A randomised phase II trial of 1 month versus 1 year of adjuvant high-dose interferon α-2b in high-risk acral melanoma patients

Background: High-dose Interferon-alpha-2b (HD-IFN) is an adjuvant treatment for melanoma. However, clinical trials for HD-IFN have not been reported in acral melanoma (AM), the predominant subtype of cutaneous melanoma in Asian population. Methods: Patients with resected high-risk (stage IIb-IIIc) AM were randomly assigned to a regimen of 4-week (arm A: 15 x 10(6) U/m(2) d1-5/w x 4w) or 1-year adjuvant HD-IFN (arm B: 15 x 10(6) U/m(2) d1-5/w x 4w + 9 x 10(6) U tiw x 48w), respectively. The endpoints were relapse-free survival (RFS), overall survival (OS) and toxicities. Results: A total of 158 patients were enrolled in this study and 147 patients were eligible for survival analysis. With a median follow-up of 36.1 months, median RFS for arm A and arm B were 17.9 months and 22.5 months, respectively (P = 0.72). Stratified analysis showed that RFS curves of patients in stage IIIb-IIIc were statistically different between arm A and arm B (P = 0.02). The median RFS of patients with more nodal metastases (n >= 3) was shorter (P = 0.004) in arm A (3.3 months) than that in arm B (11.9 months). Grade 1/2 adverse effects were observed in both groups. However, patients in arm B showed higher incidence of reversible Grade 3/4 hepatotoxicity (P = 0.03). Conclusions: The induction dose of 15 x 10(6) U/m(2) and the maintenance dose of 9 x 10(6) U were tolerable, which may be the optional dose intensity for adjuvant IFN-alpha-2b therapy in Chinese high risk AM population. No statistical significance was detected in RFS between the 4-week and 1-year regimen while a 1-year regimen may show clinical benefits in patients with stage IIIb-IIIc AM or with >= 3 nodal metastases. (C) 2011 Elsevier Ltd. All rights reserved.