Phase II trial of 5-fluorouracil and leucovorin in combination with interferon-alpha and interleukin-2 for advanced renal cell cancer

Recent clinical trials have demonstrated activity of chemoimmunotherapy with interleukin-2 (IL-2), interferon-[alpha], and 5-fluorouracil (5-FU) in advanced renal cell cancer. A phase II study was performed to evaluate the affect of adding the potentiating agent leucovorin to this combination regimen. Treatment courses consisted of IL-2 5 MIU/m2 subcutaneously days 1, 3, and 5 of weeks 1 to 4, interferon-[alpha] 3 MIU/m2 subcutaneously on days 1, 3, and 5 of weeks 1 to 4, and leucovorin 50 mg/m2 IV followed by 5-FU 450 mg/m2 IV infusion weekly weeks 1 to 4. Patients were given no treatment on weeks 5 and 6 of the 6-week treatment cycle. Of the 20 patients enrolled in the study, 16 were evaluable for toxicity and 15 were evaluable for tumor response. The most severe toxicities included three reports of grade IV diarrhea; overall, nine incidents of grade III or IV toxicity were reported. No objective antitumor responses were observed, and the median time to progression was 2.8 months. We conclude that this combination chemoimmunotherapy regimen has substantial toxicity but no significant antitumor activity in patients with advanced stage renal cell carcinoma.