Alimatravir Once-Monthly Pill Shows Promise for HIV Prevention
The development of Alimatravir HIV prevention could transform how people protect themselves from HIV. Merck has announced an early global access plan for the experimental once-monthly pill. The company, known as MSD outside the United States and Canada, aims to make the medicine affordable in low and middle-income countries if regulators approve it. This approach could expand access and reduce barriers for millions at risk.
Monthly Pill Could Change HIV Prevention
Alimatravir, also called MK-8527, is an oral pre-exposure prophylaxis, or PrEP, medicine. Unlike current PrEP tablets, it requires only one dose each month. Therefore, it may help people who struggle with taking daily medication.
The medicine is now being tested in two major clinical trials. The EXPrESSIVE-10 study, supported by the Gates Foundation, focuses on women and adolescent girls in sub-Saharan Africa. Meanwhile, the EXPrESSIVE-11 trial includes participants from 16 countries who face a higher risk of HIV exposure.
Early research is encouraging. Scientists believe the pill starts working within one hour and may protect users for an entire month. In addition, protection could continue for about one extra week if a scheduled dose is delayed.
Global Access Plan Already Underway
Merck has already signed royalty-free licensing agreements with seven generic drug manufacturers. As a result, these companies can produce and supply the medicine across 129 eligible countries after approval. Three manufacturers are based in sub-Saharan Africa, while four operate in India.
What Happens Next?
Around 40.9 million people lived with HIV worldwide during 2025, and over half were in sub-Saharan Africa. Consequently, a monthly prevention pill could improve adherence and increase healthcare access. Alimatravir works by blocking reverse transcriptase, an enzyme HIV needs to copy its genetic material. Clinical trial results are expected next year. Meanwhile, Merck is expanding production to support rapid distribution if health authorities approve the medicine.
