Lenacapavir, Gilead Sciences’ twice-yearly capsid inhibitor, demonstrated 100% efficacy for preventing HIV acquisition in a large study of young cisgender women in Africa, according to a presentation at the International AIDS Conference in July.

 

The PURPOSE 1 trial enrolled over 5,000 women ages 16 to 25 in South Africa and Uganda. They were randomized to receive lenacapavir injections once every six months or Descovy (tenofovir alafenamide/emtricitabine) or Truvada (tenofovir disoproxil fumarate/emtricitabine) pre-exposure prophylaxis (PrEP) pills once daily.

 

Lenacapavir PrEP significantly reduced HIV incidence compared with the background rate, and it was more effective than Truvada. None of the women who received lenacapavir acquired HIV. The news was not so good for Descovy, which did not provide significant protection.

 

Adherence to lenacapavir was high, with more than 90% of participants receiving their injections on time, but adherence to both daily pills was poor. All three PrEP methods were generally well tolerated. About 500 women became pregnant during the study, and there were no differences in pregnancy outcomes.

 

Lenacapavir (sold as Sunlenca) is currently only available for treatment of people with multidrug-resistant HIV. Before it can be approved for PrEP, it must demonstrate effectiveness in other populations. Results from PURPOSE 2, a parallel study of gay and bisexual men and transgender and nonbinary people, are expected in late 2024 or early 2025. Advocates stress that if this new prevention tool is approved, it must be made accessible to the people most affected by HIV worldwide.

 

“These stellar results show that twice-yearly lenacapavir for PrEP, if approved, could offer a highly effective, tolerable and discreet choice that could potentially improve PrEP uptake and persistence, helping us to reduce HIV in cisgender women globally,” said presenter Linda-Gail Bekker, MD, of the University of Cape Town in South Africa.