Gilead announced that its twice-a-year HIV injection prevented all but two cases of HIV among 2,180 participants in a Phase 3 study as it prepares to launch the drug, called lenacapavir, in 2025 for pre-exposure prophylaxis (PrEP).
The PURPOSE 2 study enrolled over 3,200 cisgender men, transgender men, transgender women and gender non-binary individuals aged 16 years or older who have sex with partners assigned male at birth, according to Gilead.
In the lenacapavir group, 99.9% of participants did not acquire HIV, translating to an HIV incidence of 0.10 per 100 person-years. Compared to a background HIV incidence of 2.37 per 100 person-years, lenacapavir reduced relative risk by 96%, meeting the primary endpoint of the study.
Lenacapavir was approved as Sunlenca in late 2022 as a treatment for people with multi-drug resistant HIV.
In the study, 1,087 people were assigned to receive Truvada — Gilead’s daily pill that’s used for prevention and treatment — and there were nine cases of HIV in that group. According to Gilead, lenacapavir was 89% more effective than Truvada in the study. That mirrors results from previous trials that suggest long-acting agents may be more effective at preventing HIV than daily pills.
Gilead announced in June that the shot fully prevented HIV in a Phase 3 PrEP trial with cisgender women. At that time, the company said data from the two trials will be used for a series of regulatory filings that it plans to begin by the end of this year. In a news release, Gilead said it hopes to make the twice-a-year injection “available to multiple populations and communities around the world who are most in need of additional HIV prevention choices.”
Gilead said it stopped the blinded study at the interim analysis at the recommendation of an independent data monitoring committee and will offer lenacapavir to all participants in the trial. The interim analysis was conducted in September, when 50% of participants had at least one year of follow up, a Gilead spokesperson told Endpoints News.
Gilead’s shares $GILD were up 3% in pre-market trading Thursday morning.
The company also said lenacapavir and Truvada were “generally well-tolerated” with no new safety concerns. Gilead plans to present detailed data at a future medical meeting.
Editor’s note: This story was updated with Gilead’s stock and when the interim analysis was conducted.