Investigational DOR/ISL is the first non-INSTI, two-drug regimen to demonstrate non-inferiority to BIC/FTC/TAF in a Phase 3 clinical trial in treatment-naïve adults with HIV-1 infection Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced topline results from the pivotal double-blind Phase 3 trial of the investigational, once-daily, oral, two-drug, single-tablet regimen of doravirine/islatravir [DOR/ISL (100 mg/0.25 mg)] in adults with HIV-1 infection who had not previously received antiretroviral treatment (treatment-naïve) ( MK-8591A-053 ). The success criterion for the primary efficacy hypothesis, as measured by the percentage of participants with HIV-1 RNA levels <50 copies/mL at Week 48, was met, with DOR/ISL demonstrating non-inferiority to once-daily oral bictegravir/emtricitabine/tenofovir alafenamide i [BIC/FTC/TAF (50 mg/200 mg/25 mg)]. The primary safety objective of the trial was also met, with the safety profile of DOR/ISL being