Long-term survival of high-risk melanoma patients immunized with a Hyper-IL-6-modified allogeneic whole-cell vaccine after complete resection

Abstract

Objective: Two single arm, Phase II trials (3 and 5) were undertaken to determine the efficacy and toxicity of an adjuvant treatment using Hyper-IL-6 gene-modified whole-cell allogeneic melanoma vaccine in patients with stage IIIB-IV resected disease. Research design and methods: Ninety-seven and 99 patients were enrolled into Trials 3 and 5, respectively. The primary endpoint was disease-free survival (DFS), and the secondary was overall survival (OS). Vaccine was administered eight times every 2 weeks (induction), every month (maintenance) until patient's death. At progression, maintenance was continued or induction was repeated followed by maintenance. Results: Median follow-up was 10.5 and 6.2 years for Trials 3 and 5, respectively. No grade 3 or 4 toxicities were observed. An extension of DFS and OS was observed, when compared with historical non-treated controls. DFS probability at 5 years for Trials 3 and 5 was, respectively, 54.8% and 40.6% for stage IIIB, 25.0% and 24.0% for IIIC, and 8.5% and 17.7% for IV. OS probability at 5 years was, respectively, 66.7% and 56.3% for IIIB, 43.8% and 39.8% for IIIC, and 26.1% and 41.2% for IV. Conclusions: Continuous vaccination, regardless of the disease progression, re-induction, and immunization of patients until death resulted in patients a long-term survival.