Patent Application
20200237764
Not Applicable.
The present invention is related to cancer treatment and, more particularly, to the identification and concurrent targeting of multiple cancer cell mutations.
With the development of advanced molecular techniques, personalized medicine has emerged to the forefront in cancer diagnosis and treatment (1). This has resulted in a shift from cytotoxic, non-specific chemotherapies to molecularly targeted approaches (2). Such targeted approaches have largely been possible as a result of the development of next-generation sequencing (NGS) techniques which perform high-throughput, massive parallel sequencing (3, 4).
Pancreatic ductal adenocarcinoma (PDAC) is an exocrine pancreatic tumor that develops from cells lining the small tubes or ducts in the pancreas: It is an extremely aggressive cancer in that PDAC accounts for up to 4% of all cancer related deaths world-wide with a 5-year survival rate of only about 25% (5).
Accordingly, the inventors herein have succeeded in devising an improved approach for the treatment of cancer including PDAC. The approach involves targeting actionable mutations in two or more genes or pathways in the cancer cells.
Thus, in various embodiments, the present invention is directed to methods for treating a cancer in a patient in need thereof. The method includes identifying two or more target genes in the cancer cells (using NGS sequencing or other methods) each of which has a pathogenic and actionable mutation; (a) a list of gene-drug substances interactions, and (b) administering to the patient one or more substances targeting the actionable mutation for each of the two or more target genes identified in the patient's tumor/cancer sample. In various aspects, the sample may be cancer cells or a cell-free sample containing cancer DNA and the two or more target genes map to different pathways. In various embodiments the cancer may be PDAC and the two or more target genes may be KRAS (or genes which signal through the mitogen/extracellular signal-related kinase (MEK) pathway) and ABL1 (or genes which signal through the tyrosine kinase (TK) pathway). The inhibitors may be the mitogen/extracellular signal-related kinase (MEK) inhibitor, trametinib and the multiple tyrosine kinase inhibitor, regorafenib).
In various other embodiments are directed to methods for identifying a treatment for a patient having cancer. The method may include (a) obtaining from the patient, a sample comprising cancer cells (b) screening the sample using an NGS technique, (c) identifying two or more target genes in the cancer cells each of which has a pathogenic and actionable mutation, (d) culturing the cancer cells in presence of one or more substances targeting the actionable mutation for each of the two or more identified target genes identified in (c), (e) measuring cancer cell viability in presence of the one or more substances and (f) determining if the viability of the cells in the presence of the one or more targeted substance is (i) less than the viability in absence of the two or more substances; (ii) less than the viability in the presence of one or more standard-of-care, non-targeted, substance; (iii) less than the viability in the presence of a targeted but non-matched substance (negative controls). In various aspects, each of the two or more identified target genes affects a different pathway. In various embodiments, the cancer is PDAC and the two or more identified target genes are KRAS and ABL1. The inhibitors may be the mitogen/extracellular signal-related kinase (MEK) inhibitor, trametinib and the tyrosine kinase inhibitor, regorafenib. The standard-of-care, non-targeted, substance may be gemcitabine and the targeted but non-matched substance may be palbociclib.
Various other embodiments are directed to a kit for identifying a treatment for a patient having cancer. The kit includes: (a) a list of patient's cancer cells aberrations obtained by NGS (or other technique); (b) a list of gene-drug substances interactions; (c) one or more substances targeting the actionable mutation for each of the two or more target genes identified from the list (a); and (d) a medium for culturing cancer cells from the patient in presence of each of the one or more substances in (b), packaged in one or more containers. In various embodiments, the cancer is PDAC and the two or more identified target genes are KRAS and ABL1. The inhibitors may be the mitogen/extracellular signal-related kinase (MEK) inhibitor, trametinib and the tyrosine kinase inhibitor, regorafenib.
These and other features, aspects and advantages of the present teachings will become better understood with reference to the following description, examples and appended claims.
Those of skill in the art will understand that the drawings, described below, are for illustrative purposes only. The drawings are not intended to limit the scope of the present teachings in any way.
The present invention is directed to the identification and targeting of two or more mutations in cancer cells in treating cancer patients.
As used herein, the following terms are defined with the following meanings, unless explicitly stated otherwise.
