Cost-Effectiveness of Cabotegravir Long-Acting for Pre-Exposure Prophylaxis Versus Current Use of Daily Oral Tenofovir Disoproxil Fumarate/Emtricitabine or No PrEP to Prevent HIV-1 in Individuals at High Risk in Spain

OBJECTIVES: Cabotegravir long-acting (CAB-LA) demonstrated a superior risk-reduction in HIV-1 acquisition versus daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in the HPTN 083 (NCT02720094) and 084 (NCT03164564) studies. The introduction of an injectable PrEP modality may benefit individuals who are contraindicated to, sub-optimally adherent to, unable to tolerate or take daily oral TDF/FTC. A published Markov model was adapted to estimate the cost-effectiveness of CAB-LA compared with TDF/FTC or no PrEP in individuals at high-risk of acquiring HIV-1 who are unable or unwilling to take TDF/FTC in Spain.

METHODS: Background HIV-1 incidence (without PrEP use) was informed by UK epidemiology data and an indirect treatment comparison based on the HPTN 083 and 084 trials, which informed PrEP effectiveness and provided a meta-regression to allow for exploration of TDF/FTC effectiveness at different levels of adherence. If HIV-1 seroconversion occurred, individuals discontinued PrEP and received lifetime HIV-related care. Secondary HIV-1 transmission and PrEP-related breakthrough resistance could occur. Utility decrements and costs were obtained from published sources. The model estimated HIV lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) from the Spanish perspective, with costs and outcomes discounted at 3.0% per annum. Deterministic and probabilistic sensitivity analyses were performed to assess uncertainty.

RESULTS: Considering a 5-year duration of risk during which PrEP is provided, the model estimated that CAB-LA prevented more lifetime HIV-1 infections compared with TDF/FTC or no PrEP and yielded 0.23 and 0.70 more QALYs, respectively. Incremental lifetime costs were €2,553 and –€27,010, respectively, resulting in ICERs of €10,968 and –€38,687. CAB-LA remained cost-effective/cost-saving in the DSA, with a 78% probability of being cost-effective versus TDF/FTC in the PSA at a willingness-to-pay threshold of €30,000/QALY (1,000 iterations).

CONCLUSIONS: CAB-LA for PrEP is cost-effective versus daily oral TDF/FTC and dominant versus no PrEP in individuals at high-risk of HIV-1 acquisition in the Spanish healthcare setting.