Back to Alimatravir (MK-8527)
Alimatravir (MK-8527)
Alimatravir, also known as MK-8527, is an investigational antiretroviral (ARV) drug that is being studied as a potential PrEP product. Below are details on its distinct characteristics and ongoing Phase III clinical trial, as well as resources to learn more.
The Basics
- Given once a month.
- An oral pill.
- Developed by Merck.
- Found to be safe and well-tolerated in a Phase II clinical trial.
- Two Phase III clinical trials are investigating efficacy for use as HIV prevention.
Access
In July 2026, Merck announced it has granted seven direct licenses to generic manufacturers in India, Kenya, South Africa, and Uganda to produce alimatravir while Phase 3 clinical trials are still enrolling.
The Trials
EXPrESSIVE 10
- Being conducted amongst approximately 4,580 cisgender women aged 16-30 in Kenya, South Africa, and Uganda.
- Evaluating the efficacy, safety, and tolerability of alimatravir compared to daily oral PrEP (TDF/FTC).
- Began enrolling participants in November 2025 and anticipated to run through October 2027.
EXPrESSIVE 11
- Being conducted amongst 4,390 cisgender men who have sex with men, transgender men, transgender women, and gender non binary individuals in Argentina, Brazil, Chile, Colombia, the Dominican Republic, France, Guatemala, Kenya, Malaysia, Peru, the Philippines, South Africa, Switzerland, Thailand, the USA, and Vietnam.
- Evaluating the efficacy, safety, and tolerability of alimatravir compared to daily oral PrEP (TDF/FTC).
- Began enrolling participants in August 2025 and anticipated to run through July 2027.
- For more information about EXPrESSIVE 11, click here.
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Further Resources
- Study Overview of EXPrESSIVE-10
- Study Overview of EXPrESSIVE-11
- Safety and pharmacokinetics of MK-8527 oral once-monthly: a phase 2 study in adults at low risk of HIV-1 exposure– Abstract from IAS 2025
- Safety and Pharmacokinetics of MK-8527, a Novel nRTTI, in Adults Without HIV– Abstract from CROI 2024
- Alimatravir details on the Long-Acting Patents and Licenses Database