The term “about” when used before a numerical designation, e.g., pH, temperature, amount, concentration, and molecular weight, including range, indicates approximations which may vary by ±5%, ±1% or ±0.1%.
As used in the specification and claims, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a pharmaceutically acceptable carrier” may include a plurality of pharmaceutically acceptable carriers, including mixtures thereof.
The term “and/or” is intended to mean either or both of two components of the invention.
The terms “subject,” “individual” and “patient” are used interchangeably herein and refer to a mammal and, particularly, to a human.
The term “device,” as used herein, refers to an apparatus or system capable of delivering a drug to patient in need thereof.
The term “in need of treatment” and the term “in need thereof” when referring to treatment are used interchangeably and refer to a judgment made by a caregiver, e.g.
physician, nurse, nurse practitioner, that a patient will benefit from treatment.
The term “pharmaceutically acceptable,” as used herein, refers to a component of a pharmaceutical composition that is compatible with the other ingredients of the formulation and not overly deleterious to the recipient thereof.
The term “carrier” refers to a diluent, adjuvant, excipient, or vehicle with which the therapeutic is administered and includes, but is not limited to such liquids and powders that are hydrophilic substances, hydrophobic substances and substances that possess both hydrophilic and hydrophobic properties such as emulsifiers.
The term “therapeutically effective amount,” as used herein, refers to the amount of an active compound or pharmaceutical agent that elicits the biological or medicinal response in a tissue, system, or individual that is being sought by a researcher, healthcare provider or individual.
The term “w/w” as used herein, is intended to refer to mass fraction, i.e., the mass of a component divided by total mass of the whole. The term “% w/w” is intended to refer to the mass fraction multiplied by 100. Similarly, the term “w/v” refers to volume concentration, i.e., the mass of a component divided by total volume of the whole and the term “% w/v” refers to the volume concentration multiplied by 100.
Various embodiment of the present invention are directed to methods for treating a cancer in a patient in need thereof and to methods for identifying a treatment method for a patient having cancer
The term “cancer” refers to a group of diseases in which abnormal cells divide without control often invading nearby tissues and spreading to other parts of the body through the blood and lymph systems. One particular cancer is pancreatic ductal adenocarcinoma (PDAC). PDAC is an extremely aggressive cancer developing from the pancreatic ducts and accounting for up to 4% of all cancer related deaths world-wide with a 5-year survival rate of only about 25% (5).
The term “sample” as used herein, refers to cancerous tissue or group of cells from a patient's cancer such as, for example, from an excisional or incisional biopsy including a core biopsy, needle aspiration biopsy and the like. A “sample” may also be cell-free fluid obtained from the patient containing DNA from the cancer.
A sample from a patient may be screened using next-generation sequencing (NGS). NGS refers to technologies capable of massively parallel sequencing millions of DNA templates (3, 4). The term includes second-generation and third-generation sequencing as distinguished from the first-generation dideoxy ‘Sanger’ sequencing. NGS techniques employ clonal amplification of DNA templates on a solid support matrix followed by cyclic sequencing. Examples of NGS include sequencing-by-synthesis (reversible terminator-based) in such products as MiSeq®, HiSeq® and NextSeq® (Illumina Inc., San Diego, Calif.), Sequencing-by-Synthesis (Semiconductor-based) in such products as Ion Torrent®, Ion Proton®, (Life Technologies® Thermo Fisher Scientific, Waltham, Mass.) and Single molecule real-time sequencing in such a product as PACBIO® RSII (Pacific Biosciences, Menlo Park, Calif.).
The term “pathogenic mutations” refers to genetic alteration that increases an individual's susceptibility or predisposition to a certain disease or disorder, such as cancer.
The term “actionable mutations” refers to mutations that affect genes or pathways that are targetable by drugs in effectively treating a certain disease or disorder, such as cancer (6, 7). The actionable mutations may map to a known pathway such that pathway-targeted therapeutics may be effective (8). Such therapeutics may include inhibitors such as the MEK inhibitor, trametinib and the multiple tyrosine kinase inhibitor, regorafenib, in particular, for the treatment of PDCA.
