Gilead and Merck: Phase 3 ISLEND trials show positive topline results for once‑weekly islatravir/lenacapavir
- Phase 3 ISLEND‑1 and ISLEND‑2 met the Week 48 primary efficacy endpoint assessed by the FDA snapshot (HIV‑1 RNA ≥50 copies/mL).
- Investigational single‑tablet regimen is islatravir 2 mg / lenacapavir 300 mg dosed once weekly.
- ISLEND‑1 (double‑blind) showed non‑inferiority versus Biktarvy; ISLEND‑2 (open‑label) showed non‑inferiority versus daily standard‑of‑care regimens.
- Safety of ISL/LEN was generally comparable to comparators; Gilead and Merck plan global regulatory filings and scientific presentation of detailed data.
Topline results
The Phase 3 ISLEND‑1 and ISLEND‑2 trials met their primary efficacy endpoint at Week 48 using the FDA snapshot algorithm (proportion with HIV‑1 RNA ≥50 copies/mL). In ISLEND‑1 (double‑blind), the once‑weekly single‑tablet islatravir/lenacapavir regimen was statistically non‑inferior to Biktarvy. In ISLEND‑2 (open‑label), the regimen was statistically non‑inferior to participants' daily standard‑of‑care antiretroviral regimens.
Regimen and study design
The investigational tablet contains islatravir 2 mg and lenacapavir 300 mg administered once weekly. ISLEND‑1 randomized virologically suppressed participants on Biktarvy 1:1 to switch or continue; ISLEND‑2 randomized participants on stable standard‑of‑care regimens to switch or continue. Key secondary endpoints include Week 96 viral outcomes, CD4 change and discontinuations for treatment‑emergent adverse events.
Safety and next steps
ISL/LEN's safety profile was reported as generally comparable to Biktarvy and to standard‑of‑care arms, with no new safety concerns identified. Gilead and Merck plan to file the Phase 3 data with regulatory authorities globally and to present detailed findings at a future scientific congress.
Mechanism and status
The combination targets multiple stages of HIV‑1 replication; islatravir is a next‑generation nucleoside analog and lenacapavir is a capsid inhibitor. The combination remains investigational and is not approved for use.
Source: Merck
