Merck announces alimatravir access programme ahead of AIDS 2026

24 July 2026. Related: Early access, Conference reports, HIV prevention and transmission, Intl AIDS 26th Rio 2026.

Simon Collins, HIV i-Base

On 24th July 2026, a few days before the AIDS 2026 conference, US drug manufacturer Merck (known as MSD outside the US and Canada) announced plans for global access to an investigational new PrEP drug. [1]

Alimatravir, also in development under the name MK-8527, is so potent that a single small pill needs to be taken only once a month. This would make global distribution much easier and less costly than injectable versions of PrEP, despite their high efficacy and acceptably. The very low dosing might also increase acceptability of oral PrEP, which currently needs multiple daily pills when taken as daily or event-based dosing.

Although injectable PrEP will dominate much of the news from AIDS 2026, many of the reports will focus on difficulties with access which was only planned after these compounds had completed phase 3 studies and been approved in the US and EU.

This announcement on access is notable because phase 3 studies of alimatravir are still ongoing, with results not expected until 2027. High efficacy though might bring this timeline forward as many other PrEP studies for both oral and injectable PrEP proved efficacy earlier than initially expected.

The plans involve Merck having signed non-exclusive, royalty-free voluntary licensing agreements with seven generic manufacturers, for access in 129 low- and middle-income countries and support for manufacturing in Africa and Latin America. This includes four companies in India and three in sub-Saharan Africa.*

The 32-page licensing agreement, including the list of countries, is available online. Middle-income countries in South America, where HIV incidence is still increasing and where demand will be high, such as Brazil, Peru, Argentina and Mexico, are not included. [2]

Similar to other HIV drugs from the same family, alimatravir is a relatively easy and inexpensive compound to manufacture.

For example, although full details will only be presented at AIDS 2026 next week, a study from the well-respected health economist Andrew Hill’s group includes an analysis that alimatravir could be available for less than US$15 a year. [3]

Such low prices will depend on large-scale discounts from generic manufacturing and health funders committing to fund initial programmes. Similar agreements have reduced the annual prices for oral TDF/FTC and injectable lenacapavir and cabotegravir-LA to less than roughly US$35, US$40 and US$160 per year, respectively.

*Three of the companies are in sub-Saharan Africa: Aspen in South Africa, Quality Chemical Industries Limited (Qcil) in Uganda and Universal Corporation Ltd (UCL) in Kenya, and four are based in India (Aurobindo, Cipla, Emcure and Viatris).

comment

This announcement is definitely welcomed. It also notes that Merck is positively responding to demands from HIV health activists to plan global access by engaging with generic manufacturers earlier in the development programme.

Even though PrEP is developed by research companies based in the US or Europe, the greatest need for PrEP comes from low- and middle-income countries in the Global South.

For PrEP to have a significant impact on the global health targets to dramatically reduce HIV transmission by 2030, it needs to be easily accessible to tens of millions of people. This in turn will need collaboration with generic manufacturers, largely based in India, who have capacity and distribution networks that match this scale.

For example, 90% of people living with HIV across the world who are currently on ART will be using generic HIV drugs.

Many high income countries also depend on generic medicines once the original patents have ended, with bulk discount pricing for many commonly used medicines including antibiotics, statins, antidepressants and diabetes medicine costing the UK’s NHS less than £1 for a month’s supply.

However, as noted above, the agreement does not currently include many middle-income countries where HIV incidence is still increasing and where demand will be high, including Brazil where the AIDS 2026 conference is being held.

Historically, in the early years of ART, Brazil was one of the few countries that manufactured generic versions of HIV medicines in order to be able to afford treatment.

To be fully effective, Merck will also need to make alimatravir available in high- and middle-income countries at an easily affordable price.

Merck’s considerable commitment should also be noted, involving more than 14 years of research since 2012 when they acquired the licence for EFdA, the precursor compound of alimatravir – a compound derived from the fermentation of soy sauce. [4]

Reference

1. Merck press release. Merck Announces Initial Access Plans for Alimatravir an Investigational Once-Monthly Oral HIV Pre-Exposure Prophylaxis in Phase 3 Development. (24 July 2026).
   https://www.merck.com/news/merck-announces-initial-access-plans-for-alimatravir-an-investigational-once-monthly-oral-hiv-pre-exposure-prophylaxis-in-phase-3-development/
2. Merck licensing agreement including country list.
   https://www.merck.com/wp-content/uploads/sites/124/2026/07/Alimatravir-Sample-VL-Agreement.pdf
3. Cross S et al. Merck MK-8527: mass production for US $15/year as PrEP. Oral abstract OAE0504.
   https://programme.aids2026.org/Abstract/Abstract/?abstractid=4194
4. Merck acquires CMX157 and EFdA and starts phase 2 study for new NNRTI. HTB (1 October 2012).
   https://i-base.info/htb/20318