Olaparib (O) in patients (pts) with pancreatic cancer with BRCA1/2 inactivating mutations: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) study.

Abstract

4637 Background: TAPUR is a phase II basket study evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of pancreatic cancer pts with germline or somatic BRCA1/2 inactivating mutations treated with O are reported. Methods: Eligible pts had advanced pancreatic cancer, no standard treatment (tx) options available, measurable disease, ECOG Performance Status (PS) 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts received O tablets or capsules dosed at 300 mg (n=27) or 400 mg (n=3), respectively, orally twice daily until disease progression. Simon 2-stage design tested the null disease control (DC) (objective response (OR) or stable disease at 16+ weeks (wks) (SD16+) according to RECIST) rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have DC, 18 more pts are enrolled. If ≥7 of 28 pts have DC, the tx is worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS), and safety. Results: Thirty pts with BRCA1/2 inactivating mutations were enrolled from Nov 2016 to Aug 2019; 20 were previously treated with platinum based therapy. Two were not evaluable and excluded from efficacy analyses. Demographics and outcomes are summarized in Table. One partial response (PR) and 7 SD16+ were observed for DC and OR rates of 31% (90% CI: 18% - 40%) and 4% (95% CI: 0% - 18%), respectively. Seven pts had at least one grade 3 AE or SAE at least possibly related to O including anemia, diarrhea, fever, elevated liver enzymes, enterocolitis, increased bilirubin, and oral mucositis. Conclusions: Monotherapy O showed anti-tumor activity in heavily pre-treated pts with pancreatic cancer with germline (5/12 pts with OR or SD16+) or somatic (3/16 pts with OR or SD16+) BRCA1/2 inactivating mutations extending findings of recent studies of O in pts with advanced pancreatic cancer. Clinical trial information: NCT02693535 . [Table: see text]