Gilead and Merck report Week 48 data for once-weekly oral HIV pill islatravir/lenacapavir

Gilead and Merck reported Week 48 Phase 3 results for once-weekly islatravir and lenacapavir, meeting the primary endpoint in both ISLEND trials. In ISLEND-1, virologic failure was 0% on the weekly pill versus 0.3% on daily Biktarvy, and in ISLEND-2 it was 0.3% versus 1.3% on standard daily regimens. The companies said the data will form the basis of regulatory submissions, and the regimen is not approved anywhere, so this is a pipeline read on a possible successor to Biktarvy rather than near-term revenue.

• ISLEND-1 (switch from Biktarvy): virologic failure 0% weekly pill vs 0.3% Biktarvy (one participant)
• ISLEND-2 (switch from daily oral regimens): virologic failure 0.3% vs 1.3%
• Both trials met non-inferiority at Week 48; no new safety concerns identified
• Detailed data presented at AIDS 2026 late-breaker sessions on July 29
• Regimen is investigational and not approved; filings are planned globally