A proto-oncogene is a normal gene that, when activated by mutation or increased copy number, becomes an oncogene and that can contribute to cancer. Proto-oncogenes may have many different functions in the cell such as providing signals that lead to cell division or regulating apoptosis.
One of the target genes may be a mutant KRAS gene. The mutated KRAS oncogene contributes to the mitogen-activated (MAP) kinase pathway which controls to cell growth and differentiation (9). KRAS is activated by GTP which produces the successive activation of RAF kinases, MEK kinases and ERK kinases and the ERKs phosphorylate transcription factors leading to cell proliferation (10). One actionable MEK inhibitor is trametinib which suppresses ERK phosphorylation through the RAF-dependent activation of MEK (11). Trametinib may be administered at about 1 to about 3 mg/day P.O. and, in particular, at 2 mg/day P.O.
Another of the target genes may be the ABL1 proto-oncogene which encodes a protein tyrosine kinase which when aberrantly activated to become an oncogene, disturbs downstream signaling pathways, causing enhanced proliferation, differentiation arrest and resistance to cell death (12). One actionable ABL1 kinase inhibitor is regorafenib which is an inhibitor of multiple protein kinases (13). Regorafenib may be administered at about 80 to about 240 mg/day P.O. and, in particular, about 160 mg/day P.O.
Various other embodiments are directed to kits identifying a treatment method for a patient having cancer. The kits may include a list of gene-drug interactions; Sample of cancer cells from the patient. List of aberration in these cancer cells obtained by NGS or other technique. The kit generates a list of possible combination targeted therapies. In kits for identifying a treatment method for a patient having PDAC, the two target genes may be KRAS and ABL1. For these two target genes, trametinib (MEK inhibitor) and regorafenib (tyrosine kinase inhibitor) are included in the kit. Further included in the kit may be media for culturing sample cancer cells obtained from the patient. Such media may be any standard culture media such as, for example, McCoy's Modified 5A media supplemented with 10% FCS, 1X penicillin/streptomycin and 1× amphotericin as may be obtained from Life Technologies-Gibco, Carlsbad, Calif. Each of the components of the kit are packaged along with appropriate instructions in one or more containers.
Aspects of the present teachings may be further understood in light of the following examples, which should not be construed as limiting the scope of the present teachings in any way.
This example illustrates the effectiveness of concurrently/simultaneously targeting multiple actionable mutations in cancer cells using a combination of therapeutic agents in a culture method.
Cancer treatment is still largely a “one size fits all” approach with the majority of treatment options and procedures (e.g., surgery, radiation therapy, chemotherapy) aimed largely at fighting a particular type of cancer (e.g., liver cancer, lung cancer, colorectal cancer) (14) However, over the past several years, the utilization of next-generation sequencing strategies has not only greatly increased our knowledge of the genetic alterations that drive cancer susceptibility and progression, but it has also clearly illustrated the unique nature of an individual patient's cancer (15). Together with advances in the development of therapies targeting the proteins and pathways affected by many of these genetic alterations, this has raised the possibility of utilizing personalized cancer treatment strategies aimed at attacking one patient's cancer (16).
In support of this notion, a number of studies have demonstrated the efficacy of monotherapies which target a particular mutation in the treatment of several different types of cancer. Although not without some risks (e.g., toxicities and drug resistances), many of these studies have demonstrated significant increases in response rates and progression free survival compared to non-targeted approaches (16-20). However, as whole genome sequencing has demonstrated, cancer genomes are generally characterized by a cocktail of genetic aberrations resulting from an overall genetic instability (i.e., mutational burden), rather than alterations in a single gene (21). Nevertheless, most cancer patients, for whom targeted therapy is implemented, are generally treated with therapies aimed at a single-agent matched aberration (monotherapy). This is despite the fact that, based on the results of such targeted monotherapies, the inventors herein believe that combinations of therapies matched to the entire set of actionable alterations presented by the cancer genomic profile of the patient would likely result in better response.
