New evidence that on-demand PrEP is highly effective in MSM

Results from Prevenir, an ongoing observational study, provided further evidence that on-demand PrEP is an effective strategy for preventing HIV acquisition in at-risk men who have sex with men (MSM). On-demand PrEP involves taking a pill containing tenofovir plus emtricitabine (TDF/FTC) before and after sex, rather than daily.

Prevenir builds on the results of a previous study, IPERGAY, with data from a cohort of 1,435 at-risk, HIV-negative individuals, nearly all of them MSM, in the Paris region. At enrolment, 44% of participants used PrEP daily and 53% used it on demand.

Jean-Michel Molina of the University of Paris Diderot reported that, so far, the study had found no breakthrough HIV infections among men taking PrEP “on demand” or those taking it daily, supporting continuing use of both dosing regimens in this population. No study participants discontinued PrEP for drug-related adverse events.