LOS ANGELES, March 12, 2025 — In a groundbreaking presentation at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco, the AIDS Clinical Trials Group (ACTG) unveiled promising results from a study investigating the impact of treating asymptomatic cytomegalovirus (CMV) in individuals living with HIV. The study suggests that antiviral therapy could significantly bolster immune function and physical health for patients dealing with the dual challenges of HIV and aging.

Cytomegalovirus (CMV) is a widespread virus that affects about 95% of people living with HIV. While modern antiretroviral therapy (ART) has dramatically improved the prognosis for individuals with HIV, CMV can persist in the body and may unduly stress the immune system, contributing to ongoing inflammation and adverse health outcomes, even when patients do not display any noticeable symptoms.

The featured study, known as A5383, explored whether the antiviral medication Letermovir, which is FDA-approved for preventing CMV infections in transplant recipients, could lead to substantial improvements in immune and physical health when administered to HIV patients already undergoing ART. The preliminary findings from this phase 2, randomized, open-label trial indicated that Letermovir treatment not only reduced inflammation over time but also led to marked increases in CD4 T cell counts, particularly benefitting women and individuals with historically low immune profiles.

ACTG Chair Dr. Joseph J. Eron of the University of North Carolina expressed enthusiasm about the findings: “This is a pivotal breakthrough in our understanding of how we can enhance immune recovery in HIV patients. The implications of this research could reshape the landscape of HIV treatment and improve the quality of life for aging individuals living with the virus.

The study's innovative design allocated participants to receive Letermovir daily for 48 weeks or to receive no treatment. Not only did the treatment yield a decrease in pro-inflammatory markers over time, but it also correlated strongly with improvements in physical performance metrics, such as chair rise performance, a critical indicator of lower body strength and mobility.

Moreover, the data revealed intriguing insights surrounding gender dynamics in HIV health outcomes. Co-Chair of the study, Dr. Sara Gianella from the University of California San Diego, noted, “Our research suggests women with HIV may experience more significant inflammation and an even wider ‘life expectancy gap’ than men. This points to a critical area for continued research, as improving outcomes for women living with HIV could dramatically level the playing field regarding health disparities.”

The ramifications of the study extend beyond just HIV patients, with potential implications also recognized for the elderly and transplant populations, where CMV's role in health outcomes has been increasingly scrutinized.

Dr. Gianella and Protocol Chair Dr. Peter Hunt from the University of California San Francisco led the A5383 study. The ACTG, funding the research under the auspices of the National Institutes of Health (NIH), aims to further explore these promising avenues, with plans for larger, more comprehensive studies to substantiate the findings.

As research continues to shed light on the intersection of HIV, aging, and CMV, this pivotal work may herald a new era of therapeutic strategies aimed at extending the lives and improving the health of those affected by these chronic conditions.