Gemcitabine Hydrochloride and Cisplatin With or Without Veliparib or Veliparib Alone in Treating Patients With Locally Advanced or Metastatic Pancreatic Cancer

PRIMARY OBJECTIVES: I. To optimize the dose of veliparib combined with fixed doses of gemcitabine hydrochloride (gemcitabine) and cisplatin in a (non-randomized, lead-in portion of Part I). II. To evaluate the response rate (Response Evaluation Criteria in Solid Tumors \[RECIST\] criteria) of gemcitabine, cisplatin, and veliparib (Arm A) and gemcitabine, cisplatin (Arm B) in BRCA and PALB2 mutation carriers with advanced pancreas adenocarcinoma. (Part I) III. To evaluate the response rate (RECIST criteria) of single-agent veliparib (Arm C) in BRCA and PALB2 carriers with previously treated pancreas adenocarcinoma. (Part II) SECONDARY OBJECTIVES: I. To evaluate the progression-free survival in study Arm A and Arm B. (Part I) II. To describe the safety and tolerability of gemcitabine, cisplatin, and veliparib and gemcitabine and cisplatin in BRCA and PALB2 carriers with advanced pancreas adenocarcinoma. (Part I) III. To determine the disease control rate (complete response \[CR\] + partial response \[PR\] + stable disease \[SD\]) and duration of response in study Arm A and Arm B. (Part I) IV. To evaluate overall survival in study Arm A and Arm B. (Part I) V. To evaluate progression-free survival for single-agent veliparib in BRCA and PALB2 mutation carriers with previously treated pancreas adenocarcinoma (Arm C). (Part II) VI. To describe the safety and tolerability of single-agent veliparib in BRCA and PALB2 mutation carriers with previously treated pancreas adenocarcinoma. (Part II) VII. To determine the disease control rate (CR + PR + SD) and duration of response in Arm C. (Part II) VIII. To evaluate overall survival in Arm C. (Part II) CORRELATIVE SCIENCE OBJECTIVES: I. To determine the genotype of BRCA1, BRCA2 and PALB2-mutated pancreas adenocarcinoma. II. To assess pre and post therapy biopsies for novel or persistent genetic alterations in genes identified in aim I. III. To quantify levels of PAR in peripheral blood mononuclear cells (PBMCs) and tumor tissues at sequential time points before and following therapy with veliparib. IV. To quantify levels of gammaH2AX and RAD51 foci in PBMCs and tumor tissue (where available) at sequential time points to assess for formation of double-stranded deoxyribonucleic acid (DNA) breaks, stalled/collapsed replication forks and evaluate homologous recombination competence. EXPLORATORY OBJECTIVES: I. To correlate the results of genotyping with gene expression to provide functional information on mutations identified. II. An exploratory assessment of differential expression of genes involved in DNA repair pathways pre and post treatment to identify candidate genes predictive of response or resistance to therapy for further study in preclinical models of disease. OUTLINE: This is a dose-escalation study of veliparib followed by a randomized, open-label study. Patients receive veliparib orally (PO) twice daily (BID) on days 1-12 or 1-21 of each cycle. Patients also receive gemcitabine hydrochloride intravenously (IV) over 30 minutes and cisplatin IV over 30 minutes on days 3 and 10 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. (CLOSED AS OF 12/13/13) Part I Lead-in/Non Randomized Portion: There will be a small lead-in, non-randomized portion to Part I, where dose levels of veliparib 20 mg po BID (dose level 0), 40 mg po BID (dose level 1) and 80 mg po BID (dose level 2), will be evaluated on a day 1-12 schedule. The doses of gemcitabine 600 mg/m2 and cisplatin 25 mg/m2 are fixed. Three-6 patients will be evaluated per dose level starting with 20 mg po BID (dose level 0). If no dose-limiting toxicity (DLT), the dose of veliparib will be increased to 40 mg po BID (dose level 1) and subsequently to 80 mg po BID (dose level 2). If no DLT is observed at the veliparib dose of 80 mg BID day 1-12, then dose level 2A will examine veliparib at 80 mg po BID day 1-21, i.e., continuous dosing of veliparib. Subsequent cohorts will only examine continuous dosing of veliparib: dose level 3 (140mg po BID) and dose level 4 (200mg po BID). Approximately 6-24 patients total will be evaluated in this lead in portion of the study PART I: Once the maximum-tolerated dose of veliparib has been established, patients are randomized to 1 of 2 treatment arms. ARM A (no prior therapy or \>= 6 months since adjuvant therapy): Patients receive veliparib PO BID on days 1-12 of each cycle and gemcitabine hydrochloride IV over 30 minutes and cisplatin IV over 30 minutes on days 3 and 10 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo computed tomography (CT) or magnetic resonance imaging (MRI) throughout study. Patients also undergo tumor tissue and blood sample collection throughout the trial and undergo tumor biopsy during screening and on study. ARM B (no prior therapy or \>= 6 months since adjuvant therapy): Patients receive gemcitabine hydrochloride IV and cisplatin IV as patients in arm A. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo CT or MRI throughout study. Patients also undergo tumor tissue and blood sample collection throughout the trial and undergo tumor biopsy during screening and on study. PART II: Patients who are eligible receive treatment in Arm C. ARM C (prior therapy): Patients receive veliparib PO BID on days 1-28 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients also undergo CT or MRI throughout study. Patients also undergo tumor tissue and blood sample collection throughout the trial. After completion of study treatment, patients are followed up at 30 days and then every 3 months thereafter.