Patent Grant
7534772
The invention relates to the treatment and prevention of cancer using immunostimulatory nucleic acids and antibodies.
Cancer is the second leading cause of death, resulting in one out of every four deaths in the United States. In 1997, the estimated total number of new diagnoses for lung, breast, prostate, colorectal and ovarian cancer was approximately two million. Due to the ever increasing aging population in the United States, it is reasonable to expect that rates of cancer incidence will continue to grow.
Cancer is a disease which involves the uncontrolled growth (i.e., division) of cells. Some of the known mechanisms which contribute to the uncontrolled proliferation of cancer cells include growth factor independence, failure to detect genomic mutation, and inappropriate cell signaling. The ability of cancer cells to ignore normal growth controls may result in an increased rate of proliferation. Although the causes of cancer have not been firmly established, there are some factors known to contribute, or at least predispose a subject, to cancer. Such factors include particular genetic mutations (e.g., BRCA gene mutation for breast cancer, APC for colon cancer), exposure to suspected cancer-causing agents, or carcinogens (e.g., asbestos, UV radiation) and familial disposition for particular cancers such as breast cancer.
Cancer is currently treated using a variety of modalities including surgery, radiation therapy and chemotherapy. The choice of treatment modality will depend upon the type, location and dissemination of the cancer. For example, surgery and radiation therapy may be more appropriate in the case of solid well-defined tumor masses and less practical in the case of non-solid tumor cancers such as leukemia and lymphoma. One of the advantages of surgery and radiation therapy is the ability to control to some extent the impact of the therapy, and thus to limit the toxicity to normal tissues in the body. However, surgery and radiation therapy are often followed by chemotherapy to guard against any remaining or radio-resistant cancer cells. Chemotherapy is also the most appropriate treatment for disseminated cancers such as leukemia and lymphoma as well as metastases.
More recently, the use of CpG containing nucleic acids has been proposed for the treatment and prevention of cancer. We have found that unmethylated CG-dinucleotides within certain sequence contexts (CpG DNA) are recognized by the vertebrate immune system as foreign DNA (bacterial or viral). CpG DNA activates a coordinated set of immune responses that include innate immunity (macrophages, dendritic cells, and natural killer cells), humoral immunity, and cellular immunity. Krieg A M et al., Pharmacol Ther 84:113-20 (1999); Krieg A M et al., Curr Top Microbiol Immunol 247:1-21 (2000); Wagner H, Adv Immunol 73:329-68 (1999). As a vaccine adjuvant, CpG DNA is at least as effective as the gold standard complete Freund's adjuvant (CFA), but induces higher Th1 activity and demonstrates less toxicity. Chu R S et al., J Exp Med 186:1623-31 (1997); Weiner G J et al., Proc Natl Acad Sci USA 94:10833-7 (1997); Roman M et al., Nat Med 3:849-54 (1997); Lipford G B et al., Eur J Immunol 27:2340-4 (1997); Davis H L et al., J Immunol 160:870-6 (1998). Recently, we identified a human CpG motif which triggers proliferation and activation of primary human B cells. Hartmann G et al., J Immunol 164:944-53 (2000).
The invention relates in some aspects to methods for treating and preventing cancer using immunostimulatory nucleic acids and antibodies. Thus in one aspect the invention is a method for treating or preventing cancer. The method involves administering to a subject having or at risk of developing cancer an effective amount to upregulate CD20 expression of a nucleic acid, and an anti-CD20 antibody. The cancer, in some embodiments, is B-cell lymphoma associated with low levels of CD20 expression. The B-cell lymphoma in other embodiments is B-cell chronic lymphocytic leukemia (B-CLL) or a marginal zone lymphoma. In some embodiments the CD20 antibody is C2B8 or Rituximab.
The invention in other aspects relates to a method for diagnosing lymphoma by isolating a B cell from a subject and identifying a change in cell surface markers when the B cell is contacted with an immunostimulatory nucleic acid, wherein the cell surface marker induced on the B cell is indicative of the type of lymphoma. In some embodiments the subject has a type of lymphoma. In some embodiments the subject is suspected of having a type of lymphoma. The method may optionally include a method for treating cancer by administering to the subject an immunostimulatory nucleic acid and an antibody specific for the cell surface antigens induced on the B cell in order to treat the cancer.
In another aspect the invention is a method for treating or preventing cancer by administering to a subject having or at risk of developing cancer an effective amount to induce expression of a surface antigen on a cancer cell surface, of a nucleic acid, and administering to the subject an antibody selected from the group consisting of an anti-CD22 antibody and an anti-CD19 antibody.
According to another aspect of the invention, a method for treating lymphoma is provided. The method includes the steps of isolating a B cell from a subject having lymphoma, identifying a surface antigen which is not expressed or which is expressed on the surface of the B cell in an amount lower than that of a control B cell, administering to the subject an antibody specific for the identified surface antigen and an immunostimulatory nucleic acid in order to treat the lymphoma, wherein the nucleic acid is administered in an effective amount to upregulate expression of the surface antigen on the lymphoma cell surface.
A method for treating a lymphoma resistant to antibody therapy is provided according to another aspect of the invention. The method includes administering to a subject having a lymphoma resistant to therapy with an antibody specific for a surface antigen, an antibody specific for the surface antigen to which the lymphoma is resistant and a nucleic acid in order to treat the lymphoma, wherein the nucleic acid is administered in an effective amount to upregulate expression of the surface antigen on the lymphoma cell surface.
The surface antigen may be any type of surface antigen which is capable of being expressed on the surface of a cancer cell and which is induced by stimulation with immunostimulatory nucleic acids. In some embodiments the surface antigen is CD20, CD40, CD22, or CD19. In other embodiments the lymphoma is B-CLL or marginal zone lymphoma. In some embodiments the antibody is an anti-CD20 antibody. In some embodiments the anti-CD20 antibody is C2B8. In another embodiment the anti-CD20 antibody is Rituximab.
In some preferred embodiments the antibody is a human IgG1 antibody. In some preferred embodiments the antibody is a murine IgG2a antibody.
In some embodiments the methods also include administering an anti-cancer therapy to the subject.
The invention also includes a method for treating cancer in a human by administering to a human an immunostimulatory nucleic acid and an antibody of IgG1 isotype (an IgG1 isotype antibody as used herein refers to a human or humanized IgG1 unless otherwise specified), which binds to a cell surface antigen of a cancer cell and wherein the nucleic acid and the antibody are administered in an effective amount for killing the cancer cell.
Optionally the nucleic acid and the antibody are administered together. Alternatively the nucleic acid and the antibody may be administered separately.
In some embodiments the method includes the step of administering a cancer therapy. As used herein the term “a cancer therapy” is meant to embrace a single medicament, a plurality of medicaments of a particular class and a plurality of medicaments of different classes, and includes but is not limited to chemotherapeutic agents, cancer vaccines, biological response modifiers, and hormone therapies.
A chemotherapeutic agent may be selected from the group consisting of methotrexate, vincristine, adriamycin, cisplatin, non-sugar containing chloroethylnitrosoureas, 5-fluorouracil, mitomycin C, bleomycin, doxorubicin, dacarbazine, taxol, fragyline, Meglamine GLA, valrubicin, carmustaine and poliferposan, MMI270, BAY 12-9566, RAS famesyl transferase inhibitor, famesyl transferase inhibitor, MMP, MTA/LY231514, LY264618/Lometexol, Glamolec, CI-994, TNP-470, Hycamtin/Topotecan, PKC412, Valspodar/PSC833, Novantrone/Mitroxantrone, Metaret/Suramin, Batimastat, E7070, BCH-4556, CS-682, 9-AC, AG3340, AG3433, Incel/VX-710, VX-853, ZD0101, ISI641, ODN 698, TA 2516/Marmistat, BB2516/Marmistat, CDP 845, D2163, PD183805, DX8951f, Lemonal DP 2202, FK 317, Picibanil/OK-432, AD 32/Valrubicin, Metastron/strontium derivative, Temodal/Temozolomide, Evacet/liposomal doxorubicin, Yewtaxan/Paclitaxel, Taxol/Paclitaxel, Xeload/Capecitabine, Furtulon/Doxifluridine, Cyclopax/oral paclitaxel, Oral Taxoid, SPU-077/Cisplatin, HMR 1275/Flavopiridol, CP-358 (774)/EGFR, CP-609 (754)/RAS oncogene inhibitor, BMS-182751/oral platinum, UFT(Tegafur/Uracil), Ergamisol/Levamisole, Eniluracil/776C85/5FU enhancer, Campto/Levamisole, Camptosar/Irinotecan, Tumodex/Ralitrexed, Leustatin/Cladribine, Paxex/Paclitaxel, Doxil/liposomal doxorubicin, Caelyx/liposomal doxorubicin, Fludara/Fludarabine, Pharmarubicin/Epirubicin, DepoCyt, ZD1839, LU 79553/Bis-Naphtalimide, LU 103793/Dolastain, Caetyx/liposomal doxorubicin, Gemzar/Gemcitabine, ZD 0473/Anormed, YM 116, Iodine seeds, CDK4 and CDK2 inhibitors, PARP inhibitors, D4809/Dexifosamide, Ifes/Mesnex/Ifosamide, Vumon/Teniposide, Paraplatin/Carboplatin, Plantinol/cisplatin, Vepeside/Etoposide, ZD 9331, Taxotere/Docetaxel, prodrug of guanine arabinoside, Taxane Analog, nitrosoureas, alkylating agents such as Melphalan, Cyclophosphamide, Aminoglutethimide, Asparaginase, Busulfan, Carboplatin, Chlorombucil, Cytarabine HCl, Dactinomycin, Daunorubicin HCl, Estramustine phosphate sodium, Etoposide (VP 16-213), Floxuridine, Fluorouracil (5-FU), Flutamide, Hydroxyurea (hydroxycarbamide), Ifosfamide, Interferon Alfa-2a, Interferon Alfa-2b, Leuprolide acetate (LHRH-releasing factor analogue), Lomustine (CCNU), Mechlorethamine HCl (nitrogen mustard), Mercaptopurine, Mesna, Mitotane (o,p′-DDD), Mitoxantrone HCl, Octreotide, Plicamycin, Procarbazine HCl, Streptozocin, Tamoxifen citrate, Thioguanine, Thiotepa, Vinblastine sulfate, Amsacrine (m-AMSA), Azacitidine, Erythropoietin, Hexamethylmelamine (HMM), Interleukin 2, Mitoguazone (methyl-GAG; methyl glyoxal bis-guanylhydrazone; MGBG), Pentostatin (2′deoxycoformycin), Semustine (methyl-CCNU), Teniposide (VM-26) and Vindesine sulfate.
In some preferred embodiments the chemotherapeutic agent may be selected from the group consisting of methotrexate, vincristine, adriamycin, cisplatin, mitomycin C, bleomycin, doxorubicin, dacarbazine, taxol, valrubicin, Novantrone/Mitroxantrone, Evacet/liposomal doxorubicin, Yewtaxan/Paclitaxel, Taxol/Paclitaxel, SPU-077/Cisplatin, HMR 1275/Flavopiridol, BMS-182751/oral platinum, Leustatin/Cladribine, Paxex/Paclitaxel, Doxil/liposomal doxorubicin, Caelyx/liposomal doxorubicin, Fludara/Fludarabine, Pharmarubicin/Epirubicin, DepoCyt, Caetyx/liposomal doxorubicin, Gemzar/Gemcitabine, Ifes/Mesnex/Ifosamide, Vumon/Teniposide, Paraplatin/Carboplatin, Plantinol/cisplatin, Vepeside/Etoposide, Taxotere/Docetaxel, prodrug of guanine arabinoside, nitrosoureas, alkylating agents such as melphalan and cyclophosphamide, Asparaginase, Busulfan, Carboplatin, Chlorombucil, Cytarabine HCl, Daunorubicin HCl, Etoposide (VP16-213), Hydroxyurea (hydroxycarbamide), Ifosfamide, Interferon Alfa-2a, Interferon Alfa-2b, Lomustine (CCNU), Mechlorethamine HCl (nitrogen mustard), Mercaptopurine, Mitoxantrone HCl, Procarbazine HCl, Thioguanine, Thiotepa, Vinblastine sulfate, Azacitidine, Interleukin 2, Pentostatin (2′deoxycoformycin), Teniposide (VM-26), GM-CSF, and Vindesine sulfate.
A cancer vaccine may be selected from the group consisting of EGF, Anti-idiotypic cancer vaccines, Gp75 antigen, GMK melanoma vaccine, MGV ganglioside conjugate vaccine, Her2/neu, Ovarex, M-Vax, O-Vax, L-Vax, STn-KHL theratope, BLP25 (MUC-1), liposomal idiotypic vaccine, Melacine, peptide antigen vaccines, toxin/antigen vaccines, MVA-based vaccine, PACIS, BCG vaccine, TA-HPV, TA-CIN, DISC-virus and ImmuCyst/TheraCys. Biological response modifiers include interferon, and lymphokines such as IL-2. Hormone replacement therapy includes tamoxifen alone or in combination with progesterone. In a further embodiment, the cancer therapy is interferon-α (e.g., INTRON® A, Schering).
The cancer may be selected from the group consisting of basal cell carcinoma, bladder cancer, bone cancer, brain and central nervous system (CNS) cancer, breast cancer, cervical cancer, colon and rectum cancer, connective tissue cancer, esophageal cancer, eye cancer, kidney cancer, larynx cancer, leukemia, liver cancer, lung cancer, Hodgkin's lymphoma, non-Hodgkin's lymphoma, melanoma, myeloma, oral cavity cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, prostate cancer, rhabdomyosarcoma, skin cancer, stomach cancer, testicular cancer, and uterine cancer. In preferred embodiments, the cancer to be treated may be selected from the group consisting of bone cancer, brain and CNS cancer, connective tissue cancer, esophageal cancer, eye cancer, Hodgkin's lymphoma, larynx cancer, oral cavity cancer (e.g., lip, tongue, mouth, and pharynx), skin cancer, and testicular cancer.
