result is a peptide that is chemically identical to its native counterpart formed by proteolysis, but is easily distinguishable by MS via a 7-Da mass shift. The newly synthesized AQUA internal standard peptide is then evaluated by LC-MS/MS. This process provides qualitative information about peptide retention by reverse-phase chromatography, ionization efficiency, and fragmentation via collision-induced dissociation. Informative and abundant fragment ions for sets of native and internal standard peptides are chosen and then specifically monitored in rapid succession as a function of chromatographic retention to form a selected reaction monitoring (LC-SRM) method based on the unique profile of the peptide standard.
The second stage of the AQUA strategy is its implementation to measure the amount of a protein or modified protein from complex mixtures. Whole cell lysates are typically fractionated by SDS-PAGE gel electrophoresis, and regions of the gel consistent with protein migration are excised. This process is followed by in-gel proteolysis in the presence of the AQUA peptides and LC-SRM analysis. (See Gerber et al., supra.) AQUA peptides are spiked in to the complex peptide mixture obtained by digestion of the whole cell lysate with a proteolytic enzyme and subjected to immunoaffinity purification as described above. The retention time and fragmentation pattern of the native peptide formed by digestion (e.g., trypsinization) is identical to that of the AQUA internal standard peptide determined previously; thus, LC-MS/MS analysis using an SRM experiment results in the highly specific and sensitive measurement of both internal standard and analyte directly from extremely complex peptide mixtures.
Since an absolute amount of the AQUA peptide is added (e.g., 250 fmol), the ratio of the areas under the curve can be used to determine the precise expression levels of a protein or phosphorylated form of a protein in the original cell lysate. In addition, the internal standard is present during in-gel digestion as native peptides are formed, such that peptide extraction efficiency from gel pieces, absolute losses during sample handling (including vacuum centrifugation), and variability during introduction into the LC-MS system do not affect the determined ratio of native and AQUA peptide abundances.
An AQUA peptide standard is developed for a known sequence previously identified by the IAP-LC-MS/MS method within in a target protein. If the site is modified, one AQUA peptide incorporating the modified form of the particular residue within the site may be developed, and a second AQUA peptide incorporating the unmodified form of the residue developed. In this way, the two standards may be used to detect and quantify both the modified an unmodified forms of the site in a biological sample.
Peptide internal standards may also be generated by examining the primary amino acid sequence of a protein and determining the boundaries of peptides produced by protease cleavage. Alternatively, a protein may actually be digested with a protease and a particular peptide fragment produced can then sequenced. Suitable proteases include, but are not limited to, serine proteases (e.g. trypsin, hepsin), metallo proteases (e.g., PUMP1), chymotrypsin, cathepsin, pepsin, thermolysin, carboxypeptidases, etc.
A peptide sequence within a target protein is selected according to one or more criteria to optimize the use of the peptide as an internal standard. Preferably, the size of the peptide is selected to minimize the chances that the peptide sequence will be repeated elsewhere in other non-target proteins. Thus, a peptide is preferably at least about 6 amino acids. The size of the peptide is also optimized to maximize ionization frequency. Thus, in some embodiments, the peptide is not longer than about 20 amino acids. In some embodiments, the peptide is between about 7 to 15 amino acids in length. A peptide sequence is also selected that is not likely to be chemically reactive during mass spectrometry, thus sequences that contain cysteine, tryptophan, or methionine are avoided.
A peptide sequence that does not include a modified region of the target region may be selected so that the peptide internal standard can be used to determine the quantity of all forms of the protein. Alternatively, a peptide internal standard encompassing a modified amino acid may be desirable to detect and quantify only the modified form of the target protein. Peptide standards for both modified and unmodified regions can be used together, to determine the extent of a modification in a particular sample (i.e. to determine what fraction of the total amount of protein is represented by the modified form). For example, peptide standards for both the phosphorylated and unphosphorylated form of a protein known to be phosphorylated at a particular site can be used to quantify the amount of phosphorylated form in a sample.
The peptide is labeled using one or more labeled amino acids (i.e., the label is an actual part of the peptide) or less preferably, labels may be attached after synthesis according to standard methods. Preferably, the label is a mass-altering label selected based on the following considerations: The mass should be unique to shift fragments masses produced by MS analysis to regions of the spectrum with low background; the ion mass signature component is the portion of the labeling moiety that preferably exhibits a unique ion mass signature in MS analysis; the sum of the masses of the constituent atoms of the label is preferably uniquely different than the fragments of all the possible amino acids. As a result, the labeled amino acids and peptides are readily distinguished from unlabeled ones by the ion/mass pattern in the resulting mass spectrum. Preferably, the ion mass signature component imparts a mass to a protein fragment that does not match the residue mass for any of the 20 natural amino acids.
The label should be robust under the fragmentation conditions of MS and not undergo unfavorable fragmentation. Labeling chemistry should be efficient under a range of conditions, particularly denaturing conditions, and the labeled tag preferably remains soluble in the MS buffer system of choice. The label preferably does not suppress the ionization efficiency of the protein and is not chemically reactive. The label may contain a mixture of two or more isotopically distinct species to generate a unique mass spectrometric pattern at each labeled fragment position. Stable isotopes, such as 2H, 13C, 15N, 17O, 18O, or 34S, are some non-limiting labels. Pairs of peptide internal standards that incorporate a different isotope label may also be prepared. Non-limiting amino acid residues into which a heavy isotope label may be incorporated include leucine, proline, valine, and phenylalanine.
Peptide internal standards are characterized according to their mass-to-charge (m/z) ratio, and preferably, also according to their retention time on a chromatographic column (e.g., an HPLC column). Internal standards that co-elute with unlabeled peptides of identical sequence are selected as optimal internal standards. The internal standard is then analyzed by fragmenting the peptide by any suitable means, for example by collision-induced dissociation (CID) using, e.g., argon or helium as a collision gas. The fragments are then analyzed, for example by multi-stage mass spectrometry (MS″) to obtain a fragment ion spectrum, to obtain a peptide fragmentation signature. Preferably, peptide fragments have significant differences in m/z ratios to enable peaks corresponding to each fragment to be well separated, and a signature is that is unique for the target peptide is obtained. If a suitable fragment signature is not obtained at the first stage, additional stages of MS are performed until a unique signature is obtained.
Fragment ions in the MS/MS and MS3 spectra are typically highly specific for the peptide of interest, and, in conjunction with LC methods, allow a highly selective means of detecting and quantifying a target peptide/protein in a complex protein mixture, such as a cell lysate, containing many thousands or tens of thousands of proteins. Any biological sample potentially containing a target protein/peptide of interest may be assayed. Crude or partially purified cell extracts are preferably employed. Generally, the sample has at least 0.01 mg of protein, typically a concentration of 0.1-10 mg/mL, and may be adjusted to a desired buffer concentration and pH.
A known amount of a labeled peptide internal standard, preferably about 10 femtomoles, corresponding to a target protein to be detected/quantified is then added to a biological sample, such as a cell lysate. The spiked sample is then digested with one or more protease(s) for a suitable time period to allow digestion. A separation is then performed (e.g. by HPLC, reverse-phase HPLC, capillary electrophoresis, ion exchange chromatography, etc.) to isolate the labeled internal standard and its corresponding target peptide from other peptides in the sample. Microcapillary LC is a one non-limiting method.
Each isolated peptide is then examined by monitoring of a selected reaction in the MS. This involves using the prior knowledge gained by the characterization of the peptide internal standard and then requiring the MS to continuously monitor a specific ion in the MS/MS or MSn spectrum for both the peptide of interest and the internal standard. After elution, the area under the curve (AUC) for both peptide standard and target peptide peaks are calculated. The ratio of the two areas provides the absolute quantification that can be normalized for the number of cells used in the analysis and the protein's molecular weight, to provide the precise number of copies of the protein per cell. Further details of the AQUA methodology are described in Gygi et al., and Gerber et al. supra.
AQUA internal peptide standards (heavy-isotope labeled peptides) may desirably be produced, as described above, to detect any quantify any unique site (e.g., the fusion junction within a ROS1 or ALK fusion polypeptide or a mutant-specific sequence within a mutant EGFR polypeptide) within a polypeptide disclosed herein. For example, an AQUA phosphopeptide may be prepared that corresponds to the fusion junction sequence of one of the ROS1 or ALK fusion polypeptides. Peptide standards for may be produced for the fusion junction and such standards employed in the AQUA methodology to detect and quantify the fusion junction (i.e. the presence of that fusion polypeptide) in a biological sample.
For example, one non-limiting AQUA peptide includes the amino acid sequence AGSTLP (SEQ ID NO: 32), which corresponds to the three amino acids immediately flanking each side of the fusion junction in the short variant of FIG-ROS1 fusion polypeptide (i.e., FIG-ROS1(S) fusion polypeptide), where the amino acids encoded by the FIG gene are italicized and the amino acids encoded by the ROS1 gene in bold. It will be appreciated that larger AQUA peptides including the fusion junction sequence (and additional residues downstream or upstream of it) may also be constructed. Similarly, a smaller AQUA peptide including less than all of the residues of such sequence (but still including the point of fusion junction itself) may alternatively be constructed. Such larger or shorter AQUA peptides are within the scope of the present disclosure, and the selection and production of AQUA peptides may be carried out as described above (see Gygi et al., Gerber et al., supra.).
It should be noted that because the sequence of the AQUA peptide spanning the fusion junction of one of the ROS1 fusion proteins described herein may also be (or be included in) the epitope to which a ROS1 fusion-specific antibody specifically binds. An “epitope” refers to either an immunogenic epitope (i.e., capable of eliciting an immune response) or an antigenic epitope (i.e., the region of a protein molecule to which an antibody can specifically bind. The number of immunogenic epitopes of a protein generally is less than the number of antigenic epitopes. See, for instance, Geysen et al., Proc. Natl. Acad. Sci. USA 81:3998-4002 (1983).
Table 3 provides a list of the sequences of all the fusion junctions of exemplary ROS1 fusion polypeptides, where the amino acids encoded by the non-ROS1 gene are italicized and the amino acids encoded by the ROS1 gene in bold.
VGV
WHR
LVG
DDF
LVG
AGV
PPK
DDF
AGS
TLP
LQV
WHR
VLQ
A longer depiction of the sequence of CD74-ROS1 including the fusion junction is provided in SEQ ID NO: 15.
In some embodiments, the mammalian cancer is from a human. In various embodiments, the biological sample is from the cancer or suspected cancer of the patient. In some embodiments, the cancer is a solid tumor cancer. In some embodiments, the cancer is leukemia. In some embodiments, the cancer is lymphoma. In some embodiments, the cancer is a lung cancer (e.g., a non-small cell lung carcinoma or a small cell lung carcinoma). In some embodiments, the cancer is a brain cancer (e.g., glioblastoma). In some embodiments, the cancer is a liver cancer (e.g., cholangiocarcinoma). In some embodiments, the cancer is colon cancer. In some embodiments, the cancer is breast cancer. In some embodiments, the cancer is ovarian cancer.
In some embodiments, the mammalian lung cancer is NSCLC (non-small cell lung carcinoma). In some embodiments, the mammalian lung cancer is SCLC (small cell lung carcinoma). In further embodiments of the methods disclosed herein, the mammal is a human, and the human may be a candidate for a ROS1-inhibiting therapeutic, an EGFR-inhibiting therapeutic, or both, for the treatment of a lung cancer. The human candidate may be a patient currently being treated with, or considered for treatment with, a ROS1 kinase inhibitor or EGFR kinase inhibitor. In another embodiment, the mammal is large animal, such as a horse or cow, while in other embodiments, the mammal is a small animal, such as a dog or cat, all of which are known to develop lung cancers, such as NSCLC and SCLC.
As used throughout the specification, the term “biological sample” is used in its broadest sense, and means any biological sample suspected of containing a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, or a mutant EGFR polypeptide including, without limitation, a ROS1 or ALK fusion polypeptide or a full length ROS1 or ALK protein (with or without the signal peptide sequence) or fragments having ROS1 or ALK kinase activity thereof. Biological samples include, without limitation, saliva, mucous, tears, blood, circulating tumor cells, serum, tissues, bone marrow, lymph/interstitial fluids, buccal cells, mucosal cells, cerebrospinal fluid, semen, feces, plasma, urine, a suspension of cells, or a suspension of cells and viruses or extracts thereof, and may include a cell, chromosomes isolated from a cell (e.g., a spread of metaphase chromosomes), genomic DNA (in solution or bound to a solid support such as for Southern analysis), RNA (in solution or bound to a solid support such as for northern analysis), cDNA (in solution or bound to a solid support). In some embodiments, the biological sample contains lung cells suspected of being cancerous.
The methods disclosed herein can include detection of two or more analytes (e.g., a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, and a mutant EGFR polypeptide (and nucleic acids encoding the same)) in the same biological sample. In these methods, a biological sample may be divided into one or more fractions (e.g., portions of a liquid sample or sections of a tissue sample) prior to detection and each analyte detected in a separate fraction. The methods do not require detection of the analytes in the same fraction of a sample or in the same cell within a sample. In other embodiments, the methods disclosed herein can be used to detect two or more analytes (e.g., a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, and a mutant EGFR polypeptide (and nucleic acids encoding the same)) in separate biological samples from the same subject. For example, two separately obtained samples from the same tumor or the same organ or tissue of a patient may be assayed independently for each of the two or more analytes. The separately obtained samples can be obtained at approximately the same time or at different times (e.g., within days, weeks, months, or years of each other).
