OBJECTIVES: Current antiretroviral therapy (ART) improves health outcomes, but for some people with HIV daily oral administration remains a challenge. Cabotegravir+rilpivirine long-acting (CAB+RPV LA), administered by a healthcare professional via intramuscular injection every 2 months (Q2M), is the first complete LA regimen for the maintenance treatment of HIV to be available in Spain. The objective of this analysis was to evaluate the cost-effectiveness of CAB+RPV LA Q2M compared with daily oral single tablet regimen (STR) ART in Spain, from the National Healthcare System (NHS) perspective.

METHODS: A published Markov cohort state-transition model was adapted to the Spanish setting and populated with data from the Phase III/IIIb studies of CAB+RPV LA (pooled ATLAS and FLAIR, ATLAS-2M) over a lifetime horizon. Direct healthcare costs (€, 2021) were informed by public sources and assumptions validated with clinical experts. At base-case, list prices for STRs, CAB+RPV LA and injectable administration costs were included. For Quality Adjusted Life-Years (QALYs) calculations, an utility advantage of 0.02 was applied for LA treatment based on a post-hoc analysis of health-related quality of life data from ATLAS and FLAIR. A reduction in adherence rate of 9.5% was assumed for STR. Costs and utilities were discounted 3% annually and several sensitivity analyses were considered, exploring treatment adherence or treatment prices.

RESULTS: CAB+RPV LA Q2M was cost-effective versus daily oral STRs, with QALY gains of 0.27 and an additional cost of €4,003, resulting in an Incremental Cost-Effectiveness Ratio (ICER) of €14,906/QALY. Cost-effectiveness results were robust to all sensitivity analyses.

CONCLUSIONS: From the Spanish NHS perspective, CAB+RPV LA Q2M is a cost-effective alternative versus STR daily oral ART, associated with small QALY gains but also with small incremental costs increase.