As a proof-of-principle of the efficacy of matched combination therapy, we have performed in vitro cell-based survival assays using CAPAN2, an established cell line derived from a human/patient pancreatic ductal adenocarcinoma (22). This cell line has been characterized and harbors several mutations, some of which were matched to available FDA-approved drugs that specifically inhibit the pathways affected by the gene aberrations found in the cells (“matched” therapy). Thus, in this study, comparisons in cell viability were made between cells treated with either: 1) the standard treatment for pancreatic ductal carcinoma (i.e. gemcitabine) (23); 2) matched monotherapy with individual drugs/inhibitors targeting selected single/unique signaling pathways altered in the cells; and 3) combination therapy matched to the same selected aberrations.
Materials
Unless otherwise indicated, all chemicals, including gemcitabine, trametinib, palbociclib, and regorafenib were obtained from SelleckChem (Houston, Tex.). McCoy's 5A modified growth media, penicillin-streptomycin, amphotericin, and fetal calf serum were obtained from Life Technologies-Gibco (Carlsbad, Calif.). All plastic-ware, including tissue culture dishes, serological pipettes, pipette tips, and microfuge tubes were from Fisher Scientific (St. Louis, Mo.).
Selection of Cell Line
The cell line was chosen by analysis of the Cancer Cell Line Encyclopedia (CCLE) which provides access to analysis and visualization of DNA copy number, mRNA expression, mutation data and more, for 1,000 cancer cell lines (24). Criteria for the selection of the cell line of interest included: 1) the total number of mutations presented by the cell line should be at least 5, but no more than 10 (to avoid intricacy of additional confounding factors); 2) the number of actionable targets should be at least 2, but no more than 3 (to limit the number of potential drug combinations to test); 3) the mutations could not be significantly overlapping and should affect distinct oncogenic pathways (to avoid redundancies in the drug treatment). From a set of 18 cell lines, we selected the CAPAN2, which originates from a human pancreatic adenocarcinoma primary tumor.
Cell Culture
The human pancreatic cancer cell line CAPAN2, was purchased from the American Type Culture Collection (ATCC; Manassas, Va.). Cells were grown in McCoy's Modified 5A media supplemented with 10% FCS, 1× penicillin/streptomycin and 1× amphotericin. For testing, cells were released from the dishes by treatment with PBS (without calcium) for ˜30 min followed by 0.25% trypsin-EDTA for 5 minutes at 37 C. Cells were collected in a 15 ml centrifuge tube and spun down in a clinical centrifuge for 5 min and then re-suspended in 1 ml of fresh media and the cells were counted using a hemocytometer. Cells (1×103-5×103) were then seeded into 96-well plates in 100 μL of media and the cells were incubated for 48 hours. After 48 hours, the media was replaced and the cells were re-incubated for another 24 hours prior to treatment with the drugs.
Cell Treatment, Viability Assay and Dose-Response Assessment
Genomic information (i.e., mutational status, copy number variations, etc) corresponding to the cell line of interest was analyzed and the combination of trametinib (MEKINIST®, MEK inhibitor counteracting the KRAS activating mutation) and regorafenib (STIVARGA®, multi-kinase inhibitor counteracting the ABL1 activating mutation), were selected as a potential therapeutic regimen for CAPAN2 cells since they target these two actionable mutations.
Stock drug solutions were prepared in complete media from master stock solutions prepared in DMSO according to the manufacturer's instructions. Using these stock solutions, 1:1, 2:1, 5:1, and 10:1 volume-volume (v/v) mixtures of regorafenib and trametinib were prepared. These mixtures were then two-fold serially diluted to generate a range of 20 concentrations in each case. The cells were incubated in drug mixtures for 48-72 hours before cell viability assay/assessment.
Cell viability was determined using a WST-1 colorimetric cell proliferation assay (Roche), according to manufacturer's instructions. The stable tetrazolium salt WST-1 is cleaved to a soluble formazan by a complex cellular mechanism that occurs primarily at the cell surface. This reduction is largely dependent on the glycolytic production of NAD(P)H in viable cells. Therefore, the amount of formazan dye formed, and estimated using a spectrophotometer (BIO-TEK 340, BIOTEK) directly correlates to the number of metabolically active cells in the culture. All testing points were done at least in triplicate.
Data were processed in Excel 2016 (Microsoft), GraphPad Prism 5 (GraphPad Software), and Dr Fit (Dr Fit software) (12). The data was used to generate dose-response curves and drug concentrations that exhibited 20%, 25% or 40% of growth inhibition (IC20, IC25 and IC40, respectively) were determined for further analysis.