Any biological sample that includes cells (or extracts of cells) from a mammalian cancer is suitable for use in the methods disclosed herein. In one embodiment, the biological sample includes cells obtained from a tumor biopsy or a tumor resection. The biopsy or resection may be obtained, according to standard clinical techniques, from primary tumors occurring in an organ of a mammal, or by secondary tumors that have metastasized in other tissues. In some instances, the biopsy or resection is frozen or fixed with formalin and embedded in paraffin. Frozen or fixed samples may be sectioned for further analysis.
In another embodiment, the biological sample includes cells obtained from a fine needle aspirate taken from a tumor, and techniques for obtaining such aspirates are well known in the art (see Cristallini et al., Acta Cytol. 36(3): 416-22 (1992)). In certain embodiments, the biological sample includes a bronchial scraping.
The biological sample may also include cells obtained from an effusion, such as a pleural effusion. Pleural effusions (liquid that forms outside the lung in the thoracic cavity and which contains cancerous cells) are known to form in many patients with advanced lung cancer (including NSCLC), and the presence of such effusion is predictive of a poor outcome and short survival time. Standard techniques for obtaining pleural effusion samples have been described and are well known in the art (see Sahn, Clin Chest Med. 3(2): 443-52 (1982)).
The biological sample may include cells obtained from a bronchoalveolar lavage. Bronchoalveolar lavage is a standard medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then recollected for examination.
In some embodiments, the biological sample includes circulating tumor cells. Circulating tumor cells (“CTCs”) may be purified, for example, using the kits and reagents sold under the trademarks Vita-Assays™, Vita-Cap™, and CellSearch® (commercially available from Vitatex, LLC (a Johnson and Johnson corporation). Other methods for isolating CTCs are described (see, for example, PCT Publication No. WO/2002/020825, Cristofanilli et al., New Engl. J. of Med. 351 (8):781-791 (2004), and Adams et al., J. Amer. Chem. Soc. 130(27): 8633-8641 (July 2008)). In a particular embodiment, a circulating tumor cell (“CTC”) may be isolated and identified as having originated from the lung.
Accordingly, the disclosure provides a method for isolating a CTC, and then screening the CTC one or more assay formats to identify the presence of a polypeptide with ROS1 kinase activity, a mutant EGFR polypeptide, or a nucleic acid molecule encoding either of the same in the CTC.
Cellular extracts of the biological samples described herein may be prepared, either crude or partially (or entirely) purified, in accordance with standard techniques, and used in the methods disclosed herein. Alternatively, biological samples including whole cells may be utilized in assay formats such as in vitro kinase assay, ELISA assays, immunohistochemistry (IHC), flow cytometry (FC), and immunofluorescence (IF), immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR), according to standard methods such as those described below (see, also, e.g., Ausubel et al., supra). Such whole-cell assays are advantageous in that they minimize manipulation of the tumor cell sample and thus reduce the risks of altering the in vivo signaling/activation state of the cells and/or introducing artifact signals. Whole cell assays are also advantageous because they characterize expression and signaling only in tumor cells, rather than a mixture of tumor and normal cells.
Thus, biological samples useful in the practice of the methods disclosed herein may be obtained from any mammal in which a cancer or suspected cancer characterized by the presence of a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, or a mutant EGFR polypeptide is present or might be present or developing. As used herein, the phrase “characterized by” with respect to a cancer (or suspected cancer) and indicated molecule (e.g., a polypeptide with ROS1 kinase activity or a polypeptide with ALK kinase activity) is meant a cancer (or suspected cancer) in which a gene translocation or mutation and/or an expressed polypeptide is present, as compared to another cancer or a normal tissue in which such translocation or aberrant expression is not present. The presence of such mutation or aberrant expression may drive (i.e., stimulate or be the causative agent of), in whole or in part, the growth and survival of such cancer or suspected cancer.
Accordingly, any biological sample (e.g., CTC, pleural effusion, needle aspirate, tumor biopsy) from a patient that is identified as having a polypeptide with ROS1 kinase activity, a mutant EGFR polypeptide, or polynucleotide encoding either of the same (e.g., a full length ROS1 polypeptide or polynucleotide or a ROS1 fusion polypeptide or polynucleotide) may indicate that the patient's originating cancer (e.g., an lung cancer such as NSCLC or SCLC) is being driven by the polypeptide with ROS1 kinase activity and/or the mutant EGFR polypeptide and thus is likely to respond to a treatment regimen that includes one or both of a ROS1 kinase-inhibiting therapeutic and an EGFR kinase-inhibiting therapeutic.
As used herein, by “likely to respond” is meant that a cancer is more likely to show growth retardation or abrogation in response to (e.g., upon contact with or treatment by) a ROS1 inhibiting therapeutic and/or EGFR inhibiting therapeutic. In some embodiments, a cancer that is likely to respond to a ROS1 inhibiting therapeutic and/or EGFR inhibiting therapeutic is one that dies (e.g., the cancer cells apoptose) in response to the ROS1 inhibiting therapeutic and/or EGFR inhibiting therapeutic.
In assessing the presence of a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, or a mutant EGFR polypeptide (or polynucleotides encoding the same) in a biological sample that includes cells from a mammalian cancer tumor, a control sample representing a cell in which such a polypeptide does not occur (e.g., healthy lung cells) may desirably be employed for comparative purposes. Ideally, the control sample includes cells from a subset of the particular cancer (e.g., lung cancer) that is representative of the subset in which the polypeptide (or polynucleotide encoding the same) does not occur. Comparing the level in the control sample versus the test biological sample thus identifies whether the mutant polynucleotide and/or polypeptide is/are present. Alternatively, since a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, or a mutant EGFR polypeptide (or polynucleotides encoding the same) may not be present in the majority of cancers, any tissue that similarly does not express a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, or a mutant EGFR polypeptide (or polynucleotides encoding the same) may be employed as a control.
The methods described herein have valuable diagnostic utility for cancers characterized by the presence of a polypeptide with ROS1 kinase activity, a polypeptide with ALK kinase activity, or a mutant EGFR polypeptide, and treatment decisions pertaining to the same. For example, biological samples may be obtained from a subject that has not been previously diagnosed as having a cancer characterized by the presence of polypeptide with ROS1 kinase activity and/or a mutant EGFR polypeptide, nor has yet undergone treatment for such cancer, and the method is employed to diagnostically identify a tumor in such subject as belonging to a subset of tumors (e.g., NSCLC or SCLC) in which a polypeptide with ROS1 kinase activity and/or a mutant EGFR polypeptide (or polynucleotide encoding the same) is present/expressed.
Alternatively, a biological sample may be obtained from a subject that has been diagnosed as having a cancer characterized by the presence of one type of kinase, such as EGFR, and has been receiving therapy, such as EGFR inhibitor therapy (e.g., erlotinib, gefitinib) for treatment of such cancer, and a method disclosed herein is employed to identify whether the subject's tumor is also characterized by the presence of polypeptide with ROS1 kinase activity (or polynucleotide encoding the same) such as full length ROS1 protein or one of the many ROS1 fusion polypeptides (e.g., SLC34A2-ROS1(S)), and is therefore likely to fully respond to the existing therapy and/or whether alternative or additional ROS1-inhibiting therapy is desirable or warranted. The methods of disclosed herein may also be employed to monitor the progression or inhibition of a polypeptide with ROS1 kinase activity-expressing cancer following treatment of a subject with a composition that includes a ROS1-inhibiting therapeutic or combination of therapeutics.
Such diagnostic assay may be carried out subsequent to or prior to preliminary evaluation or surgical surveillance procedures. The identification methods disclosed herein may be advantageously employed as a diagnostic to identify patients having cancer, such as lung cancer (e.g., non-small cell lung cancer) or colon cancer, characterized by the presence of a polypeptide with ROS1 kinase activity or ALK kinase activity, or a mutant EGFR polypeptide, which patients would be most likely to respond to therapeutics targeted at inhibiting ROS1 or ALK kinase activity or EGFR kinase activity. The ability to select such patients would also be useful in the clinical evaluation of efficacy of future ROS1-, ALK-, and/or EGFR-inhibiting therapeutics as well as in the future prescription of such drugs to patients.
The ability to selectively identify cancers in which a polypeptide with ROS1 kinase activity (or polynucleotide encoding the same) or a polypeptide with ALK kinase activity (or polynucleotide encoding the same) or a mutant EGFR polypeptide (or polynucleotide encoding the same) is/are present enables important new methods for accurately identifying such tumors for diagnostic purposes, as well as obtaining information useful in determining whether such a tumor is likely to respond to a ROS1-, ALK-, and/or EGFR-inhibiting therapeutic composition, or likely to be partially or wholly non-responsive to an inhibitor targeting a different kinase when administered as a single agent for the treatment of the cancer.
As used herein, by “cancer” or “cancerous” is meant a cell that shows abnormal growth as compared to a normal (i.e., non-cancerous) cell of the same cell type. For example, a cancerous cell may be metastatic or non-metastatic. A cancerous cell may also show lack of contact inhibition where a normal cell of that same cell type shows contact inhibition. In some embodiments, the cancer is lung cancer (e.g., non-small cell lung cancer or small cell lung cancer). As used herein, by “suspected cancer” (as in “suspected mammalian lung cancer”) or “tissue suspected of being cancerous” is meant a cell or tissue that has some aberrant characteristics (e.g., hyperplastic or lack of contact inhibition) as compared to normal cells or tissues of that same cell or tissue type as the suspected cancer, but where the cell or tissue is not yet confirmed by a physician or pathologist as being cancerous.
In some embodiments, the various methods disclosed herein may be carried out in a variety of different assay formats known to those of skill in the art. Some non-limiting examples of methods include immunoassays and peptide and nucleotide assays.
Immunoassays useful in the practice of the methods disclosed herein may be homogenous immunoassays or heterogeneous immunoassays. In a homogeneous assay the immunological reaction usually involves a specific reagent (e.g. a ROS1-specific antibody, an ALK-specific antibody, or a mutant EGFR-specific antibody), a labeled analyte, and the biological sample of interest. The signal arising from the label is modified, directly or indirectly, upon the binding of the antibody to the labeled analyte. Both the immunological reaction and detection of the extent thereof are carried out in a homogeneous solution. Immunochemical labels that may be employed include free radicals, radio-isotopes, fluorescent dyes, enzymes, bacteriophages, coenzymes, and so forth. Semi-conductor nanocrystal labels, or “quantum dots”, may also be advantageously employed, and their preparation and use has been well described. See generally, K. Barovsky, Nanotech. Law & Bus. 1(2): Article 14 (2004) and patents cited therein.
In a heterogeneous assay approach, the materials are usually the biological sample, binding reagent (e.g., an antibody), and suitable means for producing a detectable signal. Biological samples as further described below may be used. The antibody is generally immobilized on a support, such as a bead, plate or slide, and contacted with the sample suspected of containing the antigen in a liquid phase. The support is then separated from the liquid phase and either the support phase or the liquid phase is examined for a detectable signal employing means for producing such signal. The signal is related to the presence of the analyte in the biological sample. Means for producing a detectable signal include the use of radioactive labels, fluorescent labels, enzyme labels, quantum dots, and so forth. For example, if the antigen to be detected contains a second binding site, an antibody which binds to that site can be conjugated to a detectable group and added to the liquid phase reaction solution before the separation step. The presence of the detectable group on the solid support indicates the presence of the antigen in the test sample. Examples of suitable immunoassays are the radioimmunoassay, immunofluorescence methods, enzyme-linked immunoassays, and the like.
Immunoassay formats and variations thereof, which may be useful for carrying out the methods disclosed herein, are well known in the art. See generally E. Maggio, Enzyme-Immunoassay, (1980) (CRC Press, Inc., Boca Raton, Fla.); see also, e.g., U.S. Pat. No. 4,727,022 (Skold et al., “Methods for Modulating Ligand-Receptor Interactions and their application”); U.S. Pat. No. 4,659,678 (Forrest et al., “Immunoassay of Antigens”); U.S. Pat. No. 4,376,110 (David et al., “Immunometric Assays Using Monoclonal Antibodies”). Conditions suitable for the formation of reagent-antibody complexes are well known to those of skill in the art. See id. ROS1-specific antibodies may be used in a “two-site” or “sandwich” assay, with a single hybridoma cell line serving as a source for both the labeled monoclonal antibody and the bound monoclonal antibody. Such assays are described in U.S. Pat. No. 4,376,110. The concentration of detectable reagent should be sufficient such that the binding of the antigen of interest is detectable compared to background.
Antibodies useful in the practice of the methods disclosed herein may be conjugated to a solid support suitable for a diagnostic assay (e.g., beads, plates, slides or wells formed from materials such as latex or polystyrene) in accordance with known techniques, such as precipitation. Antibodies or other binding reagents binding reagents may likewise be conjugated to detectable groups such as radiolabels (e.g., 35S, 125I, 131I), enzyme labels (e.g., horseradish peroxidase, rosaline phosphatase), and fluorescent labels (e.g., fluorescein) in accordance with known techniques.
