Lenacapavir highly effective at preventing HIV in cisgender men, transgender women and non-binary people

Gilead Sciences has announced interim results from a clinical trial on pre-exposure prophylaxis (PrEP) called Purpose 2. In this study, injectable lenacapavir was compared to a pill taken once daily that contained two drugs (tenofovir DF + FTC). This pill is sold as Truvada and available in generic formulations.

Participants in this randomized, double-blind study were aged 16 and older and were recruited from Latin America, South Africa, Thailand and the U.S.

The 3,200 participants in Purpose 2 included gay and bisexual cisgender men, transgender men, transgender women and non-binary people. Participants had sex with partners assigned male at birth. 

Participants were randomly assigned in a 2:1 ratio to receive lenacapavir or Truvada. 

Researchers found that two cases of HIV infection occurred during the study in people who were taking lenacapavir. Bear in mind that these were two cases out of 2,180 people on lenacapavir. Gilead notes that 99.9% of participants on lenacapavir did not get HIV. Compared to the background rate of HIV in people not on some form of PrEP, overall, lenacapavir reduced the risk of getting HIV by 96%. Also, lenacapavir was nearly 90% more effective than Truvada at preventing HIV infections. This finding is likely driven by easier adherence requirements for lenacapavir, which is ultimately given as two injections every six months.

Gilead will release further details about Purpose 2 at a scientific conference in the future.

—Sean R. Hosein

REFERENCE:

Gilead Sciences. Gilead’s twice-yearly lenacapavir for HIV prevention reduced HIV infections by 96% and demonstrated superiority to daily Truvada in second pivotal phase 3 trial. Press release. 12 September 2024.