Subcutaneous Interleukin-2 and Interferon in metastatic renal cell carcinoma: Our experience

Low-dose subcutaneous Interleukin-2 (IL-2), alone or in combination with Interferon (IFN), is an active regimen in metastatic renal cell carcinoma. Efficacy is comparable to higher-dose continuous intravenous infusion and toxicity is much lower. However response rate is only 15-25%. In our experience the results obtained with the combination of IL-2 + IFN were disappointing: of the 15 treated patients, only one had a brief partial response. These poor results may be ascribed to the protocol used and the selection of patients. On the other hand, the best published reports in literature with the combination of IL-2 + IFN have showed poor results in “poor prognosis” patients. Chemo-immunotherapeutic regimens have been proposed; however the association of IL-2 + IFN + 5-fluorouracil obtained promising results only in “good prognosis” patients. Based on preclinical studies, we treated 7 patients with unfavourable prognosis features with a combination of IL-2 + IFN + doxorubicin. With severe hematological toxicity, we obtained one partial response and two stable disease, lasting a mean of 14 months. Though preliminary, this finding seems encouraging because it was obtained in poor prognosis patients.