RCT: Twice-Yearly Lenacapavir Reduces HIV Incidence in Men and Gender-Diverse Persons Background
28 Nov, 2024 | 12:38h | UTCBackground: Although preexposure prophylaxis (PrEP) effectively reduces HIV transmission, adherence to daily oral regimens is suboptimal among high-risk populations. Lenacapavir, a long-acting HIV-1 capsid inhibitor administered subcutaneously every six months, has shown efficacy in cisgender women, but its efficacy in men and gender-diverse individuals remains unclear.
Objective: To evaluate the safety and efficacy of twice-yearly subcutaneous lenacapavir compared to background HIV incidence and daily oral emtricitabine–tenofovir disoproxil fumarate (F/TDF) in preventing HIV infection among men and gender-diverse persons.
Methods: In this phase 3, double-blind, randomized trial, 3,271 HIV-negative participants were assigned in a 2:1 ratio to receive subcutaneous lenacapavir every 26 weeks or daily oral F/TDF, with matching placebos. Participants were cisgender men, transgender women and men, and gender-nonbinary persons aged 16 or older who have sex with male-assigned partners. The primary endpoint compared HIV incidence in the lenacapavir group to background incidence; secondary analysis compared lenacapavir to F/TDF.
Results: In the modified intention-to-treat analysis (n=3,265), HIV infections occurred in 2 participants in the lenacapavir group (0.10 per 100 person-years) and 9 in the F/TDF group (0.93 per 100 person-years). The background HIV incidence was 2.37 per 100 person-years. Lenacapavir significantly reduced HIV incidence compared to background (incidence rate ratio [IRR], 0.04; 95% CI, 0.01–0.18; P<0.001) and F/TDF (IRR, 0.11; 95% CI, 0.02–0.51; P=0.002). No significant safety concerns emerged. Injection-site reactions led to discontinuation in 1.2% of lenacapavir recipients and 0.3% of F/TDF recipients.
Conclusions: Twice-yearly subcutaneous lenacapavir significantly reduced HIV incidence compared to both the background incidence and daily oral F/TDF among men and gender-diverse persons. These findings support lenacapavir as an effective PrEP option in this population.
Implications for Practice: The introduction of a long-acting, twice-yearly injectable PrEP option like lenacapavir could improve adherence and uptake among populations challenged by daily oral regimens.
Study Strengths and Limitations: Strengths include a large, diverse participant population with significant representation of transgender and gender-nonbinary persons, and the use of an active comparator. The novel counterfactual design estimating background HIV incidence avoided ethical issues of placebo controls but may have limitations in accuracy. Limitations include a relatively short follow-up and potential impact of injection-site reactions on adherence. The emergence of resistance mutations in participants who acquired HIV while on lenacapavir is a concern needing further investigation.
Future Research: Further studies should assess the long-term safety, efficacy, and resistance patterns associated with lenacapavir use. Research into optimizing injection techniques to minimize injection-site reactions and exploring lenacapavir’s applicability in other at-risk populations is recommended.