Isobolographic Analysis
Drugs given in combination may produce effects that are greater than or less than the effect predicted from their individual potencies. Isobolographic analysis, which detects synergy, additivity, or antagonism between a drug pair (26), was carried out to assess the effects of the drug combination. In general, if the drug pair improves the inhibitory potency relative to that of each drug alone, the combination is considered synergistic; if potency remains unchanged, the effect is considered additive; and if potency is reduced, the effect is considered antagonistic. To describe the dose-dependent interaction of trametinib and regorafenib, isobolograms at effect levels of 20%, 25% and 40% inhibition of cancer cell proliferation were created. In each of these, additivity was determined by extrapolating the dose requirements for each drug in combination from its single use (IC20, IC25 and IC40). Data points above or below the line of additivity indicate antagonism or synergy, respectively.
Isobolograms were built by plotting the concentrations of trametinib on the y-axis and the concentration of regorafenib on the x-axis. The isobole of additivity was generated by plotting the IC20 (or IC25, IC40) of each drug (when used in monotherapy) on their respective axis, and connecting them with a diagonal line. The effects of the combination of trametinib and regorafenib at different dose ratios was then determined by plotting their respective IC20s (or IC25, IC40) on this XY graph.
Statistical Analysis
All values were reported as mean+/−SD. The Student's t-test was employed to evaluate the difference between treatments. A p-value lower or equal to 0.05 was considered for significance of all results.
Results
Selection of Cell Line.
The cell line in which to test the efficacy of selected drug regimens was chosen from a database encompassing molecular annotations of −1,000 cell lines (Cancer Cell Line Encyclopedia, CCLE, Novartis/Broad Institute) (24). Using a number of criteria (e.g., number and types of mutations, pathogenicity and actionability of the mutations) the list of cell lines of interest was reduced to 18 possible choices (Table 1).
From this list, CAPAN2, an epithelial cell line derived from a pancreatic ductal adenocarcinoma (PDAC) of a 56 year-old Caucasian male (23), was chosen for analysis. In optimum culture conditions, the cells present a doubling time of around 96 h (9). According to the CCLE, CAPAN2 cells bear ˜8 missense mutations, of which 3 (KRAS p.G12V; ABL1 p.G1060D; FANCC p.E521K) were found to be actionable targets (Table 1). However, since FANCC p.E521K is a heterozygous mutation for which the functional significance is unclear (27), we focused attention on the 2 other actionable mutations.
KRAS
KRAS, a small GTPase, functions in regulating cell growth and proliferation through its participation in the mitogen-activated protein kinase (MAPK) signal transduction pathway (
stimulates the downstream molecules, RAF (ARAF, BRAF and CRAF), which subsequently phosphorylates and activates the downstream mitogen-activated protein (MAP) kinase kinases, MEK1 and MEK2, and ERK1 and ERK2 (
Approximately 90% of all PDACs display activating mutations in KRAS, making it the most frequently mutated onco-protein in PDAC (15). Moreover, mutations at codon 12, such as the substitution p.G12V, account for ˜98% of all KRAS mutations in PDAC (16). The p.G12V mutation results in constitutive activation of the kinase (17) and is observed in additional tumor types, such as colorectal and non-small cell lung adenocarcinomas.
ABL1
The ABL1 proto-oncogene encodes a non-receptor tyrosine kinase involved in cell differentiation, cell division, cell adhesion and stress response (31) (
In contrast to the well-established role of the oncogenic fusion protein BCR-ABL1, which is a hallmark of chronic myeloid leukemia leading to the constitutive expression and further hyper-activity of the tyrosine kinase (34), much less is known about the role of ABL1 when mutated by point mutations in solid tumors (31). However, unlike a number of point mutations located within the tyrosine kinase domain of ABL1 which have been found to activate this non-receptor tyrosine kinase leading to cell transformation (35), the p.G1060D mutation of ABL1, seen in these cells, occurs in the actin-binding domain of the kinase. While it has not been functionally characterized, since this domain is a major determinant for the subcellular localization of the kinase to the actin cytoskeleton (which block AB1 kinase activity) and since transforming ABL1 mutations identified to date result almost exclusively in the cytoplasmic accumulation of the kinase (33,34)—this alteration putatively leads to increases in its cytoplasmic level and further activation, since the kinase activity of ABL1 is inhibited when the protein is bound to F-actin (32, 35).
