Merck announced that the U.S. Food and Drug Administration (FDA) has accepted for review the New Drug Application (NDA) for doravirine/islatravir (DOR/ISL), an investigational, once-daily oral two-drug regimen for adults with HIV-1 infection who are virologically suppressed on antiretroviral therapy.

The FDA set a target action date of April 28, 2026, under the Prescription Drug User Fee Act (PDUFA).

“The health needs of people living with HIV often change over time. We believe DOR/ISL, if approved, will offer a new complete regimen designed to meet those needs,” said Dr. Eliav Barr, chief medical officer, Merck Research Laboratories.

The NDA is supported by results from two Phase 3 trials where DOR/ISL was non-inferior to baseline antiretroviral therapy in MK-8591A-051 and to BIC/FTC/TAF in MK-8591A-052.

The safety profile of DOR/ISL was comparable to the comparator regimens. These results were presented at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI).