Interleukin-2 and interferon-alpha_2b as a daily alternating schedule in advanced renal cell cancer

Summary

Interferon-alpha (IFN-α) and interleukin-2 (Il-2) are effective as single agents in metastatic renal cell cancer (RCC) with response rates of 15–30%. Additionally, IFN-α is assumed to act synergistically with Il-2 in the induction of lymphokine-activated killer cells. (LAK cells) in vitro. With the aims of increasing the response rate by combining both cytokines and of reducing side effects, we started a clinical trial with a daily alternating schedule of 10×10⁶ units/m² s.c. rIFN-α_2b (Essex, Munich, FRG) and 3×10⁶ Cetus units/m² rIL-2 (EuroCetus, Frankfurt, FRG) in the form of 1 h infusions over a period of 14 days. Patients found to have progressive disease after two cycles of therapy were withdrawn from the study; patients with stable disease or better received two further cycles.

Of the 27 patients included in the study, 22 (16 male, 6 female) are evaluable for response. In 1 patient with multiple pulmonary metastases complete remission was achieved, in 5 patients partial remission, and in 2 a minor response. The schedule was practicable; the main side effects were influenza-like symptoms, fatigue and hypotension. Some patients suffered from arthralgias and erythemas up to 3 weeks after finishing the therapy cycle. On the whole, the side effects seem to be less severe than those arising from schedules using continuous Il-2 infusions.