A phase I trial of 5‐fluorouracil, folinic acid, and alpha‐2a‐interferon in patients with metastatic colorectal carcinoma

Abstract

The mechanisms of biochemical modulation of 5‐fluorouracil (5‐FU) cytotoxicity by folinic acid (FA) have been elucidated, and the clinical use of this combination has improved response rates and survival in patients with metastatic colorectal cancer. Recently, Phase II trials also showed potential synergism between alpha‐2a‐inter‐feron (rHuIFN‐α2a) and 5‐FU. Therefore, a Phase I trial of these three agents 5‐FU, FA, and rHuIFN‐α2a was conducted in patients with metastatic colorectal cancer. The drugs were given over 5 days, with dose escalation of either rHuIFN‐α2a or 5‐FU. Fifty‐five eligible patients were treated at eight dosing levels. The maximal tolerated dose (MTD) was as follows: 5‐FU 430 mg/m2/d intravenously (IV) on days 1 to 5, FA 200 mg/m2 IV on days 1 to 5, and rHuIFN‐α2a 4.0 × 106 U/m2/d subcutaneously on days 1 to 5. The dose‐limiting toxicities were mucositis and neutropenia. Objective responses were seen at most dosing levels, and overall 15 of 55 patients (27%; 95% confidence interval, 16% to 41%) responded (median duration, 6.5 months). A Phase II trial using the MTD is ongoing. Cancer 1992; 69:889–892. Copyright © 1992 American Cancer Society