My laboratory aims to address the unmet medical need of more effective treatments for pancreas cancer patients by developing new treatment approaches. The American Cancer Society estimates 53,070 new cases and 41,780 deaths from pancreatic cancer in the United States during 2016 and predicts that pancreatic cancer will rank 2nd of all cancer-related mortalities by the year 2030. Up to 90% of pancreatic cancer patients succumb to the disease within the first year of diagnosis. Neither current chemotherapy nor molecular therapy provides patients with an extension of survival measured by more than a few months, or the hope for sustained tumor regressions or cure. The overall research goals and scientific objectives of the different drug development efforts conducted in my laboratory are the development of novel therapeutics in pancreas cancer. These include studies from early structure-activity, in vitro, cell-based and in vivo evaluations, to IND enabling studies and clinical development. To reduce later failure all drug development efforts are guided by hypothesis-driven mechanism of action studies including early efficacy, toxicity, and pharmacokinetic studies in orthotopic, patient-derived xenotransplantation, or transgenic animal models. Scientific achievements in the last year include: 1. Preclinical and clinical development of metarrestin Metarrestin is a novel small molecule inhibitor with selective activity against the metastatic phenotype of cancer cells. It has impressive activity in pancreatic cancer metastasis models. The drug development project 'Metarrestin, a new approach towards metastasis' co-presented by me to NCIs NExT program was evaluated as 'top tier, ranked 2nd out of 28 applications, average score 2.0'. The near term goals of the metarrestin program are i. completion of IND enabling studies, including GLP long term toxicity in swine (miniature pigs) ii. compile and file IND application with FDA and commence phase I safety and MTD clinical studies with this agent at CCR The program has now moved into the late preclinical stage, and expected for 2017, to advance into clinical testing. The proposal 'Assessment of Efficacy and Biodistribution of IND Candidate Compound Metarrestin in Preclinical Murine Models for Pancreatic Ductal Adenocarcinoma' has been approved by CCR Leadership and included into CCR CAPRs portfolio. Extensive rodent pharmacology and PK studies in transgenic KPC mice have shown excellent tissue penetration of the drug with plasma:tumor AUC ratios exceeding 1:10 and intratumoral drug levels close to 100uM at non-toxic dose levels. Development of a human formulation has been completed. A pilot of PK studies in swine (mini pigs) has been started, to be followed by long term GLP toxicity studies. Production of 2kg of metarrestin produced under Good Manufacturing Practices (GMP) to be used for IND enabling GLP toxicity studies and human studies has been started. 2. Preclinical development of the 'biosimilar' anti-cancer peptide RP-182 The discovery of the strong anti-cancer activity of RP-182 in murine pancreatic tumors in our laboratory has led to a patent filing of such peptides as novel effective treatment of cancers (Int'l PCT Patent Application No. PCT/US15/55305). My laboratory has shown that RP-182 binds CD206 and targets CD206 positive M2 tumor-associated macrophages, and increases intratumoral immunity through reduction and reprogramming of this generally immune suppressive immune cell population towards an anti-tumor M1 phenotype. Additionally, RP-182 downregulates in murine pancreatic cancers PD-1L expression on cancer cells, and the addition of an anti-PD-1L immune check point inhibitor extends survival of RP-182-treated animals. Overall, results show RP-182 suppresses innate immune suppressive cues in pancreatic cancers acting as a 'biosimilar' (to mannose moeities of bioorganisms recognized by CD206 mannose-binding receptors on macrophages) and inducing death and reprogramming of CD206 positive immune cells in these tumors. A PK assay for in vivo measurements of RP-182 is now available to interrogate the pharmacology of RP-182 which will move the program of targeting the CD206 axis of the innate immune system, as part of anti-cancer combination immunotherapy approaches, into late preclinical development. 3. Preclinical development of the stem cell inhibitor -8382 The scientific goal of this program developed in my laboratory is to show selective anti-cancer stem cell activity of this small molecule inhibitor, which effectively suppresses metastasis formation, in comparison to gemcitabine chemotherapy in cell-based and in vivo assays of stemness. A series of spheroid clonogenicity assays, in vivo tumor initiation studies, and measures of stemness using flow cytometry including side population (SP) profiling experiments confirm a selective anti-cancer stem cell function of the inhibitor compared to gemcitabine. Two of the compounds new targets - TAOK3 and CDK7 - also promote cancer stemness targets. The molecule targets synergistically different mechanisms of DNA damage repair, a vulnerability of cancer stem cells. 4. Clinical development of RAS mutational isoform-directed anti-MAPK pathway therapy The major objective of this project is to proceed with clinical translation of our discovery of increased sensitivity of KRAS G12R mutational isoform-harboring cell lines and patient-derived xenotransplantation models. Unbiased gene expression analysis as well as loss of function of signaling nodes siREN screening [knockdown of signal transduction nodes; in collaboration with NCIs RAS Initiation of NCI Frederick] confirmed that different RAS genotypes are associated with different gene expression profiles and select signal transduction dependencies. A 20-patient phase II pilot treating patients whose tumor harbor G12R KRAS isoforms has been approved by the CCR Scientific Leadership Committee and CTEP which tests the hypothesis whether KRAS mutational isoforms represent an integral biomarker for response to anti-MEK therapy as novel therapy in 2nd line treatment of pancreas cancer and is a direct translation of our laboratory efforts. 5. Anti-PI3K/mTOR molecular therapy in pancreas cancer: genetic variants and activation of LKB1-AMPK signaling predict response to NVP-BEZ235 Correlation between somatic mutation status of a large panel of pancreatic cancer cell lines and drug phenotype resistance to PI3K/mTOR inhibition (no induction of apoptosis upon treatment with NVP-BEZ235) shows statistically significant associations between a. variants in the ARID1A or other genes of the chromatin remodeling complex SNF/SWI, and b. variants in any of the 11 genes APC, AXIN1, CCND1, CCND3, CTNNB1, CREBBP, EP300, MYC, RAC1, SMAD4, TP53 of the 98 genes involved in WNT signaling. and resistance to PI3K/mTOR inhibition. Phosphoprotein profiling of above cell lines and of patient-derived xenotrans-plantation models (PDX) treated with the PI3K/mTOR inhibitor showed increased AMPK activity in tumors resistant to PI3K/mTOR inhibition compared to sensitive PDX tumors. As AMPK is a major regulator of cell energy homeostasis, we compared metabolic profiles of resistant versus sensitive cell lines and found sharp differences between metabolic reliance on nutrients including increase in mitochondrial basal and maximum respiration and spare capacity in sensitive cell lines, and increased rate of glycolysis including glycolytic capacity and glycolytic reserve in resistant cell lines. The combination drug response evaluations of PI3K/mTOR inhibitors and inhibitors of glycolysis in PI3K/mTOR resistant cells to test for sensitization to PI3K/mTOR inhibition in the presence of glycolysis blockade as a novel therapeutic approach to pancreas cancer are currently ongoing.
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