Opus Genetics reported positive interim three- and six-month results from the low-dose first cohort of its Phase 1/2 BIRD-1 trial of OPGx-BEST1, an investigational gene therapy designed to address the underlying genetic cause of BEST1-related inherited retinal diseases. All five participants showed clinically meaningful visual-function improvements, while four demonstrated structural retinal recovery. Best-corrected visual acuity improved in 60% of participants and retinal sensitivity measured by microperimetry improved in 75% of evaluable participants. Structural findings included reduced vitelliform material in 67% of participants with Best vitelliform macular dystrophy and complete intraretinal-fluid reduction among participants with autosomal recessive bestrophinopathy. No serious adverse events, dose-limiting toxicities or intraocular inflammation were reported. After an August 2026 meeting with the U.S. Food and Drug Administration, Opus Genetics said it aligned on a potential randomized controlled-trial endpoint combining microperimetry improvement with patient-reported outcomes. The company plans to complete manufacturing requirements in early 2027 and begin Phase 3 dosing later that year. The higher-dose second cohort has enrolled eight participants, with additional data expected in the second quarter of 2027. Triangle Insights Group research estimates 45,400 symptomatic BEST1 patients globally. Opus Genetics shares were up 46.66% at $6.36 and reached a new 52-week high at the time of publication, according to Benzinga Pro data.