In another aspect the invention encompasses a kit. The kit includes a package including at least two containers, the first container housing an immunostimulatory nucleic acid, the second container housing an antibody specific for a cell surface antigen, and instructions for screening a cell to determine whether the immunostimulatory nucleic acid upregulates expression of the cell surface antigen. In one embodiment the antibody is selected from the group consisting of an anti-CD20 antibody, an anti-CD19 antibody, and an anti-CD22 antibody.
The nucleic acids useful according to the invention are immunostimulatory nucleic acids and in some embodiments are immunostimulatory CpG nucleic acids having an unmethylated CpG motif, immunostimulatory T-rich nucleic acids, immunostimulatory poly-G nucleic acids, bacterial DNA, yeast DNA, or eukaryotic DNA.
In some embodiments the nucleic acid does not hybridize with genomic DNA or RNA under stringent conditions. In other embodiments the nucleic acid does hybridize with genomic DNA or RNA under stringent conditions.
The nucleic acid may have natural linkages or may include at least one modified backbone internucleotide linkage. In some embodiments the modified backbone is a phosphate backbone modification. In other embodiments the modified backbone is a peptide modified oligonucleotide backbone. The nucleic acid may also include native bases or modified bases. The nucleotide backbone may be chimeric, or the nucleotide backbone is entirely modified.
The immunostimulatory nucleic acid can have any length greater than 6 nucleotides, but in some embodiments is between 8 and 100 nucleotide residues in length. In other embodiments the nucleic acid comprises at least 20 nucleotides, at least 24 nucleotides, at least 27, nucleotides, or at least 30 nucleotides. The nucleic acid may be single-stranded or double-stranded. In some embodiments the nucleic acid is isolated and in other embodiments the nucleic acid may be a synthetic nucleic acid.
The CpG nucleic acid in one embodiment contains at least one unmethylated CpG dinucleotide having a sequence including at least the following formula: 5′ X1X2CGX3X4 3′ wherein C is unmethylated, wherein X1, X2, X3, and X4 are nucleotides. In one embodiment the 5′ X1X2CGX3X4 3′ sequence of the CpG nucleic acid is a non-palindromic sequence, and in other embodiments it is a palindromic sequence.
In some embodiments X1X2 are nucleotides selected from the group consisting of: GpT, GpG, GpA, ApA, ApT, ApG, CpT, CpA, CpG, TpA, TpT, and TpG; and X3X4 are nucleotides selected from the group consisting of: TpT, CpT, ApT, TpG, ApG, CpG, TpC, ApC, CpC, TpA, ApA, and CpA. In other embodiments X1X2 are GpA or GpT and X3X4 are TpT. In yet other embodiments X1 or X2 or both are purines and X3 or X4 or both are pyrimidines or X1X2 are GpA and X3 or X4 or both are pyrimidines. In one embodiment X2 is a T and X3 is a pyrimidine.
In other embodiments the CpG nucleic acid has a sequence selected from the group consisting of SEQ ID NOs: 19, 35-37, 39-42, 91, 92, 101, 108, 111, 135, 141, 151, 274, 277, 280, 286, 319, 350, 363, 368, 375, 495-498, 517, 518, 524, 529, 545, 548, 549, 555, 557, 560-563, 566, 585, 590, 591, 595, 599, 603, 605, 611, 614-616, 650, 676, 679, 682, 684, 702, 703, 707-710, 717-720, 729-732, 752, 755, 770, and 801-803.
In some embodiments the T-rich immunostimulatory nucleic acid is a poly-T nucleic acid comprising 5′ TTTT 3′. In yet other embodiments the poly-T nucleic acid comprises 5′ X1X2TTTTX3X4 3′ wherein X1, X2, X3, and X4 are nucleotides. In some embodiments X1X2 is TT and/or X3X4 is TT. In other embodiments X1X2 is selected from the group consisting of TA, TG, TC, AT, AA, AG, AC, CT, CC, CA, CG, GT, GG, GA, and GC; and/or X3X4 is selected from the group consisting of TA, TG, TC, AT, AA, AG, AC, CT, CC, CA, CG, GT, GG, GA, and GC.
The T-rich immunostimulatory nucleic acid may have only a single poly-T motif or it may have a plurality of poly-T nucleic acid motifs. In some embodiments the T-rich immunostimulatory nucleic acid comprises at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, or at least 8 T motifs. In other embodiments it comprises at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, or at least 8 CpG motifs. In some embodiments the plurality of CpG motifs and poly-T motifs are interspersed.
In yet other embodiments at least one of the plurality of poly-T motifs comprises at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, or at least 9 contiguous T nucleotide residues. In other embodiments the plurality of poly-T motifs is at least 3 motifs and wherein at least 3 motifs each comprises at least 3 contiguous T nucleotide residues or the plurality of poly-T motifs is at least 4 motifs and wherein the at least 4 motifs each comprises at least 3 contiguous T nucleotide residues.
The T-rich immunostimulatory nucleic acid may include one or more CpG motifs. In other embodiments the T-rich immunostimulatory nucleic acid is free of one or more CpG dinucleotides.
In other embodiments the T-rich immunostimulatory nucleic acid has poly A, poly-G, and/or poly C motifs. In other embodiments the T-rich immunostimulatory nucleic acid is free of two poly C sequences of at least 3 contiguous C nucleotide residues. Preferably the T-rich immunostimulatory nucleic acid is free of two poly A sequences of at least 3 contiguous A nucleotide residues. In other embodiments the T-rich immunostimulatory nucleic acid comprises a nucleotide composition of greater than 25% C or greater than 25% A. In yet other embodiments the T-rich immunostimulatory nucleic acid is free of poly-C sequences, poly-G sequences or poly-A sequences.
In some cases the T-rich immunostimulatory nucleic acid may be free of poly-T motifs, but rather, comprises a nucleotide composition of greater than 25% T. In other embodiments the T-rich immunostimulatory nucleic acid may have poly-T motifs and also comprise a nucleotide composition of greater than 25% T. In some embodiments the T-rich immunostimulatory nucleic acid comprises a nucleotide composition of greater than 25% T, greater than 30% T, greater than 40% T, greater than 50% T, greater than 60% T, greater than 80% T, or greater than 90% T nucleotide residues.
In some embodiments the poly-G nucleic acid comprises: 5′ X1X2GGGX3X4 3′ wherein X1, X2, X3, and X4 are nucleotides. In embodiments at least one of X3 and X4 are a G or both of X3 and X4 are a G. In other embodiments the poly-G nucleic acid comprises the following formula: 5′ GGGNGGG 3′ wherein N represents between 0 and 20 nucleotides. In yet other embodiments the poly-G nucleic acid comprises the following formula: 5′ GGGNGGGNGGG 3′ (SEQ ID NO:849) wherein N represents between 0 and 20 nucleotides.
The poly-G immunostimulatory nucleic acid may include one or more CpG motifs or T-rich motifs. In other embodiments the poly-G nucleic acid is free of one or more CpG dinucleotides or poly-T motifs.
Each of the limitations of the invention can encompass various embodiments of the invention. It is, therefore, anticipated that each of the limitations of the invention involving any one element or combinations of elements can be included in each aspect of the invention.
Present cancer treatments are often ineffective as well as being associated with a high degree of patient morbidity. The invention provides methods and products for the more effective treatment of cancer using a combination of immunostimulatory nucleic acids, antibodies, and optionally cancer therapies.
The invention is based, in part, on the surprising discovery that administration to a subject of immunostimulatory nucleic acids induces the expression of cell surface antigens including CD20, CD19, and CD22 on the surface of a cancer cell and that the induction of these antigens leads to enhanced antibody-dependent cellular cytotoxicity (ADCC). It was previously believed that CpG oligonucleotides enhanced ADCC by influencing the effector cell (e.g., by activating natural killer (NK) cells). Now it has been discovered according to the invention that immunostimulatory nucleic acids actually cause the induction of specific antigens CD20, CD19, and CD22, each of which can be targeted by specific antibody therapies. The discovery that immunostimulatory nucleic acids are capable of upregulating expression of certain target antigens on the surface of cancer cells, supports the development of therapies using immunostimulatory nucleic acids in combination with specific antibodies which interact with these cell surface antigens. Thus, in one aspect, the invention provides a method for treating or preventing cancer which involves the administration to a subject of a combination of an immunostimulatory nucleic acid and an antibody which specifically interacts with CD20, CD19, and CD22 in an effective amount to prevent or treat the cancer.
Additionally, it was discovered that the increased expression of these and other cell surface antigens varies widely depending upon the histological state of the tumor cell studied. The effect of immunostimulatory nucleic acids on different types of primary malignant B cells and reactive follicular hyperplasia was extensively examined. All B-cell lymphoma cells tested increased in size and granularity, upregulated activation markers (CD80, CD86, CD40, CD54, CD69), and upregulated antigen presentation molecules (class I major histocompatibility complex (MHC I), class II major histocompatibilty complex (MHC II)) in response to immunostimulatory nucleic acids. A control poly-C oligodeoxynucleotide (ODN) showed only minor effects. The extent of phenotypic change induced by immunostimulatory nucleic acids differed from sample to sample. Immunostimulatory nucleic acids, but not control nucleic acids, increased the expression of co-stimulatory molecules (e.g., CD40, CD80, CD86, CD54) on malignant B cells without altering the phenotype of B cells derived from reactive follicular hyperplasia. Immunostimulatory nucleic acids also enhanced expression of both class I and class II MHC in most samples. CD20 expression was increased in response to immunostimulatory nucleic acids, most notably in B-CLL and marginal zone lymphoma.
Furthermore, an inverse correlation was found between baseline expression of specific cell surface antigens and their expression after exposure to immunostimulatory nucleic acids. Thus the most significant increase in expression of these molecules was found in those samples that had the lowest (or no) baseline levels. These data indicate that immunostimulatory nucleic acids may reverse low expression of co-stimulatory molecules on malignant B cells that correspond to a low level of activation, while their effects on cells that are already in an activated state are less profound.
Thus, the invention relates to methods for identifying an appropriate therapy for a lymphoma patient, and for treating the patient using that therapy. The method can be accomplished by isolating a B cell from a lymphoma patient and comparing the surface antigens expressed on the malignant B cell with those expressed on normal B cells. The antigens which are expressed in low levels or not at all on the malignant B cell can be identified. The subject can then be treated using a combination of an immunostimulating nucleic acid and an antibody which specifically recognizes the antigen(s) which are expressed in low levels or not at all on the malignant B cell.
The invention is also useful for treating cancers which are resistant to monoclonal antibody therapy. It has been discovered according to the invention, that immunostimulatory nucleic acids can reverse the resistance of tumor cells and render tumor cells which were previously non-responsive or only weakly responsive, sensitive to therapy. In particular it has been discovered that immunostimulatory nucleic acids can cause a phenotypic change to a resistant tumor cell that renders it sensitive to monoclonal antibody therapy. For instance, the monoclonal anti-CD20 antibody Rituximab has been shown to be effective clinically in several trials and has recently been approved for the therapy of follicular B cell lymphoma. Maloney D G, Semin Oncol 26:74-8 (1999); Foran J M et al., J Clin Oncol 18:317-24 (2000); Witzig T E et al., J Clin Oncol 17:3793-803 (1999); Davis T A et al., J Clin Oncol 17:1851-7 (1999); Wiseman G A et al., Clin Cancer Res 5:3281s-3286s (1999); Grillo-Lopez A J et al, Semin Oncol 26:66-73 (1999). There are reports that with lymphomas a small minority of tumors that re-emerge following Rituximab therapy can lack CD20 expression. Davis T A et al., Clin Cancer Res 5:611-5 (1999); Kinoshita T et al., J Clin Oncol 16:3916 (1998). The immunostimulatory nucleic acids of the invention are useful for treating this set of resistant tumors. Additionally, Rituximab has not been useful for the treatment of all types of B cell malignancies. Expression of CD20 is relatively low on B-CLL cells, which provides an explanation for why Rituximab is less effective for CLL than for some other B-cell malignancies. Grinaldi L et al., J Clin Pathol 51:364-9 (1998). The immunostimulatory nucleic acids of the invention are also useful for treating these tumors.
The humanized monoclonal antibody 1D10 recognizes an HLA-DR variant antigen. Link B K et al., Blood 81:3343-9 (1993). This antibody is currently being tested in a phase I clinical trial in patients with lymphoma. One limitation to the use of this antibody is that the target antigen is only expressed by approximately 50% of B-cell lymphomas. Interestingly, its expression was upregulated by immunostimulatory nucleic acids in all lymphoma samples tested. It was discovered according to the invention that immunostimulatory nucleic acids may enhance the efficacy of therapy with these and other antibodies by increasing expression of target antigen. Thus in another aspect the invention includes methods for treating lymphoma by administering to a subject an immunostimulatory nucleic acid and antibodies specific for HLA-DR. One useful antibody is the humanized monoclonal antibody 1D10. It is particularly useful for treating resistant tumors.
The invention also relates to the discovery of a specific subclass, or isotype, of antibody which when combined with immunostimulatory nucleic acids produces a synergistic immune response. Another subclass, or isotype, does not even provide an additive response when combined with immunostimulatory nucleic acids. It was discovered according to the invention that the combination of immunostimulatory nucleic acids and human antibodies of the IgG1 isotype results in an increased (synergistic) survival rate. When immunostimulatory nucleic acids are combined with human antibodies of the IgG2 isotype, no increase in survival rate is observed over the use of the IgG2 antibody alone. The IgG2 isotype (which correlates with the murine IgG1 isotype) is believed to be recognized by the Fc receptor designated CD16 that is expressed largely by NK cells. Immunostimulatory nucleic acids are known to activate NK cells, and thus, it is surprising that immunostimulatory nucleic acids do not enhance the therapeutic effect of human IgG2 or murine IgG1 antibodies. Since NK cells are believed to be involved in ADCC and are activated by immunostimulatory nucleic acids, it was surprising that antibodies of the human IgG2 (or murine IgG1) isotype do not produce a synergistic or even additive response when administered with immunostimulatory nucleic acids.
