Should High-Dose Interleukin-2 Still Be the Preferred Treatment for Patients with Metastatic Melanoma?

Abstract

For more than 20 years interleukin-2 (IL2) was the preferred treatment for medically fit metastatic melanoma patients, but recently two new agents, ipilimumab and vemurafenib, were approved for stage IV disease. Single-institution data were used to determine the long-term survival rate for IL2-treated melanoma patients, and whether use of inpatient IL2 had declined recently. Between May 1987 and April 2010, 150 patients were hospitalized for high-dose, intravenous (i.v.) IL2. The average number of IL2 patients increased from 5.4 per year during 1987-1991 to 5.8 during 1992-1997 after regulatory approval of IL2, to 8.3 during 1998-2006 after a marketing indication in metastatic melanoma was granted, but dropped to 3.0 during 2007-2010. At the time of treatment, median age was 52 years; 27% were 60 years of age or older. At the time of analysis 122 patients were deceased. Median survival from the start date of IL2 treatment was 15.6 months, with a 20% 5-year survival. Among patients enrolled in clinical trials, there were as many nonresponders who survived 5 years as responders, which is consistent with a delayed immunotherapy benefit. In the absence of long-term survival data for these newer agents, IL2 probably should still be the preferred initial treatment for most patients with metastatic melanoma who are medically fit.