Chapel Hill, N.C. — A Phase 2 study led by Dr. Joe Eron, a member of the UNC Institute for Global Health and Infectious Diseases, shows an investigational once‑weekly, all‑oral combination of islatravir (ISL) and lenacapavir(LEN) maintains high levels of virologic suppression through 48 weeks in adults living with HIV. Published in the Annals of Internal Medicine, the findings underscore a growing priority in HIV care: expanding access to simpler, more flexible treatment options that fit the realities of people’s lives.
For many people living with HIV, daily medication is effective but not always easy. Stigma, pill fatigue, and the day‑to‑day demands of life can make strict adherence challenging. Missed doses can increase the risk of viral rebound and drug resistance, making the need for alternative dosing schedules more important than ever. The investigational ISL+LEN regimen—taken once weekly—has the potential to address these challenges by reducing dosing frequency while maintaining strong antiviral activity.
Dr. Eron, the UNC Herman and Louise Smith Distinguished Professor of Medicine and Chief of Infectious Diseases, emphasized the importance of broadening treatment choices.
“People living with HIV deserve options that work not only medically, but practically. Daily pills are effective, but they’re not the right fit for everyone. Seeing such strong suppression with a once‑weekly regimen is incredibly encouraging. It suggests we may be able to offer patients a simpler approach that still delivers the control they need.”
Study Overview
The phase 2, open‑label, randomized study enrolled virologically suppressed adults across community clinics, hospitals, general practices, and research centers in the United States. Participants either switched to once‑weekly ISL+LEN or continued the first-line daily antiretroviral therapy treatment (bictegravir/emtricitabine/tenofovir alafenamide – B/F/TAF) sold under the brand name Biktarvy, for 48 weeks.
Key Findings
- High rates of viral suppression were maintained through week 48 in both groups.
- No treatment‑related serious adverse events or grade 3+ events were observed.
- No emergent resistance to ISL or LEN was detected.
- CD4+ T‑cell and lymphocyte counts remained stable with no clinically meaningful changes.
- Adherence ≥95% was achieved by 98.0% of participants receiving ISL+LEN.
Next Steps
“With these promising results, the ISL+LEN program can now move to a broad late‑stage development phase,” Eron said. “Two global phase 3 studies—ISLEND‑1 and ISLEND‑2—are now underway to evaluate the once‑weekly fixed‑dose combination in a larger and more diverse population. These studies will assess long‑term viral suppression, safety, and patient‑reported outcomes such as convenience, satisfaction, and adherence.”
Work is also progressing on a single‑tablet, once‑weekly formulation designed to simplify administration even further. Regulatory engagement is ongoing to align on future submission pathways.
Participants from the phase 2 study will continue in long‑term follow‑up to assess durability of suppression and real‑world adherence over multiple years. Additional research will explore the potential role of ISL+LEN for individuals who struggle with daily oral therapy.
UNC Institute for Global Health and Infectious Diseases
Established in 2007, the UNC Institute for Global Health & Infectious Diseases at the UNC School of Medicine started over 30 years ago with infectious disease physician researchers studying HIV in China and Malawi. Through the years, our work has expanded to include emerging pathogens, cancer, women’s health and vector-borne disease like malaria–shaping policy through evidence-based research around the world. At UNC-Chapel Hill, the Institute facilitates research excellence while nurturing emerging scientists to advance patient care and practice, addressing the most important global health issues of our time–through research, training and service.