Background
Oral HIV pre-exposure prophylaxis (PrEP) is highly effective to prevent HIV in men who have sex with men (MSM). PrEP use is usually monitored in-clinic every 3 months (mo). However, this set-up is burdensome for some PrEP users. Reducing the number of in-clinic visits by online-mediated or 6-monthly monitoring may reduce barriers, but could affect PrEP adherence. The primary objective of the study was to establish the noninferiority in terms of PrEP adherence of online-mediated PrEP monitoring (vs. in-clinic) and of 6-monthly monitoring (vs. 3-monthly).
Methods
EZI-PrEP was an 18-month, 2×2 factorial, open-label, multi-center, randomized, controlled, noninferiority trial conducted at 4 sexual health centers in the Netherlands. Participants were randomized 1:1:1:1 to one of 4 study arms: (1) in-clinic monitoring every 3 mo, (2) in-clinic monitoring every 6 mo, (3) online-mediated monitoring every 3 mo, and (4) online-mediated monitoring every 6 mo. Eligible individuals were MSM and transgender and gender diverse people aged ≥18 years, currently using oral PrEP or initiating this at study enrollment. The primary outcome is the incidence rate (IR) of unprotected acts (UA), defined as a condomless anal sex act with a casual partner not fully covered with PrEP (ie, proxy for HIV acquisition risk). Data were obtained through daily digital diary entries. We calculated the IR ratio (IRR) of UAs between online-mediated and in-clinic monitoring arms, and between 6- and 3-monthly monitoring arms. Noninferiority was concluded if the upper limit of the 97.5%CI of the IRR was <1.8.
Results
Between September 2021 and August 2022 we included 469 participants, who were randomized as follows: arm 1, n=117; arm 2, n=114; arm 3, n=119; and arm 4, n=119. During 605 person years (py) of follow-up, 816 UAs were reported; overall IR of UA was 1.3/py [95%CI:1.2-1.4]. The IR of UA was lower in the online-mediated arms than in the in-clinic arms (IRR=0.83, 95%CI:0.72-0.95). The IR of UA in the 6-month arms was similar to that in the 3-month arms (IRR=0.96, 95%CI:0.84-1.11). The results showed noninferiority with the upper limit of the 97.5%CI of both IRRs <1.8 (Figure).
Conclusions
Online-mediated and 6-monthly PrEP monitoring are non-inferior to in-clinic and to 3-monthly monitoring, respectively, regarding PrEP adherence. These findings suggest that, in terms of HIV acquisition risk, online-mediated and 6-monthly PrEP monitoring can be safely implemented as part of routine PrEP care for MSM.