Pharmaceutical company Merck said on Friday it would license seven generic drug makers to produce a low-cost version of a new monthly HIV prevention pill, raising significant optimism about the role it could play in ending the HIV epidemic.
The decision is aimed at making stocks of the drug immediately available in developing countries if the results of next year's clinical trials meet expectations for the pill.
The company's announcement Friday comes as a major international AIDS conference begins in Rio de Janeiro, against a backdrop of disappointment over limited progress in reducing HIV infection rates.
The new drug, alimatravir, is a pill taken once a month for what is called pre-exposure prophylaxis, or PrEP. It is being tested in a late-stage trial involving young women in three countries in sub-Saharan Africa, and in a separate trial in countries in Latin America, Asia, Europe and Africa involving transgender people and men who have sex with men.
According to UNAIDS, a United Nations agency, there will be 1.2 million new HIV infections in 2025. There are more tools available to prevent infection, but they do not reach many of the world's most vulnerable people. Slow but steady progress toward the goal of reducing HIV transmission rates has been derailed over the past 18 months by sharp reductions in funding from the United States and other major donor countries.
A recent analysis by the Clinton Health Access Initiative found a 42 percent decline in the number of people starting oral PrEP in 2025 in 10 countries in sub-Saharan Africa and Asia with high rates of HIV infection, compared to the previous year.
The Merck deal will allow generics to be produced for 129 low- and middle-income countries. The company said it would also manufacture a bridging supply to sell to those countries at a not-for-profit price, before the generic product hits the market and gains regulatory approval. The company did not reveal the price.
Merck will grant a royalty-free license to four generic companies in India and three in sub-Saharan Africa (drug makers in Uganda, Kenya and South Africa) in a boost to regional manufacturing efforts. That has been a priority of the African Union since the continent was largely prevented from accessing Covid vaccines until a year later than the rest of the world.
Because the production of alimatravir uses a small amount of its active pharmaceutical ingredient, and because it is a standard oral formulation, companies could produce it profitably at scale and sell it to national health systems for as little as $5 per person per year.
The timing of Merck's announcement, which came well before final clinical trial results, is unusual and appears to be an effort to avoid problems that have plagued the introduction of other PrEP products.
HIV treatment and care advocates are advising Merck on how to ensure access to the drug if trial results show it works.
“Our engagement with pharmaceutical companies has always been one of fighting, but it's amazing to sit down with them and have them say, 'We're learning from the other products,'” said Kenneth Mwehonge, executive director of the Coalition for Health Promotion and Social Development in Uganda.
Still, he added: “Everything sounds good for now, but we will wait and see how it is put into practice.”
HIV researchers hope that alimatravir will provide a high level of protection against infection, because the molecule at the heart of the drug is closely related to another highly effective HIV drug, which provided high rates of protection in studies with non-human primates, said Dr. Nina Russell, who oversees investment in HIV drug development for the Gates Foundation.
“We're more optimistic about this than usual,” he said. “It could be quite transformative.”
The Gates Foundation has invested $100 million in the drug's late-stage trial and expects to invest an additional $80 million to support efforts to get it into testing and commercialization, he said.
In studies, the drug has provided protection against HIV starting just an hour after a person takes it, and has offered about a one-week grace period of protection if people have forgotten to take their next pill earlier in the month, said Gregg Szabo, a senior vice president at Merck.
The daily PrEP pill has been widely adopted in high-income countries in communities of people at higher risk of HIV infection, such as gay men. But it has not proven to be a viable option for many people in developing countries.
Long-acting PrEP is seen as key to ending the HIV epidemic in Africa in particular. Ten countries across the continent have recently made available an injectable drug, lenacapavir, that provides close to 100 percent protection against HIV for six months.
But as funding to help African governments with the purchase and distribution of new HIV products has contracted sharply since early 2025, the hope invested in lenacapavir has dimmed. Fragile health systems may struggle to provide it or keep people coming back for it.
Alimatravir, with just 12 pills a year, would be much easier to administer than an injectable and could be distributed outside of clinics and in places such as hair salons and high schools, Mwehonge said. A young woman, he said, could get a year's supply at the same time she receives birth control pills.
The generic agreement covers all of Africa; Asian countries with large populations of people with HIV, such as Cambodia and Thailand; and some from Latin America. It does not include Brazil, where there are 55,000 new infections each year, nor Colombia, Mexico, Peru and Chile, all of which are sites for clinical trials of the drug.
Chirfi Guindo, executive vice president of strategic access, policy and communications at Merck, said the company was in talks with the Oswaldo Cruz Foundation, a Brazilian public health research institute that makes drugs, about a supply deal for Latin America.
“The intention is to find ways to make alimatravir actually available in Brazil and in the Latin American region as quickly as possible and in a way that is affordable,” he said.
Access to new products in Latin America is a persistent challenge. Middle-income countries in the region are often left out of licensing agreements, although the population most vulnerable to HIV depends on public health systems that struggle to afford innovative products.
More than seven months after lenacapavir began shipping in Africa, it is still not available in Brazil. Gilead, the company that makes lenacapavir, did not include Brazil and Mexico, which were part of the key clinical trial that showed the drug provided almost complete protection against HIV, in the licenses it granted to generic makers.
Dr. Alexandre Padilha, Brazil's health minister, said Brazil remained excluded after more than a year of negotiations with Gilead.
The country has offered to pay Gilead $400 per patient per year, which is 10 times the price of generic lenacapavir in countries covered by Gilead's voluntary licenses, he said. That price reflects significant advance purchase commitments by the U.S. government and other financiers, which drove the price down. Gilead charges $28,000 per patient in the United States.
Dr. Padilha said that although Brazil has an effective PrEP program, with 150,000 people taking oral PrEP daily, the majority are men who have sex with men. There is a clear need for other products to serve other high-risk groups, such as sex workers, who would likely find the discreetness of a twice-yearly injection attractive. But the public health system cannot afford it at the price Gilead wants Brazil to pay, he said.
“Innovation without access is an injustice,” he said. “We cannot afford the stratospheric prices they propose, in a public system.”
Gilead spokeswoman Ashleigh Koss said the company was committed to rapidly expanding access to lenacapavir.
“Discussions on access in Latin America and the Caribbean are taking place through multiple avenues, including ongoing regional discussions with the Pan American Health Organization,” he said, referring to the regional branch of the World Health Organization, which organizes the joint purchasing of medicines.
