With a modified folfirinox regimen, patients with non-metastatic pancreatic ductal carcinoma in the adjuvant achieved an unprecedented overall survival of 54.5 months compared to the previous standard gemcitabine of 35 months. This was the result of a multicenter international Phase III study presented by Thierry Conroy, Institute de Cancerologie de Lorraine, Nancy, at the 2018 ASCO Annual Meeting in Chicago on June 4, 2018.
In patients with resected pancreatic carcinoma, adjuvant therapy with gemcitabine and/or fluoropyrimidine is currently standard. However, 71 to 76% of patients relapse within two years. There is, therefore, a great need for better therapies.
The folfirinox regimen (fluorouracil, irinotecan, and oxaliplatin) proved more effective than gemcitabine in first-line therapy in patients with good performance status with metastatic pancreatic carcinoma. However, the regime has relatively many adverse effects, and a modified folfirinox regime without bolus fluorouracil proved to be better tolerated with fewer hematological side effects and less diarrhea but comparable efficacy.
Therefore, the international Phase 3 study PRODIGE 24/CCTG PA.6 compared the efficacy of mFolfirinox and gemcitabine in adjuvant therapy of patients with R0- or R1-resected pancreatic carcinoma. 77 centers in France and Canada enrolled 493 patients. 21 to 84 days after surgery, they randomly received 12 cycles of mFolfirinox (oxaliplatin, leucovorin, irinotecan, fluorouracil) or 6 cycles of gemcitabine. The primary endpoint was disease-free survival (DFS), secondary endpoints included toxicity, overall survival (OS), cancer-specific survival and metastasis-free survival.
After a median follow-up period of 33.6 months, DFS was 21.6 months in the mFolfirinox group and 12.8 months in the gemcitabine group. This corresponds to a hazard ratio (HR) of 0.58 (p < 0.0001). After 3 years, 39.7% of patients in the mFolfirinox group were still without symptoms and 21.4% in the gemcitabine group. Metastasis-free survival was 30.4 months with mFolfirinox in the median and 17.7 months with gemcitabine (HR 0.59, p < 0.0001). Patients in the mFolfirinox group lived almost 20 months longer in median (54.4 months) than patients in the gemcitabine group (35 months) (HR 0.64, p = 0.003). After 3 years, 63.4% of patients still lived with mFolfirinox treatment and 48.6% with gemcitabine treatment. The superiority of mFolfirinox was seen in all subgroups.
Grade 3/4 adverse effects were 76% more frequent in the folfirinox group than 53% in the gemcitabine group. According to Conroy, however, toxicities must be managed.
Based on these results, mFolfirinox should now be considered as a new therapy standard after resection of a pancreatic carcinoma in patients with good performance status, the authors concluded. According to Conroy, the next step will be to review the regime in the Neoadjuvant and perioperatively. Studies are already underway in this area
ASCO expert Andrew Epstein, Memorial Sloan Kettering Cancer Center, New York, also believes that mFolfirinox is a new therapy standard for these patients: "This is an important and convincing OS result," he said at an ASCO press conference. However, the regime should not be given to every patient, because it is a relatively big challenge. Only patients in good condition are suitable for this.
Richard Schilsky, Chief Medical Officer of ASCO, also pointed out that only 15 to 20% of patients could be operated on with pancreatic carcinoma. Nevertheless, this is the greatest progress in pancreatic cancer he has seen since the introduction of gemcitabine.
Conroy T et al. Unicancer GI PRODIGE 24/CCTG PA.6 trial: A multicenter international randomized phase III trial of adjuvant mFOLFIRINOX versus gemcitabine in patients with resected pancreatic ductal adenocarcinomas. 2018 ASCO Annual Meeting, Chicago, June 1-5, 2018, abstract LBA4001. https://meetinglibrary.asco.org/record/159164/abstract