LAUSR

BACKGROUND Talimogene laherparepvec (T-VEC) improves overall survival (OS) in unresectable stage IIIB/C-IV melanoma.1 T-VEC may have synergistic effects with CTLA-4 inhibitors.2 In the absence of a trial comparing T-VEC and ipilimumab (T-VEC+IPI) to T-VEC, we applied a novel indirect comparison method using extrapolated OS curves to estimate OS outcomes in a simulated trial comparing both regimens in stage IIIB/C-IV unresectable melanoma. RESEARCH DESIGN AND METHODS Two trials with extractable OS curves for a T-VEC versus T-VEC+IPI comparison were identified. Outcomes were adjusted for heterogeneity in prognostic factors using a calculated adjustment factor. T-VEC and adjusted/unadjusted T-VEC+IPI curves were plotted with 95% CIs. RESULTS Unadjusted indirect OS comparison of T-VEC versus T-VEC+IPI revealed no significant difference up to 15 months. Extrapolation beyond 15 months showed significant survival benefits for TVEC+IPI over T-VEC, confirmed in adjusted analyses. The expected OS percentage at 48 months is 32.0% (95%CI=26.6-37.3) for T-VEC, 60.0% (95%CI=46.2-69.1) for unadjusted and 81.1% (95%CI=72.3-85.9) for adjusted TVEC+IPI. CONCLUSIONS Our novel indirect comparison suggests that T-VEC+IPI may demonstrate a significantly improved OS versus T-VEC alone. Findings may portend a possible role for the addition of T-VEC to advanced melanoma treatment regimens in select patients as salvage therapy.