Efficacy, safety, and risk-benefit analysis of adjuvant interferon alfa-2b in melanoma.
A recently completed Eastern Cooperative Oncology Group trial, E1684, has shown that adjuvant therapy with high-dose recombinant interferon alfa-2b (rIFN-alpha 2b) has a significant impact on relapse-free and overall survival in melanoma patients at high risk of recurrence. Adjuvant rIFN-alpha 2b increased the median overall survival to 3.82 years in the treatment group compared with 2.78 years with observation and yielded a 5-year survival rate of 46% versus 37% with observation. This is the first adjuvant therapy to significantly extend survival in this patient population (P = .0023, one-sided). The response to therapy was greatest among those patients with clinical evidence of nodal metastasis. The toxicity associated with this regimen was substantial but tolerable. Approximately 78% of patients treated with rIFN-alpha 2b experienced grade 3 or greater toxicity, and dose modifications were required for 37% and 36% of patients in the induction or maintenance phase, respectively. Quality-of-life-adjusted survival analysis has shown that, despite the toxicity associated with rIFN-alpha 2b therapy, the quality-of-life-adjusted time gained with rIFN-alpha 2b therapy outweighs the reduced quality of life associated with treatment toxicity and relapse. These data support the use of high-dose rIFN-alpha 2b as adjuvant therapy in melanoma patients at high risk of recurrence.