Cost-minimization comparison of darunavir plus ritonavir and lopinavir/ritonavir in HIV-1 infected treatment-naïve women of childbearing age.

Background: Guidelines from the Department of Health and Human Services in the US recommend ritonavir-boosted lopinavir (LPV/r) as a preferred protease inhibitor (PI) for HIV-positive antiretroviral-naїve pregnant women. These guidelines also cite ritonavir-boosted darunavir (DRV + RTV) as an alternative PI in this clinical scenario. The purpose of this analysis was to compare economic outcomes for regimens based on these two treatments.

Study Design: An existing discrete event simulation (DES) model was adapted to conduct a cost-minimization analysis comparing the two regimens in HIV-infected women of childbearing age (WOCBA), from the perspective of a healthcare payer in the US.

Methods: The DES model was used to represent disease states, health events, healthcare encounters, pregnancy, and treatment choices in HIV-infected WOCBA starting treatment with regimens based on either LPV/r or DRV + RTV. It also incorporated parameters for individual patient characteristics, and for antiretroviral (ARV) treatment effectiveness, treatment sequencing, clinical progression, and resource use. Potential events included scheduled physician visits; viral suppression; viral rebound; AIDS-related complications; CHD events; treatment discontinuation and switching; ARV treatment side-effects (SE); and death. The primary outcomes were discounted 5-year and 10-year healthcare costs. Alternative scenarios considered different rates of switching from DRV + RTV to LPV/r upon conception.

Results: Compared with DRV + RTV, LPV/r was associated with similar clinical outcomes while offering savings at the 5- and 10-year horizons (of $24,904 and $43,502 per patient, respectively), and in extensive sensitivity analyses. The main driver of the savings was the difference in cost between PIs.

Conclusions: Starting HIV-infected ARV-treatment-naїve WOCBA on an LPV/r-based regimen is cost-saving and provides similar patient outcomes compared to a DRV + RTV-based regimen.