A cancer cell is a cell that divides and reproduces abnormally due to a loss of normal growth control. Cancer cells almost always arise from at least one genetic mutation. In some instances, it is possible to distinguish cancer cells from their normal counterparts based on profiles of expressed genes and proteins, as well as to the level of their expression. Genes commonly affected in cancer cells include oncogenes, such as ras, neu/HER2/erbB, myb, myc and abl, as well as tumor suppressor genes such as p53, Rb, DCC, RET and WT. Cancer-related mutations in some of these genes leads to a decrease in their expression or a complete deletion. In others, mutations cause an increase in expression or the expression of an activated variant of the normal counterpart.
The term “tumor” is usually equated with neoplasm, which literally means “new growth” and is used interchangeably with “cancer.” A “neoplastic disorder” is any disorder associated with cell proliferation, specifically with a neoplasm. A “neoplasm” is an abnormal mass of tissue that persists and proliferates after withdrawal of the carcinogenic factor that initiated its appearance. There are two types of neoplasms, benign and malignant. Nearly all benign tumors are encapsulated and are noninvasive; in contrast, malignant tumors are almost never encapsulated but invade adjacent tissue by infiltrative destructive growth. This infiltrative growth can be followed by tumor cells implanting at sites discontinuous with the original tumor. The method of the invention can be used to treat neoplastic disorders in humans, including but not limited to: sarcoma, carcinoma, fibroma, glioma, leukemia, lymphoma, melanoma, myeloma, neuroblastoma, retinoblastoma, and rhabdomyosarcoma, as well as each of the other tumors described herein.
“Cancer” as used herein refers to an uncontrolled growth of cells which interferes with the normal functioning of the bodily organs and systems. Cancers which migrate from their original location and seed vital organs can eventually lead to the death of the subject through the functional deterioration of the affected organs. Hemopoietic cancers, such as leukemia, are able to out-compete the normal hemopoietic compartments in a subject, thereby leading to hemopoietic failure (in the form of anemia, thrombocytopenia and neutropenia), ultimately causing death.
A metastasis is a region of cancer cells, distinct from the primary tumor location, resulting from the dissemination of cancer cells from the primary tumor to other parts of the body. At the time of diagnosis of the primary tumor mass, the subject may be monitored for the presence of metastases. Metastases are most often detected through the sole or combined use of magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, blood and platelet counts, liver function studies, chest X-rays and bone scans in addition to the monitoring of specific symptoms.
Cancers include, but are not limited to, basal cell carcinoma, biliary tract cancer; bladder cancer; bone cancer; brain and CNS cancer; breast cancer; cervical cancer; choriocarcinoma; colon and rectum cancer; connective tissue cancer; cancer of the digestive system; endometrial cancer; esophageal cancer; eye cancer; cancer of the head and neck; gastric cancer; intra-epithelial neoplasm; kidney cancer; larynx cancer; leukemia; liver cancer; lung cancer (e.g., small cell and non-small cell); lymphoma including Hodgkin's and non-Hodgkin's lymphoma; melanoma; myeloma; neuroblastoma; oral cavity cancer (e.g., lip, tongue, mouth, and pharynx); ovarian cancer; pancreatic cancer; prostate cancer; retinoblastoma; rhabdomyosarcoma; rectal cancer; renal cancer; cancer of the respiratory system; sarcoma; skin cancer; stomach cancer; testicular cancer; thyroid cancer; uterine cancer; cancer of the urinary system, as well as other carcinomas and sarcomas.
The immunostimulatory nucleic acids and antibodies are useful for treating or preventing cancer in a subject. A “subject” unless otherwise specified shall mean a human or vertebrate mammal including but not limited to a dog, cat, horse, cow, pig, sheep, goat, or primate, e.g., monkey. Thus the invention can be used to treat cancer and tumors in human and non human subjects. Cancer is one of the leading causes of death in companion animals (i.e., cats and dogs). Cancer usually strikes older animals which, in the case of house pets, have become integrated into the family. Forty-five percent of dogs older than 10 years of age are likely to succumb to the disease. The most common treatment options include surgery, chemotherapy and radiation therapy. Other treatment modalities which have been used with some success are laser therapy, cryotherapy, hyperthermia and immunotherapy. The choice of treatment depends on the type of cancer and degree of dissemination. Unless the malignant growth is confined to a discrete area in the body, it is difficult to remove only malignant tissue without also affecting normal cells.
Malignant disorders commonly diagnosed in dogs and cats include but are not limited to lymphosarcoma, osteosarcoma, mammary tumors, mastocytoma, brain tumor, melanoma, adenosquamous carcinoma, carcinoid lung tumor, bronchial gland tumor, bronchiolar adenocarcinoma, fibroma, myxochondroma, pulmonary sarcoma, neurosarcoma, osteoma, papilloma, retinoblastoma, Ewing's sarcoma, Wilms' tumor, Burkitt's lymphoma, microglioma, neuroblastoma, osteoclastoma, oral neoplasia, fibrosarcoma, osteosarcoma and rhabdomyosarcoma. Other neoplasias in dogs include genital squamous cell carcinoma, transmissable venereal tumor, testicular tumor, seminoma, Sertoli cell tumor, hemangiopericytoma, histiocytoma, chloroma (granulocytic sarcoma), corneal papilloma, corneal squamous cell carcinoma, hemangiosarcoma, pleural mesothelioma, basal cell tumor, thymoma, stomach tumor, adrenal gland carcinoma, oral papillomatosis, hemangioendothelioma and cystadenoma. Additional malignancies diagnosed in cats include follicular lymphoma, intestinal lymphosarcoma, fibrosarcoma and pulmonary squamous cell carcinoma. The ferret, an ever-more popular house pet, is known to develop insulinoma, lymphoma, sarcoma, neuroma, pancreatic islet cell tumor, gastric MALT lymphoma and gastric adenocarcinoma.
Neoplasias affecting agricultural livestock include leukemia, hemangiopericytoma and bovine ocular neoplasia (in cattle); preputial fibrosarcoma, ulcerative squamous cell carcinoma, preputial carcinoma, connective tissue neoplasia and mastocytoma (in horses); hepatocellular carcinoma (in swine); lymphoma and pulmonary adenomatosis (in sheep); pulmonary sarcoma, lymphoma, Rous sarcoma, reticuloendotheliosis, fibrosarcoma, nephroblastoma, B-cell lymphoma and lymphoid leukosis (in avian species); retinoblastoma, hepatic neoplasia, lymphosarcoma (lymphoblastic lymphoma), plasmacytoid leukemia and swimbladder sarcoma (in fish), caseous lymphadenitis (CLA): chronic, infectious, contagious disease of sheep and goats caused by the bacterium Corynebacterium pseudotuberculosis, and contagious lung tumor of sheep caused by jaagsiekte.
In one aspect, a method for treating cancer is provided which involves administering the compositions of the invention to a subject having cancer. A “subject having cancer” is a subject that has been diagnosed with a cancer. In some embodiments, the subject has a cancer type characterized by a solid mass tumor. The solid tumor mass, if present, may be a primary tumor mass. A primary tumor mass refers to a growth of cancer cells in a tissue resulting from the transformation of a normal cell of that tissue. In most cases, the primary tumor mass is identified by the presence of a cyst, which can be found through visual inspection or palpation methods, or by irregularity in shape, texture or weight of the tissue.
However, some primary tumors are not palpable and can be detected only through medical imaging techniques such as X-rays (e.g., mammography), or by needle aspirations. The use of these latter techniques is more common in early detection. Molecular and phenotypic analysis of cancer cells within a tissue will usually confirm if the cancer is endogenous to the tissue or if the lesion is due to metastasis from another site.
With respect to the prophylactic treatment methods, the invention is aimed at administering the compositions of the invention to a subject at risk of developing cancer. A subject at risk of developing a cancer is one who has a high probability of developing cancer. These subjects include, for instance, subjects having a genetic abnormality, the presence of which has been demonstrated to have a correlative relation to a higher likelihood of developing a cancer. Subjects exposed to cancer-causing agents such as tobacco, asbestos, or other chemical toxins are also subjects at risk of developing cancers used herein. When a subject at risk of developing a cancer is treated with an immunostimulatory nucleic acid, an antibody and optionally a cancer therapy, on a regular basis, such as monthly, the cancer growth will be prevented from initiating. This aspect of the invention is particularly advantageous when the subjects employed in certain trades which are exposed to cancer-causing agents on an ongoing basis. For example, many airborne, or inhaled, carcinogens such as tobacco smoke and asbestos have been associated with lung cancer.
A carcinogen is an agent capable of initiating development of malignant cancers. Exposure to carcinogens generally increases the risk of neoplasms in subjects, usually by affecting DNA directly. Carcinogens may take one of several forms such as chemical, electromagnetic radiation, or may be an inert solid body.
Substances for which there is sufficient evidence to establish a causal relationship in cancer in humans are referred to as confirmed human carcinogens. Included in this category are the following substances: Aflatoxins, Alcoholic beverages, Aluminium production, 4-aminobiphenyl, Arsenic and arsenic compounds, Asbestos, Manufacture of auramine, Azathioprine, Benzene, Benzidine, Beryllium and beryllium compounds, Betel quid with tobacco, Bis(chloromethyl)ether and chloromethyl methyl ether (technical grade), Boot and shoe manufacture and repair (occupational exposure), 1,4 Butanediol dimethanesulphonate (Myleran), Cadmium and cadmium compounds, Chlorambucil, Chlornaphazine, 1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1 nitrosourea, Chloromethyl methyl ether (technical), Chromium compounds (hexavalent), Coal gasification, Coal tar pitches, Coal tars, Coke production, Cyclophosphamide, Cyclosporin, Erionite, Ethylene oxide, Furniture and cabinet making, Underground haematite mining with exposure to radon, Iron and steel founding, Isopropyl alcohol manufacture (strong acid process), Manufacture of magenta, Melphalan, 8-Methoxypsoralen (Methoxsalen) plus ultraviolet radiation, Mineral oils-untreated and mildly-treated oils, MOPP and other combined chemotherapy for cancer, Mustard gas (sulphur mustard), 2-Naphthylamine, Nickel and nickel compounds (essentially sulphate and sulphide), Nonsteroidal estrogens (not necessarily all in group) includes diethylstilbestrol, Estrogen replacement therapy, and Combined oral contraceptives and sequential oral contraceptives, Steroidal estrogens (not all in group), Painter (occupational exposure as a painter), Phenacetin (analgesic mixtures containing), Rubber industry, Salted fish (Chinese style), Solar radiation, Shale oils, Soots, Sulphuric acid (occupational exposures to strong-inorganic-acid mists of sulphuric acid), Talc containing asbestiform fibres, Thiotepa, Tobacco products (smokeless), Tobacco smoke, Treosulphan, and Vinyl chloride.
Substances for which there is a lesser degree of evidence in humans but sufficient evidence in animal studies, or degrees of evidence considered unequivocal of mutagenicity in mammalian cells, are referred to as probable human carcinogens. This category of substances includes: Acrylamide, Acrylonitrile, Adriamycin, Anabolic steroids, Azacitidine, Benzanthracene, Benzidine-based dyes (technical grade), Direct Black 38, Direct Blue 6, Direct Brown 95, Benzopyrenel,3-Butadiene, Captafol, Bischloroethyl nitrosourea (BCNU), 1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), Chloramphenicolpara-Chloro-ortho-toluidine and its strong acid salts, Chlorozotocin, Cisplatin, Creosotes, Dibenzanthracene, Diesel engine exhaust, Diethyl sulphate, Dimethylcarbamoyl chloride, Dimethyl sulphate, Epichlorohydrin, Ethylene dibromide, N-ethyl-N-nitrosourea, Formaldehyde, Glass manufacturing industry (occupational exposure), Art glass (glass containers and pressed ware), Hairdresser or barber (occupational exposure, probably dyes), Insecticide use (occupational), IQ (2-Amino-3-methylimidazo[4,5-f]quinoline), Mate drinking (hot), 5-Methoxypsoralen, 4,4′-Methylenebis(2-chloroaniline) (MOCA), N-Methyl-N-nitro-N-nitrosoguanidine (MNNG), N-Methyl-N-nitrosourea, Nitrogen mustard, N-Nitrosodiethylamine, N-Nitrosodimethylamine, Petroleum refining (occupational refining exposures), Phenacetin, Polychlorinated biphenyls, Procarbazine hydrochloride, Silica (crystalline), Styrene-7,8-oxide, Tris(1-azaridinyl)phosphine sulphide (Thiotepa), Tris(2,3-dibromopropyl) phosphate, Ultraviolet radiation: A, B and C including sunlamps and sunbeds, and Vinyl bromide.
