NIH study finds long-acting injectable drug prevents HIV acquisition in cisgender women

Findings from an NIH-sponsored clinical trial indicate that a pre-exposure prophylaxis (PrEP) regimen containing an experimental long-acting form of cabotegravir injected once every 8 weeks was safe and more effective than a standard daily oral PrEP regimen at preventing HIV acquisition among a group of cisgender women in southern and east Africa.

Findings from an NIH-sponsored clinical trial indicate that a pre-exposure prophylaxis (PrEP) regimen containing an experimental long-acting form of cabotegravir injected once every 8 weeks was safe and more effective than a standard daily oral PrEP regimen at preventing HIV acquisition among a group of cisgender women in southern and east Africa. The findings are from a planned interim analysis of study data. To date, FDA has approved only one PrEP medication for HIV—a daily oral tablet that contains emtricitabine and tenofovir disoproxil fumarate (Truvada—Gilead Sciences). While the oral PrEP regimen is effective at preventing HIV infection when taken daily as prescribed, a safe and effective long-acting injectable form of PrEP would offer a new option for HIV prevention that may be preferable and more convenient for some women. The trial enrolled 3,223 HIV-negative, sexually active cisgender women at 20 clinical research sites in Botswana, Eswatini, Kenya, Malawi, South Africa, Uganda, and Zimbabwe, aged 18-45 years. Participants were randomly assigned to receive either injections of cabotegravir every 8 weeks and placebo daily oral tablets or placebo injections every 8 weeks and daily oral Truvada. In all, 38 women in the trial acquired HIV: 4 in the cabotegravir group and 38 in the Truvada group. An independent data and safety monitoring board (DSMB) for the trial determined, based on the study data, that long-acting injectable cabotegravir had enhanced efficacy compared with standard PrEP regimen at preventing HIV in the study population, with an HIV incidence rate of 0.21% in the cabotegravir group and 1.79% in the standard PrEP group. Based on their review, the DSMB recommended that NIAID stop the blinded phase of the trial, originally designed to continue until 2022, and share the results.