ABSTRACT
BACKGROUND: There are gaps in uptake of, adherence to, and persistence in the use of preexposure prophylaxis for human immunodeficiency virus (HIV) prevention among cisgender women. METHODS: We conducted a phase 3, double-blind, randomized, controlled trial involving adolescent girls and young women in South Africa and Uganda. Participants were assigned in a 2:2:1 ratio to receive subcutaneous lenacapavir every 26 weeks, daily oral emtricitabine-tenofovir alafenamide (F/TAF), or daily oral emtricitabine-tenofovir disoproxil fumarate (F/TDF; active control); all participants also received the alternate subcutaneous or oral placebo. We assessed the efficacy of lenacapavir and F/TAF by comparing the incidence of HIV infection with the estimated background incidence in the screened population and evaluated relative efficacy as compared with F/TDF. RESULTS: Among 5338 participants who were initially HIV-negative, 55 incident HIV infections were observed: 0 infections among 2134 participants in the lenacapavir group (0 per 100 person-years; 95% confidence interval [CI], 0.00 to 0.19), 39 infections among 2136 participants in the F/TAF group (2.02 per 100 person-years; 95% CI, 1.44 to 2.76), and 16 infections among 1068 participants in the F/TDF group (1.69 per 100 person-years; 95% CI, 0.96 to 2.74). Background HIV incidence in the screened population (8094 participants) was 2.41 per 100 person-years (95% CI, 1.82 to 3.19). HIV incidence with lenacapavir was significantly lower than background HIV incidence (incidence rate ratio, 0.00; 95% CI, 0.00 to 0.04; P<0.001) and than HIV incidence with F/TDF (incidence rate ratio, 0.00; 95% CI, 0.00 to 0.10; P<0.001). HIV incidence with F/TAF did not differ significantly from background HIV incidence (incidence rate ratio, 0.84; 95% CI, 0.55 to 1.28; P = 0.21), and no evidence of a meaningful difference in HIV incidence was observed between F/TAF and F/TDF (incidence rate ratio, 1.20; 95% CI, 0.67 to 2.14). Adherence to F/TAF and F/TDF was low. No safety concerns were found. Injection-site reactions were more common in the lenacapavir group (68.8%) than in the placebo injection group (F/TAF and F/TDF combined) (34.9%); 4 participants in the lenacapavir group (0.2%) discontinued the trial regimen owing to injection-site reactions. CONCLUSIONS: No participants receiving twice-yearly lenacapavir acquired HIV infection. HIV incidence with lenacapavir was significantly lower than background HIV incidence and HIV incidence with F/TDF. (Funded by Gilead Sciences; PURPOSE 1 ClinicalTrials.gov number, NCT04994509.).
ABSTRACT
INTRODUCTION: Oral pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention method; however, uptake and persistence have been low among southern African women. A dual prevention pill (DPP) that combines PrEP with oral contraception (OC) may increase PrEP use and better meet women's sexual and reproductive health needs. We will gauge the DPP's acceptability in two cross-over clinical trials. METHODS AND ANALYSIS: PC952 (Zimbabwe) and PC953 (South Africa) will compare acceptability, adherence and preference for an over-encapsulated DPP versus PrEP and OCs taken separately. HIV-negative, non-pregnant cisgender females in Johannesburg, South Africa (n=96, 16-40 years) and Harare, Zimbabwe (n=30, 16-24 years) will be randomised 1:1 to the order of regimens-DPP or two separate tablets-each used for three 28-day cycles, followed by a 6-month choice period in South Africa. Monthly clinic visits include HIV and pregnancy testing; safety assessments and risk reduction and adherence counselling. We will assess adherence (monthly) based on tenofovir diphosphate drug levels in dried blood spots and by self-report. We will evaluate acceptability (monthly) and preference (end of cross-over) via computer-assisted self-interviewing and in-depth interviews with a subset of participants. Data collection started in September 2022 and ended in January 2024. ETHICS AND DISSEMINATION: PC952 was approved by the Ministry of Health and Child Care, Medical Research Council, Research Council and Medicines Control Authority of Zimbabwe; the Chitungwiza City Health Ethics Committee; and the Joint Research Ethics Committee for the University of Zimbabwe Faculty of Medicine and Health Sciences and Parirenyatwa Group of Hospitals. PC953 was approved by the South African Health Products Regulatory Authority and the University of the Witwatersrand's Human Research Ethics Committee. The Population Council IRB approved both studies. We will disseminate results in open-access journals, clinical trials registries, and at local and international meetings and conferences. TRIAL REGISTRATION NUMBERS: NCT04778514, NCT04778527.
