Regeneron(US:REGN) Globenewswire·2025-10-12 14:18Core Insights - Regeneron Pharmaceuticals announced significant progress in their investigational gene therapy DB-OTO for profound genetic hearing loss, with 11 out of 12 participants in the CHORD trial experiencing clinically meaningful hearing improvements, including three achieving normal hearing levels [1][2][3] Group 1: Clinical Trial Results - The CHORD trial involved pediatric participants with profound hearing loss due to variants of the OTOF gene, with 12 participants aged 10 months to 16 years receiving DB-OTO via intracochlear infusion [2][9] - The primary endpoint was met, with 9 participants showing hearing improvements at a threshold of ≤70 decibels (dBHL) at week 24, indicating a level that typically does not require cochlear implantation [3][11] - Among participants with longer follow-up, eight showed stability or continued improvement in hearing, and all three who completed speech assessments demonstrated significant improvements in speech recognition [4][5] Group 2: Safety and Regulatory Status - The surgical procedure and DB-OTO were well tolerated, with no adverse findings related to DB-OTO reported; however, two serious adverse events were noted, unrelated to the therapy [5][6] - A U.S. regulatory submission for DB-OTO is planned for later this year, pending discussions with the FDA, which has granted multiple designations to the therapy, including Orphan Drug and Fast Track [6][7] Group 3: Background on Hearing Loss - OTOF-related hearing loss is a rare condition affecting approximately 20-50 newborns per year in the U.S., caused by variants in the OTOF gene, leading to a lack of functional otoferlin protein critical for auditory nerve communication [8][13] - The CHORD trial is a Phase 1/2 multicenter, open-label study evaluating the safety and efficacy of DB-OTO in children with OTOF-related hearing loss, currently enrolling participants across multiple countries [9][10]