Cost effectiveness analysis of Pembrolizumab versus Ipilimumab in advanced melanoma

Abstract

Melanoma is a type of skin cancer originating in the pigment-producing melanocytes, which are found between the outer layer of the skin (the epidermis) and the layer beneath (the dermis). Melanocytes produce melanin, a pigment that helps to protect the skin against damage caused by ultraviolet (UV) light from the sun (Cancer Research UK, 2014b). Based on the results of the clinical study Keynote 006, the estimated 6-month progression-free-survival was 47.3% for pembrolizumab every 2 weeks, 46.4% for pembrolizumab every 3 weeks, and 26.5% for ipilimumab. Estimated 12-month survival was 74.1%, 68.4%, and 58.2%, respectively. The response rate was improved with pembrolizumab administered every 2 weeks (33.7%) and every 3 weeks (32.9%), as compared with ipilimumab (11.9%) (P<0.001 for both comparisons). Rates of treatment-related adverse events of grade 3 to 5 severity were lower in the pembrolizumab group (13.3% and 10.1%) than in the ipilimumab group (19.9%). Pembrolizumab is a humanized monoclonal anti-programmed cell death-1 (PD-1) antibody produced in Chinese hamster ovary cells by recombinant DNA technology. Official Date for first approval by European Medicine Agency was on 17th of July 2015. The purpose of this analysis is to assess the cost-effectiveness of Pembrolizumab compared to Ipilimumab (standard of care) as a treatment option for patients with advanced melanoma in Greece from the perspective of the Greek National Health System. Method: The analysis uses a Markov model. The model includes three health states: Progression Free (PFS), Progressed Disease (PD) and death. The population was assumed identical to the population enrolled in the clinical trial KEYNOTE 006 and the data used to populate the model were drawn from international and Greek published sources. The model follows patients over time from the start of therapy till death using monthly cycles. The probabilities for OS and PFS were extracted by the reference clinical trial KEYNOTE006 and were extrapolated to a period of 120 months thus covering the life expectancy of these patients (lifetime analysis). Clinical effectiveness was combined with quality adjusted life expectancy and the corresponding cost was estimated by combining the volume of resources used with their unit costs based on current Greek reimbursement prices. In addition, sensitivity analysis was performed due to the uncertainties introduced by some of the model parameters. Pembrolizumab compared with Ipilimumab, the standard of care for advanced melanoma, showed higher cost per patient, while at the same time LYs and QALYs were improved. The ICER was estimated at €18135.64/QALY and €14701.52/LYG for the life expectancy of these patients. The sensitivity analysis showed that the results are sensitive to the cost of Pembrolizumab. Based on the results of this analysis, Pembrolizumab compared to Ipilimumab as a treatment for advanced melanoma seems to be a cost-effective treatment option for the Greek Health System.