Substances for which there is sufficient evidence in animal tests are referred to as possible human carcinogens. This category of substances includes: A-C(2-Amino-9H-pyrido[2,3-b]indole), Acetaldehyde, Acetamide, AF-2[2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide, para-Aminoazobenzene, ortho-Aminoazobenzene, 2-Amino-5-(5-nitro-2-furyl)-1,3,4-thiadiazole, Amitrole, ortho-Anisidine, Antimony trioxide, Aramite, Atrazine, Attapulgite, Azaserine, Benzo[b]fluoranthene, Benzo[j]fluoranthene, Benzo[k]fluoranthene, Benzyl violet, Bitumens (extracts of steam-refined and air-refined bitumens), Bleomycins, Bracken ferns, Bromodichloromethane, Butylated hydroxyanisole (BHA), á-Butyrolactone, Caffeic acid, Carbon black extract, Carbon tetrachloride, Carrageenan (degraded), Ceramic fibres, Chloramphenicol, Chlordane, Chlordecone, Chlorendic acid, Chlorinated paraffins of average carbon-chain length C12 and average degree of chlorination approx 60%, alpha-Chlorinated toluenes (not necessarily all in group), Benzotrichloride, para-Chloroaniline, Chloroform, Chlorophenols, Pentachlorophenol, 2,4,6-Trichlorophenol, Chlorophenoxy herbicides (not necessarily all in group), 4-Chloro-ortho-phenylenediamine, CI Acid Red 114, CI Basic Red 9, CI Direct Blue 15, Citrus Red No. 2, Cobalt and cobalt compounds, Coffee (bladder), para-Cresidine, Cycasin, Dacarbazine, Dantron (1,8-dihydroxyanthraquinone), Daunomycin, DDT, N,N′-Diacetylbenzidine, 4,4′-Diaminodiphenyl ether, 2,4-Diaminotoluene, Dibenz[a,h]acridine, Dibenz[a,j]acridine, 7H-Dibenzo[c,g]carbazole, Dibenzo[a,e]pyrene, Dibenzo[a,h]pyrene, Dibenzo[a,i]pyrene, Dibenzo[a,l]pyrene, 1,2-Dibromo-3-chloropropane, para-Dichlorobenzene, 3,3′-Dichlorobenzene, 3,3′-Dichloro-4,4′-diaminodiphenyl ether, 1,2-Dichloroethane, Dichloromethane, 1,3-Dichloropropene (technical grade), Dichlorvos, Diepoxybutane, Diesel fuel (marine), Di(2-ethylhexyl)phthalate, 1,2-Diethylhydrazine, Diglycidyl resorcinol ether, Dihydrosafrole, Diisopropyl sulfate, 3,3′-Dimethoxybenzidine, para-Dimethylaminoazobenzene, trans-2-[(Dimethylamino)methylimino]-5-[2-(5-nitro-2-furyl[vinyl]-1,3,4-oxidiazole, 2,6-Dimethylaniline (2,6-Xylidene), 3,3′-Dimethylbenzidine (ortho-tolidine), Dimethylformamide, 1,1-Dimethylhydrazine, 1,2-Dimethylhydrazine, 1,6-Dinitropyrene, 1,8-Dinitropyrene, 1,4-Dioxane, Disperse Blue, 1Ethyl acrylate, Ethylene thiourea, Ethyl methanesulphonate, 2-(2-Formylhydrazino)-4-(5-nitro-2-furyl)thiazole, Fuel oils (residual, heavy), Fusarium moniliforme (toxins derived from), Fumonisin B1; Fumonisin B2; Fusarin C, Gasoline, Gasoline engine exhausts, Glasswool, Glu-P-1 (2-Amino-6-methyldipyrido[1,2-a:3′2′-d]imidazole), Glu-P-2(-Aminodipyrido[1,2-a:3′2′-d]imidazole),Glycidaldehyde, Griseofulvin, HC Blue No 1, Heptachlor, Hexachlorobenzene, Hexachlorocyclohexanes Technical grades alpha isomer gamma isomer (lindane), Hexamethylphosphoramide, Hydrazine, Indeno[1,2,3-cd]pyrene, Iron-dextran complex, Isoprene, Lasiocarpine, Lead and lead compounds (inorganic), Magenta (containing CI Basic Red 9), Man-made mineral fibres (see glasswool, rockwool, slagwool, and ceramic fibres), MeA-a-C (2-Amino-3-methyl-9H-pyrido[2,3-b]indole), MeIQ (2-Amino-3,4-dimethylimidazo[4,5-f]-quinolone), MeIQx (2-Amino-3,8-dimethylamidazo[4,5-f]quinoxaline), Methylmercury compounds (methylmercuric chloride), Melphalan, 2-Methylaziridine, Methylazoxymethanol and its acetate, 5-Methylchrysene, 4,4′-Methylenebis(2-methylaniline), 4,4′-Methylenedianiline, Methylmethanesulphonate, 2-methyl-1-nitroanthraquinone (uncertain purity), N-methyl-N-nitrosourethane, Methylthiouracil, Metronidazole, Mirex, Mitomycin, Monocrotaline 5-(Morpholinomethyl)-3-[(5-nitrofurfurylidene)amino]-2-oxazolidinone, Nafenopin, Niridazole, 5-Nitroacenaphthene, 6-Nitrochrysene, Nitrofen (technical grade), 2-Nitrofluorenel-[(5-Nitrofurfurylidene)amino]-2-imidazolidinone, N-[4-(5-Nitro-2-furyl)-2-thiazolyl]acetamide, Nitrogen mustard, N-oxide, Nitrolotriacetic acid and its salts, 2-Nitropropanel-Nitropyrene, 4-Nitropyrene, N-Nitrosodi-n-butylamine, N-Nitrosodiethanolamine, N-Nitrosodi-n-propylamine, 3-(N-Nitrosomethylamino)propionitrile, 4-(N-Nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), N-Nitrosomethylethylamine, N-Nitrosomethylvinylamine, N-Nitrosomorpholine, N-Nitrosonomicotine, N-Nitrosopiperidene, N-Nitrosopyrrolidine, N-Nitrososarcosine, Ochratoxin A, Oil Orange, Panfuran S (containing dihydroxymethylfuratzine), Phenazopyridine hydrochloride, Phenobarbital, Phenoxybenzamine hydrochloride, Phenyl glycidyl ether, PhenytoinPhIP (2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, Pickled vegetables, traditional Asian, Polybrominated biphenyls, Ponceau MXPonceau 3R, Potassium bromate, 1,3-Propane sultone, Propylene oxide, Progestins, Medroxyprogesterone acetate, á-Propiolactone, Propylthiouracil, Rockwool, Saccharin, Safrole, Slagwool, Sodium ortho-phenylphenate, Sterigmatocystin, Streptozotocin, Styrene, Sulfallate, 2,3,7,8-Tetrachlorodibenzo-para-dioxin (TCDD), Tetrachloroethylene, Textile manufacturing (occupational exposures), Thiocetamide, 4,4′-Thiodianiline, Thiourea, Toluene, diisocyanatesortho-Toluidine, Toxaphene (polychlorinated camphenes), Trichlormethine (trimustine hydrochloride), Trp-P-1 (3-Amino-1,4-dimethyl-5-H-pyrido[4,3-b]indole), Trp-P-2 (3-Amino-1-methyl-5H-pyrido[4,3-b]indole), Trypan blue, Uracil mustard, Urethane, 4-Vinylcyclohexene, 4-Vinylcyclohexene diepoxide, Welding fumes, Wood industries and Carpentry and joinery.
Subjects at risk of developing cancer also include those who have a genetic predisposition to cancer. In many cases, genetic predisposition to cancer can be identified by studying the occurrence of cancer in family members. Examples of genetic predisposition to common forms of cancer include, but are not limited to, mutation of BRCA1 and BRCA2 in familial breast cancer, mutation of APC in familial colony cancer (familial polyposis coli), mutation of MSH2 and MLH1 in hereditary nonpolyposis colon cancer (HNPCC), mutation of p53 in Li-Fraumeni syndrome, mutation of Rb1 in retinoblastoma, mutation of RET in multiple endocrine neoplasia type 2 (MEN2), mutation of VHL in renal cancer and mutation of WT1 in Wilms' tumor. Other cancers for which a familial predisposition has been identified include ovarian, prostate, melanoma and lung cancer.
It has been estimated that almost half of all currently diagnosed cancers will be treated with some form of cancer medicament. However, many forms of cancer, including melanoma, colorectal, prostate, endometrial, cervical and bladder cancer, do not respond well to treatment with cancer medicaments. In fact, only about 5-10 percent of cancers can be cured using cancer medicaments alone. These include some forms of leukemias and lymphomas, testicular cancer, choriocarcinoma, Wilms' tumor, Ewing's sarcoma, neuroblastoma, small-cell lung cancer and ovarian cancer. Treatment of still other cancers, including breast cancer, requires a combination therapy of surgery or radiotherapy in conjunction with a cancer medicament.
The immunostimulatory nucleic acids are administered in combination with antibodies which specifically bind to cancer cell surface antigens. These antibodies include but are not limited to anti-CD20 antibodies, anti-CD40 antibodies, anti-CD19 antibodies, anti-CD22 antibodies, anti-HLA-DR antibodies, anti-CD80 antibodies, anti-CD86 antibodies, anti-CD54 antibodies, and anti-CD69 antibodies. These antibodies are available from commercial sources or may be synthesized de novo.
Commercially available anti-CD20 antibodies include but are not limited to those presented in Table 1 below.
Antibodies are well known to those of ordinary skill in the science of immunology. As used herein, the term “antibody” means not only intact antibody molecules but also fragments of antibody molecules retaining specific binding ability. Such fragments are also well known in the art and are regularly employed both in vitro and in vivo. In particular, as used herein, the term “antibody” means not only intact immunoglobulin molecules but also the well-known active fragments F(ab′)2, and Fab. F(ab′)2, and Fab fragments which lack the Fc fragment of intact antibody, clear more rapidly from the circulation, and may have less non-specific tissue binding of an intact antibody. Wahl R L et al., J Nucl Med 24:316-25 (1983). Antibody fragments which are particularly useful according to the methods of the invention are those which are bispecific and constructed to enhance FcR binding, e.g., include an Fe portion. These include, but are not limited to Medarex antibodies (MDX-210, 220, 22, 447, and 260). Other non-Fc containing fragments which interact with the antigens induced on the cell surface are also useful. These are particularly useful in combination with immunotoxins and/or radioactivity. The fragments can be delivered separately from the immunotoxins or radioactivity or conjugated thereto (e.g., radiolabled antibodies or antibody fragments).
Within the antigen-binding portion of an antibody, as is well-known in the art, there are complementarity-determining regions (CDRs), which directly interact with the epitope of the antigen, and framework regions (FRs), which maintain the tertiary structure of the paratope (see, in general, Clark, 1986; Roitt, 1991). In both the heavy chain Fd fragment and the light chain of IgG immunoglobulins, there are four framework regions (FR1 through FR4) separated respectively by three complementarity-determining regions (CDR1 through CDR3). The CDRs, and in particular the CDR3 regions, and more particularly the heavy chain CDR3, are largely responsible for antibody specificity.
It is now well-established in the art that the non-CDR regions of a mammalian antibody may be replaced with similar regions of conspecific or heterospecific antibodies while retaining the epitopic specificity of the original antibody. This is most clearly manifested in the development and use of “humanized” antibodies in which non-human CDRs are covalently joined to human FR and/or Fc/pFc′ regions to produce a functional antibody. Thus, for example, PCT International Publication Number WO 92/04381 teaches the production and use of humanized murine RSV antibodies in which at least a portion of the murine FR regions have been replaced by FR regions of human origin. Such antibodies, including fragments of intact antibodies with antigen-binding ability, are often referred to as “chimeric” antibodies. A “humanized monoclonal antibody” as used herein is a human monoclonal antibody or functionally active fragment thereof having human constant regions and a binding CDR3 region from a mammal of a species other than a human. Humanized monoclonal antibodies may be made by any method known in the art. Humanized monoclonal antibodies, for example, may be constructed by replacing the non-CDR regions of a non-human mammalian antibody with similar regions of human antibodies while retaining the epitopic specificity of the original antibody. For example, non-human CDRs and optionally some of the framework regions may be covalently joined to human FR and/or Fc/pFc′ regions to produce a functional antibody. There are entities in the United States which will synthesize humanized antibodies from specific murine antibody regions commercially, such as Protein Design Labs (Mountain View Calif.).
European Patent Application 0239400, the entire contents of which is hereby incorporated by reference, provides an exemplary teaching of the production and use of humanized monoclonal antibodies in which at least the CDR portion of a murine (or other non-human mammal) antibody is included in the humanized antibody. Briefly, the following methods are useful for constructing a humanized CDR monoclonal antibody including at least a portion of a mouse CDR. A first replicable expression vector including a suitable promoter operably linked to a DNA sequence encoding at least a variable domain of an Ig heavy or light chain and the variable domain comprising framework regions from a human antibody and a CDR region of a murine antibody is prepared. Optionally a second replicable expression vector is prepared which includes a suitable promoter operably linked to a DNA sequence encoding at least the variable domain of a complementary human Ig light or heavy chain respectively. A cell line is then transformed with the vectors. Preferably the cell line is an immortalized mammalian cell line of lymphoid origin, such as a myeloma, hybridoma, trioma, or quadroma cell line, or is a normal lymphoid cell which has been immortalized by transformation with a virus. The transformed cell line is then cultured under conditions known to those of skill in the art to produce the humanized antibody.
As set forth in European Patent Application 0239400 several techniques are well known in the art for creating the particular antibody domains to be inserted into the replicable vector. (Preferred vectors and recombinant techniques are discussed in greater detail below.) For example, the DNA sequence encoding the domain may be prepared by oligonucleotide synthesis. Alternatively a synthetic gene lacking the CDR regions in which four framework regions are fused together with suitable restriction sites at the junctions, such that double-stranded synthetic or restricted subcloned CDR cassettes with sticky ends could be ligated at the junctions of the framework regions. Another method involves the preparation of the DNA sequence encoding the variable CDR containing domain by oligonucleotide site-directed mutagenesis. Each of these methods is well known in the art. Therefore, those skilled in the art may construct humanized antibodies containing a murine CDR region without destroying the specificity of the antibody for its epitope.
Human monoclonal antibodies may be made by any of the methods known in the art, such as those disclosed in U.S. Pat. No. 5,567,610, issued to Borrebaeck et al., U.S. Pat. No. 5,565,354, issued to Ostberg, U.S. Pat. No. 5,571,893, issued to Baker et al, Kozbor D et al., J Immunol 133:3001-5 (1984), Brodeur et al., Monoclonal Antibody Production Techniques and Applications, pp. 51-63 (Marcel Dekker, Inc, New York, 1987), and Boerner P et al., J Immunol 147:86-95 (1991). In addition to the conventional methods for preparing human monoclonal antibodies, such antibodies may also be prepared by immunizing transgenic animals that are capable of producing human antibodies (e.g., Jakobovits A et al., Proc Natl Acad Sci USA 90:2551-5 (1993); Jakobovits A et al., Nature 362:255-8 (1993); Bruggermann et al., Year in Immunology 7:33 (1993); and U.S. Pat. No. 5,569,825 issued to Lonberg).
