Category: News

You can trace a direct line between the recent headline-grabbing FDA approval of HIV prevention and treatment drugs to research at the Washington National Primate Research Center (WaNPRC). And the history of WaNPRC’s involvement in fighting the HIV epidemic goes back years.

While media coverage of Yeztugo, formally known as lenacapavir or Sunlenca, is understandably focused on the successful human trials, it might not have gotten to human trials at all were it not for animal studies, including those done at WaNPRC.

Yeztugo is a promising tool for many patients. According to the Centers for Disease Control and Prevention, approximately 1.1 million people in the U.S. are living with HIV. Even though fewer people are getting HIV each year — with about 36,300 new cases in 2018 and 31,800 in 2022 — the disease still hits certain groups harder than others. Experts think one big reason HIV is still a problem is because many people who could benefit from medicine that prevents it (called PrEP, or Pre–Exposure Prophylaxis) either don’t know about it, can’t easily get it, or forget to take it every day. So, a twice-a-year shot has the potential to boost the longstanding effort to reduce HIV rates over the coming years. While Yeztugo is for PrEP, Sunlenca is used as a treatment of HIV in combination with other medications. How these drugs got to this point is where WaNPRC researchers and monkeys enter the picture.

In lieu of a cure, the focus has been on using PrEP to halt transmission between people.

In the mid-1990s, Dr Che-Chung Tsai, a WaNPRC affiliate scientist, showed that an experimental drug, called tenofovir, when administered to pigtail macaques just before or after exposure to SIV (a virus very similar to HIV that causes AIDS in nonhuman primates) study completely protected the animals from infection without adverse effects.

This success led Gilead to develop the licensed version of tenofovir (called Truvada) that has been now used for two decades in the US and worldwide to reduce HIV transmission. This success led Gilead to pursue more options. Among those was lenacapavir, now known by the brand name “Yeztugo and Sunlenca.”

Before Yeztugo and Sunlenca could be tested in humans, it had to be first tested in petri dishes to show it could neutralize the virus. Years of work led to optimizing the drug’s ability to neutralize the virus in a dish. But showing a drug works well in a dish is not enough. To determine the feasibility of using this drug in people, essential studies in nonhuman primates were needed to determine the dose of drug needed to block infection in the body, to determine where the drug goes in the body and if it was safe. This is where WaNPRC once again enters the picture. Dr. Tsai’s early work with Truvada showed the value of the pigtail macaque in predicting the success of a treatment for human use and this led to researchers testing this new drug to reach out to WaNPRC to support this research by providing pigtail macaques for their crucial preclinical study prior to advancing this drug to human clinical trials.

“Female pigtail macaques are preferred for studies to develop antivirals and vaccines to prevent vaginal and rectal transmission of HIV due to their close similarity to both males and females. In particular, female pigtail macaques exhibit the closest similarity to the human female menstrual cycle and have played a crucial role for decades in studies of HIV transmission and prevention in women”said WaNPRC Director Deborah Fuller, who lauded the work leading up to this new drug.

But the work doesn’t end there. WaNPRC is continuing to support studies that aim to halt the spread of HIV.  Dr. Rodney Ho, a WaNPRC affiliate researcher and professor in pharmaceutical sciences at the University of Washington pigtail macaques at WaNPRC is developing a different long-acting HIV drug combination, intended to provide even longer lasting HIV viral suppression. His innovation recently entered human clinical trials in collaboration with WaNPRC’s Associate Director of Research, Dr. Kristina Adams Waldorf.

He touts his contributions in establishing the methods were used to enable the ability of PrEP to directly improve human health. With antiviral drugs preventing transmission, Ho said, “life expectance greatly increases. There’s no public burden on health care costs and a higher quality of life for patients who can live out their normal lives.”

The story of Yeztugo and Sunlenca is a powerful example of how early-stage research at WaNPRC laid the foundation for medical breakthroughs that can saved millions of lives.  The WaNPRC’s contributions underscore the role of nonhuman primates in translating discoveries into real-world solutions.  WaNPRC is committed to this mission and will continue to play a key role in developing the next-gen treatments to prevent and treat HIV and to improve the quality of life and health of people.

Routine groundwater monitoring of a well at the Washington National Primate Research

Centers (WaNPRC) located on the Salt River Pima-Maricopa Indian Community (SRPMIC)

land recently identified perchlorate levels that reached the designated threshold for

activating the facility’s contingency plan. Perchlorate is a chemical compound that can be

both manufactured and naturally occurring.

The perchlorate levels were detected by the sampling vendor hired by the company

contracted to Nammo Defense Systems (NDS). Nammo is taking the lead to facilitate

environmental cleanup of the site. As part of the remediation responsibilities, regular

groundwater testing results are provided to the WaNPRC and all relevant regulatory

partners. Although no statewide regulatory limit for perchlorate in groundwater exists in

Arizona, the Arizona Department of Health Services has developed a drinking water

health-based guidance level of 11 micrograms per liter (μg/L) for the compound. This

concentration was developed to protect the most sensitive population, children. The most

recent detected levels of 6.6 micrograms per liter (μg/L) does not exceed this level but it

does exceed the action threshold established in coordination with University of

Washington, WaNPRC, and NDS, and this prompted immediate protective measures.

NDS activated the contingency plan to safeguard the health and safety of the research

animals at WaNPRC and began delivering potable water to the facility to minimize

operational impacts while strategic consideration for a long-term water filtration solution

is developed.

NDS also notified and is actively coordinating with regulatory and community partners,

including the Salt River Pima-Maricopa Indian Community (SRPMIC), the US

Environmental Protection Agency (EPA), and the Arizona Department of Environmental

Quality (ADEQ). WaNPRC is also actively collaborating with these agencies as it follows its

response strategy.

