Gilead Sciences, Inc. presented the first data from its ongoing Phase 1 study investigating two novel, once-yearly formulations of lenacapavir, the company’s injectable HIV-1 capsid inhibitor, for the investigational use of HIV prevention as pre-exposure prophylaxis (PrEP). The data were presented during an oral abstract session at the Conference on Retroviruses and Opportunistic Infections (CROI 2025) and were also published today in The Lancet . Data will support the future development of once-yearly lenacapavir for PrEP, for which Gilead plans to launch a Phase 3 study in the second half of 2025.

The Phase 1 study data showed that the two different formulations of once-yearly lenacapavir administered via intramuscular injection achieved and maintained plasma concentrations exceeding those associated with HIV prevention efficacy observed in the Phase 3 PURPOSE 1 trial (NCT04994509) and PURPOSE 2 trial (NCT04925752). The previously reported PURPOSE 1 and PURPOSE 2 data showed that twice-yearly subcutaneous lenacapavir demonstrated superiority at reducing HIV infections when compared to background HIV incidence (bHIV) and once-daily oral Truvada® (emtricitabine 200mg and tenofovir disoproxil fumarate 300mg; F/TDF) in a broad and geographically diverse range of people.

“Gilead is continuing to innovate in our work to develop additional person-centered long-acting injectable and oral options to help people find an HIV prevention choice that is right for them,” said Jared Baeten, MD, PhD, Senior Vice President, Virology Therapeutic Area Head, Gilead Sciences. “Once-yearly lenacapavir, if approved, could become an important new HIV prevention option that could help address PrEP adherence and persistence challenges for individuals who need or want PrEP around the world.”