NIH Announces First Trial Assessing Safety of Injectable HIV PrEP in Women

For pre-exposure prophylaxis (PrEP) to be effective, adherence to the treatment regimen is key. Researchers are continually looking for ways to make it easier for patients to accomplish this goal. The development of a new, injectable form of PrEP is one step toward solving this issue. The new drug, cabotegravir, was tested in a large-scale clinical trial in men who have sex with men (MSM) and transgender women who have sex with men earlier this year, and now, the National Institutes of Health (NIH) have announced plans for a new trial testing its effectiveness in sexually-active women.

For the double-blind trial, which will take place in southern and eastern Africa, investigators will examine whether injectable cabotegravir can safely protect women from HIV when injected every 8 weeks. Approximately 3200 sexually-active women between the ages of 18 and 45 will be enrolled at 20 different sites across 7 countries. Women will be randomly assigned to receive either cabotegravir or oral Truvada, which is the only HIV PrEP medication currently licensed in the United States.

According to a press release on the study, published by the NIH, “Participants will be in the study for an average of 3.6 years. During the first 5 weeks after enrollment, they will receive 2 daily oral tablets: either cabotegravir or Truvada, and a placebo pill. Beginning in the sixth week, participants in the cabotegravir group will receive injections of cabotegravir and placebo tablets to be taken orally daily, while participants in the Truvada group will receive placebo injections and Truvada tablets to be taken orally daily. Injections will be administered by study staff. The first 2 injections will be 4 weeks apart, then once every 8 weeks for an average of 2.6 years. After completing the injections, all participants will be offered 48 weeks of PrEP with daily oral Truvada. Subsequently, all participants will be transitioned to locally available HIV prevention services for PrEP, as available. Study results are expected in 2022.”

In addition to counseling services on HIV prevention and support to help them adhere to their regimen, the participants will also receive condoms and lubricant. Sexually transmitted infection (STI) testing will be performed on all participants and they will be treated if an STI is present. HIV testing will occur every 8 weeks. The NIH states that “those who become HIV-infected during the trial will stop receiving the study products and be referred to local medical providers for appropriate HIV care and treatment.”

When speaking on this study in the press release, Sinead Delany-Moretlwe, MBBC, PhD, protocol chair of the HPTN 084 trial and associate professor and director of research at the Wits Reproductive Health and HIV Institute at the University of the Witwatersrand in Johannesburg, South Africa, said, “Injectable cabotegravir has the potential to give sexually active women a choice of biomedical HIV prevention tools for the first time—somewhat similar to the choices available to women for contraception. Current HIV prevention tools can be especially difficult for women to control or negotiate with a partner. An effective, long-acting injectable drug would allow a woman to discreetly protect herself from HIV during sex.”

Adding to this, Mina Hosseinipour, MD, MPH, HPTN 084 protocol co-chair and professor of medicine at the UNC School of Medicine in Chapel Hill, North Carolina, and scientific director of UNC Project-Malawi in Lilongwe, Malawi, stated, “[The trial] also will examine how women experience long-acting injectable cabotegravir—whether they find it desirable and usable. Understanding what types of HIV prevention fit best in women’s lives will help further refine HIV prevention research, delivering tools that are ultimately safe, effective and desired.”

At the 9th IAS Conference on HIV Science this year, Contagion® interviewed Alex Rinehart, PhD, director, global prevention strategy at ViiV Healthcare, on what makes cabotegravir a unique medication for HIV. His exclusive interview can be viewed below:

The phase 3 trial is sponsored by the NIH’s National Institute of Allergy and Infectious Diseases, which is also co-funding it through a partnership with ViiV and the Bill & Melinda Gates Foundation. The NIH-funded HIV Prevention Trials Network (HPTN) is conducting the study, called HPTN 084, and the study medications are being provided by ViiV and Gilead Sciences.