Abstract Introduction Italian oral PrEP implementation faced challenges until the drug reimbursement approval in 2023. National real-life data on effectiveness are lacking. This study aimed to report incidence rates (IR) of HIV and other sexually transmitted infections (STIs), along with probabilities and predictors of poor adherence and PrEP discontinuation. Methods Prospective national cohort study (ItaPrEP) on oral PrEP users (PrUs) in 8 Italian centers (Sep2017-Nov2023) that could partially provide free drug supplies. IRs of HIV and STIs, and Kaplan-Meier estimated probabilities of poor adherence and discontinuation were evaluated. Mixed-effect logistic models with random intercept on the center, were used to explore the association between risk factors and poor adherence and discontinuation. Results 1,758 PrUs were included, 98% MSM. 5 HIV seroconversions were observed with an IR 0.187/100 PYFU (95%CI:0.061-0.436). IR/100 PYFU were 13.1 (95%CI:11.7-14.5) for syphilis, 23.8 (95%CI:22-25.7) for chlamydia, 24.2 (95%CI:22.4-26.1) for gonorrhoea. The 2-year probability of poor adherence and discontinuation was 57.9% (95%CI:54.8-61.0) and 37.1% (95%CI:34.3-40.1), respectively. Chemsex and switching schedule were associated with poor adherence, unlike a high educational level. Age 40y, free drug supplies, and laboratory monitoring were associated with a lower risk of discontinuation, while chemsex with a higher risk. Conclusions In this Italian oral PrEP program, the HIV incidence was lower than that observed in pivotal RCTs in high-risk populations and close to that of observational real-life studies. Identifying fragile groups (youngest, low educational level and chemsex users), and addressing barriers (free drugs and monitoring), are key to targeting strategies to improve oral PrEP implementation.
Mazzotta et al. (2025) studied this question.