Merck and Gilead preview full Phase 3 data for once-weekly islatravir and lenacapavir HIV regimen

Merck and Gilead used a July 21 release to preview the full Phase 3 ISLEND results for the investigational once-weekly oral HIV regimen of islatravir and lenacapavir, ahead of late-breaking presentations on July 29 at AIDS 2026. In both trials the regimen kept virus suppressed in adults who switched therapy, meeting the Week 48 primary endpoint first reported in June. The regimen is not approved.

• ISLEND-1 (switch from Biktarvy): 0% vs 0.3% with HIV-1 RNA at or above 50 copies/mL at Week 48
• ISLEND-2 (switch from daily standard care): 0.3% vs 1.3% at Week 48
• Investigational only; the companies say the data will support regulatory submissions