Association of HIV Preexposure Prophylaxis Use With HIV Incidence Among Men Who Have Sex With Men in China: A Nonrandomized Controlled Trial

IMPORTANCE: Evidence on HIV preexposure prophylaxis (PrEP) among Chinese men who have sex with men (MSM) is critical to guide its large-scale implementation in low- and middle-income countries. OBJECTIVE: To evaluate incident HIV infection, adherence, safety, and changes in sexual behaviors among MSM using daily PrEP (D-PrEP) and event-driven PrEP (ED-PrEP) in 4 cities in China. DESIGN, SETTING, AND PARTICIPANTS: This nonrandomized controlled trial was conducted among HIV-seronegative MSM from December 11, 2018, to November 30, 2020, in Beijing, Shenyang, Chongqing, and Shenzhen. Participants self-chose D-PrEP or ED-PrEP regimens at baseline and could switch regimens during the 12-month study period. HIV-negative MSM who declined to initiate PrEP (nonusers) in the same cities joined a separate parallel prospective cohort and served as control individuals. INTERVENTIONS: PrEP consisted of coformulated tenofovir disoproxil fumarate, 300 mg, and emtricitabine, 200 mg. MAIN OUTCOMES AND MEASURES: The main outcome was incident HIV infection. Poisson regression was used to obtain the HIV incidence rate ratio (IRR). RESULTS: A total of 1530 MSM were included in the analysis (median age, 30 [IQR, 25-37] years). At baseline, 520 MSM chose D-PrEP (median age, 29 [IQR, 25-35] years) and 503 chose ED-PrEP (median age, 29 [IQR, 25-36] years). The median HIV Risk Index score was 18 (IQR, 12-22) among D-PrEP users and 18 (IQR, 11-22) among ED-PrEP users. Among 507 PrEP nonusers, the median age was 33 (IQR, 27-43) years, and the median HIV Risk Index score was 12 (IQR, 7-18). Although PrEP users had more baseline behaviors associated with HIV risk, the HIV incidence was lower among all PrEP users (adjusted IRR, 0.09 [95% CI, 0.04-0.21]), ED-PrEP users (adjusted IRR, 0.05 [95% CI, 0.01-0.22]), and D-PrEP users (adjusted IRR, 0.12 [95% CI, 0.04-0.33]) compared with PrEP nonusers. There was no difference in HIV incidence between D-PrEP users and ED-PrEP users (IRR, 0.33 [95% CI, 0.06-2.04]). Event-driven PrEP users consumed 40% fewer tablets than D-PrEP users during the study period. Adherence, defined as the proportion of self-reported days with sexual intercourse in which PrEP was taken according to prescription of at least 90%, increased over time among ED-PrEP users (from 57.4% to 77.8%; P < .001 for trend) and decreased over time among D-PrEP users (from 75.1% to 72.1%; P = .02 for trend). Daily PrEP users reported fewer adverse events than ED-PrEP users (193 of 520 [37.1%] vs 241 of 503 [47.9%]). CONCLUSIONS AND RELEVANCE: The findings of this study suggest that D-PrEP and ED-PrEP regimens are associated with lower incidence of HIV and a good safety profile among high-risk MSM in China. TRIAL REGISTRATION: Chinese Clinical Trial Registry number: ChiCTR-IIN-17013762