Intermittent High-Dose Intravenous Interferon Alfa-2b for Adjuvant Treatment of Stage III Melanoma: Final Analysis of a Randomized Phase III Dermatologic Cooperative Oncology Group Trial

Abstract

Purpose To evaluate the efficacy, safety, tolerability, and quality of life (QoL) in patients receiving intravenous, intermittent high-dose interferon alfa-2b (IFN-α-2b [iHDI]) compared with standard high-dose IFN-α-2b (HDI). Patient and Methods Patients with stage III resected lymph node or in-transit metastasis from cutaneous malignant melanoma were randomly assigned to receive either a standard HDI regimen or three courses of IFN-α-2b 20 MIU/m2 administered intravenously 5 days a week for 4 weeks then repeated every 4 months. Distant metastasis-free survival was the primary end point for efficacy analysis. In addition, relapse-free survival, overall survival, safety as determined by Common Terminology Criteria for Adverse Events criteria, and QoL were secondary end points. Results Of 649 patients enrolled, 22 patients were excluded from the intent-to-treat analysis. The remaining 627 patients were well balanced between the arms according to sex, age, and stage. After a median follow-up of 55 months, a multivariable Cox model revealed no significant differences for distant metastasis-free survival (hazard ratio [HR], 1.21; P = .12) or overall survival (HR, 1.01; P = .85). In contrast, the difference for relapse-free survival was significant (HR, 1.27; P = .03), favoring standard HDI. Early termination of treatment because of adverse events or QoL occurred significantly more often with HDI than with iHDI (26.0% v 14.8%; P < .001). Conclusion Although the safety and QoL profiles for the intermittent regimen were favorable, no significant difference was observed for survival while the HR for relapse with iHDI was increased. Therefore, an iHDI regimen, as tested here, cannot be recommended as adjuvant treatment for high-risk melanoma.