Gilead's Twice-Yearly HIV Prevention Shot Succeeds in Key Trial

Gilead recently revealed that its bi-annual HIV injection, lenacapavir, significantly prevented HIV infections in a large Phase 3 study. Out of 2,180 participants, only two cases of HIV were reported, demonstrating the drug's potential as a pre-exposure prophylaxis (PrEP) method. The company plans to launch lenacapavir in 2025.

The PURPOSE 2 study, which included over 3,200 participants, focused on individuals aged 16 and older who engage in sexual activities with partners assigned male at birth. This cohort included cisgender men, transgender men, transgender women, and gender non-binary individuals. The results showed that 99.9% of those in the lenacapavir group did not acquire HIV, translating to an HIV incidence rate of 0.10 per 100 person-years. This is a significant reduction compared to the background HIV incidence rate of 2.37 per 100 person-years, marking a 96% reduction in relative risk and successfully meeting the study's primary endpoint.

Lenacapavir, already approved as Sunlenca in late 2022 for treating multi-drug resistant HIV, showed promising results in this study. In the trial, 1,087 participants received Truvada, Gilead’s daily pill for HIV prevention and treatment, with nine cases of HIV reported in this group. Lenacapavir proved to be 89% more effective than Truvada, aligning with previous research suggesting that long-acting agents could be more efficient than daily pills for HIV prevention.

In June, Gilead announced that the injection also fully prevented HIV in a Phase 3 trial involving cisgender women. The company intends to use data from both trials for a series of regulatory submissions, starting by the end of the year. Gilead aims to make the twice-yearly injection accessible to various populations globally who need more HIV prevention options.

The study was halted at the interim analysis upon the recommendation of an independent data monitoring committee, and Gilead plans to offer lenacapavir to all trial participants. This interim analysis, conducted in September, occurred when 50% of the participants had at least one year of follow-up.

Gilead’s stock saw a 3% rise in pre-market trading following the announcement. The company also reported that both lenacapavir and Truvada were “generally well-tolerated” with no new safety concerns emerging. Detailed data from the study is expected to be presented at an upcoming medical conference.