A phase II trial of preoperative FOLFIRINOX followed by gemcitabine-based chemoradiotherapy in patients with borderline resectable pancreatic ductal adenocarcinoma (BR PDAC).

Abstract

4638 Background: Preoperative (preop) therapy is widely accepted as the standard of care for patients (pt) with BR PDAC with limited evidence for a specific regimen. This study aimed to assess the efficacy of FOLFIRINOX (FOL) chemotherapy followed by gemcitabine-based chemo-radiotherapy (RT) as preop therapy in pt with BR-PDAC. Methods: This single arm Simon two stage phase II trial in pt with BR PDAC was conducted in two phases. The first phase included 4 cycles of FOL, and the second included weekly gemcitabine (1000 mg/m2) for 6 cycles with concomitant intensity-modulated RT (50.4 Gy in 28 fractions)(Gem/RT).The primary aim was to compare R0 resection rate (H0: ≤40% vs Ha≥60%) using one-sample one-sided Z test. Secondary outcomes, including overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan-Meier method. Results: Of 22 enrolled pt, 18 (81.8%) completed preoperative treatment. Median age at diagnosis was 63.4 years and 12 (54.5%) were female. There were 10 (45.5%) Hispanics, 4 (18.2%) non-Hispanic black, and 8 (36.4%) non-Hispanic white. Tumor location was predominantly head/neck (21, 95.5%), 15 (68.1%) had T2/3, and 9 (40.9%) had N2 (clinical) disease. Fourteen (64.6%) pt, had venous involvement, 5 (22.7%) had arterial, and 3 (13.6%), both. In the first phase, 20 (90.9%) completed 4 cycles of FOL, 6 (27.3%) required dose-reduction and dose was delayed in 12 (54.5%). Stable disease (SD) was achieved in 10 (52.6%), partial response (PR) in 8 (42.1%) and disease progression (PD) in 1 (5.3%) pt. Of 21 pt that entered the second phase, 18 (85.7%) completed 6 cycles of Gem/RT, 5 (26.3%) required dose-reduction and dose was delayed in 6 (31.6%). SD was achieved in 10 (55.6%), PR in 3 (16.7%) and PD in 5 (27.8%). All pt experienced at least one grade 1 adverse event (AE) and 12 (54.5%) at least one grade 3/4 AE, of which neutropenia was the most common-11 (50%). Of the 15 (68.1%) pt who underwent surgical resection, 12 (80%) achieved R0 margins and 5 (33.3%) required vascular reconstruction. The R0 rate among pt that received >1 cycle of FOLFIRINOX was 54.5%. Adjuvant chemotherapy was offered to 6/15 pt (40%). The PFS and OS will be reported. Conclusions: An R0 resection rate of 54.5% with this limited sample size is significant at the 10% level. Neoadjuvant FOLFIRINOX followed by concomitant Gem/RT was well-tolerated. The study will be amended to include adjuvant FOL in line with the PRODIGE intergroup adjuvant study results. Clinical trial information: NCT01897454 .