Fluorouracil and recombinant alfa-2a-interferon: an active regimen against advanced colorectal carcinoma

Based on in vitro studies that have demonstrated synergy between recombinant alfa-2a-interferon (rIFNα-2a) and the fluoropyrimidine, fluorouracil (5FU), against two human colon cancer cell lines, a pilot clinical trial was initiated to determine the effects of the combination of 5FU and rIFNα-2a in patients with advanced, unresectable colorectal carcinoma. A total of 30 patients were enrolled; all were evaluable. 5FU was administered as a loading course, 750 mg/m² daily for 5 days by continuous infusion followed by weekly bolus therapy. rIFNα-2a, 9 MU, was administered subcutaneously three times per week. Of 17 previously untreated patients evaluable for response, 13 achieved a response. Three patients had disease progression. No previously treated patients had a major response. There was one death clearly related to therapy, an event preceded by watery diarrhea and neutropenic sepsis. Other toxicities were reversible and responded to dose reduction. With a median follow-up of 16+ months, median survival has not been reached among the previously untreated patient cohort. We conclude that the combination of 5FU and rIFNα-2a is an active regimen against disseminated colorectal cancer in previously untreated patients.