Cell-based assays, such flow cytometry (FC), immunohistochemistry (IHC), or immunofluorescence (IF) are particularly desirable in practicing the methods disclosed herein, since such assay formats are clinically-suitable, allow the detection of expression of a protein with ROS1 kinase activity or a protein with ALK kinase activity in vivo, and avoid the risk of artifact changes in activity resulting from manipulating cells obtained from, e.g. a tumor sample in order to obtain extracts. Accordingly, in some embodiments, the methods disclosed herein are implemented in a flow-cytometry (FC), immunohistochemistry (IHC), or immunofluorescence (IF) assay format.
Flow cytometry (FC) may be employed to determine the expression of polypeptide with ROS1 kinase activity or ALK kinase activity or a mutant EGFR polypeptide in a mammalian tumor before, during, and after treatment with one or more drugs targeted at inhibiting ROS1, ALK, and/or EGFR kinase activity. For example, tumor cells from a fine needle aspirate may be analyzed by flow cytometry for expression and/or activation of a polypeptide with ROS1 kinase activity or ALK kinase activity or a mutant EGFR polypeptide or polynucleotide encoding the same, as well as for markers identifying cancer cell types, etc., if so desired. Flow cytometry may be carried out according to standard methods. See, e.g. Chow et al., Cytometry (Communications in Clinical Cytometry) 46: 72-78 (2001). Briefly and by way of example, the following protocol for cytometric analysis may be employed: fixation of the cells with 2% paraformaldehyde for 10 minutes at 37° C. followed by permeabilization in 90% methanol for 10 minutes on ice. Cells may then be stained with the primary antibody (e.g., a full-length ROS1-specific or a ROS1 fusion polypeptide-specific antibody or an EGFR mutant-specific antibody), washed and labeled with a fluorescent-labeled secondary antibody. The cells would then be analyzed on a flow cytometer (e.g. a Beckman Coulter FC500) according to the specific protocols of the instrument used. Such an analysis would identify the level of expressed full-length ROS1 or ALK or a ROS1 fusion or ALK fusion polypeptide or mutant EGFR polypeptide in the tumor. Similar analysis after treatment of the tumor with one or more ROS1-, ALK-, or EGFR-inhibiting therapeutics would reveal the responsiveness of the tumor to the targeted inhibitor of ROS1 or ALK kinase or EGFR kinase.
Immunohistochemical (IHC) staining may be also employed to determine the expression and/or activation status of polypeptide with ROS1 kinase activity or a mutant EGFR polypeptide in a mammalian cancer (e.g., a lung cancer) before, during, and after treatment with a therapeutic targeted at inhibiting ROS1 kinase activity and/or EGFR kinase activity. IHC may be carried out according to well-known techniques. See, e.g., A
Immunofluorescence (IF) assays may be also employed to determine the expression and/or activation status of a polypeptide with ROS1 kinase activity (e.g., full length ROS1 polypeptide or a ROS1 fusion polypeptide) or a mutant EGFR polypeptide in a mammalian cancer before, during, and after treatment with a therapeutic targeted at inhibiting ROS1 kinase activity and/or EGFR kinase activity. IF may be carried out according to well-known techniques. See, e.g., J. M. Polak and S. Van Noorden (1997) I
A variety of other protocols, including enzyme-linked immunosorbent assay (ELISA), radio-immunoassay (RIA), western blotting analysis, in vitro kinase assay, and fluorescent-activated cell sorting (FACS), for measuring expression and/or activity of a polypeptide with ROS1 kinase activity are known in the art and provide a basis for diagnosing the presence of the polypeptide with ROS1 kinase activity (e.g., a full-length ROS1, or an ROS1 fusion polypeptide such as an FIG-ROS1(S) fusion polypeptide) or the presence of a polypeptide with ALK kinase activity (e.g., full length ALK or an ALK fusion polypeptide such as NPM-ALK fusion polypeptide) or the presence of a mutant EGFR polypeptide. Normal or standard values for ALK or ROS1 (full length or fusion) polypeptide expression are established by combining body fluids or cell extracts taken from normal mammalian subjects, preferably human, with an antibody that specifically binds to a polypeptide with ROS1 kinase activity or a polypeptide with ALK kinase activity under conditions suitable for complex formation. The amount of standard complex formation may be quantified by various methods, but preferably by photometric means. Quantities of full length ROS1 polypeptide expressed in subject, control, and disease samples from biopsied tissues are compared with the standard values. Deviation between standard and subject values establishes the parameters for diagnosing disease. Note that in some tissues (e.g., lung cancer) since the proteins with ROS1 kinase activity or proteins with ALK kinase activity (e.g., SLC34A2-ROS1(S) and EML4-ALK (796aa variant)) or mutant EGFR polypeptides were discovered in cancerous tissue, no normal lung tissue biological samples are expected to contain these proteins with ROS1 kinase activity or ALK kinase activity (or polynucleotides encoding the same) or mutant EGFR polypeptides.
In another aspect, the disclosure provides methods for detecting the presence of a polynucleotide encoding a polypeptide with ROS1 kinase activity or ALK kinase activity or a polynucleotide encoding a mutant EGFR polypeptide in a biological sample from a mammalian lung cancer or suspected mammalian lung cancer, said methods including the steps of: (a) obtaining a biological sample from a mammalian lung cancer or suspected mammalian lung cancer and (b) utilizing a reagent that specifically binds to said polynucleotide encoding said polypeptide to determine whether said polynucleotide is present in said biological sample, wherein detection of specific binding of said reagent to said biological sample indicates said polynucleotide encoding said polypeptide with ROS1 kinase activity or ALK kinase activity or mutant EGFR polypeptide is present in said biological sample.
The presence of a polynucleotide encoding a polypeptide having ROS1 kinase activity or ALK kinase activity or a mutant EGFR polypeptide can be assessed by any standard methods. In addition, these methods can be combined with methods to detect the polypeptide having ROS1 kinase activity or ALK kinase activity or mutant EGFR polypeptide as described above.
Full length ROS1 polynucleotide or ROS1 fusion polynucleotide-specific binding reagents, full length ALK polynucleotide or ALK fusion polynucleotide-specific binding reagents, and mutant EGFR polynucleotide-specific binding reagents useful in practicing the methods disclosed herein may also be mRNA, oligonucleotide or DNA probes that can directly hybridize to, and detect, fusion or truncated polypeptide expression transcripts in a biological sample. Such probes are discussed in detail herein. Briefly, and by way of example, formalin-fixed, paraffin-embedded (PPFE) patient samples may be probed with a fluorescein-labeled RNA probe followed by washes with formamide, SSC and PBS and analysis with a fluorescent microscope.
Polynucleotides encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide may also be used for diagnostic purposes. The polynucleotides that may be used include oligonucleotide sequences, antisense RNA and DNA molecules, and PNAs. The polynucleotides may be used to detect and quantitate gene expression in biopsied tissues in which expression of a polypeptide with ROS1 or ALK kinase activity (e.g., a ROS1 or ALK fusion polypeptide or full length ROS1 or ALK) or a mutant EGFR polypeptide may be correlated with disease. The diagnostic assay may be used to distinguish between absence, presence, and excess expression of a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, and to monitor regulation of levels of a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide during therapeutic intervention.
In one embodiment, hybridization with PCR primers that are capable of detecting polynucleotide sequences, including genomic sequences, encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide may be used to identify nucleic acid sequences that encode such polypeptides with ROS1 or ALK kinase activity or mutant EGFR polypeptides. The specificity of the probe, whether it is made from a highly specific region, e.g., 10 unique nucleotides in the fusion junction, or a less specific region, e.g., the 3′ coding region, and the stringency of the hybridization or amplification (maximal, high, intermediate, or low) will determine whether the probe identifies only naturally occurring sequences encoding ROS1 or ALK kinase polypeptides (e.g., full length ROS1 or ALK or a ROS1 or ALK fusion protein) or mutant EGFR polypeptides, alleles, or related sequences.
Probes may also be used for the detection of related sequences. The hybridization probes (e.g., FISH probes or Southern or Northern blotting probes) of the subject methods may be DNA or RNA and derived from the nucleotide sequences of encoding polypeptides with ROS1 kinase activity, polypeptides with ALK kinase activity, or mutant EGFR polypeptides. In some embodiments, where the polypeptide having ROS1 or ALK kinase activity is a fusion protein, the hybridization probes encompassing the fusion junction, or from genomic sequence including promoter, enhancer elements, and introns of the naturally occurring ROS1 or ALK gene and the fusion partner gene (e.g., for ROS1, SLC34A2, FIG, or CD74; for ALK, NPM, EML4, TFG, etc.).
A ROS1 fusion polynucleotide (i.e., a polynucleotide encoding a ROS1 fusion polypeptide such as FIG-ROS1(S) or CD74-ROS1), full length ROS1 polynucleotide, ALK fusion polynucleotide (i.e., a polynucleotide encoding an ALK fusion polynucleotide such as EML4-ALK(796 aa variant), full length ALK polynucleotide, or mutant EGFR polynucleotide may be used in Southern or northern analysis, dot blot, or other membrane-based technologies; in PCR technologies; or in dip stick, pin, ELISA or chip assays utilizing fluids or tissues from patient biopsies to detect altered expression of a polypeptide with ROS1 kinase activity or expression of a mutant EGFR polypeptide. Such qualitative or quantitative methods are well known in the art. In a particular aspect, the nucleotide sequences encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide may be useful in assays that detect activation or induction of various cancers, including lung cancer (e.g., non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma) and colon cancer. Polynucleotides encoding a polypeptide with ROS1 kinase activity or a mutant EGFR polypeptide may be detectably labeled by standard methods, and added to a fluid or tissue sample from a patient under conditions suitable for the formation of hybridization complexes. After a suitable incubation period, the sample is washed and the signal is quantitated and compared with a standard value. If the amount of signal in the biopsied or extracted sample is significantly altered from that of a comparable control sample, the nucleotide sequences have hybridized with nucleotide sequences in the sample, and the presence of altered levels of nucleotide sequences encoding a polypeptide with ROS1 or ALK kinase activity (e.g., a ROS1 or ALK fusion polypeptide or full length ROS1 or ALK polypeptide) or a mutant EGFR polypeptide in the sample indicates the presence of the associated disease. Such assays may also be used to evaluate the efficacy of a particular therapeutic treatment regimen in animal studies, in clinical trials, or in monitoring the treatment of an individual patient.
In some embodiments, the methods disclosed herein are carried out using a nucleic acid amplification (e.g., PCR) assay format. Polymerase chain reaction (PCR) is standard to those of skill in the art. See, e.g., M
Methods which may also be used to quantitate the expression of a nucleotide encoding a polypeptide with ROS1 or ALK kinase activity (e.g., ROS1 or ALK fusion polypeptide or full ROS1 or ALK polypeptide) or a mutant EGFR polypeptide include radiolabeling or biotinylating nucleotides, co-amplification of a control nucleic acid, and standard curves onto which the experimental results are interpolated (Melby et al., J. Immunol. Methods, 159: 235-244 (1993); Duplaa et al. Anal. Biochem. 229-236 (1993)). The speed of quantitation of multiple samples may be accelerated by running the assay in an ELISA format where the oligomer of interest is presented in various dilutions and a spectrophotometric or colorimetric response gives rapid quantitation.
In another embodiment, the polynucleotides encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide may be used to generate hybridization probes which are useful for mapping the naturally occurring genomic sequence. The sequences may be mapped to a particular chromosome or to a specific region of the chromosome using well-known techniques. Such techniques include fluorescence in-situ hybridization (FISH), FACS, or artificial chromosome constructions, such as yeast artificial chromosomes, bacterial artificial chromosomes, bacterial P1 constructions or single chromosome cDNA libraries, as reviewed in Price, C. M., Blood Rev. 7: 127-134 (1993), and Trask, B. J., Trends Genet. 7: 149-154 (1991).
In further embodiments, fluorescence in-situ hybridization (FISH) is employed in the methods disclosed herein (as described in Verma et al. H
In situ hybridization of chromosomal preparations and physical mapping techniques such as linkage analysis using established chromosomal markers may be used for extending genetic maps. Often the placement of a gene on the chromosome of another mammalian species, such as mouse, may reveal associated markers even if the number or arm of a particular human chromosome is not known. New sequences can be assigned to chromosomal arms, or parts thereof, by physical mapping. This provides valuable information to investigators searching for disease genes using positional cloning or other gene discovery techniques. Once the disease or syndrome has been crudely localized by genetic linkage to a particular genomic region, for example, AT to 11q22-23 (Gatti et al., Nature 336: 577-580 (1988)), any sequences mapping to that area may represent associated or regulatory genes for further investigation. The nucleotide sequence may also be used to detect differences in the chromosomal location due to translocation, inversion, etc., among normal, carrier, or affected individuals.
Polynucleotides encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR may be detected by nucleotide sequencing, e.g., of chromosomal or expressed (e.g., mRNA, cDNA) nucleic acids. Methods of nucleic acid sequencing are well known and include chain termination sequencing and other sequencing techniques, such as single-molecule real-time sequencing, ion semiconductor sequencing, pyrosequencing, sequencing by synthesis (e.g., offered by Illumina), and sequencing by ligation (SOLiD sequencing).
