Gilead Claims Twice-Annual Injection Better At Preventing HIV Than Daily PrEP Pill

Clinical trial results come as Gilead continues to face lawsuits over side effects of some of its older HIV drugs, claiming the manufacturer delayed introduction of safer formulations to extend it’s monopoly over the HIV market.

A proposed twice-yearly injection could be more effective at preventing HIV than Gilead Science’s daily pill Truvada, which has been the go-to treatment for individuals facing a high risk of being infected.

The drug company issued a press release on September 12, indicating that a blinded phase 3 clinical trial showed injections of lenacapavir prevented HIV infections in 99.9% of participants, and Gilead is now openly offering the twice-annual injections to those who participated.

The study compared outcomes among individuals who received two injections of lenacapavir per year against those who received a once-daily pill of Truvada, which is the most widely used pre-exposure prophylaxis (PrEP) available to help sexually active men and transgender women avoid an HIV infection.

“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,” said researcher Onyema Ogbuagu in the statement released by Gilead.

The clinical trial, PURPOSE 2, involved 2,180 participants, including cisgender men, transgender men and women, and those identifying as non-binary in the U.S., Argentina, Brazil, Mexico, Peru, South Africa and Thailand, all of whom had sex with partners who were assigned male at birth. Two-thirds of the participants were given the injections, while the remaining one-third were given daily Truvada.

The company’s researchers claim an interim analysis found that there were only two cases of HIV among participants, while 99.9% saw no HIV infections, which is better than prevention with Truvada or no PrEP treatment at all.

“Twice-yearly lenacapavir was 89% more effective than once-daily Truvada,” Gilead indicated in the press release. “In the trial, lenacapavir and Truvada were generally well-tolerated and no significant or new safety concerns were identified.”

As a result, Gilead has unblinded the clinical trial, meaning participants who were given Truvada can now receive the lenacapavir injections.

This was the second phase-three trial of lenacapavir, which would only need to be taken twice a year, as an injection. Gilead indicates it plans to use the dataset in its push with the U.S. Food and Drug Administration and other health regulators worldwide, in the hope of beginning to file for approval by the end of this year, and for the injections to become available globally by 2025.

Truvada became available as a generic drug in 2021 when its patent protections expired.