Significantly, as is well-known in the art, only a small portion of an antibody molecule, the paratope, is involved in the binding of the antibody to its epitope (see, in general, Clark, W. R. (1986) The Experimental Foundations of Modern Immunology Wiley & Sons, Inc., New York; Roitt, I. (1991) Essential Immunology, 7th Ed., Blackwell Scientific Publications, Oxford). The pFc′ and Fc regions, for example, are effectors of the complement cascade but are not involved in antigen binding. An antibody from which the pFc′ region has been enzymatically cleaved, or which has been produced without the pFc′ region, designated an F(ab′)2 fragment, retains both of the antigen binding sites of an intact antibody. Similarly, an antibody from which the Fc region has been enzymatically cleaved, or which has been produced without the Fc region, designated an Fab fragment, retains one of the antigen binding sites of an intact antibody molecule. Proceeding further, Fab fragments consist of a covalently bound antibody light chain and a portion of the antibody heavy chain denoted Fd. The Fd fragments are the major determinant of antibody specificity (a single Fd fragment may be associated with up to ten different light chains without altering antibody specificity) and Fd fragments retain epitope-binding ability in isolation.
Other antibodies useful according to the invention are antibodies of the IgG1 isotype. As mentioned above, anti-IgG1 isotype antibody as used herein refers to a human or humanized anti-IgG1 unless otherwise specified. IgG1 isotype antibodies are well known in the art and include at least the antibodies listed in Table 2 below.
131I LYM-1 (Oncolym ™)
In some embodiments the nucleic acid and antibody are administered in combination with a cancer therapy. As used herein, a “cancer therapy” refers to an agent which prevents growth of a cancer cell by decreasing or slowing the rate of growth, by inhibiting growth altogether, or by killing or inducing apoptosis of the cancer cell. Thus, as used herein, “treating cancer” includes preventing the development of a cancer, reducing the symptoms of cancer, and/or inhibiting the growth of an established cancer. In other aspects, the cancer therapy is administered to a subject at risk of developing a cancer for the purpose of reducing the risk of developing the cancer. Various types of medicaments for the treatment of cancer are described herein. For the purpose of this specification, cancer therapies are classified as chemotherapeutic agents, cancer vaccines, hormone therapy, biological response modifiers, surgical procedures, and radiotherapy aimed at treating cancer. Additionally, the methods of the invention are intended to embrace the use of more than one cancer therapy along with the immunostimulatory nucleic acids and antibody. As an example, where appropriate, the immunostimulatory nucleic acids may be administered with a both a chemotherapeutic agent and a radiotherapy.
Cancer therapies function in a variety of ways. Some cancer therapies work by targeting physiological mechanisms that are specific to tumor cells. Examples include the targeting of specific genes and their gene products (i.e., proteins primarily) which are mutated in cancers. Such genes include but are not limited to oncogenes (e.g., Ras, Her2, bcl-2), tumor suppressor genes (e.g., EGF, p53, Rb), and cell cycle targets (e.g., CDK4, p21, telomerase). Cancer therapies can alternately target signal transduction pathways and molecular mechanisms which are altered in cancer cells.
Other cancer therapies target cells other than cancer cells. For example, some medicaments prime the immune system to attack tumor cells (i.e., cancer vaccines). Still other medicaments, called angiogenesis inhibitors, function by attacking the blood supply of solid tumors. Since the most malignant cancers are able to metastasize (i.e., exit the primary tumor site and seed a distal tissue, thereby forming a secondary tumor), medicaments that impede this metastasis are also useful in the treatment of cancer. Angiogenic mediators include basic FGF, VEGF, angiopoietins, angiostatin, endostatin, TNF-α, TNP-470, thrombospondin-1, platelet factor 4, CAI, and certain members of the integrin family of proteins. One category of this type of medicament is a metalloproteinase inhibitor, which inhibits the enzymes used by the cancer cells to exit the primary tumor site and extravasate into another tissue.
As used herein, chemotherapeutic agents encompass both chemical and biological agents. These agents function to inhibit a cellular activity which the cancer cell is dependent upon for continued survival. Categories of chemotherapeutic agents include alkylating/alkaloid agents, antimetabolites, hormones or hormone analogs, and miscellaneous antineoplastic drugs. Most if not all of these agents are directly toxic to cancer cells and do not require immune stimulation. Chemotherapeutic agents which are currently in development or in use in a clinical setting are shown in Table 3 below.
Another useful anti-cancer therapy is Interferon-α (e.g., INTRON® A, Schering).
The compounds useful according to the invention are nucleic acids. The nucleic acids may be double-stranded or single-stranded. Generally, double-stranded molecules may be more stable in vivo, while single-stranded molecules may have increased activity. The terms “nucleic acid” and “oligonucleotide” refer to multiple nucleotides (i.e., molecules comprising a sugar (e.g., ribose or deoxyribose) linked to a phosphate group and to an exchangeable organic base, which is either a substituted pyrimidine (e.g., cytosine (C), thymine (T) or uracil (U)) or a substituted purine (e.g., adenine (A) or guanine (G)) or a modified base. As used herein, the terms refer to oligoribonucleotides as well as oligodeoxyribonucleotides. The terms shall also include polynucleosides (i.e., a polynucleotide minus the phosphate) and any other organic base-containing polymer. The terms “nucleic acid” and “oligonucleotide” also encompass nucleic acids or oligonucleotides with a covalently modified base and/or sugar. For example, they include nucleic acids having backbone sugars which are covalently attached to low molecular weight organic groups other than a hydroxyl group at the 3′ position and other than a phosphate group at the 5′ position. Thus modified nucleic acids may include a 2′-O-alkylated ribose group. In addition, modified nucleic acids may include sugars such as arabinose instead of ribose. Thus the nucleic acids may be heterogeneous in backbone composition thereby containing any possible combination of polymer units linked together such as peptide-nucleic acids (which have amino acid backbone with nucleic acid bases). In some embodiments the nucleic acids are homogeneous in backbone composition.
Nucleic acids also can include base analogs such as C-5 propyne modified bases. Wagner R W et al., Nature Biotechnol 14:840-4 (1996). Purines and pyrimidines include but are not limited to adenine, cytosine, guanine, thymine, 5-methylcytosine, 2-aminopurine, 2-amino-6-chloropurine, 2,6-diaminopurine, hypoxanthine, and other naturally and non-naturally occurring nucleobases, substituted and unsubstituted aromatic moieties.
The nucleic acid is a linked polymer of bases or nucleotides. As used herein with respect to linked units of a nucleic acid, “linked” or “linkage” means two entities are bound to one another by any physicochemical means. Any linkage known to those of ordinary skill in the art, covalent or non-covalent, is embraced. Such linkages are well known to those of ordinary skill in the art. Natural linkages, which are those ordinarily found in nature connecting the individual units of a nucleic acid, are most common. The individual units of a nucleic acid may be linked, however, by synthetic or modified linkages.
Whenever a nucleic acid is represented by a sequence of letters it will be understood that the nucleotides are in 5′→3′ order from left to right and that “A” denotes adenosine, “C” denotes cytosine, “G” denotes guanosine, “T” denotes thymidine, and “U” denotes uracil unless otherwise noted.
Nucleic acid molecules useful according to the invention can be obtained from natural nucleic acid sources (e.g., genomic nuclear or mitochondrial DNA or cDNA), or are synthetic (e.g., produced by oligonucleotide synthesis). Nucleic acids isolated from existing nucleic acid sources are referred to herein as native, natural, or isolated nucleic acids. The nucleic acids useful according to the invention may be isolated from any source, including eukaryotic sources, prokaryotic sources, nuclear DNA, mitochondrial DNA, etc. Thus, the term nucleic acid encompasses both synthetic and isolated nucleic acids. The term “isolated” as used herein refers to a nucleic acid which is substantially free of other nucleic acids, proteins, lipids, carbohydrates or other materials with which it is naturally associated. The nucleic acids can be produced on a large scale in plasmids, (see Sambrook T et al., “Molecular Cloning: A Laboratory Manual”, Cold Spring Harbor Laboratory Press, New York, 1989) and separated into smaller pieces or administered whole. After being administered to a subject the plasmid can be degraded into oligonucleotides. One skilled in the art can purify viral, bacterial, eukaryotic, etc., nucleic acids using standard techniques, such as those employing restriction enzymes, exonucleases or endonucleases.
For use in the instant invention, the nucleic acids can be synthesized de novo using any of a number of procedures well known in the art. For example, the b-cyanoethyl phosphoramidite method (Beaucage S L et al., Tetrahedron Lett 22:1859, 1981); nucleoside H-phosphonate method (Garegg et al., Tetrahedron Lett 27:4051-4, 1986; Froehler et al., Nucl Acid Res 14:5399-407, 1986; Garegg et al., Tetrahedron Lett 27:4055-8, 1986; Gaffney et al., Tetrahedron Lett 29:2619-22, 1988). These chemistries can be performed by a variety of automated oligonucleotide synthesizers available in the market.
In some embodiments, the nucleic acids useful according to the invention are immunostimulatory nucleic acids. An immunostimulatory nucleic acid is any nucleic acid, as described above, which is capable of modulating an immune response. A nucleic acid which modulates an immune response is one which produces any form of immune stimulation, including, but not limited to, induction of cytokines, B-cell activation, T-cell activation, monocyte activation. Immunostimulatory nucleic acids include, but are not limited to, CpG nucleic acids, methylated CpG nucleic acids, T-rich nucleic acids, poly-G nucleic acids, and nucleic acids having phosphate modified backbones, such as phosphorothioate backbones.
A “CpG nucleic acid” or a “CpG immunostimulatory nucleic acid” as used herein is a nucleic acid containing at least one unmethylated CpG dinucleotide (cytosine-guanine dinucleotide sequence, i.e., “CpG DNA” or DNA containing a 5′ cytosine followed by 3′ guanosine and linked by a phosphate bond) and activates a component of the immune system. The entire CpG nucleic acid can be unmethylated or portions may be unmethylated but at least the C of the 5′ CG 3′ must be unmethylated.
In one embodiment the invention provides a CpG nucleic acid represented by at least the formula:
5′ N1X1CGX2N2 3′
wherein X1 and X2 are nucleotides and N is any nucleotide and N1 and N2 are nucleic acid sequences composed of from about 0-25 N's each. In some embodiments X1 is adenine, guanine, or thymine and X2 is cytosine, adenine, or thymine. In other embodiments X1 is cytosine and/or X2 is guanine.
In other embodiments the CpG nucleic acid is represented by at least the formula:
5′ N1X1X2CGX3X4N2 3′
wherein X1, X2, X3, and X4 are nucleotides. In some embodiments, X1X2 are nucleotides selected from the group consisting of: GpT, GpG, GpA, ApA, ApT, ApG, CpT, CpA, CpG, TpA, TpT, and TpG; and X3X4 are nucleotides selected from the group consisting of: TpT, CpT, ApT, TpG, ApG, CpG, TpC, ApC, CpC, TpA, ApA, and CpA; N is any nucleotide and N1 and N2 are nucleic acid sequences composed of from about 0-25 N's each. In some embodiments, X1X2 are GpA or GpT and X3X4 are TpT. In other embodiments X1 or X2 or both are purines and X3 or X4 or both are pyrimidines or X1X2 are GpA and X3 or X4 or both are pyrimidines.
In some embodiments N1 and N2 of the nucleic acid do not contain a CCGG or CGCG quadmer or more than one CCG or CGG trimer. The effect of a CCGG or CGCG quadmer or more than one CCG or CGG trimer depends in part on the status of the nucleic acid backbone. For instance, if the nucleic acid has a phosphodiester backbone or a chimeric backbone the inclusion of these sequences in the nucleic acid will only have minimal if any affect on the biological activity of the nucleic acid. If the backbone is completely phosphorothioate or significantly phosphorothioate then the inclusion of these sequences may have more influence on the biological activity or the kinetics of the biological activity, but compounds containing these sequences are still useful. In another embodiment the CpG nucleic acid has the sequence 5′ TCN1TX1X2CGX3X4 3′ (SEQ ID NO:850).
A “T-rich nucleic acid” or “T-rich immunostimulatory nucleic acid” is a nucleic acid which includes at least one poly-T sequence and/or which has a nucleotide composition of greater than 25% T nucleotide residues and which activates a component of the immune system. A nucleic acid having a poly-T sequence includes at least four Ts in a row, such as 5′ TTTT 3′. Preferably the T-rich nucleic acid includes more than one poly-T sequence. In preferred embodiments the T-rich nucleic acid may have 2, 3, 4, etc., poly-T sequences, such as oligonucleotide #2006 (5′ TCGTCGTTTTGTCGTTTTGTCGTT 3′, SEQ ID NO: 729). One of the most highly immunostimulatory T-rich oligonucleotides discovered according to the invention is a nucleic acid composed entirely of T nucleotide residues, e.g., oligonucleotide #2183 (5′ TTTTTTTTTTTTTTTTTTTTTTTT 3′, SEQ ID NO: 841). Other T-rich nucleic acids have a nucleotide composition of greater than 25% T nucleotide residues, but do not necessarily include a poly-T sequence. In these T-rich nucleic acids the T nucleotide resides may be separated from one another by other types of nucleotide residues, i.e., G, C, and A. In some embodiments the T-rich nucleic acids have a nucleotide composition of greater than 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 99%, T nucleotide residues and every integer % in between. Preferably the T-rich nucleic acids have at least one poly-T sequence and a nucleotide composition of greater than 25% T nucleotide residues.
