Merck and Gilead's combination HIV treatment succeeds in two phase 3 trials, on track to become first weekly oral therapy

The combination of Merck's islatravir (2 mg dose) and Gilead's lenacapavir (300 mg dose) achieved its primary efficacy endpoint in both the Islend-1 and Islend-2 trials, with no new safety concerns identified. Islend-1 tested non-inferiority in patients who switched from Gilead's once-daily pill Biktarvy; Islend-2 tested it against standard-of-care antiretroviral regimens.

The regimen represents a long-acting oral therapy designed for weekly dosing, offering less frequent administration than existing HIV treatments. Gilead and Merck plan to submit data to regulatory authorities worldwide and present findings at a future scientific congress.

Analysts from Jefferies viewed the data positively but noted that Biktarvy is expected to remain the standard of care due to its well-established efficacy, citing five-year data showing 97% of patients remain suppressed. Questions remain about the long-term safety and resistance profile of the islatravir/lenacapavir combination.