It shall be understood that all of the methods (e.g., PCR, FISH, sequencing) that detect polynucleotides encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, may be combined with other methods that detect polypeptides with ROS1 or ALK kinase activity or a mutant EGFR polypeptide or polynucleotides encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide. For example, detection of a FIG-ROS1(S) fusion polynucleotide in the genetic material of a biological sample (e.g., FIG-ROS1(S) in a circulating tumor cell) may be followed by western blotting analysis or immuno-histochemistry (IHC) analysis of the proteins of the sample to determine if the FIG-ROS1(S) polynucleotide was actually expressed as a FIG-ROS1(S) fusion polypeptide in the biological sample. Such western blotting or IHC analyses may be performed using an antibody that specifically binds to the polypeptide encoded by the detected FIG-ROS1(S) polynucleotide, or the analyses may be performed using antibodies that specifically bind either to full length FIG (e.g., bind to the N-terminus of the protein) or to full length ROS1 (e.g., bind an epitope in the kinase domain of ROS1). Such assays are known in the art (see, e.g., U.S. Pat. No. 7,468,252).
In another example, the CISH technology of Dako allows chromatogenic in situ hybridization with immuno-histochemistry on the same tissue section. See Elliot et al., Br J Biomed Sci 2008; 65: 167-171, 2008 for a comparison of CISH and FISH.
Another aspect of the disclosure provides methods for diagnosing a patient as having a cancer or a suspected cancer driven by an ROS1 kinase, an ALK kinase, or a mutant EGFR polypeptide. The methods include contacting a biological sample of said cancer or a suspected cancer (where the biological sample contains at least one nucleic acid molecule) with a probe that hybridizes under stringent conditions to a nucleic acid molecule encoding a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, and wherein hybridization of said probe to at least one nucleic acid molecule in said biological sample identifies said patient as having a cancer or a suspected cancer driven by a ROS1 kinase or a mutant EGFR polypeptide.
Yet another aspect of the disclosure provides a method for diagnosing a patient as having a cancer or a suspected cancer driven by a ROS1 kinase or ALK kinase or a mutant EGFR polypeptide. The method includes contacting a biological sample of said cancer or suspected cancer (where said biological sample contains at least one polypeptide) with a reagent that specifically binds to a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, wherein specific binding of said reagent to at least one polypeptide in said biological sample identifies said patient as having a lung cancer or a suspected lung cancer driven by a ROS1 kinase or an ALK kinase or a mutant EGFR polypeptide.
In various embodiments, the identification of a lung cancer or suspected lung cancer as being driven by a ROS1 kinase or a mutant EGFR polypeptide will identify that patient having that lung cancer or suspected lung cancer as being likely to respond to a ROS1-inhibiting therapeutic, an EGFR-inhibiting therapeutic, or both.
In order to provide a basis for the diagnosis of disease (e.g., a lung cancer) characterized by expression of a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, a normal or standard profile for expression may be established. This may be accomplished by combining body fluids or cell extracts taken from normal subjects, either animal or human, with a polynucleotide sequence, or a fragment thereof, which encodes a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide, under conditions suitable for hybridization or amplification. Standard hybridization may be quantified by comparing the values obtained from normal subjects with those from an experiment where a known amount of a substantially purified polynucleotide is used. Standard values obtained from normal samples may be compared with values obtained from samples from patients who are symptomatic for disease. Deviation between standard and subject values is used to establish the presence of disease.
Once disease is established and a treatment protocol is initiated, hybridization assays may be repeated on a regular basis to evaluate whether the level of expression in the patient begins to approximate that which is observed in the normal patient. The results obtained from successive assays may be used to show the efficacy of treatment over a period ranging from several days to months.
A similar normal or standard profile for expression or activity level of a polypeptide having ROS1 or ALK kinase activity or a mutant EGFR polypeptide can be established. For example, for protein expression, the profile can be established using a reagent that specifically binds to the polypeptide can also be established using, e.g., an antibody that specifically binds to the polypeptide (e.g., binds to full length ROS1 or binds to the fusion junction of a ROS1 fusion polypeptide) and comparing levels of binding in normal subject with levels of binding in patients symptomatic for lung cancer. Similarly, for ROS1, ALK, or EGFR kinase activity levels, a standard in vitro kinase assay (see Ausubel et al., supra; Sambrook et al., supra) can be performed on a samples taken from normal patients as compared to samples taken from patients symptomatic for lung cancer.
In various embodiments, the inhibition of ROS1 or ALK expression or kinase activity is determined using a reagent that specifically binds to a ROS1 or ALK fusion polynucleotide, a reagent that specifically binds to ROS1 or ALK fusion polypeptide, a reagent that specifically binds to a full length ROS1 or ALK polynucleotide, or a reagent that specifically binds to a full length ROS1 or ALK polypeptide. In some additional embodiments, the inhibition of ROS1 or ALK expression or kinase activity is determined using a reagent that specifically binds to the full length protein of a fusion partner of a ROS1 fusion polypeptide or a ALK fusion protein. For example, for ROS1, the reagent may specifically bind a FIG or CD74 or SLC34A2 polynucleotide or specifically binds to a full length FIG or CD74 or SLC34A2 polypeptide. For ROS1, the reagent may specifically binds to a full length NPM or EML4 or ATIC or CARS or TFG or KIF5B or RANBP2 or TPM3, or ALO17 or MSN or TPM4 or ATIC or MYH9 or CLTC or SEC31L1 polynucleotide, or may specifically binds to a full length NPM or EML4 or ATIC or CARS or TFG or KIF5B or RANBP2 or TPM3, or ALO17 or MSN or TPM4 or ATIC or MYH9 or CLTC or SEC31L1 polypeptide.
In various embodiments, the expression and/or activity of said ALK or ROS1 polypeptide is inhibited with a composition that includes a therapeutic selected from the group consisting of crizotinib (also known as PF-02341066), ASP3026, NVP TAE-684, AP26113, CEP-14083, CEP-14513, CEP11988, WHI-P131 and WHI-P154.
As used herein, a “ROS1 inhibitor” or a “ROS1-inhibiting compound” means any composition that includes one or more compounds, chemical or biological, that inhibit, either directly or indirectly, the expression and/or activity of a polypeptide with ROS1 kinase activity. Such inhibition may be in vitro or in vivo. “ROS1 inhibitor therapeutic” or “ROS1-inhibiting therapeutic” means a ROS1-inhibiting compound used as a therapeutic to treat a patient harboring a cancer (e.g., a lung cancer such as NSCLC or SCLC) characterized by the presence of a polypeptide with ROS1 kinase activity such as aberrantly expressed full length ROS1 protein or a ROS1 fusion polypeptide (e.g., one of the FIG-ROS1 fusion proteins) described herein.
In some embodiments of the disclosure, the ROS1 inhibitor is a reagent that specifically binds to a ROS1 fusion polypeptide (e.g., FIG-ROS1(S), FIG-ROS1(L), FIG-ROS1(XL), SLC34A2-ROS1(VS), SLC34A2-ROS1(S), SLC34A2-ROS1(L), or CD74-ROS1), a reagent that specifically binds to a full length ROS1 polypeptide, an siRNA targeting a ROS1 fusion polynucleotide (e.g., an SLC34A2-ROS1(S) fusion polynucleotide) or an siRNA targeting a full length ROS1 polynucleotide. Non-limiting siRNAs for inhibiting ROS1 protein expression are as follows:
The ability of these two siRNAs to inhibit ROS1 kinase activity has been described (see U.S. Patent Publication No. 20100221737, incorporated by reference.
In some embodiments, a ROS1 inhibitor is selected from the group consisting of crizotinib (also known as PF-02341066), ASP3026 (ClinicalTrials.gov Identifier: NCT01284192), NVP TAE-684 (Gu et al., 2011, PLos ONE, 6:e15640), CH5424802 (Sakamoto et al., 2011, Cancer Cell, 19:679-690), and AP26113 (ClinicalTrials.gov Identifier: NCT01449461; Katayama et al., 2011, Proc. Natl. Acad. Sci. USA, 108:7535-40). Additional ROS1 inhibitors are disclosed, e.g., in WO 2012/016133, US 2012/0065233, and El-Deeb et al., 2009, Bioorg. Med. Chem. Lett., 19:5622-26.
As used herein, a “ALK inhibitor” or a “ALK-inhibiting compound” means any composition that includes one or more compounds, chemical or biological, that inhibits, either directly or indirectly, the expression and/or activity of a polypeptide with ALK kinase activity. Such inhibition may be in vitro or in vivo. “ALK inhibitor therapeutic” or “ALK-inhibiting therapeutic” means a ALK-inhibiting compound used as a therapeutic to treat a patient harboring a cancer (e.g., a lung cancer such as NSCLC or SCLC) characterized by the presence of a polypeptide with ALK kinase activity such as aberrantly expressed full length ALK protein or a ALK fusion polypeptide (e.g., one of the EM4-ALK fusion proteins) described herein.
The ALK and/or ROS1-inhibiting therapeutic may be, for example, a kinase inhibitor, such as a small molecule or antibody inhibitor. It may be a pan-kinase inhibitor with activity against several different kinases, or a kinase-specific inhibitor. Since ROS1, ALK, LTK, InsR, and IGF1R belong to the same family of tyrosine kinases, they may share similar structure in the kinase domain. Thus, in some embodiments, an ALK and/or ROS1 inhibitor also inhibits the activity of an ALK kinase, an LTK kinase, an insulin receptor, or an IGF1 receptor. ROS1-30 inhibiting compounds are discussed in further detail below. Patient biological samples may be taken before and after treatment with the inhibitor and then analyzed, using methods described above, for the biological effect of the inhibitor on ALK or ROS1 kinase activity, including the phosphorylation of downstream substrate protein. Such a pharmacodynamic assay may be useful in determining the biologically active dose of the drug that may be preferable to a maximal tolerable dose. Such information would also be useful in submissions for drug approval by demonstrating the mechanism of drug action.
In another embodiment, the expression and/or activity of said polypeptide is inhibited with a composition that includes a ROS1 or ALK inhibiting therapeutic selected from the group consisting of PF-02341066, NVP TAE-684, AP26113, CEP-14083, CEP-14513, CEP11988, WHI-P131 and WHI-P154.
Various EGFR inhibitors are known and can be used in the methods disclosed herein, including gefitinib, erlotinib, cetuximab, afatinib, necitumumab, nimotuzumab, PF299804 (Jänne et al., 2011, Clin. Cancer Res., 17:1131-39), RO5083945 (glycoengineered anti-EGFR monoclonal antibody; Hoffmann-La Roche; Markman et al., 2010, J. Clin. Oncol., 28:15s, abstr 2522), ABT-806 (humanized anti-EGFR monoclonal antibody; Abbott), NVP-TAE684 (Katayama et al., 2011, Proc. Natl. Acad. Sci. USA, 108:7535-40), and AP26113 (ibid.).
In accordance with the present disclosure, the polypeptide with ROS1 or ALK kinase activity or mutant EGFR polypeptide may occur in at least one subgroup of human cancer. Accordingly, the progression of a mammalian cancer in which a polypeptide with ROS1 or ALK kinase activity or mutant EGFR polypeptide is expressed may be inhibited, in vivo, by inhibiting the activity of ROS1 or ALK kinase or mutant EGFR polypeptide in such cancer. ROS1 or ALK activity in cancers characterized by expression of a polypeptide with ROS1 or ALK kinase activity may be inhibited by contacting the cancer with a therapeutically effective amount of a ROS1-inhibiting and/or ALK-inhibiting therapeutic. Additionally, mutant EGFR activity may be inhibited by contacting the cancer with a therapeutically effective amount of an EGFR inhibiting therapeutic. Accordingly, the disclosure provides, in part, a method for inhibiting the progression of cancers (e.g., lung cancers) that express a polypeptide with ROS1 or ALK kinase activity and a mutant EGFR polypeptide by inhibiting the expression and/or activity of ROS1 or ALK kinase and the mutant EGFR polypeptide in the cancer by contacting the cancer (e.g., a lung cancer) with a therapeutically effective amount of an ROS1-inhibiting therapeutic and/or an EGFR-inhibiting therapeutic.
As used herein, by “therapeutically effective amount” or “pharmaceutically effective amount” is mean an amount of an ROS1-inhibiting therapeutic, ALK-inhibiting therapeutic, and/or EGFR-inhibiting therapeutic that is adequate to inhibit the cancer (or cell thereof) or suspected cancer (or cells thereof), as compared to an untreated cancer or suspected cancer, by either slowing the growth of the cancer or suspected cancer, reducing the mass of the cancer or suspected cancer, reducing the number of cells of the cancer or suspected cancer, or killing the cancer. When two or more therapeutics are administered to a patient in combination, the effective amount of each therapeutic may be less than if the therapeutic were to be administered alone.