In one embodiment the T-rich nucleic acid is represented by at least the formula:
5′ X1X2TTTTX3X4 3′
wherein X1, X2, X3, and X4 are nucleotides. In one embodiment X1X2 is TT and/or X3X4 is TT. In another embodiment X1X2 are any one of the following nucleotides TA, TG, TC, AT, AA, AG, AC, CT, CC, CA, CG, GT, GG, GA, and GC; and X3X4 are any one of the following nucleotides TA, TG, TC, AT, AA, AG, AC, CT, CC, CA, CG, GT, GG, GA, and GC.
In some embodiments it is preferred that the T-rich nucleic acid does not contain poly-C (CCCC), poly-A (AAAA), poly-G (GGGG), CpG motifs, or multiple GGs. In other embodiments the T-rich nucleic acid includes these motifs. Thus in some embodiments of the invention the T-rich nucleic acids include CpG dinucleotides and in other embodiments the T-rich nucleic acids are free of CpG dinucleotides. The CpG dinucleotides may be methylated or unmethylated.
Poly-G containing nucleic acids are also immunostimulatory. A variety of references, including Pisetsky D S et al., Mol Biol Rep 18:217-21 (1993); Krieger M et al., Annu Rev Biochem 63:601-37 (1994); Macaya R F et al., Proc Natl Acad Sci USA 90:3745-9 (1993); Wyatt J R et al., Proc Natl Acad Sci USA 91:1356-60 (1994); Rando and Hogan, 1998, In: Applied Antisense Oligonucleotide Technology, eds. Krieg A M and Stein C, pp. 335-352; and Kimura Y et al., J Biochem (Tokyo) 116:991-4 (1994) also describe the immunostimulatory properties of poly-G nucleic acids.
Poly G nucleic acids preferably are nucleic acids having the following formulas:
5′ X1X2GGGX3X4 3′
wherein X1, X2, X3, and X4 are nucleotides. In preferred embodiments at least one of X3 and X4 are a G. In other embodiments both of X3 and X4 are a G. In yet other embodiments the preferred formula is 5′ GGGNGGG 3′, or 5′ GGGNGGGNGGG 3′ (SEQ ID NO:849) wherein N represents between 0 and 20 nucleotides. In other embodiments the poly-G nucleic acid is free of unmethylated CG dinucleotides, such as, for example, the nucleic acids listed in Table 4 below as SEQ ID NOs: 12-14, 23, 56, 100, 155, 163, 182, 227, 237, 246, 400, 407, 429, 430, 432, 435, 438, 439, 446, 450, 451, 480, 487, 493, 522, 661, 662, 671-673, 807, 808, 821, 823, and 834. In other embodiments the poly-G nucleic acid includes at least one unmethylated CG dinucleotide, such as, for example, the nucleic acids listed in Table 4 below as SEQ ID NOs: 6, 7, 22, 26, 28-30, 87, 115, 141, 177, 191, 209, 254, 258, 267, 303, 317, 329, 335, 344, 345, 395, 414, 417, 418, 423-426, 428, 431, 433, 434, 436, 437, 440, 442-445, 447-449, 458, 460, 463, 467-469, 474, 515, 516, 594, 638-640, 663, 664, 727, 752, 776, 795, 799, 817, 818, 831, and 832.
Nucleic acids having modified backbones, such as phosphorothioate backbones, also fall within the class of immunostimulatory nucleic acids. U.S. Pat. Nos. 5,723,335 and 5,663,153 issued to Hutcherson, et al. and related PCT publication WO95/26204 describe immune stimulation using phosphorothioate oligonucleotide analogues. These patents describe the ability of the phosphorothioate backbone to stimulate an immune response in a non-sequence specific manner.
The immunostimulatory nucleic acids may be any size but in some embodiments are in the range of between 6 and 100 or in some embodiments between 8 and 35 nucleotides in size. Immunostimulatory nucleic acids can be produced on a large scale in plasmids. These may be administered in plasmid form or alternatively they can be degraded into oligonucleotides.
“Palindromic sequence” shall mean an inverted repeat (i.e., a sequence such as ABCDEE′D′C′BA′ in which A and A′ are bases capable of forming the usual Watson-Crick base pairs and which includes at least 6 nucleotides in the palindrome. In vivo, such sequences may form double-stranded structures. In one embodiment the nucleic acid contains a palindromic sequence. In some embodiments when the nucleic acid is a CpG nucleic acid, a palindromic sequence used in this context refers to a palindrome in which the CpG is part of the palindrome, and optionally is the center of the palindrome. In another embodiment the nucleic acid is free of a palindrome. A nucleic acid that is free of a palindrome does not have any regions of 6 nucleotides or greater in length which are palindromic. A nucleic acid that is free of a palindrome can include a region of less than 6 nucleotides which are palindromic.
A “stabilized nucleic acid molecule” shall mean a nucleic acid molecule that is relatively resistant to in vivo degradation (e.g., via an exonuclease or endonuclease). Stabilization can be a function of length or secondary structure. Nucleic acids that are tens to hundreds of kbs long are relatively resistant to in vivo degradation. For shorter nucleic acids, secondary structure can stabilize and increase their effect. For example, if the 3′ end of an oligonucleotide has self-complementarity to an upstream region, so that it can fold back and form a sort of stem loop structure, then the oligonucleotide becomes stabilized and therefore exhibits more activity.
Some stabilized oligonucleotides of the instant invention have a modified backbone. It has been demonstrated that modification of the oligonucleotide backbone provides enhanced activity of the nucleic acids when administered in vivo. Nucleic acids, including at least two phosphorothioate linkages at the 5′ end of the oligonucleotide and multiple phosphorothioate linkages at the 3′ end, preferably 5, may provide maximal activity and protect the oligonucleotide from degradation by intracellular exo- and endo-nucleases. Other modified oligonucleotides include phosphodiester modified oligonucleotide, combinations of phosphodiester and phosphorothioate oligonucleotide, methylphosphonate, methylphosphorothioate, phosphorodithioate, and combinations thereof. Each of these combinations and their particular effects on immune cells is discussed in more detail in PCT Published Patent Application WO98/18810 claiming priority to U.S. Ser. No. 08/738,652 (now issued as U.S. Pat. No. 6,207,646 B1) and Ser. No. 08/960,774 (now issued as U.S. Pat. No. 6,239,116 B1), filed on Oct. 30, 1996 and Oct. 30, 1997 respectively, the entire contents of which is hereby incorporated by reference. It is believed that these modified oligonucleotides may show more stimulatory activity due to enhanced nuclease resistance, increased cellular uptake, increased protein binding, and/or altered intracellular localization. Both phosphorothioate and phosphodiester nucleic acids are active in immune cells.
Other stabilized oligonucleotides include: nonionic DNA analogs, such as alkyl- and aryl-phosphates (in which the charged phosphonate oxygen is replaced by an alkyl or aryl group), phosphodiester and alkylphosphotriesters, in which the charged oxygen moiety is alkylated. Oligonucleotides which contain diol, such as tetraethyleneglycol or hexaethyleneglycol, at either or both termini have also been shown to be substantially resistant to nuclease degradation.
For use in vivo, nucleic acids are preferably relatively resistant to degradation (e.g., via endonucleases and exonucleases). Secondary structures, such as stem loops, can stabilize nucleic acids against degradation. Alternatively, nucleic acid stabilization can be accomplished via phosphate backbone modifications. One type of stabilized nucleic acid has at least a partial phosphorothioate modified backbone. Phosphorothioates may be synthesized using automated techniques employing either phosphoramidate or H-phosphonate chemistries. Aryl- and alkyl-phosphonates can be made, e.g., as described in U.S. Pat. No. 4,469,863; and alkylphosphotriesters (in which the charged oxygen moiety is alkylated as described in U.S. Pat. No. 5,023,243 and European Patent No. 092,574) can be prepared by automated solid phase synthesis using commercially available reagents. Methods for making other DNA backbone modifications and substitutions have been described. Uhlmann E et al., Chem Rev 90:544-84 (1990); Goodchild J, Bioconjugate Chem 1:165-87 (1990).
The immunostimulatory nucleic acids having backbone modifications useful according to the invention in some embodiments are S- or R-chiral immunostimulatory nucleic acids. An “S chiral immunostimulatory nucleic acid” as used herein is an immunostimulatory nucleic acid wherein at least two nucleotides have a backbone modification forming a chiral center and wherein a plurality of the chiral centers have S chirality. An “R chiral immunostimulatory nucleic acid” as used herein is an immunostimulatory nucleic acid wherein at least two nucleotides have a backbone modification forming a chiral center and wherein a plurality of the chiral centers have R chirality. The backbone modification may be any type of modification that forms a chiral center. The modifications include but are not limited to phosphorothioate, methylphosphonate, methylphosphorothioate, phosphorodithioate, 2′-OMe and combinations thereof. In other embodiments they are non-chiral. A non-chiral nucleic acid is any nucleic acid which does not have at least two chiral centers.
The chiral immunostimulatory nucleic acids must have at least two nucleotides within the nucleic acid that have a backbone modification. All or less than all of the nucleotides in the nucleic acid, however, may have a modified backbone. Of the nucleotides having a modified backbone (referred to as chiral centers), a plurality have a single chirality, S or R. A “plurality” as used herein refers to an amount greater than or equal to 75%. Thus, less than all of the chiral centers may have S or R chirality as long as a plurality of the chiral centers have S or R chirality. In some embodiments at least 75%, 80%, 85%, 90%, 95%, or 100% of the chiral centers have S or R chirality. In other embodiments at least 75%, 80%, 85%, 90%, 95%, or 100% of the nucleotides have backbone modifications.
The S- and R- chiral immunostimulatory nucleic acids may be prepared by any method known in the art for producing chirally pure oligonucleotides. Stec et al. teach methods for producing stereopure phosphorothioate oligodeoxynucleotides using an oxathiaphospholane. Stec W J et al., J Am Chem Soc 117:12019 (1995). Other methods for making chirally pure oligonucleotides have been described by companies such as ISIS Pharmaceuticals. U.S. patents which disclose methods for generating stereopure oligonucleotides include U.S. Pat. Nos. 5,212,295, 5,359,052, 5,506,212, 5,512,668, 5,521,302, 5,599,797, 5,837,856, 5,856,465, and 5,883,237, each of which is hereby incorporated by reference in its entirety.
Other sources of nucleic acids useful according to the invention include standard viral and bacterial vectors, many of which are commercially available. In its broadest sense, a “vector” is any nucleic acid material which is ordinarily used to deliver and facilitate the transfer of nucleic acids to cells. The vector as used herein may be an empty vector or a vector carrying a gene which can be expressed. In the case when the vector is carrying a gene the vector generally transports the gene to the target cells with reduced degradation relative to the extent of degradation that would result in the absence of the vector. In this case the vector optionally includes gene expression sequences to enhance expression of the gene in target cells such as immune cells, but it is not required that the gene be expressed in the cell.
In general, vectors include, but are not limited to, plasmids, phagemids, viruses, other vehicles derived from viral or bacterial sources. Viral vectors are one type of vector and include, but are not limited to, nucleic acid sequences from the following viruses: retrovirus, such as Moloney murine leukemia virus, Harvey murine sarcoma virus, murine mammary tumor virus, and Rous sarcoma virus; adenovirus, adeno-associated virus; SV40-type viruses; polyoma viruses; Epstein-Barr viruses; papilloma viruses; herpes virus; vaccinia virus; polio virus; and RNA virus such as a retrovirus. One can readily employ other vectors not named but known to the art. Some viral vectors are based on non-cytopathic eukaryotic viruses in which non-essential genes have been replaced with a nucleic acid to be delivered. Non-cytopathic viruses include retroviruses, the life cycle of which involves reverse transcription of genomic viral RNA into DNA.
Standard protocols for producing empty vectors or vectors carrying genes (including the steps of incorporation of exogenous genetic material into a plasmid, transfection of a packaging cell lined with plasmid, production of recombinant retroviruses by the packaging cell line, collection of viral particles from tissue culture media, and/or infection of the target cells with viral particles) are provided in Kriegler M, “Gene Transfer and Expression, A Laboratory Manual,” W.H. Freeman Co., New York (1990) and Murry E J, Ed., “Methods in Molecular Biology,” vol. 7, Humana Press, Inc., Cliffton, N.J. (1991).
Other vectors include plasmid vectors. Plasmid vectors have been extensively described in the art and are well-known to those of skill in the art. See e.g., Sambrook et al., “Molecular Cloning: A Laboratory Manual,” Second Edition, Cold Spring Harbor Laboratory Press, 1989. In the last few years, plasmid vectors have been found to be particularly advantageous for delivering genes to cells in vivo because of their inability to replicate within and integrate into a host genome. Some plasmids, however, having a promoter compatible with the host cell, can express a peptide from a gene operatively encoded within the plasmid. Some commonly used plasmids include pBR322, pUC18, pUC19, pcDNA3.1, pSV40, and pBlueScript. Other plasmids are well-known to those of ordinary skill in the art. Additionally, plasmids may be custom designed using restriction enzymes and ligation reactions to remove and add specific fragments of DNA.
It has recently been discovered that plasmids (empty or gene-carrying) can be delivered to the immune system using bacteria. Modified forms of bacteria such as Salmonella can be transfected with the plasmid and used as delivery vehicles. The bacterial delivery vehicles can be administered to a host subject orally or by other administration means. The bacteria deliver the plasmid to immune cells, e.g., dendritic cells, probably by passing through the gut barrier. High levels of immune protection have been established using this methodology. Such methods of delivery are useful for the aspects of the invention utilizing systemic delivery of nucleic acid.
As used herein, administration of an immunostimulatory nucleic acid is intended to embrace the administration of one or more immunostimulatory nucleic acids which may or may not differ in terms of their profile, sequence, backbone modifications and biological effect. As an example, CpG nucleic acids and T-rich nucleic acids may be administered to a single subject along with an antibody and optionally a cancer therapy. In another example, a plurality of CpG nucleic acids which differ in nucleotide sequence may also be administered to a subject.
Some of the nucleic acids useful according to the invention and described herein are presented in Table 4 below.
