Abstract LB-003: High complete and partial response rate in a phase Ib pilot trial with cisplatin plus albumin-bound paclitaxel and gemcitabine in patients with advanced pancreatic cancer

Abstract

Abstract Background: The genomes of metastatic pancreatic cancers contain a myriad of intrachromosomal aberrations indicating a likely high prevalence of DNA repair deficiencies indicating sensitivity to DNA damaging agents such as the platinum’s. Because of this, the drug cisplatin was added to an albumin-bound paclitaxel + gemcitabine regimen, which has already been determined to improve survival over gemcitabine alone in a randomized phase III trial (NEJM 2013; 369:1691-1703). Objectives: To determine the efficacy and safety of albumin-bound paclitaxel and gemcitabine plus cisplatin for patients with advanced pancreatic cancer Methods: Eligibility criteria included Stage IV pancreatic cancer, no prior chemotherapy for systemic disease, KPS ≥ 70; life expectancy ≥ 12 weeks and measurable disease. The doses were albumin-bound paclitaxel 125 mg/m2 undiluted, gemcitabine 1000 mg/m2 in 500 ml of normal saline (NS), each infused over 30 minutes on days 1 and 8 of a 21 day cycle, along with 3 different dose levels of cisplatin (25, 37.5 or 50 mg/m2) in 500 ml of NS infused over 60 minutes, after the nab-paclitaxel infusion. Pre and post cisplatin hydration was given. Results: To date, 10 patients have been entered on study with all patients being evaluable, (baseline and at least one follow up CT scans completed). There have been 2 complete responses (20%), 6 partial responses (PR), (60%), 1 stable disease (10%), and 1 patient with progressive disease (10%), by RECIST 1.1 criteria. An exponential decrease in CA19-9 correlating with the t1/2 of the marker was noted. Response was seen rapidly with PR observed at the first staging evaluation at 9 weeks in 7 of 10 patients. The 8th patient achieved a PR at 18 weeks. Serious adverse events occurred in 4 patients: non-neutropenic sepsis/pneumonia (n = 1), and non-neutropenic bacteremia (n = 1) in the cisplatin 25 mg/m2 cohort; clostridium difficile colitis (n = 1) with cisplatin 37.5 mg/m2; and neutropenic fever/pneumonia (n = 1) with cisplatin 50mg/m2. Discussion: The study has completed phase Ib and will be expanded at the phase II dose of cisplatin 25 mg/m2 for a total of 25 patients. If this favorable response rate is confirmed, this 3 drug regimen could be further developed both for patients with advanced disease as well as in neoadjuvant and adjuvant settings. Supported by grants from the Seena Magowitz Foundation and the SU2C Dream Team Citation Format: Gayle S. Jameson, Erkut Borazanci, Elizabeth Poplin, Michael T. Barrett, John Crowley, Adam Rosenthal, Amy Stoll-D'Astice, Karen L. Ansaldo, Steven Boone, Leticia Lebron, Ramesh K. Ramanathan, Ronald L. Korn, Daniel D. Von Hoff. High complete and partial response rate in a phase Ib pilot trial with cisplatin plus albumin-bound paclitaxel and gemcitabine in patients with advanced pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-003. doi:10.1158/1538-7445.AM2015-LB-003