A ROS1-inhibiting therapeutic and/or ALK-inhibiting therapeutic may be any composition that includes at least one ROS1 or ALK inhibitor. Such compositions also include compositions including only a single ROS1- or ALK-inhibiting compound, as well as compositions that include multiple therapeutics (including those against other RTKs), which may also include a non-specific therapeutic agent like a chemotherapeutic agent or general transcription inhibitor.
In some embodiments, a ROS1-inhibiting therapeutic and/or ALK-inhibiting therapeutic useful in the practice of the methods disclosed herein is a targeted, small molecule inhibitor. Small molecule targeted inhibitors are a class of molecules that typically inhibit the activity of their target enzyme by specifically, and often irreversibly, binding to the catalytic site of the enzyme, and/or binding to an ATP-binding cleft or other binding site within the enzyme that prevents the enzyme from adopting a conformation necessary for its activity. Because of the close similarity in structure and function between the ROS1 kinase and the ALK kinase, any ALK kinase inhibitor is predicted to also inhibit ROS1 kinase.
Accordingly, in another aspect, the disclosure provides methods of treating a patient for lung cancer, that include: detecting the presence in a biological sample from a lung of a patient having or suspected of having lung cancer of one or more polypeptides selected from the group consisting of a polypeptide having ROS1 kinase activity, a polypeptide having ALK kinase activity, and a mutant EGFR polypeptide (in any combination); and administering an effective amount of an ALK/ROS1-inhibiting therapeutic and/or an EGFR-inhibiting therapeutic to the patient, thereby treating the subject for lung cancer.
It should be noted that when a ROS1 or ALK inhibitor and an EGFR inhibitor are administered to a patient, that the inhibitory molecule may be one that inhibits both ROS1 or ALK and EGFR. For example, NVP TAE-684 inhibits ROS1 (Gu et al., 2011, PLos ONE, 6:e15640), ALK (Galkin et al., 2007, Proc. Natl. Acad. Sci. USA, 104:270-275) and EGFR (Katayama et al., 2011, Proc. Natl. Acad. Sci. USA, 108:7535-40), as does AP26113 (Katayama et al., 2011, Proc. Natl. Acad. Sci. USA, 108:7535-40). Additional molecules may be identified that inhibit both ROS1 and/or ALK and EGFR.
As used herein, by “protein having ALK kinase activity” is meant any polypeptide that retains the full kinase domain of ALK and thus, has ALK kinase activity. Non-limiting polypeptides with ALK kinase activity include full length ALK (see U.S. Pat. No. 5,770,421), NPM-ALK, ALO17-ALK, TFG-ALK, MSN-ALK, TPM3-ALK, TPM4-ALK, ATIC-ALK, MYH9-ALK, CLTC-ALK, SEC31L1-ALK, RANBP2-ALK, CARS-ALK, EML4-ALK, KIF5B-ALK, and TFG-ALK (see, e.g., Palmer et al., Biochem. J. 420:345-361, 2009 (and the articles cited therein), Rikova et al., Cell 131:1190-1203, 2007; Soda et al., Nature 448:561-566, 2007; Morris et al., Science 263:1281-84, 1994; Du et al., J. Mol. Med. 84:863-875, 2007; Panagopoulos et al., Int. J. Cancer 118:1181-86, 2006; Cools et al., Genes Chromosomes Cancer 34:354-362, 2002; Debelenko et al., Lab. Invest. 83:1255-65, 2003; Ma et al., Genes Chromosomes Cancer 37:98-105, 2003; Lawrence et al., Am. J. Pathol. 157:377-384, 1995; Hernandez et al., Blood 94:3265-68, 1999; Takeuchi K., Clin Cancer Res. 15:3143-49, 2009; Tort et al., Lab. Invest. 81:419-426, 2001; Trinei et al., Cancer Res. 60:793-798, 2000; and Touriol et al., Blood 95:3204-07, 2000. See also Pulford et al., J. Cell. Physiol., 199:330-358, 2004.
In various embodiments, the patient is a human. In various embodiments, the lung cancer is non-small cell lung cancer or is small cell lung cancer.
One useful small-molecule kinase inhibitor is Pfizer, Inc.'s compound crizotinib (also known as PF-02341066), which inhibits ALK, ROS1, and MET kinase activity, and its properties have been well described. See You et al., Cancer Res 67: 4408 (2007) and U.S. Patent Pub. No. 2008/0300273. Additional small molecule kinase inhibitors that target ROS1 include TAE-684 (from Novartis), CH5424802 (Chugai; see Sakamoto, H. et al., Cancer Cell 19: 679-690, 2011), AP26113 (Ariad Pharmaceuticals, Inc.), and CEP-14083, CEP-14513, and CEP-11988 (Cephalon; see Wan et al., Blood 107: 1617-23, 2006). TAE-684, a 5-chloro-2,4-diaminophenylpyrimidine, has also been shown to inhibit the ALK kinase. Galkin, et al., Proc. National Acad. Sci. 104:270-275, 2007.
Additional small molecule inhibitors and other inhibitors (e.g., indirect inhibitors) of ROS1 kinase activity may be rationally designed using X-ray crystallographic or computer modeling of ROS1 three dimensional structure, or may found by high throughput screening of compound libraries for inhibition of key upstream regulatory enzymes and/or necessary binding molecules, which results in inhibition of ROS1 or ALK kinase activity. Such approaches are well known in the art, and have been described. ROS1 inhibition or ALK inhibition by such therapeutics may be confirmed, for example, by examining the ability of the compound to inhibit ROS1 or ALK kinase activity, but not other kinase activity, in a panel of kinases, and/or by examining the inhibition of ROS1 or ALK activity in a biological sample that includes cancer cells (e.g., lung cancer cells). Methods for identifying compounds that inhibit a cancer characterized by the expression/presence of polypeptide with ROS1 or ALK kinase activity are further described below.
ROS1-inhibiting therapeutics, ALK-inhibiting therapeutics, and/or EGFR-inhibiting therapeutics useful in the methods disclosed herein may also be targeted antibodies that specifically bind to critical catalytic or binding sites or domains required for ROS1 or ALK activity, and inhibit the kinase by blocking access of ligands, substrates or secondary molecules to a and/or preventing the enzyme from adopting a conformation necessary for its activity. The production, screening, and therapeutic use of humanized target-specific antibodies has been well-described. See Merluzzi et al., Adv Clin Path. 4(2): 77-85 (2000). Commercial technologies and systems, such as Morphosys, Inc.'s Human Combinatorial Antibody Library (HuCAL®), for the high-throughput generation and screening of humanized target-specific inhibiting antibodies are available.
The production of various anti-receptor kinase targeted antibodies and their use to inhibit activity of the targeted receptor has been described. See, e.g. U.S. Patent Publication No. 20040202655, U.S. Patent Publication No. 20040086503, U.S. Patent Publication No. 20040033543. Standardized methods for producing, and using, receptor tyrosine kinase activity-inhibiting antibodies are known in the art. See, e.g., European Patent No. EP1423428,
Phage display approaches may also be employed to generate ROS1-specific, ALK-specific, or EGFR-specific antibody inhibitors, and protocols for bacteriophage library construction and selection of recombinant antibodies are provided in the well-known reference text C
A library of antibody fragments displayed on the surface of bacteriophages may be produced (see, e.g. U.S. Pat. No. 6,300,064) and screened for binding to a polypeptide with ROS1 kinase activity or ALK kinase activity or an EGFR polypeptide (e.g., a mutant EGFR polypeptide). See European Patent No. EP1423428.
Antibodies identified in screening of antibody libraries as described above may then be further screened for their ability to block the activity of ROS1, ALK, or EGFR (e.g., a mutant EGFR), both in vitro kinase assay and in vivo in cell lines and/or tumors. ROS1, ALK, or EGFR inhibition may be confirmed, for example, by examining the ability of such antibody therapeutic to inhibit ROS1, ALK, or EGFR kinase activity in a panel of kinases, and/or by examining the inhibition of ROS1, ALK, or EGFR activity in a biological sample that includes cancer cells, as described above. In some embodiments, a ROS1-inhibiting compound reduces ROS1 kinase activity, but reduces the kinase activity of other kinases to a lesser extent (or not at all). Likewise, in some embodiments, an ALK-inhibiting compound reduces ALK kinase activity, but reduces the kinase activity of other kinases to a lesser extent (or not at all). Similarly, in some embodiments, an EGFR-inhibiting compound reduces EGFR kinase activity, but reduces the kinase activity of other kinases to a lesser extent (or not at all). Methods for screening such compounds for ROS1, ALK, and/or EGFR kinase inhibition are further described above.
ROS1-inhibiting, ALK-inhibiting, or EGFR-inhibiting compounds that useful in the practice of the disclosed methods may also be compounds that indirectly inhibit ROS1, ALK, or EGFR activity by inhibiting the activity of proteins or molecules other than ROS1, ALK, or EGFR kinase itself. Such inhibiting therapeutics may be targeted inhibitors that modulate the activity of key regulatory kinases that phosphorylate or de-phosphorylate (and hence activate or deactivate) ROS1, ALK, or EGFR itself, or interfere with binding of ligands. As with other receptor tyrosine kinases, ROS1, ALK, and EGFR regulate downstream signaling through a network of adaptor proteins and downstream kinases. As a result, induction of cell growth and survival by ROS1, ALK, or EGFR activity may be inhibited by targeting these interacting or downstream proteins.
ROS1, ALK, or EGFR kinase activity may also be indirectly inhibited by using a compound that inhibits the binding of an activating molecule necessary for these full length and fusion polypeptide (e.g., an CD74-ROS1 or an EML4-ALK fusion polypeptide) to adopt its active conformation (i.e., such that the kinase domain is able to be activated). For example, the production and use of anti-PDGF antibodies has been described. See U.S. Patent Publication No. 20030219839, “Anti-PDGF Antibodies and Methods for Producing Engineered Antibodies,” Bowdish et al. Inhibition of ligand (PDGF) binding to the receptor directly down-regulates the receptor activity.
ROS1, ALK, and/or EGFR inhibiting compounds or therapeutics may also include anti-sense and/or transcription inhibiting compounds that inhibit ROS1, ALK, or EGFR kinase activity by blocking transcription of the gene encoding polypeptides with ROS1, ALK, or EGFR kinase activity. The inhibition of various receptor kinases, including VEGFR, EGFR, and IGFR, and FGFR, by antisense therapeutics for the treatment of cancer has been described. See, e.g., U.S. Pat. Nos. 6,734,017; 6,710,174, 6,617,162; 6,340,674; 5,783,683; 5,610,288.
Antisense oligonucleotides may be designed, constructed, and employed as therapeutic agents against target genes in accordance with known techniques. See, e.g. Cohen, J., Trends in Pharmacol. Sci. 10(11): 435-437 (1989); Marcus-Sekura, Anal. Biochem. 172: 289-295 (1988); Weintraub, H., Sci. AM. Pp. 40-46 (1990); Van Der Krol et al., BioTechniques 6: 958-976 (1988); Skorski et al., Proc. Natl. Acad. Sci. USA (1994) 91: 4504-4508 Inhibition of human carcinoma growth in vivo using an antisense RNA inhibitor of EGFR has recently been described. See U.S. Patent Publication No. 20040047847. Similarly, a ROS1-inhibiting or ALK-inhibiting therapeutic that includes at least one antisense oligonucleotide against a mammalian ROS1 or ALK gene or a mammalian ROS1 or ALK fusion protein-encoding polynucleotide may be prepared according to standard methods. Pharmaceutical compositions that include ROS1-inhibiting antisense compounds may be prepared and administered as further described below.
Small interfering RNA molecule (siRNA) compositions, which inhibit translation, and hence activity, of ROS1, ALK, or EGFR through the process of RNA interference, may also be desirably employed in the methods disclosed herein. RNA interference, and the selective silencing of target protein expression by introduction of exogenous small double-stranded RNA molecules having sequence complimentary to mRNA encoding the target protein, has been well described. See, e.g. U.S. Patent Publication No. 20040038921, U.S. Patent Publication No. 20020086356, and U.S. Patent Publication 20040229266.
Double-stranded RNA molecules (dsRNA) have been shown to block gene expression in a highly conserved regulatory mechanism known as RNA interference (RNAi). Briefly, the RNAse III Dicer processes dsRNA into small interfering RNAs (siRNA) of approximately 22 nucleotides, which serve as guide sequences to induce target-specific mRNA cleavage by an RNA-induced silencing complex RISC (see Hammond et al., Nature (2000) 404: 293-296). RNAi involves a catalytic-type reaction whereby new siRNAs are generated through successive cleavage of longer dsRNA. Thus, unlike antisense, RNAi degrades target RNA in a non-stoichiometric manner. When administered to a cell or organism, exogenous dsRNA has been shown to direct the sequence-specific degradation of endogenous messenger RNA (mRNA) through RNAi.
A wide variety of target-specific siRNA products, including vectors and systems for their expression and use in mammalian cells, are now commercially available. See, e.g., Promega, Inc. (www.promega.com); Dharmacon, Inc. (www.dharmacon.com). Detailed technical manuals on the design, construction, and use of dsRNA for RNAi are available. See, e.g., Dharmacon's “RNAi Technical Reference & Application Guide”; Promega's “RNAi: A Guide to Gene Silencing.” ROS1-inhibiting siRNA products are also commercially available, and may be suitably employed in the methods disclosed herein. See, e.g., Dharmacon, Inc., Lafayette, Colo. (Cat Nos. M-003162-03, MU-003162-03, D-003162-07 thru -10 (siGENOME™ SMARTselection and SMARTpool® siRNAs).
