Combined interferon alpha with levamisole in patients with metastatic renal cell carcinoma

To evaluate the efficacy and toxicity of interferon alpha-2b (IFN-alpha2b) and levamisole treatment regimen in patients with metastatic renal cell carcinoma (RCC). Seventeen patients with metastatic RCC were treated using recombinant IFN-alpha2b at a dose of 10 MU/m2 body surface subcutaneously three times in a week, for 3 months, with levamisole 50 mg t.d.s orally on days 1-3 on alternate weeks. The mean follow-up period was 10.7 (range 2-23) months. We achieved 1 complete response (lasting for 12+ months) and 1 partial response (lasting for 15 months), for an objective response rate of 11.7%. A further 7 patients (41%) had a stabilization of disease. The overall toxicity was moderate, with mainly grade I or II side effects. Grade III toxicities reported among 3 patients including vomiting (2 patients) and anorexia (1 patient). There was no treatment related death. Although additions of levamisole to IFN-alpha do not result in any significant increase in treatment toxicity, the response rate appears to be no better than IFN-alpha monotherapy reported in the literature.