Long-Acting PrEP for People With High Vulnerability to HIV Acquisition in Brazil: A Cost-Effectiveness Analysis

In Brazil, men who have sex with men (MSM) and transgender women (TGW) remain heavily affected by HIV. Long-acting pre-exposure prophylaxis (LA PrEP) with injectable cabotegravir (CAB-LA) or lenacapavir (LEN-LA) is more effective at preventing HIV acquisition than oral PrEP. Our objective was to assess the potential clinical and economic impact of offering CAB-LA or LEN-LA to MSM and TGW with high vulnerability to HIV acquisition in Brazil and determine the maximum cost at which they would be cost-effective.

We used the CEPAC microsimulation model of HIV prevention and treatment to evaluate two strategies for MSM and TGW aged 18-49: (1) SOC: standard-of-care oral PrEP at current coverage, and (2) SOC+LA: offering oral and LA PrEP (either CAB-LA or LEN-LA). Input parameters are derived from Brazil-based data from 2010 to 2024 and published studies: HIV incidence (%/year, MSM: 3.4 [age 18-29 years], 1.1 [30-49 years]; TGW: 5.0 [18-29 years], 1.7 [30-49 years]), relative risk reduction, LA versus oral PrEP (66% [CAB-LA]; 89% [LEN-LA]), PrEP coverage (20% [oral PrEP]; 20% [LA PrEP]) and oral PrEP cost (programmatic+drug = $207/year). Outcomes include lifetime HIV risk, life expectancy (LE) and incremental cost-effectiveness ratio (ICER) of SOC+LA versus SOC in 2024 USD/year of life saved (YLS). We identified the maximum LA PrEP cost with ICER below the established Brazilian willingness-to-pay threshold of $8740/YLS.

Compared to SOC, SOC+CAB-LA would decrease MSM lifetime HIV risk from 21.4% to 16.8%, increase undiscounted LE from 39.0 to 39.4 years. For TGW, SOC+CAB-LA would decrease lifetime HIV risk from 29.5% to 23.4%, increase LE from 36.0 to 36.9 years. Results for SOC+LEN-LA would be similar to SOC+CAB-LA. SOC+LA would remain cost-effective for MSM at cost below $710/year for CAB-LA and $740/year for LEN-LA. Findings are most sensitive to LA PrEP cost, HIV incidence, and whether and by how much LA PrEP increases coverage.

Offering LA PrEP with cabotegravir or lenacapavir in addition to oral PrEP for MSM and TGW in Brazil could markedly improve clinical outcomes and be cost-effective at ∼$700/year. Cost agreements are critical to ensure these prevention options are accessible in high-incidence settings.