An AIDS patient in a community hospital in the Central African Republic. Sub-Saharan Africa, which has high rates of HIV infection, has been the scene of a trial to test the effectiveness of a new strategy to prevent infection.
Barbara Debout/AFP via Getty Images
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Barbara Debout/AFP via Getty Images
For more than a decade, taking a daily pill like Truvada has been the standard of care for HIV prevention efforts.
In clinical trials, this type of preventive medication, called pre-exposure prophylaxis (PrEP), can be 99% effective in preventing new HIV infections during sex. In reality, however, this is not always the case.
Women don’t always take their pills. In a study in South Africa, women reported feeling a stigma around the pill: their sexual partners might think they were taking it because they were already HIV-positive or because they had other partners.
A new trial, called PURPOSE 1, is pioneering a new prevention strategy: a twice-yearly injection of a drug called lenacapavir. The trial was funded by Gilead Sciences, the drug’s California-based manufacturer.
In this randomized, double-blind study of 5,300 cisgender women in South Africa and Uganda, 2,134 received the injection and the rest took one of two types of daily PrEP pills. The trial began in August 2021, and so far, no women who received the injections have acquired HIV. Participants who received one of the two oral PrEP options, Truvada and Descovy, had infection rates of about 2%, which is consistent with infection rates for oral PrEP in other clinical trials.
The results were significant enough that the Data Monitoring Committee, an independent panel of experts appointed to assess the progress of clinical trials, recommended that Gilead end its blinded trial and offer lenacapavir to all study participants. On June 20, Gilead announced the results, and now all participants can choose to receive the shot.
The study focuses on women in sub-Saharan Africa and draws on HIV data. Despite representing 10% of the world’s population, sub-Saharan African women account for two-thirds of those living with HIV, or 25.7 million out of 38.4 million. And each week, about 4,000 adolescent girls and young women in Africa are newly infected with HIV.
The first reactions are positive
The trial has not yet been peer-reviewed, but these early results have been greeted with enthusiasm.
“It’s fantastic,” says Dr. Jason Zucker, an assistant professor of medicine and infectious disease specialist at Columbia University’s Vagelos College of Physicians and Surgeons. “It’s hard to take a drug every day. A drug that’s given every six months has great potential.”
Dr. Philip Grant, associate clinical professor and director of the HIV Clinic at Stanford University School of Medicine, agrees that lenacapvir could help fill a gap in prevention options. “It would be a big benefit for populations that have adherence issues,” he says.
Although oral PrEP is 99% effective in some trials, its effectiveness drops dramatically in real-world settings. One study found that PrEP was only 26% effective in some populations, such as men under 30.
“The medications are effective when you take them,” Zucker says. “A medication that’s given every six months has a lot of potential because, basically, if you can get two visits a year, you’re protected for 12 months.”
Advocacy groups have also expressed enthusiasm for lenacapavir’s preliminary results as a PrEP option. “Lenacapavir would be a real ‘game changer,’ particularly for people facing stigma and discrimination in low- and middle-income countries,” reads a statement from the People’s Medicines Alliance, a global coalition of more than 100 organizations in 33 countries that advocate for greater access to the medicines.
The drug is not new; its use is
Lenacapavir is not a new drug. It has been approved by the FDA in the United States for the treatment of multidrug-resistant HIV. treatment Since 2022. But PURPOSE 1 is the first clinical trial to test it for HIV. prevention.
The PURPOSE 1 trial is part of a broader effort to improve HIV prevention in the Global South. It is one of many studies that are part of ongoing efforts to end the HIV epidemic by 2030.
An ongoing PURPOSE 2 trial is studying the effectiveness of lenacapavir in cisgender men, transgender men, transgender women, and nonbinary individuals who have sex with partners assigned male at birth in Argentina, Brazil, Mexico, Peru, South Africa, Thailand, and the United States.
Eventual approval and widespread use would come with challenges. According to an analysis presented at the 24th International AIDS Conference (AIDS 2022), PrEP drugs would need to cost less than $54 per year per patient in South Africa, for example, to afford them. The cost of lenacapavir as an HIV treatment in the United States in 2023 was $42,250 per new patient per year. Oral PrEP options, by contrast, can cost less than $4 per month.
“The biggest lack of prevention is not medication, but access to it,” says Dr. Grant.
Campaigners in Uganda and South Africa (MIG5) have urged Gilead Sciences to license lenacapavir to the Medicines Patent Pool, a United Nations-backed organization that partners with governments, industry and other organizations to license medicines. This would allow generic versions of the drug to be made at a fraction of the cost.
These activists fear that history will repeat itself: In 2021, cabotegravir, a long-acting injectable PrEP drug made by ViiV Healthcare, was approved by the FDA. The drug is more effective than oral options and requires only 2 injections every 2 months. But despite the approval of generic versions of the drug, these versions still have to go through the World Health Organization’s review process to show that they are as effective as the brand-name version. Because this process takes time, generic cabotegravir will likely not be available in Africa until 2027.
Since Gilead announced lenacapavir’s success, the company has said it plans to “deliver lenacapavir rapidly, sustainably, and in sufficient quantities, if approved, to high-incidence, resource-limited countries.” Its access strategy includes developing a voluntary licensing program that would allow generic versions to be produced before the original patent expires. When NPR asked Dr. Jared Baeten, Gilead’s vice president of HIV clinical development, about timelines, he said estimates would depend on “another trial, regulatory review, and approval.”
“Cost is going to play a major role in all of this,” Dr. Zucker says. “I think and hope we’ll do everything we can to try to reduce the barriers to access.”