A large clinical trial in South Africa and Uganda has demonstrated that a twice-yearly injection of the new pre-exposure prophylaxis drug, lenacapavir, provides young women with total protection from HIV infection.
The Purpose 1 trial, involving 5,000 participants at sites in Uganda and South Africa, compared the effectiveness of lenacapavir to two daily pills: Truvada (F/TDF) and Descovy (F/TAF). Lenacapavir, a fusion capsid inhibitor administered every six months, showed 100% efficacy, with none of the 2,134 women who received the injection contracting HIV.
In contrast, 16 of the 1,068 women (1.5%) taking Truvada and 39 of 2,136 women (1.8%) on Descovy contracted HIV. These results led to the independent data safety monitoring board recommending the trial’s “blinded” phase be stopped, allowing all participants to choose their preferred PrEP.
This breakthrough offers a promising prevention tool, particularly for young women in eastern and southern Africa, who face higher HIV infection rates and challenges in maintaining daily PrEP regimens.
The trial will continue in an “open label” phase, with participants informed of their treatment groups and given the choice of PrEP. A sister trial, Purpose 2, is underway among cisgender men, and transgender and nonbinary people who have sex with men in various regions.
Gilead Sciences, the trial sponsor, plans to submit the results to regulators, including those in Uganda and South Africa, and the World Health Organization. The goal is to integrate lenacapavir into real-world settings and make it accessible to all who need protection against HIV.
