The US Food and Drug Administration (FDA) has accepted Opus Genetics's investigational new drug application for OPGx-BEST1, a gene therapy for the treatment of bestrophin-1 (BEST1)-related inherited retinal disease.

A multicenter, open-label phase 1/2 study will evaluate the safety, tolerability, and preliminary efficacy of a single subretinal injection of OPGx-BEST1 in patients with genetically confirmed BEST1-related IRD, the company said in a press release. The trial will also explore biological activity through functional and anatomical endpoints, including changes in visual function and retinal structure.

Best disease, or vitelliform macular dystrophy, is a rare, inherited retinal condition causing macular degeneration by mutations in the BEST1 gene, leading to progressive vision loss and sometimes blindness. Opus Genetics reports that OPGx-BEST1 therapy delivers a functional copy of the BEST1 gene directly to the retinal pigment epithelium cells where the defective gene resides. 

Opus Genetics says it will initiate the trial later this year. RP