When Wesley Sundquist first started researching the human immunodeficiency virus — HIV — he wasn’t seeking out a treatment.
Rather, the chair of the University of Utah’s Department of Biochemistry in the Spencer Fox Eccles School of Medicine said he and his team were interested in the virus molecules’ capsids — their shells holding genome material the virus needs to reproduce.
But last week, decades after Sundquist first started his HIV research in the early ‘90s, the U.S. Food and Drug Administration approved lenacapavir, a drug Gilead Sciences created using his findings, for HIV prevention.
According to researchers, the drug can be administered to people once every six months to significantly reduce their chances of contracting HIV. According to the World Health Organization, one test proved the drug effective at preventing HIV in cisgender women when none of 2,138 participants given the drug were infected. A second trial, according to WHO, was conducted with cisgender men, transgender men, transgender women and gender nonbinary people who have sex with male partners. The organization reported that 99.9% of the participants given lenacapavir were not infected with HIV.
Sundquist said the unusual cone shape of HIV molecules’ capsids spawned his interest.
“We really didn’t know what we were going to find,” he said. “We were genuinely curious about how proteins could make a cone, and also that it was important medically. … We didn’t know where this was going to end.”
His and other research teams found that the virus cannot replicate if the conical capsid is unstable. The drug, he explained, bonds to the capsid and destabilizes it.
“It’s the structure itself — it actually breaks,” he said, comparing it to cracking a glass of liquid to have the contents drain out.
He credited Gilead for their interest in his findings as “they were the ones who sort of thought we should take a chance on this as a drug target” when most companies did not share t perspective.
Lenacapavir was awarded Science magazine’s 2024 Breakthrough of the Year. Sundquist, Gilead virologist Tomas Cihlar and former Gilead medicinal chemist John O. Link received the 2025 Warren Alpert Prize. And Sundquist and Cihlar were on the list of Time magazine’s 100 Most Influential People of 2025. Although the awards didn’t start flowing until fairly recently, he stressed that it’s been a long process.
For Sundquist and other researchers, he said, “it was breakthrough of the year 25 years ago, not this year. But of course it just takes time to discover things and then translate them and then test them clinically.”
Even as professionals celebrate what lenacapavir could mean for the future of HIV and AIDS, Sundquist said he worries that the drug built off of his discovery might not reach the people who need it most.
While lenacapavir is being sold in the United States under the brand name Yeztugo, Gilead has allowed six pharmaceutical manufacturers to sell generic versions of the drug “subject to required regulatory approvals, in 120 high-incidence, resource-limited countries, which are primarily low- and lower-middle income countries.”
But Sundquist does worry that the U.S. program that could help the drug get there — the President’s Emergency Plan for AIDS Relief, or PEPFAR, launched during the George W. Bush administration — is at risk of losing its resources as the Trump White House slashes foreign aid and medical funding.
The Associated Press reported earlier this month that the Trump administration asked Congress to rescind $400 million that had been allocated to help assist with the global HIV epidemic. The administration said it would cut “only those programs that neither provide life-saving treatment nor support American interests.”
According to nonprofit medical policy analysis group KFF — formerly the Kaiser Family Foundation — the administration has limited current PEPFAR activities to only treating and caring for the HIV-infected, preventing mother-to-child transmission, administering pre-exposure medicine to pregnant and breastfeeding women and HIV testing.
“That program is in danger,” said Sundquist, who specified his views are his own and not the university’s. “It feels fragile that just at a time when we have this brand new tool that actually prevents people from getting infected by HIV, it may not be broadly distributed.”
Moreover, he stressed his research’s dependence on long-term funding from the National Institutes of Health, from which the Trump administration has cut more than $12 billion of funding in terminated research grants and contracts since the beginning of the year, as reported by Reuters. Without the assurance of funding over multiple years, Sundquist said he doesn’t think his team’s discovery would have been possible.
“We just couldn’t have done our work. … We started in ‘92, we finished about 2004, so that’s 12 consecutive years of being funded by the NIH,” he said.
And though HIV infection is not as prevalent or threatening as the AIDS epidemic was in the ‘90s, he emphasized that HIV is still a big problem. In 2023 alone, 1.3 million people were newly infected with the virus globally, according to the Centers for Disease Control and Prevention.
Sundquist said he hopes lenacapavir’s future global distribution isn’t unfunded before the drug — and his research — can reach those who need it.
