Once-weekly HIV pill clears phase 3 hurdle

Clinical takeaway: If approved, once-weekly oral islatravir/lenacapavir could become the first non-daily HIV treatment pill, offering a potentially practice-changing option that maintains viral suppression while reducing treatment burden.

In the phase 3 ISLEND-1 and ISLEND-2 trials, adults with virologically suppressed HIV who switched from daily antiretroviral therapy to once-weekly oral islatravir 2 mg/lenacapavir 300 mg (ISL/LEN) maintained high rates of viral suppression through 48 weeks. ISL/LEN met noninferiority criteria versus both daily Biktarvy and other standard-of-care oral regimens. In ISLEND-1, no participants receiving ISL/LEN had HIV-1 RNA ≥50 copies/mL at week 48, compared with 0.3% on Biktarvy. In ISLEND-2, virologic failure occurred in 0.3% of ISL/LEN recipients versus 1.3% of those continuing standard therapy.

Safety was generally comparable to existing regimens, with stable CD4+ counts and low discontinuation rates. Participants who switched to ISL/LEN also reported higher treatment satisfaction and lower treatment burden.

The findings will be presented at the 2026 International AIDS Conference.

“Having a treatment option with once weekly dosing can expand choice to help address individual needs and preferences,” said investigator Amy Colson, MD.

If approved, ISL/LEN could become the first once-weekly oral HIV treatment, representing a potential shift beyond daily pill-taking. By reducing dosing frequency while maintaining efficacy, the regimen could expand treatment choice, improve convenience, and help support long-term adherence for people living with HIV.

Source: Gilead Sciences and Merck. (2026 July 21). Investigational Once-weekly Oral HIV Treatment Regimen of Islatravir and Lenacapavir Maintained Virological Suppression in Adults With HIV Who Switched Antiretroviral Therapy