Randomized Phase II Trial Evaluating Two Sequential Treatments in First Line of Metastatic Pancreatic Cancer: Results of the PANOPTIMOX-PRODIGE 35 Trial.

Purpose: Metastatic pancreatic cancer (mPC) still harbors a dismal prognosis. Our previous trial (PRODIGE 4-ACCORD 11) demonstrated the superiority of 6-month chemotherapy with fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) over gemcitabine for overall survival. The high limiting oxaliplatin-related neurotoxicity supports the evaluation of an oxaliplatin stop-and-go strategy and a sequential strategy in mPC.

Methods: In this phase II study, patients were randomly assigned to receive either 6 months of FOLFIRINOX (arm A), 4 months of FOLFIRINOX followed by leucovorin plus fluorouracil maintenance treatment for controlled patients (arm B), or a sequential treatment alternating gemcitabine and fluorouracil, leucovorin, and irinotecan every 2 months (arm C). The primary end point was progression-free survival at 6 months.

Results: Between January 2015 and November 2016, 276 patients (mean age: 63 years; range: 40-76 years) were enrolled (A: 91, B: 92, and C: 90). Grade 3 or 4 neurotoxicity occurred in 10.2% of patients in arm A and 19.8% in arm B. The median ratio of received dose/targeted dose of oxaliplatin was 83% in arm A and 92% in arm B. The 6-month progression-free survival was 47.1% in A, 42.9% in B, and 34.1% in C. The median overall survival was 10.1 months in arm A, 11.2 in arm B, and 7.3 in arm C. Median survival without deterioration in quality-of-life scores was higher in the maintenance arm (11.4 months) than in arms A and C (7.2 and 7.5 months, respectively).

Conclusion: Maintenance with leucovorin plus fluorouracil appears to be feasible and effective in patients with mPC controlled after 4 months of induction chemotherapy with FOLFIRINOX. Severe neurotoxicity was higher in the maintenance therapy arm, probably because of the higher cumulative dose of oxaliplatin.