Core Insights - The pharmaceutical industry is advancing innovative treatments for chronic disease management, with Merck & Co. Inc. announcing new data from Phase 3 studies on the two-drug regimen of doravirine/islatravir (DOR/ISL) for adults with virologically suppressed HIV-1 infection [1] Group 1: Study Findings - The MK-8591A-052 trial showed that DOR/ISL maintained viral suppression and was non-inferior to the three-drug regimen BIC/FTC/TAF, with no treatment-emergent resistance observed [3] - In the MK-8591A-052 trial, participants switching to DOR/ISL experienced minimal weight changes at Week 48, with a mean weight change of -0.03 kg compared to +0.28 kg for BIC/FTC/TAF [4] - The percentage of participants experiencing significant weight gain (≥5% and ≥10%) was lower in the DOR/ISL group compared to the BIC/FTC/TAF group [4] Group 2: Body Composition and Lipid Changes - Changes in lean body mass, peripheral fat, trunk fat, body mass index, and waist-to-hip ratio were small and comparable between DOR/ISL and BIC/FTC/TAF treatment groups [5] - Minimal changes in fasting lipids were observed across both trials, with no substantial differences between DOR/ISL and comparator groups [6] - Less than 5% of participants with type 2 diabetes modified their medication across treatment groups, indicating stability in diabetic management [6] Group 3: Regulatory and Market Impact - The FDA has accepted the New Drug Application for DOR/ISL, with a target action date set for April 28, 2026 [7] - At the time of publication, Merck & Co shares were down 0.96% at $83.89 [7]

Core Insights - Merck announced new data from Phase 3 trials evaluating the investigational two-drug regimen of doravirine/islatravir (DOR/ISL) for adults with virologically suppressed HIV-1 infection, showing minimal changes in weight and body composition, and no clinically meaningful effects on fasting lipids and insulin resistance [1][3][4] Group 1: Trial Results - In trial MK-8591A-052, adults switching to DOR/ISL from BIC/FTC/TAF exhibited minimal changes in weight at Week 48, with a mean weight change of -0.03 kg for DOR/ISL compared to +0.28 kg for BIC/FTC/TAF [5] - The percentage of participants experiencing a 5% weight gain was 14.6% for DOR/ISL and 16.0% for BIC/FTC/TAF, indicating comparable outcomes [5] - Both trials showed no clinically meaningful changes in fasting lipids or insulin resistance, with similar results across treatment groups [3][6] Group 2: Safety and Efficacy - Drug-related adverse events were similar between DOR/ISL and BIC/FTC/TAF, with 10.2% for DOR/ISL and 9.4% for BIC/FTC/TAF [10] - Rates of serious adverse events were also comparable, with 7.3% for DOR/ISL and 7.6% for BIC/FTC/TAF [10] - The trials reported no treatment-emergent resistance to DOR or ISL, reinforcing the safety profile of the investigational regimen [1][4] Group 3: Regulatory Status - The FDA accepted the New Drug Application (NDA) for DOR/ISL, with a target action date set for April 28, 2026 [7] Group 4: Demographics and Study Design - The MK-8591A-052 trial included 513 adults with a median age of 47 years, with 21.4% assigned female sex at birth and 30.8% identifying as Black or African American [8] - The MK-8591A-051 trial involved 551 adults, with a median age of 51 years, and a similar demographic distribution [11][12]