OBJECTIVE: The “Ending the HIV Epidemic in the US” initiative aims to increase the use of pre-exposure prophylaxis (PrEP) among individuals at risk of acquiring HIV-1 infection in the United States (US). To assess the impact of increased PrEP use, this analysis examines the number of individuals needed to treat (NNT) with different PrEP options (cabotegravir-long-acting [CAB-LA] or oral PrEP [FTC/TDF]) to avoid 1 new HIV infection in the US.
METHODS: NNT was estimated for two scenarios (1) comparing PrEP use with no PrEP use and (2) comparing CAB-LA use with oral PrEP use. Both scenarios were examined for the overall US PrEP-eligible population and for important subpopulations, such as men who have sex with men (by race/ethnicity), transgender women, and high-risk cisgender women. NNT for each PrEP option was calculated for each scenario by estimating the HIV risk difference between (1) PrEP options and no PrEP or (2) CAB-LA and oral PrEP and inverting the result. HIV incidence data for individuals receiving no PrEP were taken from published literature and public sources. HIV incidence data for individuals receiving PrEP were taken from clinical trials.
RESULTS: Compared with no PrEP, NNT with PrEP to avoid 1 new HIV infection was 35 for CAB-LA and 49 for oral PrEP for the overall PrEP-eligible population. NNT was consistently lower for CAB-LA (ranging 27-39) than for oral PrEP (ranging 33-114) across all subpopulations. Compared with oral PrEP use, NNT with CAB-LA to avoid 1 new HIV infection was 118 for the overall PrEP-eligible population and ranged from 59 to 158 across all subpopulations.
CONCLUSIONS: For populations at increased risk, CAB-LA for PrEP could represent a more efficient option for preventing additional HIV infections in the US.
