Merck and Gilead reported that a combination of Merck’s islatravir and Gilead’s lenacapavir met primary efficacy endpoints in two Phase 3 trials evaluating a weekly oral HIV regimen for people who were virologically suppressed. The Islend-1 trial assessed switching off Gilead’s once-daily Biktarvy, while Islend-2 studied switching off standard-of-care antiretroviral regimens. The companies said there were no new safety concerns and plan submissions to regulatory authorities globally. Analysts highlighted that, despite the efficacy results, Biktarvy’s real-world standard-setting may still be difficult to displace without long-term resistance and safety clarity. The program adds pressure to the long-acting oral space as weekly dosing could reshape adherence and patient choice if regulatory outcomes remain favorable.