Long-term cure after complete resection and adjuvant immunotherapy for distant melanoma metastases.

Abstract

8534 Background: In phase II trials, postoperative therapy with Canvaxin allogeneic melanoma cell vaccine plus Bacillus Calmette-Guerin (BCG) improved the survival of patients with stage IV melanoma. A multicenter, phase III placebo-controlled study was undertaken to investigate the vaccine’s efficacy. Methods: After complete resection of melanoma involving up to 5 distant sites, patients were randomized to treatment with BCG plus Canvaxin (BCG-Canvaxin) or BCG plus placebo (BCG-placebo). The primary endpoint was overall survival (OS); secondary endpoints were disease-free survival (DFS) and skin test responsiveness to the study agent. Results: Between May 1998 and April 2005, 496 patients were randomized. In April 2005, entry to the study was terminated due to low probability of demonstrating treatment differences. However, 256 patients from sites enrolled in a follow-up study were monitored until March 2010. Median OS and 5-year and 10-year rates of OS were 39.1 months, 43.3% and 33.3%, respectively, in the BCG-placebo group, versus 34.9 months, 42.5% and 36.4%, respectively, in the BCG-Canvaxin group (hazard ratio, 1.053; 95% confidence interval, 0.81 to 1.36; p=0.6964). Median DFS, 5-year DFS, and 10-year DFS were 7.6 months, 23.8% and 21.7%, respectively, for the BCG-placebo group, versus 8.5 months, 30.0%, and 30.0%, respectively, for the BCG-Canvaxin group (hazard ratio, 0.882; 95% confidence interval, 0.708 to 1.097; p=0.2595). Positive skin test results correlated with improved survival. Conclusions: BCG-Canvaxin was not superior to BCG-placebo, but the highly favorable long-term survival for combined groups indicates that complete metastasectomy should be considered as initial therapy for patients with resectable stage IV melanoma (ClinicalTrials.gov identifier: NCT00052156).