SALT LAKE CITY — In a significant achievement for the field of biochemistry, University of Utah biochemist Wesley Sundquist celebrated a major milestone last week when the Food and Drug Administration (FDA) approved an innovative antiviral drug for the prevention of HIV. This drug, known as lenacapavir, is based on pivotal research conducted in Sundquist's lab, which laid the groundwork for a highly effective and long-lasting prophylactic measure against HIV, the virus that causes AIDS.
Developed by the California-based pharmaceutical company Gilead Sciences, lenacapavir has garnered recognition as the Breakthrough of the Year by Science, a leading scientific journal. With the FDA's approval, this revolutionary drug, marketed under the brand name Yeztugo, will soon be accessible in the U.S., where approximately 31,000 individuals are diagnosed with HIV each year.
Sundquist's contributions to HIV research date back to the late 1990s. His team focused on purifying and analyzing the protein shell that encapsulates the virus's genetic material. Through their investigations, they uncovered the structure of the viral shell and its assembly process. A crucial finding revealed that the shell is highly sensitive to alterations; even minor modifications to its proteins significantly hindered the virus's replication speed. This discovery suggested that targeting the viral protein shell, known as the capsid, could lead to effective drug development.
These groundbreaking insights piqued the interest of Gilead Sciences, which subsequently enlisted Sundquist as a consultant. This collaboration ultimately culminated in the creation of lenacapavir, a drug that binds to the viral protein shell, preventing it from assembling correctly and entering host cell nuclei.
Phase 3 clinical trials demonstrated the drug's remarkable efficacy, showcasing its ability to completely prevent HIV transmission for up to six months. "There are still 1.3 million new infections worldwide, and this could really change that trajectory," Sundquist noted. While successful implementation and funding are necessary for the drug's rollout, Sundquist remains optimistic about its potential impact on global HIV transmission rates.
Unlike existing HIV medications, lenacapavir stands out for its potential to prevent HIV infection entirely. With around 40 million people living with HIV globally and the virus responsible for approximately 600,000 deaths annually, according to the World Health Organization, lenacapavir's efficacy could represent a major advancement in public health. In extensive clinical trials conducted in South Africa and Uganda, two regions heavily affected by HIV, not one of the over 2,000 women who received lenacapavir contracted the virus during the study period. "Lenacapavir almost completely prevents the transmission of HIV into at-risk populations," Sundquist stated. "This is just an amazing result."
The FDA's approval of lenacapavir is just the latest accolade for Sundquist, who recently received the 2025 Warren Alpert Prize from Harvard University and was named one of Time magazine's 100 most influential people in the world earlier this year. Sundquist views his lab as a source of innovative approaches to medicine, driven by a deep curiosity to unravel complex biological mechanisms. "The same drive that compels adventurers to explore mountains motivates us to understand how molecular machines operate," he remarked.
Despite his recent successes, Sundquist acknowledges that the fight against 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," he emphasized. The quest for an effective HIV vaccine continues to pose significant challenges, but Sundquist remains committed to advancing research in this critical area.