It has recently been established that small dsRNA less than 49 nucleotides in length, and preferably 19-25 nucleotides, that include at least one sequence that is substantially identical to part of a target mRNA sequence, and which dsRNA optimally has at least one overhang of 1-4 nucleotides at an end, are most effective in mediating RNAi in mammals. See U.S. Patent Publication Nos. 20040038921 and 20040229266. The construction of such dsRNA, and their use in pharmaceutical preparations to silence expression of a target protein, in vivo, are described in detail in such publications.
If the sequence of the gene to be targeted in a mammal is known, 21-23 nt RNAs, for example, can be produced and tested for their ability to mediate RNAi in a mammalian cell, such as a human or other primate cell. Those 21-23 nt RNA molecules shown to mediate RNAi can be tested, if desired, in an appropriate animal model to further assess their in vivo effectiveness. Target sites that are known, for example target sites determined to be effective target sites based on studies with other nucleic acid molecules, for example ribozymes or antisense, or those targets known to be associated with a disease or condition such as those sites containing mutations or deletions, can be used to design siRNA molecules targeting those sites as well.
Alternatively, the sequences of effective dsRNA can be rationally designed/predicted screening the target mRNA of interest for target sites, for example by using a computer folding algorithm. The target sequence can be parsed in silico into a list of all fragments or subsequences of a particular length, for example 23 nucleotide fragments, using a custom Perl script or commercial sequence analysis programs such as Oligo, MacVector, or the GCG Wisconsin Package.
Various parameters can be used to determine which sites are the most suitable target sites within the target RNA sequence. These parameters include but are not limited to secondary or tertiary RNA structure, the nucleotide base composition of the target sequence, the degree of homology between various regions of the target sequence, or the relative position of the target sequence within the RNA transcript. Based on these determinations, any number of target sites within the RNA transcript can be chosen to screen siRNA molecules for efficacy, for example by using in vitro RNA cleavage assays, cell culture, or animal models. See, e.g., U.S. Patent Publication No. 20030170891. An algorithm for identifying and selecting RNAi target sites has also recently been described. See U.S. Patent Publication No. 20040236517.
Commonly used gene transfer techniques include calcium phosphate, DEAE-dextran, electroporation and microinjection and viral methods (Graham et al. (1973) Virol. 52: 456; McCutchan et al., (1968), J. Natl. Cancer Inst. 41: 351; Chu et al. (1987), Nucl. Acids Res. 15: 1311; Fraley et al. (1980), J. Biol. Chem. 255: 10431; Capecchi (1980), Cell 22: 479). DNA may also be introduced into cells using cationic liposomes (Feigner et al. (1987), Proc. Natl. Acad. Sci. USA 84: 7413). Commercially available cationic lipid formulations include Tfx 50 (Promega Corp., Fitchburg, Wis.) or Lipofectamin 200 (Life Technologies, Carlsbad, Calif.). Alternatively, viral vectors may be employed to deliver dsRNA to a cell and mediate RNAi. See U.S Patent Publication No. 20040023390.
Transfection and vector/expression systems for RNAi in mammalian cells are commercially available and have been well described. See, e.g., Dharmacon, Inc. (Lafayette, Colo.), DharmaFECT™ system; Promega, Inc., siSTRIKET™ U6 Hairpin system; see also Gou et al. (2003) FEBS. 548, 113-118; Sui, G. et al. A DNA vector-based RNAi technology to suppress gene expression in mammalian cells (2002) Proc. Natl. Acad. Sci. 99, 5515-5520; Yu et al. (2002) Proc. Natl. Acad. Sci. 99, 6047-6052; Paul, C. et al. (2002) Nature Biotechnology 19, 505-508; McManus et al. (2002) RNA 8, 842-850.
siRNA interference in a mammal using prepared dsRNA molecules may then be effected by administering a pharmaceutical preparation that includes the dsRNA to the mammal. The pharmaceutical composition is administered in a dosage sufficient to inhibit expression of the target gene. dsRNA can typically be administered at a dosage of less than 5 mg dsRNA per kilogram body weight per day, and is sufficient to inhibit or completely suppress expression of the target gene. In general a suitable dose of dsRNA will be in the range of 0.01 to 2.5 milligrams per kilogram body weight of the recipient per day, preferably in the range of 0.1 to 200 micrograms per kilogram body weight per day, more preferably in the range of 0.1 to 100 micrograms per kilogram body weight per day, even more preferably in the range of 1.0 to 50 micrograms per kilogram body weight per day, and most preferably in the range of 1.0 to 25 micrograms per kilogram body weight per day. A pharmaceutical composition including the dsRNA is administered once daily, or in multiple sub-doses, for example, using sustained release formulations well known in the art. The preparation and administration of such pharmaceutical compositions may be carried out accordingly to standard techniques, as further described below.
Such dsRNA may then be used to inhibit ROS1 expression and activity in a cancer, by preparing a pharmaceutical preparation that includes a therapeutically-effective amount of such dsRNA, as described above, and administering the preparation to a human subject having a lung cancer or suspected lung cancer (e.g., a NSCLC or SCLC) expressing a polypeptide with ROS1 or ALK kinase activity (such as, for example, aberrant expression of full length ROS1 or ALK protein or expression of a ROS1 or ALK fusion protein), for example, via direct injection to the tumor. The similar inhibition of other receptor tyrosine kinases, such as VEGFR and EGFR using siRNA inhibitors has recently been described. See U.S. Patent Publication No. 20040209832, U.S. Patent Publication No. 20030170891, and U.S. Patent Publication No. 20040175703.
ROS1-inhibiting and/or EGFR-inhibiting therapeutics useful in the practice of the methods disclosed herein may be administered to a mammal by any means known in the art including, but not limited to oral or peritoneal routes, including intravenous, intramuscular, intraperitoneal, subcutaneous, transdermal, airway (aerosol), rectal, vaginal and topical (including buccal and sublingual) administration.
For oral administration, a ROS1-inhibiting and/or EGFR-inhibiting therapeutic will generally be provided in the form of tablets or capsules, as a powder or granules, or as an aqueous solution or suspension. Tablets for oral use may include the active ingredients mixed with pharmaceutically acceptable carriers and excipients such as inert diluents, disintegrating agents, binding agents, lubricating agents, sweetening agents, flavoring agents, coloring agents and preservatives. Suitable inert diluents include sodium and calcium carbonate, sodium and calcium phosphate, and lactose, while corn starch and alginic acid are suitable disintegrating agents. Binding agents may include starch and gelatin, while the lubricating agent, if present, will generally be magnesium stearate, stearic acid or talc. If desired, the tablets may be coated with a material such as glyceryl monostearate or glyceryl distearate, to delay absorption in the gastrointestinal tract.
Capsules for oral use include hard gelatin capsules in which the active ingredient is mixed with a solid diluent, and soft gelatin capsules wherein the active ingredients is mixed with water or an oil such as peanut oil, liquid paraffin or olive oil. For intramuscular, intraperitoneal, subcutaneous and intravenous use, the pharmaceutical compositions will generally be provided in sterile aqueous solutions or suspensions, buffered to an appropriate pH and isotonicity. Suitable aqueous vehicles include Ringer's solution and isotonic sodium chloride. The carrier may consist exclusively of an aqueous buffer (“exclusively” means no auxiliary agents or encapsulating substances are present which might affect or mediate uptake of the ROS1- and/or EGFR-inhibiting therapeutic). Such substances include, for example, micellar structures, such as liposomes or capsids, as described below. Aqueous suspensions may include suspending agents such as cellulose derivatives, sodium alginate, polyvinyl-pyrrolidone and gum tragacanth, and a wetting agent such as lecithin. Suitable preservatives for aqueous suspensions include ethyl and n-propyl p-hydroxybenzoate.
ROS1-inhibiting and/or EGFR-inhibiting therapeutic compositions may also include encapsulated formulations to protect the therapeutic (e.g., a dsRNA compound or an antibody that specifically binds a ROS1 fusion polypeptide or mutant EGFR polypeptide) against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No. 4,522,811; PCT publication WO 91/06309; and European patent publication EP-A-43075. An encapsulated formulation may include a viral coat protein. The viral coat protein may be derived from or associated with a virus, such as a polyoma virus, or it may be partially or entirely artificial. For example, the coat protein may be a Virus Protein 1 and/or Virus Protein 2 of the polyoma virus, or a derivative thereof.
ROS1-inhibiting and/or EGFR-inhibiting therapeutics can also include a delivery vehicle, including liposomes, for administration to a subject, carriers and diluents and their salts, and/or can be present in pharmaceutically acceptable formulations. For example, methods for the delivery of nucleic acid molecules are described in Akhtar et al., 1992, Trends Cell Bio., 2, 139; D
ROS1-inhibiting and/or EGFR-inhibiting therapeutics (i.e., a ROS1- or EGFR-inhibiting compound being administered as a therapeutic) can be administered to a mammalian tumor by a variety of methods known to those of skill in the art, including, but not restricted to, encapsulation in liposomes, by iontophoresis, or by incorporation into other vehicles, such as hydrogels, cyclodextrins, biodegradable nanocapsules, and bioadhesive microspheres, or by proteinaceous vectors (see PCT Publication No. WO 00/53722). Alternatively, the therapeutic/vehicle combination is locally delivered by direct injection or by use of an infusion pump. Direct injection of the composition, whether subcutaneous, intramuscular, or intradermal, can take place using standard needle and syringe methodologies, or by needle-free technologies such as those described in Conry et al., 1999, Clin. Cancer Res., 5, 2330-2337 and PCT Publication No. WO 99/3 1262.
Pharmaceutically acceptable formulations of ROS1-inhibiting and/or EGFR-inhibiting therapeutics include salts of the above-described compounds, e.g., acid addition salts, for example, salts of hydrochloric, hydrobromic, acetic acid, and benzene sulfonic acid. A pharmacological composition or formulation refers to a composition or formulation in a form suitable for administration, e.g., systemic administration, into a cell or patient, including for example a human. Suitable forms, in part, depend upon the use or the route of entry, for example oral, transdermal, or by injection. Such forms should not prevent the composition or formulation from reaching a target cell. For example, pharmacological compositions injected into the blood stream should be soluble. Other factors are known in the art, and include considerations such as toxicity and forms that prevent the composition or formulation from exerting its effect.
Administration routes that lead to systemic absorption (e.g., systemic absorption or accumulation of drugs in the blood stream followed by distribution throughout the entire body) are desirable and include, without limitation: intravenous, subcutaneous, intraperitoneal, inhalation, oral, intrapulmonary and intramuscular. Each of these administration routes exposes the ROS1-inhibiting therapeutic to an accessible diseased tissue or tumor. The rate of entry of a drug into the circulation has been shown to be a function of molecular weight or size. The use of a liposome or other drug carrier containing the compounds can potentially localize the drug, for example, in certain tissue types, such as the tissues of the reticular endothelial system (RES). A liposome formulation that can facilitate the association of drug with the surface of cells, such as, lymphocytes and macrophages is also useful. This approach can provide enhanced delivery of the drug to target cells by taking advantage of the specificity of macrophage and lymphocyte immune recognition of abnormal cells, such as cancer cells.
By “pharmaceutically acceptable formulation” is meant, a composition or formulation that allows for the effective distribution of the nucleic acid molecules in the physical location most suitable for their desired activity. Non-limiting examples of agents suitable for formulation with the nucleic acid molecules include: P-glycoprotein inhibitors (such as Pluronic P85), which can enhance entry of drugs into the CNS (Jolliet-Riant and Tillement, 1999, Fundam. Clin. Pharmacol., 13, 16-26); biodegradable polymers, such as poly(DL-lactide-coglycolide) microspheres for sustained release delivery after intracerebral implantation (Emerich et al, 1999, Cell Transplant, 8, 47-58) (Rosermes, Inc. Cambridge, Mass.); and loaded nanoparticles, such as those made of polybutylcyanoacrylate, which can deliver drugs across the blood brain barrier and can alter neuronal uptake mechanisms (Prog Neuro-psychopharmacol Biol Psychiatry, 23, 941-949, 1999). Other non-limiting examples of delivery strategies for the ROS1-inhibiting compounds useful in the methods disclosed herein include material described in Boado et al., 1998, J. Pharm. Sci., 87, 1308-15; Tyler et al., 1999, FEBS Lett., 421, 280-284; Pardridge et al., 1995, PNAS USA., 92, 5592-96; Boado, 1995, Adv. Drug Delivery Rev., 15, 73-107; Aldrian-Herrada et al., 1998, Nucleic Acids Res., 26, 4910-4916; and Tyler et al., 1999, PNAS USA., 96, 7053-7058.
