A randomized phase III trial of biochemotherapy versus interferon-alpha-2b for adjuvant therapy in patients at high risk for melanoma recurrence

Abstract

The objective of this study was to compare the clinical benefit of biochemotherapy and interferon-alpha-2b (IFN) as adjuvant therapy. Biochemotherapy has higher response rates than other regimens in patients with metastatic melanoma. We conducted a randomized phase III study comparing the clinical benefit of biochemotherapy and IFN as adjuvant therapy. Patients who had undergone lymphadenectomy for melanoma metastatic to regional lymph nodes were randomly assigned to either biochemotherapy or IFN, and IFN patients were further randomized to either high-dose IFN (HDI) or intermediate-dose IFN (IDI). The primary end point was relapse-free survival (RFS); the secondary end point was overall survival (OS). The planned enrollment was 200 patients, the number required to have 80% power to detect, at a significance level of 5%, an improvement in median RFS from 18 to 36 months and an improvement in median OS from 40 to 80 months between the IFN and biochemotherapy groups. A futility analysis was performed because of slow accrual. One hundred and thirty-eight patients were enrolled - 71 in the biochemotherapy group, 34 in the HDI subgroup, and 33 in the IDI subgroup. No significant differences in median RFS or OS between the HDI and IDI subgroups were observed. With a median follow-up of 49.3 months, neither the biochemotherapy nor IFN group had reached median RFS or OS, and there were no significant differences in estimated median RFS or OS (P=0.86 and 0.45, respectively) between the two groups. Biochemotherapy is not more effective than IFN as adjuvant therapy for melanoma. These findings support early termination of this trial.