A Phase II trial of high-dose intravenous interferon alpha-2 in advanced colorectal cancer.

Twenty-one patients with metastatic colorectal cancer were treated with high-dose intravenous interferon alpha-2 (30-50 X 10(6) units/m2) administered daily for 5 consecutive days. Courses of therapy were repeated every 2 to 3 weeks. No tumor responses were seen among 15 evaluable patients. In two subjects, disease remained stable for 3 and 7 months, respectively. Toxicity was substantial and a de-escalation of dose was frequently required. Fevers, gastrointestinal symptoms, fatigue, leukopenia, and elevated serum transaminases were common. High-dose interferon was found to be ineffective in the treatment of metastatic colorectal cancer. A daily dose of 50 X 10(6) units/m2 was greater than the maximum tolerated dose in this group of patients.