Phase II trial of 5-fluorouracil, folinic acid and recombinant α-2a-interferon in patients with advanced colorectal cancer

A clinical trial regimen modulating 5-fluorouracil (5-FU) with both folinic acid (FA) and recombinant α-2a-interferon (rα.-2a-IFN) was noted to have a response rate of 54% and median survival of 16.3 months (Grem ef a/., J Clin Oncol 1993, 111737–45). Reported herein is a phase II trial performed to further examine this regimen in metastatic colorectal cancer. Fifty-one patients with histologically proven, measurable advanced colorectal cancer with no prior therapy for metastatic disease were enrolled. rα-2a-IFN, 5 MIU/m/day was given s.c. on days 1–7. FA, 500 mg/m/day, and 5-FU, 370 mg/m/day, were given i.v. on days 2–6. Cycles were repeated at 3 week intervals. Three complete and 12 partial responses were observed for an overall response rate of 29% (95% confidence interval18–45%). The median time to treatment failure and median survival were 4.6 and 15.5 months, respectively. Dose-limiting toxicities encountered were gastrointestinal, and included diarrhea, stomatitis, nausea and vomiting. These results do not support the concept of using concurrent rα-2a-IFN and FA as biochemical modulators of 5-FU. We observed increased toxicity and similar efficacy compared to using either modulator separately with 5-FU.