Merck (MSD) has kicked off a pair of phase 3 trials evaluating the safety and efficacy of MK-8527, an investigational once-monthly, oral nucleoside reverse transcriptase translocation inhibitor (NRTTI) for HIV pre-exposure prophylaxis (PrEP).
The EXPrESSIVE-11 trial will evaluate the safety and efficacy of MK-8527 among people with greater likelihood of HIV-1 exposure in 16 countries and will begin enrolling in August 2025. In collaboration with the Gates Foundation, the EXPrESSIVE-10 trial will evaluate the safety and efficacy of MK-8527 in women and adolescent girls in sub-Saharan Africa and will begin enrolling in the next few months.
“With only 18% of global PrEP need currently met, there is a clear and urgent need for options like MK-8527 that may offer the ability to prevent infection. These phase 3 trials are a key step toward translating progress into longer-acting options that could help turn the tide on HIV,” said Trevor Mundel, president of global health at the Gates Foundation.
MK-8527 inhibits reverse transcriptase through multiple mechanisms of action, including inhibition of translocation and delayed chain termination.
Last month, the U.S. FDA approved Gilead’s twice-yearly injectable PrEP drug, Yeztugo (lenacapavir), offering an alternative to the current standard of care for HIV prevention, Truvada, Gilead’s once-daily pill.