- The FDA approved lenacapavir, an HIV prevention drug based on University of Utah biochemist Wesley Sundquist's research.
- Developed by Gilead Sciences, lenacapavir binds HIV's protein shell, preventing virus replication.
- In trials, not one of the more than 2,000 women who received a dose of lenacapavir contracted HIV over the course of the study.
SALT LAKE CITY — University of Utah biochemist Wesley Sundquist achieved yet another milestone last week when the Food and Drug Administration approved an antiviral drug for HIV prevention based on his findings.
Sundquist's lab at the U. laid the foundation for the development of a highly effective, long-lasting prophylactic — or preventive measure — against HIV, the virus that causes AIDS.
The resulting drug — lenacapavir — was developed by California-based pharmaceutical company Gilead Sciences and has since been named the "Breakthrough of the Year" by Science, a top scientific journal.
Now, the FDA's decision will make the drug, which is being marketed under the brand name Yeztugo, available in the U.S., where 31,000 people are infected with HIV every year.
But Sundquist's work that led to the drug dates back to the late '90s.
By purifying and analyzing the protein shell that surrounds the virus' genetic material, Sundquist's team discovered what the shell looks like and how it's put together.
In a crucial step, the research team found that the virus' shell is highly sensitive to changes. Making even small tweaks to the proteins that make up the shell stopped the virus from replicating as quickly, which suggested that drugs that affect the protein shell could prove to be effective.
It was these insights that caught the attention of Gilead Sciences, prompting the company to search for drugs that target HIV's protein shell — otherwise known as a capsid — tapping Sundquist as a consultant and eventually leading to the development of lenacapavir.
The drug itself binds the viral protein shell of HIV, preventing it from assembling properly and productively entering the nucleus of host cells.
"It's more potent than any drug available, but more importantly, it's very long-lasting. So what the Phase 3 clinical trials show is that it completely protects people from transmission for six months," Sundquist said. "There are still 1.3 million new infections worldwide, and this could really change that trajectory. Of course, the rollout has to be funded and be successful, but right now there's no reason to think this won't have a major impact."
Unlike other HIV drugs, lenacapavir is noteworthy due to its potential for preventing HIV entirely.
Across the globe, about 40 million people live with HIV and the virus is responsible for 600,000 deaths annually, according to data from the World Health Organization.
In large clinical trials in South Africa and Uganda — two HIV hot spots — not one of the more than 2,000 women who received a dose of lenacapavir contracted HIV over the course of the study.
"Lenacapavir almost completely prevents the transmission of HIV into at-risk populations," Sundquist said. "This is just an amazing result."
The FDA approving the drug is just another notch in Sundquist's belt, as he was also awarded the 2025 Warren Alpert Prize from Harvard University last week. In April, Sundquist was named as one of Time magazine's 100 most influential people in the world.
"We view ourselves as sort of the feedstock for new ways of approaching medicine," Sundquist said. "We're driven by curiosity to discover things that we don't understand. And I think that's not so different from other kinds of adventurers. The same thing that drives people to discover or climb mountains, I think, drives us to discover how a molecular machine works."
Despite the recent success, Sundquist remains driven, saying the work on HIV is far from over.
"We still need a vaccine. That would be even better because then you could give everyone the vaccine and protect everyone, not just at-risk individuals," Sundquist said. "That's been a very difficult problem."
