Phase I trial of continuous infusion recombinant interleukin-2 and intermittent recombinant interferon-alpha 2a: clinical effects.

A phase I trial of high-dose continuous infusion rIL-2 over 5 days and i.m. recombinant human interferon-alpha (rHuIFN-alpha 2a) three times weekly in 23 patients with advanced malignancy has been completed. Cohorts of patients were treated at three different dose levels: rIL-2 3.0 x 10(6) u/m2 plus rHuIFN-alpha 2a either 5.0 or 10.0 x 10(6) u/m2, and rIL-2 4.5 x 10(6) u/m2 plus rHuIFN-alpha 2a 5.0 x 10(6) u/m2 over 4 weeks. Dose-limiting toxicity consisted of pulmonary and neurologic side effects, and the maximal tolerated dose was 3.0 x 10(6) u/m2 on days 1-5 or rIL-2, and 10.0 x 10(6) u/m2 three times weekly of rHuIFN-alpha 2a. Four partial responses (renal carcinoma, three; endometrial carcinoma, one) were seen. In conclusion, toxicity of this schedule of rIL-2 and rHuIFN-alpha 2a was significant, but manageable. Further investigation is needed to define the antitumor activity of this combination.