Landmark Trial in South Africa and Uganda Finds Twice Yearly HIV Prevention Injection Safe and Highly Effective

AVAC Calls for Accelerated Regulatory Review and Ambitious Introduction Plans

June 20, 2024

AVAC welcomes the groundbreaking results of the PURPOSE 1 HIV prevention study among adolescent girls and young women in South Africa and Uganda. Preliminary safety and efficacy results were reported today by Gilead Sciences, the developer of the lenacapavir, one of the HIV prevention drugs that was being studied in the trial. An independent data and safety monitoring board (DSMB), at a scheduled review of the trial data, found the regimen to be safe and highly effective, with no infections seen among trial participants who received injectable lenacapavir. 

“This is one of the most important results we’ve seen to date in an HIV prevention study,” said Mitchell Warren, AVAC’s executive director. “Adding additional HIV prevention options means more people may find an option that is right for them. Beyond expanded choice, a twice-yearly injection has the potential to transform the way we deliver HIV prevention to people who need and want it most – from an easier to follow regimen for individuals to a decreased burden on healthcare systems that are stretched to the limit.” 

“We are incredibly excited about this result, especially about what it can mean for women in Africa,” says Nandisile Sikwana, Regional Stakeholder Engagement Manager for AVAC, and a member of the PURPOSE 1 Global Community Advisory Group. “We applaud Gilead’s commitment to Good Participatory Practice in this and the other PURPOSE studies. While we wait for full data from the study, including adherence data of oral F/TAF, it is imperative that planning for rollout of lenacapavir be accelerated. We know that even with the most ambitious timeline, it will take time for lenacapavir to be rolled out,” says Sikwana.

The PURPOSE 1 study enrolled over 5,300 cisgender adolescent girls and young women ages 16-26 in South Africa and Uganda. The study is evaluating injectable lenacapavir for PrEP and daily oral emtricitabine/tenofovir alafenamide (F/TAF) for PrEP. A companion trial, PURPOSE 2, is underway in Argentina, Brazil, Mexico, Peru, South Africa, Thailand and the US, testing twice-yearly lenacapavir for PrEP among cisgender men who have sex with men, transgender women, transgender men, and gender non-binary people. Results from PURPOSE 2 are expected by early 2025. Additional studies in critical populations, including PURPOSE 3 among cisgender women in the US and PURPOSE 4 among people who use injection drugs, are also underway, and it will be imperative to understand how today’s results influence these trials. A schematic of the suite of studies is here.

Gilead’s plans for submission to regulatory agencies and future access, including the US Food and Drug Administration (FDA), are not yet clear. But the results reported today make this urgent. “We expect to see a timeline that takes into account a full analysis of PURPOSE 1 data and the coming data from PURPOSE 2 from Gilead as soon as possible, and we urge regulatory agencies to prepare to fast track regulatory review,” Warren said. “We also call on WHO to be prepared to quickly include lenacapavir, if approved by regulatory agencies, in HIV prevention guidelines. There is no time to waste if we are to translate these exciting clinical trial results into actual public health impact and expand the toolbox of HIV prevention choices.”

“We now know that lenacapivir for PrEP is safe and highly effective among women,” Sikwana added. “Even as we await the results of the trial among other essential populations and for regulatory submission and review, there is urgent work to be done now by communities, policy makers, funders and program implementers to design and build HIV prevention programs and prepare health systems to deliver the growing array of biomedical PrEP options, including the addition of twice-yearly injectable lenacapavir. The full range of PrEP products – including oral PrEP – must be made feasible choices for all people who need and want HIV prevention options.”

Lessons learned from roll out of daily oral PrEP, and more recently the dapivirine vaginal ring and injectable cabotegravir, can help speed regulatory approval and guideline development in key countries, design of effective programs, and community understanding of and acceptance of lenacapavir for PrEP.

“AVAC and a cadre of international partners have been working together to plan for successful, accelerated introduction of lenacapavir. Since oral PrEP was first shown to be safe and effective 14 years ago, the global health community has failed in delivering PrEP at scale and with equity – and we have, therefore, not seen the impact that we need. The lessons from the past are clear, and we now must act on them and move with speed, scale and urgency. There can be no excuses and no delays,” said Warren. “We look forward to working with civil society partners, Gilead, international donors, normative agencies and national governments to ensure that this groundbreaking HIV prevention option is made available as quickly as possible and that we don’t squander this opportunity to drive down new HIV infections.”