In Table 4 with respect to sequences the letter symbols aside from a, c, t, and g are defined as follows: “b” indicates a biotin moiety attached to that end of the oligonucleotide when it is single and is listed on the 5′ or 3′ end of oligonucleotide; “d” represents a, g, or t; “f” represents fluorescein isothiocyanate (FITC) moiety attached to the 5′ or 3′ end of oligonucleotide; “h” represents a, c, or t; “i” represents inosine; “n” represents any nucleotide; “z” represents 5-methylcytosine.
Also in Table 4 with respect to backbones the notations are defined as follows: “o” represents phosphodiester; “os” represents phosphorothioate and phosphodiester chimeric with phosphodiester on 5′ end; “os2” represents phosphorodithioate and phosphodiester chimeric with phosphodiester on 5′ end; “p-ethoxy” represents p-ethoxy backbone (see, e.g., U.S. Pat. No. 6,015,886); “po” represents phospholdiester; “s” represents phosphorothioate; “s2” represents phosphorodithioate; “s2o” represents phosphorodithioate and phosphodiester chimeric with phosphodiester on 3′ end; “so” represents phosphorothioate and phosphodiester chimeric with phosphodiester on 3′ end; and “sos” represents chimeric phosphorothioate/phosphodiester with phosphorothioate at the 5′ and 3′ ends.
The nucleic acids are delivered in effective amounts. The term “effective amount” of a immunostimulatory nucleic acid refers to the amount necessary or sufficient to realize a desired biologic effect. For example, an effective amount of an immunostimulatory nucleic acid could be that amount necessary to cause activation of the immune system. According to some aspects of the invention, an effective amount is that amount of an immunostimulatory nucleic acid and that amount of an antibody, which when combined or co-administered, results in the prevention or the treatment of the cancer. In some embodiments a synergistic effect is observed. A synergistic amount is that amount which produces an anti-cancer response that is greater than the sum of the individual effects of either the immunostimulatory nucleic acid and the antibody alone. For example, a synergistic combination of an immunostimulatory nucleic acid and an antibody provides a biological effect which is greater than the combined biological effect which could have been achieved using each of the components (i.e., the nucleic acid and the antibody) separately. The biological effect may be the amelioration and or absolute elimination of symptoms resulting from the cancer. In another embodiment, the biological effect is the complete abrogation of the cancer, as evidenced for example, by the absence of a tumor or a biopsy or blood smear which is free of cancer cells.
The effective amount of immunostimulatory nucleic acid necessary to treat a cancer or in the reduction of the risk of developing a cancer may vary depending upon the sequence of the immunostimulatory nucleic acid, the backbone constituents of the nucleic acid, and the mode of delivery of the nucleic acid. The effective amount for any particular application can also vary depending on such factors as the cancer being treated, the particular immunostimulatory nucleic acid being administered (e.g., the nature, number or location of immunostimulatory motifs in the nucleic acid), the size of the subject, or the severity of the disease or condition. One of ordinary skill in the art can empirically determine the effective amount of a particular immunostimulatory nucleic acid and antibody combination without necessitating undue experimentation. Combined with the teachings provided herein, by choosing among the various active compounds and weighing factors such as potency, relative bioavailability, patient body weight, severity of adverse side-effects and preferred mode of administration, an effective prophylactic or therapeutic treatment regimen can be planned which does not cause substantial toxicity and yet is entirely effective to treat the particular subject.
Therapeutic doses of cancer therapies are well known in the field of medicine for the treatment of cancer. These dosages have been extensively described in references such as Remington's Pharmaceutical Sciences, 18th ed., 1990; as well as many other medical references relied upon by the medical profession as guidance for the treatment of cancer. Therapeutic dosages of immunostimulatory nucleic acids have also been described in the art and methods for identifying therapeutic dosages in subjects are described in more detail herein.
Subject doses of the compounds described herein typically range from about 0.1 μg to mg per administration, which depending on the application could be given daily, weekly, or monthly and any other amount of time therebetween. More typically mucosal or local doses range from about 10 μg to 5 mg per administration, and most typically from about 100 μg to 1 mg, with 2-4 administrations being spaced hours, days or weeks apart. More typically, immune stimulant doses range from 1 μg to 10 mg per administration, and most typically 10 μg to 1 mg, with daily or weekly administrations. Subject doses of the compounds described herein for parenteral delivery, wherein the compounds are delivered without another therapeutic agent are typically 5 to 10,000 times higher than the effective mucosal dose or for immune stimulant applications, and more typically 10 to 1,000 times higher, and most typically 20 to 100 times higher. More typically parenteral doses for these purposes range from about 10 μg to 5 mg per administration, and most typically from about 100 μg to 1 mg, with 2-4 administrations being spaced hours, days or weeks apart. In some embodiments, however, parenteral doses for these purposes may be used in a range of 5 to 10,000 times higher than the typical doses described above.
For any compound described herein the therapeutically effective amount can be initially determined from animal models, e.g., the animal models described herein. A therapeutically effective dose can also be determined from human data for CpG nucleic acids which have been tested in humans (human clinical trials have been initiated and the results publicly disseminated) and for compounds which are known to exhibit similar pharmacological activities. Higher doses may be required for parenteral administration, as described above. The applied dose can be adjusted based on the relative bioavailability and potency of the administered compound. Adjusting the dose to achieve maximal efficacy based on the methods described above and other methods as are well-known in the art is well within the capabilities of the ordinarily skilled artisan.
The formulations of the invention are administered in pharmaceutically acceptable solutions, which may routinely contain pharmaceutically acceptable concentrations of salt, buffering agents, preservatives, compatible carriers, adjuvants, and optionally other therapeutic ingredients.
For use in therapy, an effective amount of the nucleic acid can be administered to a subject by any mode that delivers the nucleic acid to a subject. “Administering” the pharmaceutical composition of the present invention may be accomplished by any means known to the skilled artisan. Some routes of administration include but are not limited to oral, intranasal, intratracheal, inhalation, ocular, vaginal, rectal, parenteral (e.g., intramuscular, intradermal, intravenous or subcutaneous injection) and direct injection.
For oral administration, the compounds (i.e., nucleic acids and antibodies) can be delivered alone without any pharmaceutical carriers or formulated readily by combining the active compound(s) with pharmaceutically acceptable carriers well known in the art. The term “pharmaceutically-acceptable carrier” means one or more compatible solid or liquid filler, dilutants or encapsulating substances which are suitable for administration to a human or other vertebrate animal. The term “carrier” denotes an organic or inorganic ingredient, natural or synthetic, with which the active ingredient is combined to facilitate the application. The components of the pharmaceutical compositions also are capable of being commingled with the compounds of the present invention, and with each other, in a manner such that there is no interaction which would substantially impair the desired pharmaceutical efficiency.
Such carriers enable the compounds of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a subject to be treated. Pharmaceutical preparations for oral use can be obtained as solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. Optionally the oral formulations may also be formulated in saline or buffers for neutralizing internal acid conditions.
Dragee cores may be provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings for identification or to characterize different combinations of active compound doses.
Pharmaceutical preparations which can be used orally include push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. The push-fit capsules can contain the active ingredients in admixture with filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In soft capsules, the active compounds may be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. Microspheres formulated for oral administration may also be used. Such microspheres have been well defined in the art. All formulations for oral administration should be in dosages suitable for such administration.
For buccal administration, the compositions may take the form of tablets or lozenges formulated in conventional manner.
For administration by inhalation, the compounds for use according to the present invention may be conveniently delivered in the form of an aerosol spray, from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. Capsules and cartridges of e.g., gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.
The compounds, when it is desirable to deliver them systemically, may be formulated for parenteral administration by injection, e.g., by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents.
Pharmaceutical formulations for parenteral administration include aqueous solutions of the active compounds in water-soluble form. Additionally, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.
Alternatively, the active compounds may be in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.
The compounds may also be formulated in rectal or vaginal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
In addition to the formulations described previously, the compounds may also be formulated as a depot preparation. Such long acting formulations may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
The pharmaceutical compositions also may comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include but are not limited to calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.
Suitable liquid or solid pharmaceutical preparation forms are, for example, aqueous or saline solutions for inhalation, microencapsulated, encochleated, coated onto microscopic gold particles, contained in liposomes, nebulized, aerosols, pellets for implantation into the skin, or dried onto a sharp object to be scratched into the skin. The pharmaceutical compositions may also include granules, powders, tablets, coated tablets, (micro)capsules, suppositories, syrups, emulsions, suspensions, creams, drops or preparations with protracted release of active compounds, in whose preparation excipients and additives and/or auxiliaries such as disintegrants, binders, coating agents, swelling agents, lubricants, flavorings, sweeteners or solubilizers are customarily used as described above. The pharmaceutical compositions are suitable for use in a variety of drug delivery systems. For a brief review of present methods for drug delivery, see Langer R, Science 249:1527-33 (1990), which is incorporated herein by reference.
The nucleic acids and/or antibodies may be administered per se (neat) or in the form of a pharmaceutically acceptable salt. When used in medicine the salts should be pharmaceutically acceptable, but non-pharmaceutically acceptable salts may conveniently be used to prepare pharmaceutically acceptable salts thereof. Such salts include, but are not limited to, those prepared from the following acids: hydrochloric, hydrobromic, sulphuric, nitric, phosphoric, maleic, acetic, salicylic, p-toluene sulphonic, tartaric, citric, methane sulphonic, formic, malonic, succinic, naphthalene-2-sulphonic, and benzene sulphonic. Also, such salts can be prepared as alkaline metal or alkaline earth salts, such as sodium, potassium or calcium salts of the carboxylic acid group.
Suitable buffering agents include: acetic acid and a salt (1-2% w/v); citric acid and a salt (1-3% w/v); boric acid and a salt (0.5-2.5% w/v); and phosphoric acid and a salt (0.8-2% w/v). Suitable preservatives include benzalkonium chloride (0.003-0.03% w/v); chlorobutanol (0.3-0.9% w/v); parabens (0.01-0.25% w/v) and thimerosal (0.004-0.02% w/v).
The nucleic acids or other therapeutics useful in the invention may be delivered in mixtures with additional antibodies. A mixture may consist of several antibodies in addition to the nucleic acid.
A variety of administration routes are available. The particular mode selected will depend, of course, upon the particular nucleic acids or antibodies selected, the particular condition being treated and the dosage required for therapeutic efficacy. The methods of this invention, generally speaking, may be practiced using any mode of administration that is medically acceptable, meaning any mode that produces effective levels of an immune response without causing clinically unacceptable adverse effects. Preferred modes of administration are discussed above.
The compositions may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing the compounds into association with a carrier which constitutes one or more accessory ingredients. In general, the compositions are prepared by uniformly and intimately bringing the compounds into association with a liquid carrier, a finely divided solid carrier, or both, and then, if necessary, shaping the product. Liquid dose units are vials or ampoules. Solid dose units are tablets, capsules and suppositories.
Other delivery systems can include time-release, delayed release or sustained release delivery systems. Such systems can avoid repeated administrations of the compounds, increasing convenience to the subject and the physician. Many types of release delivery systems are available and known to those of ordinary skill in the art. They include polymer base systems such as poly(lactide-glycolide), copolyoxalates, polycaprolactones, polyesteramides, polyorthoesters, polyhydroxybutyric acid, and polyanhydrides. Microcapsules of the foregoing polymers containing drugs are described in, for example, U.S. Pat. No. 5,075,109. Delivery systems also include non-polymer systems that are: lipids including sterols such as cholesterol, cholesterol esters and fatty acids or neutral fats such as mono-, di-, and tri-glycerides; hydrogel release systems; sylastic systems; peptide based systems; wax coatings; compressed tablets using conventional binders and excipients; partially fused implants; and the like. Specific examples include, but are not limited to: (a) erosional systems in which an agent of the invention is contained in a form within a matrix =such as those described in U.S. Pat. Nos. 4,452,775, 4,675,189, and 5,736,152, and (b) diffusional systems in which an active component permeates at a controlled rate from a polymer such as described in U.S. Pat. Nos. 3,854,480, 5,133,974 and 5,407,686. In addition, pump-based hardware delivery systems can be used, some of which are adapted for implantation.
The nucleic acid may be directly administered to the subject or may be administered in conjunction with a pharmaceutically acceptable carrier or a delivery vehicle. The nucleic acid and optionally other therapeutic agents may be administered alone (e.g., in saline or buffer) or using any delivery vehicles known in the art. One type of delivery vehicle is referred to herein as a nucleic acid delivery complex. A “nucleic acid delivery complex” shall mean a nucleic acid molecule associated with (e.g., ionically or covalently bound to; or encapsulated within) a targeting means (e.g., a molecule that results in higher affinity binding to target cell (e.g., dendritic cell surfaces and/or increased cellular uptake by target cells). Examples of nucleic acid delivery complexes include nucleic acids associated with: a sterol (e.g., cholesterol), a lipid (e.g., a cationic lipid, virosome or liposome), or a target cell specific binding agent (e.g., a ligand recognized by target cell specific receptor). Preferred complexes may be sufficiently stable in vivo to reduce significant uncoupling prior to internalization by the target cell. However, the complex may be cleavable under appropriate conditions within the cell so that the nucleic acid may be released in a functional form.
