KEMRI Joins Global Study to Test Once-Monthly Oral HIV Prevention Drug

By Stella Njung’e

In a major stride in the global fight against HIV/AIDS, the Institute has joined an international clinical trial testing a once-monthly oral drug for HIV prevention that is likely to be a game-changer in the decades-long battle to curb new infections. This breakthrough could revolutionize prevention efforts by improving adherence and empowering women to take greater control of their health.

The study, known as the EXPrESSIVE-10 trial (MK-8527-010), will evaluate the efficacy, safety, and tolerability of a once-monthly oral HIV pre-exposure prophylaxis (PrEP) drug, MK-8527, compared to the current standard daily pill, emtricitabine/tenofovir disoproxil fumarate (FTC/TDF). The assessment will be based on the annual incidence rate of confirmed HIV-1 infections

Being conducted across 31 clinical research sites in Kenya, Uganda, and South Africa, the study will enrol 4,580 sexually active women aged 16 to 30 years. MK-8527, the experimental drug inhibits reverse transcriptase through multiple mechanisms of action, including inhibition of translocation and delayed chain termination.

If successful, the once-monthly pill could significantly enhance adherence, offering women greater control and privacy in protecting themselves against HIV, in turn lowering the number of new infections.

According to the National AIDS and STI Control Programme (NASCOP), young women and adolescent girls account for more than one-third of new HIV infections in Kenya, underscoring the need for more effective, women-centred prevention options.

In Kenya, the EXPrESSIVE-10 trial is being implemented at four sites, three of which are KEMRI-owned: KEMRI-PHRD (Partners in Health and Research Development), Thika led by Prof. Nelly Mugo , KEMRI–RCTP Kisumu led by Prof. Elizabeth Bukusi, Kargeno Research and Policy Hub led by Dr. Mariciannah Onono and the newly launched Rachuonyo Clinical Trial Site, led by Kenyatta National Hospital’s, Dr. Irene Inwani, OGW, with Prof. Carey Farquhar, Director of the University of Washington Kenya Research and Training Center, serving as Co-Principal Investigator.

The Rachuonyo site is a collaborative initiative between Rachuonyo County, Kenyatta National Hospital (KNH), and the University of Washington (UW), with support from Merck Sharp & Dohme LLC and the Bill & Melinda Gates Foundation.

On Tuesday, 4th, October 2025, the Rachuonyo site was officially opened by County Executive Committee Member for Public Health and Medical Services, Homa Bay County, Ms. Grace Mercy Osewe, who expressed optimism about the study’s potential impact.

“I believe this is a significant step toward HIV prevention,” she said. “With just one monthly dose, compliance will improve, and as a global community, we can work together to reduce costs. With HIV prevalence still high in this county, we are honoured as a county to host this site.”

Teams from the participating KEMRI sites, led by Prof. Mugo, attended the launch in Homa Bay. Speaking during the ceremony, Director of the KNH Research, Training and Innovation Centre and Co-PI, Prof. John Kinuthia, expressed enthusiasm for the collaboration.

“We are very excited about this partnership. If successful, this study will bring new hope for women, who remain among the most vulnerable to HIV infection,” he noted.

His remarks were echoed by Director of the International Clinical Research Center (ICRC) and Co-PI for the EXPrESSIVE-10 trial at the UW, Prof. Connie Celum, “The EXPrESSIVE-10 study represents our collective commitment to ending HIV by expanding prevention choices that meet the needs of women globally,” said Prof. Celum, “Through strong partnerships and scientific innovation, we can accelerate progress toward an HIV-free generation.”

“We look forward to working closely with our local and international partners to ensure the success of this study,” said Prof. Nelly Mugo. “The EXPrESSIVE-10 trial represents an important step in expanding prevention options for women and strengthening Kenya’s contribution to global HIV research.”

Also present were Director of the Center for AIDS Research (CFAR) at the University of Alabama and Co-PI for the trial, Prof. Renee Heffron, as well as Chief Officer for Public Health Evelyn Ododa, and other county officials.