Clinical and safety profile of high-dose interleukin-2 treatment in elderly patients with metastatic melanoma and renal cell carcinoma

Objective: High-dose interleukin-2 (IL-2) is effective immunotherapy for the treatment of metastatic melanoma and renal cell carcinoma (RCC) but has been contraindicated in elderly patients. This study assessed the safety and therapeutic efficacy of high-dose IL-2 in patients ≥65 years of age with metastatic melanoma and RCC. Methods: A prospectively collected clinical database of 104 consecutive melanoma or RCC patients treated with high-dose IL-2 between 2009 and 2012 was used to compare clinical outcomes and adverse events in patients ≥65 years of age with those of younger patients. Results: There were 22 (21%) patients ≥65 years and 82 (79%) patients <65 years of age. The mean number of IL-2 doses was lower in older patients during cycle 1 of treatment (7.2 vs. 8.6, p = 0.012). There were no other differences in dosing pattern by age group. There was a higher rate of selected cardiac, constitutional, hematologic, metabolic and renal toxicities in younger patients (p < 0.05). Overall, objective responses and survival were not affected by age, though older patients had a higher partial response rate (p = 0.04). Conclusions: IL-2 is safe and has comparable therapeutic effectiveness in patients ≥65 years. Age should not be considered a contraindication to treatment with IL-2 in otherwise eligible patients.