405O_PR Cost-effectiveness of pembrolizumab compared to ipilimumab and chemotherapy as a first line treatment for patients with advanced melanoma in Hong Kong

Abstract

Background: Pembrolizumab (Pembro) has been shown to improve overall survival (OS) and progression free survival (PFS) compared with ipilimumab (Ipi) in patients with Ipi naïve advanced melanoma; however, there are no published data on the costeffectiveness for Pembro compared with treatments currently used in Hong Kong for advanced melanoma. Methods: A partitioned-survival model based on data from a recent randomized phase 3 study (KEYNOTE-006) was used to derive cost and time in PFS, OS, and postprogression survival for Pembro and Ipi. Other comparators include dacarbazine (DTIC), temozolomide (TMZ), and the paclitaxel-carboplatin combination (PC). A combination of clinical trial data, literature data, results of meta-analysis, and melanoma registry data was used to derive PFS and OS curves. The base-case time horizon for the model was 10 years with costs and health outcomes discounted at a rate of 5% per year. Individual patient level data on utilities and frequencies of adverse events were obtained from an interim analysis of the KEYNOTE-006 (cut-off date: 3-Mar-15) for Pembro and Ipi. Cost data included drug acquisition, treatment administration, adverse event management, and clinical management of advanced melanoma. Cost information was obtained. The distribution of patient weight from the Hong Kong population was applied to calculate the drug costs. The incremental cost effectiveness ratio (ICER) expressed as cost in US Dollars (USD) per quality-adjusted life years (QALYs) was the main outcome. Sensitivity analyses (probabilistic and oneway) were performed to test the robustness of the results. Results: The ICER for Pembro as a 1L treatment for advanced melanoma was USD 8,034 compared with Ipi and USD 53,123 compared to DTIC. Results comparing Pembro to TMZ and to PC were similar to that of comparing with DTIC. Conclusions: Pembro is cost effective relative to Ipi for the treatment of advanced melanoma in Hong Kong. When compared with chemotherapy (DTIC, TMZ and PC), the resulting ICER is also lower than theWHOthreshold of three times gross domestic product (GDP) per capita, which, for Hong Kong, is currently at USD 119,274.