Drug Treatment
Gemcitabine Monotherapy.
Gemcitabine (GEMZAR®) monotherapy, which has been the standard of care for pancreatic cancer for several decades, is the most common cytotoxic drug used in treatment of this disease (23). This pyrimidine analogue is phosphorylated in the cell and gets incorporated into the DNA where it inhibits DNA synthesis (37), therefore targeting all proliferative cells (without restriction to tumor cells), and thus resulting in important side effects (such as severe myelosuppression with neutropenia and bleeding, alopecia, nausea and vomiting, fatigue). Despite the fact that gemcitabine-treatment only results in modest improvements in terms of overall survival when compared to the best supportive care (5 to 6 months, compared to 3 months), as of 2017, gemcitabine remains the standard of care for advanced pancreatic adenocarcinoma (38).
In this study, CAPAN2 cells were treated with a two-fold serial dilution of gemcitabine with concentrations ranging from 2 nM to 1 mM for 48-72 hours. Under these culture conditions, gemcitabine was found to have little, if any, effect on cell survival (
Trametinib Monotherapy.
In CAPAN2 cells, the p.G12V mutation in KRAS results in constitutively active mitogen/extracellular signal-related kinase (MEK), which is downstream of KRAS in the MAPK signaling pathway (
Regorafenib Monotherapy.
As described above, the p.G1060D mutation in ABL1 is likely an activating mutation leading to increases in the cytoplasmic concentration of this non-receptor tyrosine kinase (
Palbociclib Monotherapy.
Pancreatic ductal adenocarcinoma has been found to exhibit a range of genetic alterations, including loss or silencing of CDKN2A, a tumor suppressor gene which encodes the p16ink4a protein (an inhibitor of the cyclin dependent kinases 4 and 6 (CDK4/6)) (41). Loss of function mutations of CDKN2A results in deregulation of the cell cycle via CDK4 and CDK6 leading to enhanced cell proliferation. While the status of CDKN2A in CAPAN2 cells remains unclear, some groups have demonstrated the expression of the p16 protein, while others have indicated that CDKN2A is inactivated in these cells (42). The cells were treated for 48-72 hours with a 2-fold serial dilution of the CDK4/6 inhibitor, palbociclib with concentrations ranging from 125 μM to 2 nM. Palbociclib was found to have no significant effect on the survival of the CAPAN2 cells used in this study (
Combination Therapy with Trametinib and Regorafenib.
Simultaneous treatment of CAPAN2 cells with trametinib and regorafenib was then used to investigate the effects of matched combination therapies on CAPAN2 cell survival. Co-administration of these two inhibitors at 1:1 concentrations resulted in significant increases in cell death compared to treatment with either drug alone (i.e., monotherapy) with an IC20 of 2 nM (
Interestingly, however, the dose-response curve of cell viability for this 1:1 combination of these drugs displays a biphasic U-inverted shape, with a loss of efficiency between 15 nM and 1 μM (
To investigate whether the presence of both drugs enhances the individual effects of each drug alone, the “Fixed-Ratio-Model” was employed (43-45). In this model, based on Loewe's concept of (43-45), combination index (CI) values were calculated based on the slope and ICx value of each dose-response curve (drug alone or in combination) and used to define whether the drug-drug interactions are synergistic (CI<1), additive (CI=1), or antagonistic (CI>1) (Fi. 4). Following this, the combination index (CI) resulting in a decrease of 20% of cell survival is equal to 0.345, 25% of cell survival is equal to 0.320, while that for 40% survival was found to be greater than 1. This indicates that for ED80 and ED75 there are synergistic effects of the combination of drugs on CAPAN2 cell proliferation, when both drugs are used at equal concentrations. (33).
However, co-administration of the drugs at 2:1 concentrations of regorafenib to trametinib was somewhat different (
Trametinib and Regorafenib Cytotoxicities Synergize in Pancreatic Ductal Adenocarcinoma Cancer Cells.
