Core Insights - Merck (MRK) has received FDA acceptance for the new drug application (NDA) for its investigational two-drug regimen doravirine/islatravir (DOR/ISL) aimed at treating virologically suppressed adults with HIV-1 infection, with a decision expected by April 28, 2026 [1][7] Drug Efficacy and Studies - If approved, DOR/ISL would be the first non-integrase inhibitor-based two-drug regimen demonstrating comparable efficacy and safety to the current three-drug standard, BIC/FTC/TAF, in phase III studies [2] - The NDA is supported by data from two pivotal phase III studies (MK-8591A-051 and MK-8591A-052), which showed that DOR/ISL (100 mg/0.25 mg) was non-inferior to comparator antiretroviral therapies in adults with virologically suppressed HIV-1 [3] Ongoing Research and Collaborations - Merck is continuing its HIV research with additional trials, including MK-8591A-053 and MK-8591A-054, which evaluate DOR/ISL in treatment-naïve individuals and those from earlier studies, respectively [9][10] - The company is collaborating with Gilead Sciences (GILD) to evaluate islatravir in combination with GILD's lenacapavir in a phase II study for HIV treatment [10] Stock Performance - Year to date, Merck's shares have decreased by 15.5%, contrasting with a 0.2% rise in the industry [4]