Results of two sequential phase II studies of interleukin-2 (IL2) in metastatic renal cell carcinoma and melanoma: high-dose continuous intravenous IL2 infusion and subcutaneous IL2 administration in combination with alpha interferon.

The results of two sequential trials, the first one with high dose interleukin 2 (IL2) by continuous intravenous infusion and the second one with subcutaneous IL2 and alpha-interferon (alpha IFN), performed in consecutive patients with metastatic melanoma and renal carcinoma at the Clinica Universitaria de Navarra are presented. In the high-dose continuous IL2 trial, recombinant IL2, 18 x 10(6) IU/m2, was administered daily by continuous infusion five days a week for two weeks, and the treatment cycle was repeated after a rest of 2 weeks. Twenty two patients were treated and objective responses were observed in 3 (13.3%). Toxicity was frequent and severe, and all but one required dose reduction. The mortality rate was 9% (2/22). In the subcutaneous IL2 and alpha IFN trial, subcutaneous IL2, 4.8 x 10(6) IU/m2, was administered daily, five days a week, for 3 consecutive weeks. IL2 dose was given every 8 hours on the first day and every 12 hours on the second day, as a loading induction dose. Concomitant alpha-IFN, 3 x 10(6) IU/m2 was given subcutaneously once a day on days 1, 3 and 5 weekly each week for the duration of IL2 therapy. Of the 24 patients treated with this combination, 3 partial responses were noticed (12.5%) and the toxicity was mild to moderate. These results suggest that both, IL2 alone or IL2 in combination with alpha-IFN are minimally active and that any improvement in tolerance might impair its antitumor activity.