Promising New PrEP Findings and More: Dr. Dieffenbach’s HIV Research Highlights from Day 3 of CROI 2019

Content From: HIV.govPublished: March 07, 20194 min read


In their final conversation from CROI 2019, Dr. Carl Dieffenbach and Anne Rancourt of NIH’s National Institute of Allergy and Infectious Diseases (NIAID) discussed research presented on a new formulation of pre-exposure prophylaxis (PrEP). They also described findings that advance our understanding of the effects of inflammation associated with HIV infection. Finally, they fielded a viewer’s question about HIV treatment as prevention and looked ahead to HIV research findings anticipated later this year.

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Potential New Form of PrEP

Dr. Dieffenbach reviewed the findings from the DISCOVER trial, which evaluated the safety and efficacy of a combination of the drugs emtricitabine and tenofovir alafenamide (F/TAF) for PrEP. (The combination is currently approved by the Food and Drug Administration for use as HIV treatment under the brand name Descovy®.) He discussed the design of this Phase 3 clinical trial, noting it directly compared this potential new formulation for PrEP to the only currently approved PrEP medication, Truvada® (emtricitabine and tenofovir disoproxil fumarate, F/TDF). This two-year study involved 5,387 gay, bisexual, and other men who have sex with men and transgender women at high risk of acquiring HIV in 11 countries in North America and Europe. Half were given F/TAF and the other half F/TDF. Both are once-daily, oral pills. Researchers observed a very low rate of HIV infection on either F/TAF or F/TDF—significantly less than the background rate in those at risk but not on PrEP in the United States. The researchers concluded that the new formulation had an excellent safety profile and is similarly effective (“noninferior” was their term) as F/TDF at preventing HIV acquisition. The drug would require regulatory approval for widespread use as PrEP. Read the study abstractExit Disclaimer. View the presentation by Dr. Brad HareExit Disclaimer.

Inflammation and HIV

Dr. Dieffenbach also discussed several studies presented at the conference about the effects of HIV-associated inflammation on overall health. Inflammation is a complex biological response to potentially harmful stimuli. HIV infection is associated with underlying inflammation despite treatment, and a growing body of evidence suggests that inflammation may increase the risk for a range of health problems. His colleague, NIAID’s Dr. Irini Sereti, delivered a plenary presentation at the conference, “Inflammation: Taming the Flames,” which examined what is known about immune activation and inflammation in HIV and its association with accelerating the detrimental effect of other factors such as smoking, diabetes, and aging. View the plenary presentation by NIH’s Dr. Irini SeretiExit Disclaimer.

Other inflammation-related studies focused on the link between HIV and cardiovascular disease. An NIH-supported study shed light on the relationship between weight gain in people with HIV and immune activation that can give rise to complications like heart disease and cancer. These findings, presented by Dr. Sara Bares, suggest that HIV-related weight gain and immune activation may amplify each other, especially in women. Read a related blog post. View the presentation by Dr. Sara Bares of the University of Nebraska Medical CenterExit Disclaimer.

Wrapping Up and Looking Ahead

Before they wrapped up their final conversation from CROI 2019, Dr. Dieffenbach fielded a viewer question about his thoughts on the biggest barriers to capitalizing on the powerful benefits of HIV treatment as prevention and communicating the U=U (undetectable = untransmittable) message. The message is based on the substantial scientific evidence that people living with HIV who take HIV medicine every day as prescribed and get and keep an undetectable viral load have effectively no risk of sexually transmitting HIV to their HIV-negative partners. Watch the video to learn what Dr. Dieffenbach thinks are two significant barriers to realizing the full benefits of HIV treatment as prevention.

Finally, Dr. Dieffenbach shared his reflections on key takeaways from this year’s CROI and looked ahead to other HIV research findings anticipated later in the year.

About the Conference

The annual CROI conference, taking place in Seattle this week, has gathered basic, translational, and clinical scientists from more than 70 countries. They are sharing and discussing the latest studies, notable developments, and best research methods in the ongoing battle against HIV, AIDS, and related infectious diseases. Visit the conference websiteExit Disclaimer for abstracts, session descriptions, webcastsExit Disclaimer, and other materials being released over the course of the week.