CostEffectiveness Analysis of Raltegravir in Treatment Experienced HIV

Cost-Effectiveness Analysis of Raltegravir in Treatment -Experienced HIV Patients in Switzerland Elamin H. Elbasha 1, Thomas D. Szucs 2, Mohammad A. Chaudhary 1, Ritesh N. Kumar 1, Alexander Roediger 3, John R. Cook 1 & Milos Opravil 4 Merck and Co. Inc, USA; 2 University of Zurich, Switzerland, 3 Merck Sharpe and Dohme, Zurich, Switzerland, 4 University Hospital Zurich, Switzerland. 1

Model Overview State-transition cohort model was developed using Mathematica Version 6 – Continuous-time Markov process with limited history Two treatment strategies evaluated: A. Placebo + OBT B. Raltegravir + OBT Three sets of differential equations estimated within the model corresponding to 3 broad health states: – Patients with No Opportunistic infections (OI) – Patients with History of OI – Patients with Current OI 2

HIV Diseases Progression Model 3

Cost-Effectiveness of Raltegravir + OBT versus OBT Treatment Strategy Life Expectancy (Years) Dis. QALYs (Years) Discounted Lifetime Cost (1000 CHF) Placebo + OBT 24. 33 14. 07 1, 323. 8 Raltegravir + OBT 28. 13 16. 30 1, 435. 5 Parameter Assumption ICER (CHF/QALY) Raltegravir Treatment duration 1 year 23, 710 Raltegravir Treatment duration 3 years 37, 431 Raltegravir Treatment duration 5 years 50, 086 Raltegravir Treatment duration 10 years 64, 026 Raltegravir Treatment duration Lifetime 96, 102 Assumes raltegravir daily cost of CHF 46. 44; QALY = quality-adjusted life year; ICER = incremental cost-effectiveness ratio 4

Summary Long-term outcomes of raltegravir therapy were evaluated using a cohort state-transition model. The Model suggests raltegravir provides substantial clinical benefits in terms of longer life expectancy and better quality of life Raltegravir is cost-effective when added to OBT versus OBT alone Cost-effectiveness results are sensitive to cost of raltegravir and treatment duration with raltegravir 5