Therapeutic compositions that include surface-modified liposomes containing poly(ethylene glycol) lipids (PEG-modified, or long-circulating liposomes or stealth liposomes) may also be suitably employed in the methods disclosed herein. These formulations offer a method for increasing the accumulation of drugs in target tissues. This class of drug carriers resists opsonization and elimination by the mononuclear phagocytic system (MPS or RES), thereby enabling longer blood circulation times and enhanced tissue exposure for the encapsulated drug (Lasic et al. Chem. Rev. 1995, 95, 2601-2627; Ishiwata et al., Chem. Pharm. Bull. 1995, 43, 1005-1011). Such liposomes have been shown to accumulate selectively in tumors, presumably by extravasation and capture in the neovascularized target tissues (Lasic et al., Science 1995, 267, 1275-1276; Oku et al., 1995, Biochim. Biophys. Acta, 1238, 86-90). The long-circulating liposomes enhance the pharmacokinetics and pharmacodynamics of DNA and RNA, particularly compared to conventional cationic liposomes which are known to accumulate in tissues of the MPS (Liu et al., J. Biol. Chem. 1995, 42, 24864-24870; PCT Publication No. WO 96/10391; PCT Publication No. WO 96/10390; and PCT Publication No. WO 96/10392). Long-circulating liposomes are also likely to protect drugs from nuclease degradation to a greater extent compared to cationic liposomes, based on their ability to avoid accumulation in metabolically aggressive MPS tissues such as the liver and spleen.
Therapeutic compositions may include a pharmaceutically effective amount of the desired compounds in a pharmaceutically acceptable carrier or diluent. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical art, and are described, for example, in R
In some embodiments, the ROS1-inhibiting therapeutic and/or the EGFR-inhibiting therapeutic is administered in an effective amount. By “effective amount” or “effective dose” is meant the amount of the therapeutic required to prevent, inhibit the occurrence, or treat (alleviate a symptom to some extent, preferably all of the symptoms) of a disease state (e.g., lung cancer). The effective dose depends on the type of disease, the therapeutic used, the route of administration, the type of mammal being treated, the physical characteristics of the specific mammal under consideration, concurrent medication, and other factors that those skilled in the medical arts will recognize. Generally, an effective amount is an amount between 0.1 mg/kg and 100 mg/kg body weight/day of active ingredients is administered dependent upon potency of the negatively charged polymer.
Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (about 0.5 mg to about 7 g per patient per day). The amount of active ingredient that can be combined with the carrier materials to produce a single dosage form varies depending upon the host treated and the particular mode of administration. Dosage unit forms generally contain between from about 1 mg to about 500 mg of an active ingredient. It is understood that the specific dose level for any particular patient depends upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
For administration to non-human animals, the composition can also be added to the animal feed or drinking water. It can be convenient to formulate the animal feed and drinking water compositions so that the animal takes in a therapeutically appropriate quantity of the composition along with its diet. It can also be convenient to present the composition as a premix for addition to the feed or drinking water.
A ROS1-inhibiting and/or EGFR-inhibiting therapeutic useful in the practice of the disclosure may include a single compound as described above, or a combination of multiple compounds, whether in the same class of inhibitor (e.g., antibody inhibitor), or in different classes (e.g., antibody inhibitors and small-molecule inhibitors). Such combination of compounds may increase the overall therapeutic effect in inhibiting the progression of a fusion protein-expressing cancer. For example, the therapeutic composition may a small molecule inhibitor, such as Crizotinib (also known as PF-02341066) produced by Pfizer, Inc. (see U.S. Pub. No. 2008/0300273) alone, or in combination with other Crizotinib analogues targeting ROS1 activity and/or small molecule inhibitors of ROS1, such as NVP-TAE684 produced by Novartis, Inc., or the CH5424802 compound described in Sakamoto et al., Cancer Cell 19: 679-690, 2011. The therapeutic composition may also include one or more non-specific chemotherapeutic agent in addition to one or more targeted inhibitors. Such combinations have recently been shown to provide a synergistic tumor killing effect in many cancers. The effectiveness of such combinations in inhibiting ROS1 and/or EGFR activity and tumor growth in vivo can be assessed as described below.
The disclosure also provides, in part, methods for determining whether a compound inhibits the progression of a cancer (e.g., a lung cancer) characterized by a polypeptide with ROS1 or ALK kinase activity, a mutant EGFR polypeptide or polynucleotide encoding the same by determining whether the compound inhibits the ROS1, ALK, or EGFR kinase activity of the polypeptide in the cancer. In some embodiments, inhibition of activity of ROS1 or ALK or a mutant EGFR polypeptide is determined by examining a biological sample that includes cells from bone marrow, blood, or a tumor. In another embodiment, inhibition of activity of ROS1 or ALK or mutant EGFR kinase is determined using at least reagent that specifically binds to a ROS1 or ALK polypeptide (e.g., a ROS1-specific antibody or an ALK-specific antibody) or a mutant EGFR polypeptide, or a reagent that specifically binds to a ROS1 or ALK polypeptide- or mutant EGFR polypeptide-encoding polynucleotide (e.g., an siRNA or an antisense).
The tested compound may be any type of therapeutic or composition as described above. Methods for assessing the efficacy of a compound, both in vitro and in vivo, are well established and known in the art. For example, a composition may be tested for ability to inhibit ROS1 or a mutant EGFR polypeptide in vitro using a cell or cell extract in which ROS1 kinase is activated or that expresses a mutant EGFR polypeptide. A panel of compounds may be employed to test the specificity of the compound for ROS1 or EGFR (as opposed to other targets, such as PDGFR).
Another technique for drug screening which may be used provides for high throughput screening of compounds having suitable binding affinity to a protein of interest, as described in PCT Publication No. WO 84/03564. In this method, as applied to polypeptides having ROS1 or ALK activity or mutant EGFR polypeptides, large numbers of different small test compounds are synthesized on a solid substrate, such as plastic pins or some other surface. The test compounds are reacted with a polypeptide disclosed herein, or fragments thereof, and washed. Bound polypeptide is then detected by methods well known in the art. A purified polypeptide can also be coated directly onto plates for use in the aforementioned drug screening techniques. Alternatively, non-neutralizing antibodies can be used to capture the peptide and immobilize it on a solid support.
A compound found to be an effective inhibitor of ROS1 or mutant EGFR activity in vitro may then be examined for its ability to inhibit the progression of a cancer expressing a polypeptide with kinase activity (such as lung cancer or other cancer such as a liver cancer, lung cancer, colon cancer, kidney cancer, or a pancreatic cancer), in vivo, using, for example, mammalian xenografts harboring human lung, liver, pancreatic, kidney, lung, or colon tumors that express a polypeptide with ROS1 or ALK kinase activity or a mutant EGFR polypeptide. In this procedure, cancer cell lines known to express a protein having ROS1 or ALK kinase activity (e.g., full length ROS1 or ALK or one of the ROS1 or ALK fusion proteins) or a mutant EGFR polypeptide may be placed subcutaneously in an animal (e.g., into a nude or SCID mouse, or other immune-compromised animal). The cells then grow into a tumor mass that may be visually monitored. The animal may then be treated with the drug. The effect of the drug treatment on tumor size may be externally observed. The animal is then sacrificed and the tumor removed for analysis by IHC and western blot. Similarly, mammalian bone marrow transplants may be prepared, by standard methods, to examine drug response in hematological tumors expressing a protein with ROS1 or ALK kinase activity or a mutant EGFR polypeptide. In this way, the effects of the drug may be observed in a biological setting most closely resembling a patient. The drug's ability to alter signaling in the tumor cells or surrounding stromal cells may be determined by analysis with phosphorylation-specific antibodies. The drug's effectiveness in inducing cell death or inhibition of cell proliferation may also be observed by analysis with apoptosis specific markers such as cleaved caspase 3 and cleaved PARP.
Toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. In some embodiments, the compounds exhibit high therapeutic indices.
In practicing the disclosed method for determining whether a compound inhibits progression of a tumor characterized by the presence of a polypeptide with ROS1 kinase activity (or polynucleotide encoding the same), biological samples that include cells from mammalian xenografts (or bone marrow transplants) may also be advantageously employed. Non-limiting xenografts (or transplant recipients) are small mammals, such as mice, harboring human tumors (or leukemias) that express a polypeptide with ROS1 or ALK kinase activity (e.g., a ROS1 or ALK fusion polypeptide or full length ROS1 or ALK) or a mutant EGFR polypeptide. Xenografts harboring human tumors are well known in the art (see Kal, Cancer Treat Res. 72: 155-69 (1995)) and the production of mammalian xenografts harboring human tumors is well described (see Winograd et al., In Vivo. 1(1): 1-13 (1987)). Similarly the generation and use of bone marrow transplant models is well described (see, e.g., Schwaller, et al., EMBO J. 17: 5321-333 (1998); Kelly et al., Blood 99: 310-318 (2002)).
The following Examples are provided only to further illustrate, and are not intended to limit its scope, except as provided in the claims appended hereto. The present disclosure encompasses modifications and variations of the methods taught herein which would be obvious to one of ordinary skill in the art. Materials, reagents and the like to which reference is made are obtainable from commercial sources, unless otherwise noted.
ROS1 fusion proteins have previously been described in NSCLC cell lines and NSCLC human tumor samples (as well as in other tissues such as liver cancer and brain cancer). To determine whether or not the ROS1 fusion proteins discovered in NSCLC could be detected by immunohistochemistry, a ROS1-specific rabbit monoclonal antibody was used. The ROS1-specific antibody (namely rabbit monoclonal antibody ROS1 D4D6) that was used in these studies has been described previously (see PCT Publication No. WO2010/093928), and specifically binds a region on the human ROS1 kinase protein that is C-terminal to the kinase domain of the ROS1 protein. While the D4D6 antibody is not yet commercially available, similar ROS1-specific antibodies are commercially available from a variety of suppliers including, without limitation, the Ros (C-20) antibody, Catalog No. sc-6347 from Santa Cruz Biotechnology, Inc., (Santa Cruz, Calif.) and the ROS1 (69D6) antibody, Catalog No #3266 from Cell Signaling Technology, Inc. (Danvers, Mass.).
For these studies, a cohort of 556 human samples of NSCLC tumors were prepared as paraffin blocks. All tumor samples were evaluated by a pathologist, and were found to comprise 246 adenocarcinoma, 64 bronchioaveolar carcinoma, 226 squamous and 20 large cell carcinoma cases. The identifications of selected samples, including ROS1 and mutant-EGFR positive samples, were confirmed by an independent pathologist.
Immunohistochemistry:
4-6 μm tissue sections were deparaffinized and rehydrated through xylene and graded ethanol, respectively (e.g., through three changes of xylene for 5 minutes each, then rehydrated through two changes of 100% ethanol and 2 changes of 95% ethanol, each for 5 minutes). Slides were rinsed in diH2O, then subjected to antigen retrieval in a Decloaking Chamber (Biocare Medical, Concord, Calif.) using 1.0 mM EDTA, pH 8.0 and manufacturer's settings: SP1 125° C. for 30 seconds and SP2 90° C. for 10 seconds. Slides were quenched in 3% H2O2 for 10 minutes, then washed in diH2O. After blocking in Tris buffered saline positive 0.5% Tween-20 (TBST)/5% goat serum in a humidified chamber, slides were incubated overnight at 4° C. with ROS1 (D4D6) XP™ Rabbit mAb at 0.19 μg/ml diluted in SignalStain® Antibody Diluent (#8112 Cell Signaling Technology, Danvers, Mass.). After washing with TBST, detection was performed with either ENVISION+ (Dako, Carpinteria, Calif.) or SIGNALSTAIN® Boost IHC Detection Reagent (HRP, Rabbit) (catalog #8114 Cell Signaling Technology, Danvers, Mass.) with a 30 minute incubation at room temperature in a humidified chamber. After washing the slides (e.g., three times in TBST) the slides were next exposed to NovaRed (Vector Laboratories, Burlingame, Calif.) prepared per the manufacturer's instructions.
Slides were developed for 1 minute and then rinsed in diH2O, Slides were counterstained by incubating in hematoxylin (ready to use commercially available from Invitrogen (Carlsbad, Calif.) Catalog #00-8011) for 1 minute, rinsed for 30 seconds in diH2O, incubated for 20 seconds in bluing reagent (Richard Allan Scientific, Kalamazoo, Mich. (a Thermo Scientific company), Catalog #7301), and then finally washed for 30 seconds in diH2O, Slides were dehydrated in 2 changes of 95% ethanol for 20 seconds each and 2 changes of 100% ethanol for 2 minutes each. Slides were cleared in 2 changes of xylene for 20 seconds each, then air dried. Coverslips were mounted using VectaMount (Vector Laboratories, Burlingame, Calif.). Slides were air dried, then evaluated under the microscope. Images (20×) were acquired using an Olympus CX41 microscope equipped with an Olympus DP70 camera and DP Controller software.
Out of the 556 NSCLC tumors screened by immunohistochemistry with the ROS1-specific Rmab ROS1 D4D6, 9 ROS1-positive tumors were identified. The breakdown was as follows:
Of the 246 adenocarcinomas, 8 (or 3.3%) were positive for ROS1 kinase.
Of the 20 large cell carcinomas, 1 (or 5.0%) were positive for ROS1 kinase.
