Merck and Gilead reported two phase 3 trials showing efficacy for a once-weekly oral HIV regimen combining Merck’s islatravir with Gilead’s lenacapavir. The companies said both studies met primary endpoints and that no new safety concerns emerged. In Islend-1, the combination was non-inferior in participants switching off Gilead’s daily Biktarvy. In Islend-2, the regimen performed on par in those switching off standard-of-care antiretroviral therapy. The companies plan to submit the data globally. The update matters for a category where adherence and long-term resistance are key constraints; weekly dosing would represent a major shift from current daily regimens if regulatory review supports the data.