Gilead’s Twice-Yearly Shot Shows 100% Efficacy in Phase III HIV Prevention Trial in Women

Pictured: Signage outside Gilead's headquarters in California

Pictured: Signage outside Gilead’s headquarters in California

Gilead Sciences reported zero cases of HIV infection occurred in the lenacapavir candidate group, compared to 16 cases in the Truvada arm and 39 incidents for those treated with Descovy, Gilead’s approved daily PrEP pills.

Gilead Sciences’ antiviral demonstrated 100% efficacy for HIV prevention in cisgender women in Phase III trial results announced Thursday. The twice-yearly lenacapavir shot proved superior to Gilead’s already-approved oral medicines for HIV prevention, Truvada and Descovy.

In the PURPOSE 1 trial, zero cases of HIV infection occurred among 2,134 women in the lenacapavir group, compared to 16 cases in the 1,068 women in the Truvada arm and 39 incidents among 2,136 women treated with Descovy. The long-acting shot was well-tolerated with no significant safety concerns, according to Gilead.

“To have no infections in over 2,000 women... that’s a remarkable result,” Joe Eron, principal investigator at the HIV/AIDS Clinical Research Unit at University of North Carolina-Chapel Hill, told STAT News.

While oral pre-exposure prophylaxis (PrEP) medications show high efficacy when taken daily, prior clinical trials for Descovy and Truvada found issues with patients adhering to the dosing. Superiority over Descovy was the primary endpoint of the PURPOSE 1 study, with proven efficacy over Truvada being the second endpoint. An independent data monitoring committee recommended Gilead unblind the trial and offer lenacapavir to all patients.

“Twice-yearly lenacapavir for PrEP could help address the stigma and discrimination some people may face when taking or storing oral PrEP pills, as well as potentially help increase PrEP adherence and persistence given its twice-yearly dosing schedule,” Linda-Gail Bekker, director of the Desmond Tutu HIV Center at the University of Cape Town, South Africa, said in a statement.

Lenacapavir is in development as a PrEP in patients at risk of HIV infection. Additional trials are assessing the biannual injections among a broader scope of patients including cisgender men, transgender men and women and non-binary individuals.

Gilead will file for regulatory approval with results from both PURPOSE 1 and, if positive, PURPOSE 2 to gain approval for “communities most in need of additional HIV prevention options.”

HIV products increased by 6% for the California-based pharma to $18.2 billion in revenue in 2023 compared to the prior year. Approved in 2019, Descovy sales make up about $2 billion of that number. There are over one million new HIV infections every year. The virus contributes to over 480,000 deaths worldwide annually.

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.
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