A variety of ROS1 IHC staining patterns ranging from weak cytoplasmic to strong perinuclear aggregates were observed (see
The presence of either the SLC34A2-ROS1 fusion protein and/or the CD74-ROS1 protein (or another ROS1 fusion protein) in human NSCLC tumor samples was detected using a fluorescence in situ hybridization (FISH) assay, as previously described. See, e.g., Verma et al. H
For analyzing rearrangements involving ROS1, a dual color break-apart probe was designed. A proximal probe (BAC clone RP1-179P9) and two distal probes (BAC clone RP11-323017, RP1-94G16) (all of which are commercially available, for example, from Invitrogen Inc., Carlsbad, Calif., as Catalog Nos. RPCI1.C and RPCI11.C) were obtained. The locations at which these probes bind to the ROS1 gene are shown schematically in
FISH-positive cases for ROS1 were defined as >15% split signals in tumor cells. The Nikon C1 Confocal microscope, 60× objective and trifilter (dapi, TRITC, FITC) was used for scoring each case. For image acquisition the Olympus BX-51 widefield fluorescence microscope with 40× objective and Metamorph software was used to generate tricolor images.
Thus, the ROS1 rearrangement probe contains two differently labeled probes on opposite sides of the breakpoint of the ROS1 gene in the wild type (WT) sequence (see
As shown in
The FISH analysis revealed a low incidence of this ROS1 mutation in the sample population studied. Of the initial 123 tumors screened, two out of 123 tumors or 1.6% of tumors contained the ROS1 fusion mutations. However, given the high incidence of NSCLC worldwide (over 151,00 new cases in the U.S. annually, alone), there are expected to be a significant number of patients that harbor this mutant ROS1, which patients may benefit from a ROS1-inhibiting therapeutic regime.
From Example 1, one of the tumor samples, namely Tumor 749, showed ROS1 staining that was localized to vesicular compartments (see
To determine what the FISH pattern of this Tumor 749 was, a third distal probe RP11-213A17, was obtained from Invitrogen to further investigate whether the ROS1 mutation in this tumor might be due to a FIG-ROS1 fusion. Fusions between the FIG gene and the ROS1 gene have been described in glioblastoma, cholangiocarcinoma, and liver cancer (see Charest et al., Genes Chromosomes Cancer 37: 58-71, 2003; Charest et al., Proc. Natl. Acad. Sci. USA 100: 916-921, 2003; and PCT Publica NO. WO2010/093928), but this fusion has never been described in lung before. Since the fusion between the FIG gene and the ROS1 gene results not a translocation or inversion but, rather, results from an intrachromosomal deletion on chromosome 6 of 240 kilobases, a new set of FISH probes was designed.
The FISH probes used in the IHC confirmation testing described previously (see Example 2 above) identified those tumors and cells with ROS1 balanced translocations that could be due to the presence of one of the SLC34A2-ROS1 fusion protein or the CD74-ROS1 fusion protein. The FISH pattern in lung 749 suggested that the rearrangement was not one of these two fusions but potentially that of FIG-ROS1. To determine if lung ID 749 was indeed FIG-ROS1 positive, another FISH probe set was designed (
To isolate and sequence the ROS1 fusion from tumor 749 (which was a Formalin-Fixed, Paraffin-Embedded Tumor), the following protocol was used.
RT-PCR from FFPE Tumor Samples:
RNA from 3×10 μm sections was extracted following standard protocols (RNeasy FFPE Kit, Qiagen). First strand cDNA was synthesized from 500 ng of total RNA with the use of SuperScript III first strand synthesis system (Invitrogen) with gene specific primers. Then the FIG-ROS1 fusion cDNA was amplified with the use of PCR primer pairs FIG-F3 and ROS1-GSP3.1 for the short isoform and FIG-F7 and ROS1-GSP3.2 for the long isoforms. GAPDH primers were purchased from Qiagen (Valencia, Calif.).
The primers for FIG were selected because based on the FISH patterns observed in tumor 749 and the published information on the FIG-ROS1 fusion, tumor 749 was expected to be a FIG-ROS1 fusion.
As predicted, the ROS1 fusion protein in tumor 749 was indeed a FIG-ROS1 fusion, specifically the FIG-ROS1 (S) fusion previously described (see PCT Publication No. WO2010/0923828).
The amino acid sequence of FIG-ROS1(S) is set forth in SEQ ID NO: 24 and the nucleotide sequence of FIG-ROS1(S) is set forth in SEQ ID NO: 23.
FIG-ROS1(L) in liver cancer has also been described (see PCT Publication No. WO2010/0923828). The amino acid and nucleotide sequence of FIG-ROS1(L) is set forth in SEQ ID NOs 22 and 21, respectively. In addition, based on analysis of the gene structure of the FIG and the ROS1 genes, a third FIG-ROS1 variant (namely FIG-ROS1(XL) has been proposed (see PCT Publication No. WO2010/0923828). The amino acid and nucleotide sequence of FIG-ROS1(XL) is set forth in SEQ ID NOs 26 and 25, respectively. Given this finding of FIG-ROS1(S) in NSCLC, other variants of FIG-ROS1 fusion protein may also be found in NSCLC.
The presence of aberrantly expressed full length ROS1 protein or a ROS1 fusion protein (e.g., one of the SLC34A2-ROS1 fusion proteins, CD74-ROS1 fusion protein, or one of the FIG-ROS1 fusion proteins) in a human lung cancer sample may be detected using either genomic or reverse transcriptase (RT) polymerase chain reaction (PCR), previously described. See, e.g., Cools et al., N. Engl. J. Med. 348: 1201-1214 (2003).
Briefly and by way of example, tumor or pleural effusion samples may be obtained from a patient having NSCLC using standard techniques. PCR probes against truncated ROS1 kinase, SLC34A2-ROS1 fusion protein, CD74-ROS1, or FIG-ROS1 are constructed. RNeasy Mini Kit (Qiagen) may be used to extract RNA from the tumor or pleural effusion samples. DNA may be extracted with the use of DNeasy Tissue Kit (Qiagen). For RT-PCR, first-strand cDNA is synthesized from, e.g., 2.5 mg of total RNA with the use, for example, of SuperScript™ III first-strand synthesis system (Invitrogen) with oligo (dT)20. Then, the ROS1 gene or ROS1 fusion gene (e.g., SLC34A2-ROS1, CD74-ROS1, or FIG-ROS1) is amplified with the use of primer pairs, e.g. SLC34A2-F1 and ROS1-P3 (see Example 5 above). For genomic PCR, amplification of the fusion gene may be performed with the use of Platinum Taq DNA polymerase high fidelity (Invitrogen) with primer pairs, e.g. SLC34A2-F1 and ROS1-R1, or SLC34A2-F1 and ROS1-R2.
Such an analysis will identify a patient having a cancer characterized by expression of the truncated ROS1 kinase (and/or ROS1 fusion protein such as FIG-ROS1, SLC34A2-ROS1, or CD74-ROS1), which patient is a candidate for treatment using a ROS1-inhibiting therapeutic.
The small molecule, TAE-684, a 5-chloro-2,4-diaminophenylpyrimidine, inhibits the ALK kinase. The structure of TAE-684 is provided in Galkin, et al., Proc. National Acad. Sci. 104(1) 270-275, 2007, incorporated by reference. Another small molecule, namely crizotinib, also inhibits the ALK kinase, as well as the MET kinase. The structure of crizotinib (also called PF-02341066) is provided in Zou H Y et al., Cancer Research 67: 4408-4417, 2007 and U.S. Patent Publication No. 20080300273, incorporated by reference.
Whether TAE-684 and/or crizotinib also inhibits kinase activity of ROS1 fusion polypeptides was determined.
BaF3 and Karpas 299 cells were obtained from DSMZ (Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH, Germany). BaF3 cells, which need interleukin-3 to survive, were maintained at 37° C. in RPMI-1640 medium (Invitrogen) with 10% fetal bovine serum (FBS) (Sigma) and 1.0 ng/ml murine IL-3 (R&D Systems). Karpas 299 cells (a lymphoma cell line) were grown in RPMI-1640 with 10% FBS.
BaF3 cells were transduced with retrovirus encoding FIG-ROS1(S), FIG-ROS1(L), or FLT-3ITD (the Internal tandem duplication mutation in FLT3 causes AML leukemia), and selected for IL3 independent growth. Karpas 299 cells, which express NPM-ALK, was used as a positive control. Retroviruses were generated as previously described (see PCT Publication No. WO 2010/093928, incorporated by reference).
A MTS assay was performed using the CellTiter 96 Aqueous One Solution Reagent (Promega, Catalog No G3582). Briefly, 1×105 cells/well in 24 well plates were grown in 1 mL medium that included 0 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM or 1000 nM TAE-684. After 72 hours, 20 μl of the CellTiter 96 Aqueous One Solution Reagent was added into each well of a 96 well assay plate (flat bottom), and then 100 μl of cells grown with or without treatment. Media-only wells were used as controls. The 96 well plate was incubated for 1-4 hours at 37° C., and then viable cells were counted by reading the absorbance at 490 nm using a 96 well plate reader.
As shown in
The mechanism of death of the BaF3 and Karpas 299 cells was next assessed by measuring the percentage of cleaved-caspase 3 positive cells by flow cytometry assay using cleaved caspase-3 as a marker for apoptosis. These results were obtained using the protocol publicly available from Cell Signaling Technology, Inc. (Danvers, Mass.). As shown in
To further identify the mechanism of action of TAE-684 on the FIG-ROS1 fusion polypeptides, all four cell lines (i.e., Karpas 299 cells and BaF3 cells transduced with retrovirus encoding FIG-ROS1(S), FIG-ROS1(L), and FLT-3ITD) were subjected to western blotting analysis following treatment with 0, 10, 50, or 100 nM TAE-684 for three hours. All antibodies were from Cell Signaling Technology, Inc. (Danvers, Mass.)
As shown in
A parallel set of experiments was next done on the same cells using the same protocols with the addition of another negative control, namely BaF3 cells transduced with the neo-myc tag, to compare two ALK therapeutics, namely TAE-684 and crizotinib.
As shown in
Western blotting analysis following treatment with 0, 0.1, 0.3, or 1.0 uM crizotinib for three hours was next performed using antibodies available from Cell Signaling Technology, Inc. As shown in
In addition to ROS1 kinase, NSCLC have also been described which contain proteins having ALK activity (see, e.g., U.S. Pat. Nos. 7,700,339; 7,605,131; 7,728,120). Using the IHC methods described above in Example 1, numerous FFPE samples of human NSCLC tumors were screened for specific binding by anti-ROS1 or anti-ALK antibodies. Such antibodies are commercially available from numerous sources.
The same samples were also screened with FISH for the ROS1 gene or for the ALK gene using standard methods. For example, a FISH protocol for the ROS1 gene is described in the Examples above. A FISH protocol for the ALK is described in U.S. Pat. No. 7,700,339, herein incorporated by reference. Likewise, another FISH assay is described in US Patent Publication No. 20110110923, incorporated herein by reference). The results of the screening are shown below in Tables 5 (ROS1 positive samples) and 6 (ALK positive samples).
Based on this screening of human NSCLC by both IHC and by FISH, it was found that ALK and ROS1 expression in these tumors is mutually exclusive. In other words, if an NSCLC tumor is driven by ALK, it will not express ROS1. Likewise, if an NSCLC tumor is driven by ROS1, it will not express ALK. Thus, a therapeutic such as crizotinib or TAE-684 that inhibits both ROS1 activity and ALK activity will be particularly effective in treating NSCLC.
The mutational status of all ROS1 and ALK positive tumors in the patient cohorts was examined using IHC with mutation specific EGFR antibodies (EGFR L858R and EGFR E746-A750del (Yu et al., 2009, Clin. Cancer Res., 15:3023-28)). The slides were stained with EGF Receptor (L858R Mutant Specific) (43B2) Rabbit mAb (1.2 μg/ml), EGF Receptor (E746-A750del Specific) (6B6) XP® Rabbit mAb (8.5 μg/ml) or EGF Receptor (D38B1) XP® Rabbit mAb (0.28 μg/ml), (#3197, #2085 and #4267, respectively, all Cell Signaling Technology, Danvers, Mass.) all diluted in SignalStain® Antibody Diluent (#8112 Cell Signaling Technology, Danvers, Mass.), incubated for 1 hour at room temperature, washed, then incubated with SignalStain® Boost IHC Detection Reagent (HRP, Rabbit) (Cell Signaling Technology, #8114) for 30 minutes. All slides were exposed to NOVARED substrate (Vector Laboratories, Burlingame, Calif.), and coverslips were then mounted. Images (20×) were acquired using an Olympus CX41 microscope equipped with an Olympus DP70 camera and DP Controller software.
As expected, all ROS1 and ALK positive tumors expressed total EGFR. Unexpectedly, two EGFR L858R/ALK positive (patients 3 and 8), one EGFR L858R/ROS1 positive (patient 1) and one EGFR E746-A750del/ROS1 positive (patient 6) tumors were identified (see
It is to be understood that while the disclosure has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.
This application claims the benefit of U.S. Provisional Application No. 61/635,057, filed Apr. 18, 2012, and U.S. Provisional Application No. 61/787,033, filed Mar. 15, 2013. The entire contents of the foregoing applications are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US13/37139 | 4/18/2013 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61635057 | Apr 2012 | US | |
| 61787033 | Mar 2013 | US |
