Interleukin-2: clinical applications

Interleukin-2 (IL-2) is a promising immunotherapeutic agent for the treatment of metastatic melanoma, acute myelogenous leukemia, and metastatic renal cell carcinoma. While high-dose IL-2 regimens have shown clinical benefit in the treatment of melanoma and renal cell carcinoma, serious dose-limiting toxicities have limited their clinical use in a broader group of patients. Low-dose IL-2 therapy has produced disappointing clinical response rates in melanoma. While the response rates to low-dose IL-2 have been better in renal cell carcinoma, the quality of these responses relative to those seen with high-dose IL-2 therapy remains a concern. The addition of IL-2 to chemotherapeutic regimens (biochemotherapy) has been associated with overall response rates of up to 60% in patients with metastatic melanoma, but this has yet to be translated into a confirmed improvement in survival. It remains to be determined whether further modifications of IL-2-based regimens or the addition of newer agents to IL-2 will produce better tumor response and survival.