Cost-effectiveness of combination therapy with etravirine in treatment-experienced adults with HIV-1 infection.

Objective: To assess the cost-effectiveness of etravirine (INTELENCE), a novel nonnucleoside reverse transcriptase inhibitor, used in combination with a background regimen that included darunavir/ritonavir, from a Canadian Provincial Ministry of Health perspective.

Design: A Markov model with a 3-month cycle time and six health states based on CD4 cell count ranges was developed to follow a hypothetical cohort of treatment-experienced adults with HIV-1 infection through initial and subsequent treatment regimens.

Methods: Costs (in 2009 Canadian dollars), utilities, and HIV-related mortality data for each health state as well as non-HIV-related mortality data were estimated from Canadian sources and published literature. Transition probabilities between health states and first-year hospitalization and mortality rates were derived from clinical trial data. Incremental 1-year costs per additional adult with viral load less than 50 copies/ml at 48 weeks and incremental lifetime costs per quality-adjusted life-year (QALY) gained were estimated using a 5% discount rate. Sensitivity and variability analyses and model validation were performed.

Results: Etravirine was associated with an increased probability of achieving less than 50 copies/ml at 48 weeks of 0.205 and an estimated gain of 0.66 discounted (1.48 undiscounted) QALYs over a lifetime. The incremental 1-year cost per additional person with viral load less than 50 copies/ml was $23,862. The lifetime incremental cost per QALY gained was $49,120. For the uncertainty ranges and variability scenarios tested for the lifetime horizon, the cost-effectiveness ratio was between $28,859 and 66,249.

Conclusion: When compared with optimized standard of care including darunavir/ritonavir, adding etravirine represents a cost-effective option for treatment-experienced adults in Canada.