Next, we generated isobolograms and determined the dose requirements for each drug at 20%, 25% and 40% cancer cell death as a read-out for synergy. As shown in
More than 80% of pancreatic cancers are ductal adenocarcinomas (PDAC) (47) and as the fourth most common cause of cancer-related death, it is one of the most lethal solid malignancies (48). Although, gemcitabine has been the only validated standard regimen for advanced PDAC for more than a decade, the 5-year survival rate for this disease has not significantly improved over the past 4 decades (38).
Approximately 90% of all PDACs display mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS), the most frequently mutated oncogene/protein in PDAC (28). Moreover, mutations at codon 12, such as p.G12V (seen in the CAPAN2 cells used in this study), account for ˜98% of all KRAS mutations in PDAC (29). The p.G12V mutation results in constitutive activation of this protein kinase leading to a series of downstream signaling events that mediate uncontrolled increases in cellular proliferation, motility, adhesion, invasion, blocking of apoptosis and resistance to chemotherapy (30). Despite this, no specific RAS inhibitor has been identified and this protein kinases has been widely perceived as “undruggable” (49).
Nevertheless, the development and commercialization of therapeutic agents that, at least indirectly, can block KRAS function through the inhibition of its downstream effectors have been developed. For example, trametinib (MEKINIST®), a selective inhibitor of MEK, is a downstream inhibitor of the MAP kinase signaling pathway constitutively activated by the KRAS p.G12V mutation (49), and it has been demonstrated that such MAP kinase inhibitors are an important therapy for targeting RAS (40).
ABL1, a non-receptor tyrosine kinase, regulates a diverse set of cellular processes controlling cell growth, survival, invasion, adhesion and migration (31). The p.G1060D mutation of ABL1, seen in these CAPAN2 cells, occurs in the actin-binding domain of the kinase and although it has not been functionally characterized, it is believed that this is an activating mutation since it could lead to increases in the cytoplasmic levels of ABL and thus its kinase activity, which is blocked by its binding to the filamentous actin cytoskeleton (33,34). The multi-kinase inhibitor regorafenib, has been shown to target non-receptor tyrosine kinases, including ABL1 (40).
In the present study, we show that both trametinib and regorafenib (individually and in combination) inhibit cell proliferation in CAPAN2 cells bearing activating mutations in KRAS and ABL1. In fact, combinations of these two inhibitors were found to lead to increased cell death at much lower concentrations than either of the drugs in isolation (
The biphasic response observed when the cells were treated with combination of trametinib and regorafenib, was not seen at any concentration following treatment with either matched monotherapy (
Overall the study reports the systematic analysis of monotherapies and combination of anti-cancer drugs matched to genome alterations and support the notion that: 1) matched monotherapies targeting actionable alterations provide significant increases in cell death compared to the standard of care; and 2) more importantly, matched combination therapies have the potential to provide even more effective treatments than either matched monotherapies or the standard of care. When taken together with the recent advances in cancer tumor genomics analysis, and in drug design and development, it is clear that researchers and clinicians now have the opportunity and means to treat cancer as the personal disease that it is.
The detailed description set-forth above is provided to aid those skilled in the art in practicing the present invention. However, the invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed because these embodiments are intended as illustration of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, 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 which do not depart from the spirit or scope of the present inventive discovery. Such modifications are also intended to fall within the scope of the appended claims.
All publications, patents, patent applications and other references cited in this application are incorporated herein by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application or other reference was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Citation of a reference herein shall not be construed as an admission that such is prior art to the present invention.
Specifically intended to be within the scope of the present invention, and incorporated herein by reference in its entirety, are the following publications:
The present application is a continuation of International Application No. PCT/US18/46570 entitled “Drug Combinations for Targeting Multiple Mutations in Cancer” filed on Aug. 13, 2018, which published in English as WO 2019/033123 on Feb. 14, 2019, which claims priority from U.S. Provisional Application Ser. No. 62/544,693 entitled “Drug Combinations for Targeting Multiple Mutations in Cancer” filed on Aug. 11, 2017, which are each expressly incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US18/46570 | 8/13/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62544693 | Aug 2017 | US |
