Merck signs early voluntary licenses for investigational monthly HIV prevention pill

USA—Merck & Co. has signed voluntary licensing agreements with seven generic drug manufacturers to support the future availability of its investigational HIV pre-exposure prophylaxis (PrEP) pill, alimatravir, in low- and middle-income countries (LMICs).

Following a similar approach by Gilead Sciences, Merck is putting its global access strategy in place before the phase 3 trial evaluating alimatravir for HIV prevention has completed enrollment or generated efficacy data.

According to the company, this marks the first time a voluntary licensing programme for an investigational HIV prevention medicine has been established at such an early stage.

The agreements are nonexclusive and cover Aspen Pharmacare, Quality Chemical Industries and UCL Kenya in sub-Saharan Africa, as well as Aurobindo, Cipla, Emcure and Viatris in India.

Merck said the inclusion of manufacturers in sub-Saharan Africa is also a first for an initial voluntary license covering an HIV medicine, potentially helping to establish regional production capacity closer to some of the communities with the highest HIV burden.

“People across Africa need more options to prevent HIV. A once-monthly pill could provide a different choice for people in how to protect themselves, subject to successful trials and regulatory approval,” Jean Kaseya, director general of the Africa Centres for Disease Control and Prevention, said in a statement.

He welcomed Merck’s decision to engage African manufacturers at an early stage.

Licenses cover 129 countries

The licensing agreements will allow generic manufacturers to supply alimatravir in 129 LMICs if the medicine receives regulatory approval.

Merck said the arrangement will support targeted regional manufacturing in Africa and Latin America.

The company said early preparations could help make alimatravir available as broadly and quickly as possible following approval.

Merck announced the licensing strategy on July 24, ahead of the 26th International ADIS Conference in Rio de Janeiro, Brazil.

Gilead pursued a comparable strategy in 2024 by signing not-for-profit licensing agreements with six manufacturers for its HIV PrEP medicine Yeztugo (lenacapavir).

However, Gilead concluded those agreements after positive results from the phase 3 PURPOSE 1 and PURPOSE 2 trials.

Yeztugo is administered twice a year following an initial oral loading dose.

Gilead has faced criticism over the limited number of Yeztugo doses available through its access programmes, with the constraints partly linked to the complex preparations required to scale up production.

Monthly pill versus twice-yearly injection

Alimatravir, also known as MK-8527, belongs to a class of medicines called nucleoside reverse transcriptase translocation inhibitors (NRTTIs).

The drug is designed to prevent HIV from replicating by binding to the viral reverse transcriptase enzyme.

Merck previously explored another NRTTI, islatravir, as a potential PrEP medicine but abandoned the programme after high doses were associated with reductions in total lymphocyte and CD4+ T-cell counts among trial participants.

From a logistics perspective, an oral monthly pill could offer advantages over an injectable PrEP option.

However, adherence remains critical to HIV prevention, and Yeztugo’s twice-yearly dosing may be more convenient than a monthly regimen.

In two phase 3 trials, Yeztugo demonstrated near-complete protection against HIV infection, supported in part by high adherence.

Meanwhile, Merck and Gilead are collaborating on a once-weekly HIV treatment combining islatravir and lenacapavir.

Data from two phase 3 trials presented at AIDS 2026 showed that the combination was as effective as daily regimens, including Gilead’s Biktarvy, at maintaining HIV suppression.