The nucleic acids may be delivered by non-invasive methods as described above. Non-invasive delivery of compounds is desirable for treatment of children, elderly, animals, and even adults and also to avoid the risk of needle-stick injury. Delivery vehicles for delivering compounds to mucosal surfaces have been described and include but are not limited to: Cochleates (Gould-Fogerite et al., 1994, 1996); Emulsomes (Vancott et al., 1998, Lowell et al., 1997); ISCOMs (Mowat et al., 1993, Carlsson et al., 1991, Hu et al., 1998, Morein et al., 1999); Liposomes (Childers et al., 1999, Michalek et al., 1989, 1992, de Haan 1995a, 1995b); Live bacterial vectors (e.g., Salmonella, Escherichia coli, Bacillus Calmette -Guérin, Shigella, Lactobacillus) (Hone et al., 1996, Pouwels et al., 1998, Chatfield et al., 1993, Stover et al., 1991, Nugent et al., 1998); Live viral vectors (e.g., Vaccinia, adenovirus, Herpes Simplex) (Gallichan et al., 1993, 1995, Moss et al., 1996, Nugent et al., 1998, Flexner et al., 1988, Morrow et al., 1999); Microspheres (Gupta et al., 1998, Jones et al., 1996, Maloy et al., 1994, Moore et al., 1995, O'Hagan et al., 1994, Eldridge et al., 1989); nucleic acid vaccines (Fynan et al., 1993, Kuklin et al., 1997, Sasaki et al., 1998, Okada et al., 1997, Ishii et al., 1997); Polymers (e.g., carboxymethylcellulose, chitosan) (Hamajima et al., 1998, Jabbal-Gill et al., 1998); Polymer rings (Wyatt et al., 1998); Proteosomes (Vancott et al., 1998, Lowell et al., 1988, 1996, 1997); Sodium Fluoride (Hashi et al., 1998); Transgenic plants (Tacket et al., 1998, Mason et al., 1998, Haq et al., 1995); Virosomes (Gluck et al., 1992, Mengiardi et al., 1995, Cryz et al., 1998); Virus-like particles (Jiang et al., 1999, Leibl et al., 1998).
The invention also includes kits. The kits generally include a package with a plurality of containers housing active agents and instructions for carrying out the methods of the invention. The active agents include but are not limited to immunostimulatory nucleic acids, antibodies such as antibodies specific for a cell surface antigen, and anti-cancer therapies.
The following examples are provided to illustrate specific instances of the practice of the present invention and are not to be construed as limiting the present invention to these examples. As will be apparent to one of ordinary skill in the art, the present invention will find application in a variety of compositions and methods.
Introduction:
Extensive cross-talk exists between healthy B cells and T cells. There is evidence that malignant B cells also communicate with T cells. However, malignant cells appear to differ from their normal counterparts in a number of ways, including a decreased tendency to undergo apoptosis in response to normal signals, altered expression of a variety of surface markers, and altered ability to function as effective antigen presenting cells. Lagneaux L et al., Blood 91:2387-96 (1998); Gordon J et al., Leukemia 7 Suppl 2:S5-9 (1993); Gordon J et al., Adv Exp Med Biol 406:139-44 (1996); Chaperot L et al., Exp Hematol 27:479-88 (1999). Immunotherapeutic approaches have recently become part of our therapy of some subtypes of B-cell malignancy. Improved immunotherapy of B-cell malignancy will need to be designed based on the growing understanding of the cellular immunology of this disease. Schultze J L et al., J Mol Med 77:322-32 (1999).
A variety of cellular receptors and antigens are involved in growth, differentiation and apoptosis of B-cell malignancies. Antibodies or ligands against a variety of antigens can cause growth inhibition or even apoptosis including CD20, surface immunoglobulins, MHC II, CD80, CD86 and CD40. Maloney D G, Semin Oncol 26:74-8 (1999); McLaughlin P et al., Semin Oncol 26:79-87 (1999); Shan D et al., Blood 91:1644-52 (1998); Coiffier B et al., Blood 92:1927-32 (1998); McLaughlin P et al., Oncology (Huntingt) 12:1763-70, 1775-7 (1998); Tutt A L et al., J Immunol 161:3176-85 (1998); Funakoshi S et al., Blood 83:2787-94 (1994); Mayumi M et al., J Allergy Clin Immunol 98:S238-47 (1996); Higaki Y et al., Immunol Cell Biol 72:205-14 (1994); Elsasser D et al., Blood 87:3803-12 (1996); Link B K et al., Blood 81:3343-9 (1993); Link B K et al., Int J Cancer 77:251-6 (1998). The relative contribution of antibody dependent cellular cytotoxicity (ADCC) versus trans-membrane signaling mediated by anti-B cell antibodies remains unclear. In the present study, we examined how CpG-DNA impacts on the phenotype, apoptosis and proliferation of different types of B-cell malignancy including follicular B-cell lymphoma and B-CLL.
Materials and Methods:
Cell culture: Fresh lymph node samples were obtained from the operating suite and were minced with a scalpel under aseptic conditions. The resulting suspension was passed sequentially through a sterilized sieve-tissue grinder containing a nylon mesh screen, a 150 μm mesh screen and a 60 μm mesh screen. Alternatively, mononuclear cells were obtained from peripheral blood or pleural fluid as described. Hartmann G et al., J Pharmacol Exp Ther 285:920-8 (1998). Red blood cells were removed by resuspending the cells in 5 ml ACK lysis buffer according to standard procedures. Cells were frozen slowly and stored in liquid nitrogen. For analysis, cells were thawed and resuspended in 10% (v/v) heat-inactivated (56° C., 1 h) FCS (HyClone, Logan, U T), 1.5 mM L-glutamine (all from Gibco BRL, Grand Island, N.Y.) and incubated on a 96-well-plate (1×106 cells/ml) in the presence of ODN as indicated below. Not all assays were performed for all samples because of the limited number of cells available for some samples.
Oligonucleotides: Nuclease-resistant phosphorothioate-modified oligodeoxynucleotide (ODN) were purchased from Operon Technologies (Alameda, Calif.) and Hybridon Specialty Products (Milford, Mass.). Sequences were as follows: CpG ODN 2006: 5′-TCGTCGTTTTGTCGTTTTGTCGTT-3′ (SEQ ID NO: 729), and control ODN 2017: 5′-CCCCCCCCCCCCCCCCCCCC-3′ (SEQ ID NO: 168). ODN was diluted in TE (10 mM Tris-HCl, 1 mM EDTA, pH 8) using pyrogen-free reagents. ODN was added at a final concentration of 5 μg/ml.
Flow cytometry: Cells were washed and resuspended in ice-cold PBS or Annexin V binding buffer (10 mM HEPES/NaOH, 140 mM NaCl, 2.5 mM CaCl2, pH 7.4). Murine or human serum was added (final concentration 1%) to block non-specific binding of antibodies. Surface antigen staining was performed as described. Hartmann G et al., J Pharmacol Exp Ther 285:920-8 (1998). In brief, 1×105 cells per sample were stained with CyChrome-labeled anti-CD19 and FITC- or PE-labeled antibodies as indicated for 20 min on ice. They were then washed and analyzed by flow cytometry. Monoclonal antibodies to CD40 (5C3), CD69 (FN50), CD80 (L307.4), CD86 (IT2.2), CD54 (HA58), MHC I (G46-2.6) and MHC II (TU39) as well as isotype controls (IgG1, MOPC-21 and IgG2a, G155-178) were purchased from PharMingen, San Diego, Calif. FITC-labeled polyclonal anti-human Ig was purchased from Southern Biotech, Birmingham, Ala. 1D10, a monoclonal humanized antibody directed against a variant of HLA-DR was produced in our laboratory as described earlier. Link B K et al., Blood 81:3343-9 (1993). C2B8, a monoclonal humanized anti-CD20 antibody, was purchased from IDEC Pharmaceuticals, San Diego, Calif. 1D10 and C2B8 were labeled with FITC according to standard protocols. The analysis gate was set on viable cells identified according to FSC/SSC characteristics and Annexin V staining (>97% viable cells within analysis gate). Spectral overlap was corrected by appropriate compensation. Flow cytometric data from 1×104 cells per sample were acquired on a FACScan (Beckton Dickinson Immunocytometry Systems, San Jose, Calif.). Data were analyzed using the computer program FlowJo (version 2.5.1, Tree Star, Inc., Stanford, Calif.).
CFSE staining: CFSE 5-(and 6-) carboxyfluorescein diacetate succinimidyl ester, Molecular Probes, USA, is a fluorescein-derived intracellular fluorescent label which is divided equally between daughter cells upon cell division. Staining of cells with CFSE allows both quantification and immunophenotyping of proliferating cells in a mixed cell suspension. Interference between oligonucleotide degradation products and thymidine uptake (standard proliferation assay) is avoided by using this method. The technique has described in detail previously. Lyons A B et al., J Immunol Methods 171:131-7 (1994). Briefly, cells were washed twice in PBS, resuspended in PBS (1×107 cells/ml) containing CFSE at a final concentration of 1 μM, and incubated at 37° C. for 10 minutes. Cells were washed three times with PBS.
TUNEL assay: A two-color DNA strand break labeling assay, based on a modification of the assay described by Li et al. (Li X et al., ExpCell Res 222:28-37 (1996)) was used to assess B-cell proliferation in response to CpG ODN. This assay involved terminal transferase-mediated dUTP nick end labeling (TUNEL) before and after induction of DNA strand breaks in BrdU-labeled cells. Briefly, cells were cultured for 3 days with and without ODN. They were then incubated for 16 hours in 10 μM BrdU and placed onto slides by cytospin. Cells were then in 1% paraformaldehyde in PBS for 15 minutes followed by 20 minutes in 70% ethanol. DNA cleavage indicative of apoptosis cells was detected by labeling the 3′-DNA end of nicked strands with FITC-ddUTP (Boehringer-Mannheim). The use of dideoxy-dUTP prevented further elongation of the 3′-ends in subsequent steps. Slides were then placed face-down on a 2 mm support at both ends on a UV transilluminator and exposed for 5 minutes. The new DNA strand breaks induced by photolysis at sites of BrdU incorporation (i.e., proliferating cells) were detected by a second TUNEL labeling using tetramethylrhodamine-dUTP (TMR-dUTP, Boehringer-Mannheim). Both TUNEL staining steps included incubating slides in 50 μl of TdT mix (34 μl distilled water, 10 μl of 5×TdT buffer, 5 μl of 25 mM cobalt chloride, 12.5 units terminal transferase and 0.5 nmol fluorochrome-conjugated-dUTP) (Boehringer-Mannheim) under a coverslip for one hour at 37° C. in a humidified chamber. The slides were then washed in 5 quick changes of distilled water followed by 3 changes of 2×SSC containing 30% formamide for 5 minutes each at room temperature. After the second TUNEL labeling step, cells were counterstained for CD19, and also stained with Wright solution for blood cell differentiation and mounted in Vectashield media containing DAPI counterstain (Vector Laboratories, Burlingame, Calif.). The morphology and staining of cells were assessed using both visible light and fluorescence microscopy. Apoptotic cells were identified by green fluorescence (FITC label), and proliferating cells by red fluorescence (TMR label). The percentage of apoptotic and proliferating cells was determined by counting at least 200 cells per sample by three observers blinded to whether cells were treated with ODN. Mean and standard error were determined for each sample based on these three readings.
Our prior studies demonstrated that activation of naive human B cells by CpG ODN results in increased cell size (FSC) and granularity (SSC). Hartmann G et al., J Immunol 164:944-53 (2000). We therefore first determined whether such changes also occur in malignant B cells. Primary malignant B cells were obtained from lymph node biopsies, peripheral blood, or pleural fluid of patients with various types of B-cell malignancy. In addition, cells from the lymph node of a patient with benign reactive follicular hyperplasia were studied. Nine samples in total were evaluated (see Table 5). Cells were incubated for 72 hours in media containing CpG ODN 2006 (5 μg/ml) or control ODN 2017. FSC and SSC were examined with gating on CD19+ viable cells (
Expression of CD20, CD40, CD69, CD80, CD86, surface Ig, CD54, MHC I, MHC II, and an HLA-DR variant antigen (moAb 1D10) were examined on viable CD19+ cells after incubation of cells with CpG ODN for 72 hours. Each of these markers was upregulated to varying extents in response to the CpG ODN 2006 compared to the control ODN 2017 (
CD20 was expressed to varying degrees in all samples tested. As is well known, baseline CD20 expression was lower in the B-CLL samples when compared to the B-cell malignancies of other histologies. CpG-ODN 2006 but not the control ODN 2017 increased CD20 expression in both B-CLLs and both marginal zone lymphomas. No or only little upregulation was seen in the other lymphoma samples. Non-malignant CD19+ cells derived from the reactive follicular hyperplasia decreased CD20 expression in response to CpG (
CpG induces a strong proliferative response of primary human B cells. Hartmann G et. al., J Immunol 164:944-53 (2000). Two techniques were used to assess whether CpG ODN is capable of inducing proliferation of B-CLL cells. For select samples, cells were stained with CFSE and incubated for four days. Proliferation of cells is indicated by a loss of CFSE stain with every cell division. In B-CLL, CD5 can be used to identify malignant B cells among CD19+ cells. Proliferation of malignant B cells (CD5+ and CD19+) was lower than proliferation of normal B cells (CD5− and CD19+) (
No consistent pattern was apparent related to determining whether CpG ODN altered the percent of dead cells as determined by morphological criteria (see Table 6).
A TUNEL assay was utilized to assess the effect of CpG ODN on both proliferation and apoptosis. The results are shown in Table 7.
Example 3
CpG ODN when combined with antibody of murine subtype IgG2a dramatically promotes survival in mice having tumors. Mice were injected i.p. with 5000 T3C cells on day 0. They were then given 100 μg anti-idiotype monoclonal antibody as either IgG1 (MS5A10) or IgG2a (MS11G6) on days 5, 7, and 10. In this model, the target antigen is the idiotype expressed by the lymphoma cells. Therefore, the anti-tumor antibodies are also “anti-idiotype.” These antibodies (MS5A10 and MS11G6) are simultaneously both anti-tumor antibodies and anti-idiotype antibodies. Twenty micrograms of CpG ODN 1826 (5′ TCCATGACGTTCCTGACGTT 3′; SEQ ID NO: 560) was given at the same time. Results are shown in
The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the invention. The present invention is not to be limited in scope by examples provided, since the examples are intended as a single illustration of one aspect of the invention and other functionally equivalent embodiments are within the scope of the invention. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims. The advantages and objects of the invention are not necessarily encompassed by each embodiment of the invention.
All references, patents and patent publications that are recited in this application are incorporated in their entirety herein by reference.
This application claims the benefit of U.S. Provisional Application No. 60/213,346, filed Jun. 22, 2000.
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