Twice-Yearly Sunlenca Beats Truvada as PrEP for Women

Twice-yearly Sunlenca (lenacapavir) demonstrated 100% efficacy for use of HIV prevention in cisgender women, according to an interim analysis of the phase 3 PURPOSE 1 trial. The trial met its key efficacy endpoints, including superiority to once-daily oral Truvada (emtricitabine 200mg and tenofovir disoproxil fumarate 300mg) and background HIV incidence.

Linda-Gail Bekker, MBChB, Ph.D.

“While we know traditional HIV prevention options are highly effective when taken as prescribed, twice-yearly lenacapavir for PrEP could help address the stigma and discrimination some people may face when taking or storing oral PrEP pills, as well as potentially help increase PrEP adherence and persistence,” Linda-Gail Bekker, MBChB, Ph.D., director of the Desmond Tutu HIV Center at the University of Cape Town, South Africa, said in a news release.

Developed by Gilead Sciences, Sunlenca is part of a new class of drugs called capsid inhibitors. Sunlenca works by blocking the HIV-1 virus’ protein shell (the capsid) and disrupts the HIV viral life cycle at several points. The twice-yearly treatment was approved in 2022 to treat patients whose HIV is not adequately controlled. About 2% of adults living with HIV are unable to maintain virus suppression due to resistance, intolerance or safety.

Sunlenca has a price of $42,250 per year during the initial year of therapy, and then $39,000 annually for maintenance years. Gilead provides a copay program with a limit of $9,600 per year. The terms indicate that Gilead may reduce or discontinue the copay assistance if patients are subject to copay accumulator or maximizer programs or excludes financial assistance from counting toward deductibles.

The PURPOSE 1 trial enrolled more than 5,300 cisgender women and adolescents 16 to 25 years of age in South Africa and Uganda to evaluate subcutaneous two-yearly Sunlenca and once daily oral Descovy (emtricitabine 200mg and tenofovir alafenamide 25mg), which is used for pre-exposure prophylaxis, or PrEP. The drugs are being tested in parallel, with one group receiving Sunlenca and one group taking Descovy. A third group was assigned once-daily oral Truvada, which is used both to both treat HIV-1 infection and as PrEP. The three drugs are manufactured by Gilead.

The trial found that there were no cases of HIV among the 2,134 women who received Sunlenca. There were 16 cases of HIV among the 1,060 women who received Truvada. There were 39 cases among the 2,136 women who received Descovy.

Based on these results, an independent Data Monitoring Committee (DMC) recommended that Gilead stop the blinded phase of the trial and offer Sunlenca to all participant as part of the open-label trial.

Gilead expects results from its ongoing PURPOSE 2 trial in late 2024 or early 2025. This trial is assessing Sunlenca for PrEP among cisgender men who have sex with men, transgender men, transgender women and gender non-binary individuals who have sex with partners assigned male at birth.