Hendrickson, Kristin

358 Background: Effective therapy for the treatment of PDAC remains one of the greatest unmet oncology clinical needs. The addition of C to G and AP has shown promising clinical data in a previously reported study [J Clin Oncol 35, 2017 (suppl 4S; abstract 341)]. In preclinical work, vitamin D (Vit D) analog therapy decreases myeloid derived suppressor cells and regulatory T cells, turning PDAC into a more immune-friendly microenvironment. This trial combines AP/C/G with Vit D analog P and the anti-PD-1 antibody N as a combination therapy for patients with previously untreated metastatic PDAC. This trial evaluates the efficacy and safety of NAPPCG in that patient population (NCT02754726). Methods: Eligibility criteria include Stage IV PDAC, no prior chemotherapy for systemic disease, KPS ≥ 70, and measurable disease. Doses are AP 125 mg/m2 undiluted, G 1000 mg/m2 in 250 ml of normal saline (NS), each infused over 30 minutes with C 25 mg/ m2 in 500 ml of NS infused over 60 minutes on days 1, 8, 22, and 29 of a 42-day cycle. N is given at a fixed dose of 240 mg as a 60 minute infusion on days 1, 15, and 29. P is given at a fixed dose of 25 µg IV twice weekly. Primary objective is to determine the efficacy of the combination for patients with previously untreated metastatic PDAC through determining CR, ORR, PFS, and OS. The secondary objective is to evaluate safety in patients with previously untreated metastatic PDAC. Results: Trial was initiated May 2016 and10 patients have been enrolled in the initial phase of the study and are evaluable (baseline and ≥1 follow up CT scan). Most common drug-related grade (Gr) 3-4 adverse events (AE’s), n = 10, are thrombocytopenia 100% (gr 3 = 50%, gr 4 = 50%) with no serious bleeding events, anemia 50% (gr 3 = 50%, gr 4 = 0%), and colitis 20% (gr 3 = 20%, gr 4 = 0%). By RECIST 1.1 criteria, the best response is 8 PR and 2 SD, yielding an 80% ORR. Median PFS is 8.2 months. Median OS has not been reached. Conclusions: Although a small study, the high response rate is encouraging. This regimen is being expanded to 25 patients with plans to include exploratory inflammatory biomarkers. Clinical trial information: NCT02754726.

TPS511 Background: Despite decades of basic and clinical research, effective therapy for the treatment of patients with pancreatic ductal adenocarcinoma (PDAC) remains one of the greatest unmet clinical needs in oncology today. Albumin-bound paclitaxel (AP) and gemcitabine (G) reported on an improvement in overall survival in metastatic (m) PDAC [NEJM 2013; 369:1691-1703]. The addition of cisplatin (C) has shown promising clinical data in previously reported studies [Cancer Res 2015; 75(15 Suppl):Abstract nr LB-003]. Through further preclinical work, vitamin D analog therapy decreases myeloid derived suppressor cell (MDSC) and regulating T cells (Tregs) thus turning PDAC into a more immune friendly microenvironment. This trial combines AP/C/G with the vitamin D analog paricalcitol (P) and the antibody-PD-1 drug Nivolumab (N) as a combination therapy for individuals with previously untreated metastatic PDAC. This trial evaluates the efficacy and safety of NAPPCG in patients in that population (NCT02754726). Methods: Key eligibility criteria include Stage IV PDAC, no prior chemotherapy for systemic disease, KPS ≥ 70; life expectancy ≥ 12 weeks and measurable disease. Key exclusion criteria include prior PD-1 or PD-L1 therapy. Doses are AP 125 mg/m2 undiluted, G 1000 mg/m2 in 500 ml of normal saline (NS), each infused over 30 minutes with C 25mg/ m2 in 500 ml of NS infused over 60 minutes on days 1, 8, 22, and 29 of a 42 day cycle. N is given at a fixed dose of 240 mg as a 60 minute infusion on days 1, 15, and 29. P is given at a fixed dose of 25 µg IV on days 1,4,8,12,15,22,26,29,32,36,and 39. Primary objective is to determine the efficacy of the combination NAPPCG for patients with previously untreated metastatic PDAC through determining CR, ORR, PFS, and OS. The secondary objective is to evaluate the safety of NAPPCG in patients with previously untreated metastatic PDAC. The study initiated accrual in April of 2016. If 4 of the first 10 patients are determined to have a PR the trial will expand to a total of 25 patients. Clinical trial information: NCT02754726.