For questions or concerns, please contact: uwnews@uw.edu.

June 18, 2025

WaNPRC Director Dr. Deborah Fuller today welcomed Dr Raimon Duran-Struuck as a core faculty member of the Washington National Primate Research Center.  Dr Duran-Struuck is the Chair and a Professor in the UW Department of Comparative Medicine (DCM).

A passionate advocate for research animals, Dr Duran-Struuck says he’s inspired by the professionalism and care of people in research and the quality of our work with nonhuman primates. He says he’s “very excited” to contribute to advancing human and animal health.

“I’ve been working with NHPs for a long time, and I’ve always thought NHPs are an extremely valuable model to leverage our discoveries for safety and efficacy,” he said. “At end of the day what I tell my residents is that what we do here is to enhance discoveries. Think of a child w leukemia or a patient who depends on our discoveries. To me, that translates to being a small part of a big team that hopefully will be part of a big discovery.”

As an experienced lab animal veterinarian, researcher and instructor to medical students, Dr Duran-Struuck specializes in lab animal medicine and transplant immunology. He has published studies about immunotherapies for transplant rejection and Graft Versus Host Disease, which is a complication that can result from transplants of stem cells to treat blood disorders.

“I’m thrilled to welcome Raimon on board,” said Director Deborah Fuller.  “He brings a unique and highly impactful research program in transplant immunology that will further broaden the expertise of our world-renowned Gene Therapy and Regenerative Unit. As chair of DCM, Raimon also plays a crucial role in supporting all non-NHP animal research at UW and I very much value his expertise and efforts to support our common goals.”

Dr Duran-Struuck received his BS is biochemistry from Tufts University before earning his DVM there. He received his PhD in Immunology from the Universitat Autonoma de Barcelona. Prior to joining DCM, he was an Associate Professor in the Department of Pathobiology and a Director of Regulatory Affairs for University Lab Animal Resources at the University of Pennsylvania. Prior to that, he held research, clinical, and teaching positions at the Transplantation Biology Research Center at Massachusetts General Hospital, the Harvard University Department of Surgery, Tufts University, and Columbia University Medical Center.

Scientists and our public health infrastructure are critical for pandemic preparedness. Zika virus, a mosquito-borne disease with devastating effects on fetal brain development, continues to present a significant public health threat with far-reaching consequences for the U.S. economy and society. The virus gained global attention during the 2015-2018 epidemic, which was found to cause severe birth defects and disrupted birth rates and economies, across the Americas.

WaNPRC Associate Director of Research Kristina Adams Waldorf has been pivotal in identifying the threats posed by the Zika virus, and her findings are a perfect example of why research is essential to protect the U.S. public health and our economy. Dr Adams Waldorf’s research conclusively proved that Zika virus caused fetal brain injury, which reduced alternate theories and focused public health efforts.

Although the Zika virus epidemic began in Brazil, it wasn’t long before cases began spreading in Florida and Texas. This is why studying viruses in faraway places that can travel in the blood of an infected person and jump into mosquito populations in the U.S. is so important.

In early 2016, the news about Zika virus had reached mainstream newspapers in the U.S. Then, in the summer of 2016, the virus was found to be spreading locally in areas of Miami. Seemingly overnight, key voting populations and economic drivers in Florida were galvanized to support the scientific research for Zika virus.

“I was being contacted by real estate developers in Florida, who were seeing the value for housing cratering in areas of Miami near the Zika virus outbreak,” Adams Waldorf said. “Grandparents in Florida began donating to my research program, because their adult children were canceling visits to Florida based on fear of acquiring Zika virus.”

This fear was sufficient to cripple real estate and tourism in Florida, creating a crisis directly linking the virus with economic disruptions. A part of the economy that employs more than a million people and accounts for more than a billion dollars in economic activity had officials deeply worried. A decline in birth rates and an increase in medication abortion in Central and South America reflected the same worries of many American women and young families, who were trying to get pregnant.

The Zika virus outbreak also led to one extremely unusual incident in which the U.S. Central Intelligence Agency approached Dr. Adams Waldorf about the threat of bioterrorism from Zika.

“The CIA was concerned at the time that bad actors might be intentionally spreading Zika virus in the U.S. to create social and economic havoc in Florida and Texas,” Adams Waldorf said. “But this threat isn’t a complex international spy mystery. It’s about sick people getting on planes. This is why studying viruses that cause fetal birth defects is so important for our national security. They might seem unimportant and faraway, but they are literally in our backyard.”

The Adams Waldorf Lab is now studying the ways that fetal brain injury from Zika and other viruses can be detected during a pregnancy, which was a flash point for women who wanted to get pregnant or were currently pregnant during the Zika epidemic. Reassuring pregnant women that their pregnancies were healthy would have gone a long way to bolstering public health during this epidemic.

Government officials chose to spray areas of Miami, where Zika virus infected mosquitoes had been identified to eliminate the danger that it posed to Florida citizens. Fortunately, Zika virus was eliminated in Florida through these efforts, but the risk remains for a new epidemic.

Zika virus is now present in mosquitos and other animals throughout South and Central America, Dr. Adams Waldorf said. Once there are enough children in these populations that lack Zika virus immunity, because they weren’t alive or didn’t get infected in the 2015-2018 epidemic, there may be a new Zika virus epidemic.

The Adams Waldorf Laboratory is also identifying other viruses that could wreak havoc on public health and the economy. For example, the Oropouche virus is spread by midges and mosquitos and can be passed from a pregnant woman to their fetus. Oropouche has been associated with birth defects and stillbirths, similar to Zika. But the overall risk is still unknown and needs further study.

Studying birth defects caused by viruses is central to both public health and national security. But that can’t happen without researchers doing the basic science that will give public policymakers the information they need to make informed decisions.