A phase I-II study of high-dose recombinant human interleukin-2 in disseminated renal-cell carcinoma

Natural interleukin-2 is a lymphokine with an immunoregulatory function. The recombinant interleukin-2 (rIL-2) is cloned from a human lymphoblastoid T-cell line for this trial. The gene is expressed in E-coli, allowing production of large quantities of rIL-2. This study is an open label phase I-II trial designed to evaluate the toxicity and efficacy of a rIL-2 in disseminated renal cell carcinoma. After surgical resection of the primary tumor, 3 X 10(6) units/m2 day rIL-2 is administered by 2-hr IV infusions daily for 5 days every other week for a total of eight cycles. At the conclusion of eight cycles of therapy, the patients were re-evaluated for response. Patients with complete and partial responses were eligible to receive an additional eight cycles every other week. Patients demonstrating progressive disease during this study were withdrawn. The toxicities of the high-dose rIL-2 included transient hypotension, pyrexia, malaise, and skin rashes. The transient hypotension responded to fluid replacement, and the other toxicities also responded to symptomatic treatment. The early results in ten patients indicate two partial and one complete response. We have concluded that administration of high-dose interleukin-2 has acceptable toxicities with encouraging response and deserves a phase III study.