SWOG S1505: Results of perioperative chemotherapy (peri-op CTx) with mfolfirinox versus gemcitabine/nab-paclitaxel (Gem/nabP) for resectable pancreatic ductal adenocarcinoma (PDA).

Abstract

4504 Background: Clinical outcomes after curative treatment of resectable PDA remain suboptimal. To assess the potential of early control of systemic disease with multiagent peri-op CTx, we conducted a prospective trial in the National Clinical Trials Network. Methods: S1505 was a randomized phase II trial of peri-op CTx (12 weeks pre-, 12 weeks post-op) with either mFOLFIRINOX (Arm 1) or Gem/nabP (Arm 2). Eligibility required confirmed tissue diagnosis of PDA, ECOG PS 0 or 1, and resectable disease per Intergroup criteria. Primary outcome was 2-year overall survival (OS), using a “pick the winner” design; for 100 eligible patients (pts), accrual up to 150 pts was planned to account for cases deemed ineligible at central radiology review. We previously presented data on eligibility (ASCO 2019 abstr 4137). Here we present the final efficacy and toxicity results for the eligible pts. Results: From 2015 to 2018, 147 pts were enrolled; there were 102 eligible pts; 55 in Arm 1; 47 in Arm 2. For Arms 1 and 2 respectively: median age, 66 (44-76) and 64 (46-76) years; males, 36 (65%) and 24 (51%); and ECOG PS 0, 34 (62%) and 31 (66%) pts. Treatment details are shown in Table. For Arm 1 and Arm 2, respectively: Two-year OS was 41.6% and 48.8%; median OS was 22.4 months and 23.6 months. Neither arm’s 2-year OS estimate was statistically significantly higher than the a priori threshold of 40% (p=0.42 in Arm 1 and p=0.12 in Arm 2). Median disease-free survival (DFS) after resection was 10.9 months in Arm 1 and 14.2 months in Arm 2 (p=0.87). Conclusions: We have demonstrated: 1) two-year OS of 41.6% (median 22.4 months) with mFOLFIRINOX and 48.8% (median 23.6 months) with Gem/nabP for all eligible pts starting treatment for resectable PDA; 2) post-resection DFS of 10.9 months and 14.2 months, respectively; 3) adequate safety and high resectability rates with peri-op CTx; 4) little evidence that either regimen improves OS compared with the historical standard. Clinical trial information: NCT02562716 . [Table: see text]