07:40 AM EDT, 10/15/2025 (MT Newswires) -- Merck ( MRK ) said Wednesday that data from two late-stage studies of the investigational two-drug regimen of doravirine and islatravir in adults with HIV-1 infection that had been virologically suppressed in previous trials maintained viral suppression and demonstrated non-inferiority to a commonly used three-drug regimen.

The once-daily, orally ingested drug showed no observed treatment-related resistance to doravirine and islatravir, but showed minimal changes in weight and body composition after switching from the three drug combination of bictegravir, emtricitabine, and tenofovir alafenamidei at 48 weeks, the company said.

In both trials, adults who switched to Merck's ( MRK ) combo saw no clinically meaningful changes in fasting lipids or insulin resistance, the company said.

The US Food and Drug Administration has already accepted the new drug application for the drug combination, with a target action date set for April 28, the company said.