Potential impact and cost-effectiveness of oral HIV pre-exposure prophylaxis for men who have sex with men in Cotonou, Benin: a mathematical modelling study.

Abstract

Oral HIV pre-exposure prophylaxis (PrEP) can effectively reduce HIV incidence. A 2020-21 demonstration project assessed the feasibility and health outcomes of offering oral PrEP to men who have sex with men (MSM) in Cotonou, Benin. We evaluated the epidemiological impact and cost-effectiveness of this project and the potential scale-up of oral HIV PrEP for MSM in Cotonou. We calibrated an HIV transmission-dynamic model structured by age and risk within a Bayesian framework to MSM-specific HIV prevalence and treatment data, parameterised with project behavioural and cost (including PrEP drug, implementation, and HIV care costs) data. We estimated the impact and cost-effectiveness of the 2020-21 Cotonou demonstration project (PrEP coverage, 5-10% of all MSM who are not living with HIV in Grand Cotonou; and adherence, 13-21% taking at least four of seven required doses [ie, at least four doses per week for daily users and at least four of seven expected doses given reported sexual activity for on-demand users]) and of its potential scale-up over 5 years (from 2022 to 2027), reaching 30% coverage of MSM in Grand Cotonou and with demonstration project adherence levels. We additionally modelled ideal PrEP adherence (100% taking at least four of seven required doses). We estimated the percentage of cumulative new HIV infections averted among participating MSM over 1 year and among all MSM in Grand Cotonou and their female partners over 20 years, and cost-effectiveness as cost per disability-adjusted life-year (DALY) averted over 20 years. Costs and DALYs were discounted 3% annually. We found that the demonstration project averted an estimated 21·5% (95% uncertainty interval 16·6 to 26·2) of HIV infections among participants over 1 year. With ideal adherence, cases that would be averted increased to 95·2% (90·8 to 98·8). A 5-year PrEP scale-up could avert 3·2% (1·6 to 4·8) of HIV infections among all MSM and female partners over 20 years, at US$388 (36 to 2792) per DALY averted. With ideal adherence, this decreased to -$28 (-126 to 589) per DALY averted. Low adherence to PrEP restricted the impact of the demonstration project. At 30% coverage among MSM by 2027, PrEP scale-up would be cost-effective at a $1225 threshold with 86·6% probability, and it could be more cost-effective if high adherence could be reached without substantially increasing costs. Canadian Institutes of Health Research and US National Institutes of Health. For the French translation of the abstract see Supplementary Materials section.