Twice-yearly lenacapavir 89% more effective than Truvada

New data from the PURPOSE 2 study shows that twice-yearly lenacapavir is 89% more effective at preventing HIV than oral Truvada, with 99.9% of participants in the lenacapavir group not acquiring HIV.

PURPOSE 2 follows on from the success of the original PURPOSE study. The phase 3, double-blind, multicenter, randomised study, evaluates the safety and efficacy of twice-yearly lenacapavir injections as PrEP in more than 3,200 cisgender men, transgender men, transgender women and gender non-binary individuals aged 16 years or older who have sex with partners assigned male at birth. There were 88 trial sites in Argentina, Brazil, Mexico, Peru, South Africa, Thailand and the United States.

Participants were randomised into two groups, with some taking once-daily oral Truvada and the others receiving lenacapavir injections every six months. This would then be compared against background HIV incidence.

During an interim review of the study data, it was decided that the data backing lenacapavir’s efficacy and safety was strong enough for the Data Monitoring Committee (DMC) to recommend that Gilead stop the blinded phase of the trial and offer open-label lenacapavir to all participants.

There were 2 HIV infections among the 2,180 participants in the lenacapavir group (incidence 0.10 per 100 person-years); meaning that 99.9% of participants did not acquire HIV in the lenacapavir group. The results demonstrated the superiority of twice-yearly lenacapavir over background HIV rates (incidence 2.37 per 100 person-years), with 96% relative risk reduction.

In the Truvada group, there were 9 HIV infections among 1,087 individuals (incidence 0.93 per 100 person-years). Twice-yearly lenacapavir was 89% more effective than once-daily Truvada.

During the trial, both lenacapavir and Truvada were generally well-tolerated and no significant or new safety concerns were identified.

Commenting on the results so far, PURPOSE 2 Principal Investigator Onyema Ogbuagu, MBBCh, FACP, FIDSA, Associate Professor of Medicine and Pharmacology at Yale School of Medicine and Director of the Yale Antivirals and Vaccines Research Program, said:

“The difficulty some people can experience with taking an oral pill every day, including challenges with adherence and stigma, have hindered uptake and persistence of the standard of care for too long, thus blunting PrEP’s impact on HIV prevention”

“The incredible efficacy demonstrated in the PURPOSE 2 trial, the potential benefits of a twice-yearly injection, and the diversity of trial sites and participants show the impact that lenacapavir for PrEP could have for people around the world who need new choices to reduce their chances of acquiring HIV. This breakthrough adds significantly to our arsenal of tools to move us closer to achieving an AIDS-free generation.”

Whilst the clinical data around lenacapavir continues to be impressive, there are still concerns from both the HIV and sexual health communities and the larger medical world around pricing and access to this game-changing medication.

For more information, please see the Gilead Sciences website.