Combination of 5-fluorouracil and recombinant interferon alpha-2B in advanced gastric cancer. A phase I study.

Based on recent preclinical data suggesting synergism between 5-fluorouracil (5-FU) and interferon alpha (IFN-alpha) and clinical activity of the combination therapy in colon cancer, 14 patients with advanced gastric cancer were treated with combination therapy of 5-FU and recombinant interferon alpha-2b (rIFN alpha-2b) (Intron A, Schering, Kenilworth, NJ, U.S.A.). The maximum tolerated dose was 5-FU 750 mg/m2/day given as a continuous infusion daily for 5 days followed by weekly bolus injection of the same initial daily dose, plus rIFN alpha-2b 5 X 10(6) U given subcutaneously 3 times weekly starting day 1 of 5-FU infusion. The dose-limiting toxicities were fatigue/weakness, diarrhea, and neurologic toxicities such as somnolence and confusion. The other common side effects were nausea, fever, leukocytopenia, thrombocytopenia, and the darkening of the skin. Of 13 evaluable patients, 4 had a partial response (duration 6, 14, 24, and 28 weeks). These data suggest that combination therapy of 5-FU plus rIFN alpha-2b is tolerable and has manageable side effects in patients with advanced gastric cancer. Further Phase II study will be needed to define the antitumor activity of this combination.