Opus Genetics doses first patient in phase 1/2 clinical trial, BIRD-1, evaluating OPGx-BEST1

Opus Genetics has dosed the first patient in its OPGx-BEST1 phase 1/2 clinical trial, BIRD-1, for Best disease (BEST1).

Best disease, also known as vitelliform macular dystrophy, is a rare, inherited retinal condition causing macular degeneration by mutations in the BEST1 gene, leading to progressive vision loss and potentially blindness. The BEST1 gene is responsible for providing instructions to produce bestrophin, a protein that acts as a channel to manage the movement of charged chloride ions in and out of retinal cells.¹

BIRD-1 is a multi-center, adaptive, open-label, dose-exploring study evaluating the safety, tolerability, and preliminary efficacy of OPGx-BEST1 in patients with Best Vitelliform Macular Dystrophy (BVMD) or Autosomal-Recessive Bestrophinopathy (ARB). The trial will consist of 2 dosing cohorts and will explore biological activity through functional and anatomical endpoints, including changes in visual function and retinal structure.¹

According to the company, OPGx-BEST1 leverages its proprietary AAV-based gene therapy platform, which is designed to deliver a functional copy of the BEST1 gene directly to the retinal pigment epithelium (RPE) cells. It is administered via a one-time subretinal injection.

George Magrath, MD, CEO of Opus Genetics, commented on the dosing in a press release from the company, saying, “This milestone reinforces our mission to develop one-time gene therapies for inherited retinal diseases that previously had no treatment options. It’s a privilege to collaborate with leaders in the field like Drs. Pennesi, Fan, and Wykoff. We are deeply thankful to the Retina Foundation of the Southwest, Retina Consultants of Texas, and most importantly, the patients and families who place their trust in us. Together, we are striving to build a future where no one loses their sight to inherited retinal disease.”

Mark Pennesi, MD, PhD; Kenneth Fan, MD; and Charles Wykoff, MD, PhD, are the doctors conducting the trial. Pennesi commented, “This milestone highlights the significant progress being made in ophthalmic gene therapy and the potential power of collaboration between industry and academia to bring new hope to families affected by inherited retinal diseases.”

“The successful dosing of the first patient underscores both the potential promise of gene therapy in ophthalmology and the dedication of the entire community working to make these treatments a reality. It’s inspiring to see years of scientific progress translate into potentially meaningful advances for patients and families,” added Wykoff.

Initial data from the trial is expected in the first quarter of 2026.

Recently, Opus Genetics completed a Type B Regenerative Medicine Advanced Therapy (RMAT) meeting with the US Food and Drug Administration (FDA) regarding OPGx-LCA5, its gene therapy candidate for Leber congenital amaurosis (LCA) caused by mutations in the LCA5 gene.²

The trial is a phase 1/2 open-label, ascending-dose study of the safety and efficacy of OPGx-LCA5. Recently, the company released positive 3-month pediatric data, showing significant measurable gains in vision in teenagers and maintenance of visual gains to 18 months in adults who were treated earlier.

References:

1. Opus Genetics Announces Dosing of First Participant in OPGx-BEST1 Phase 1/2 Gene Therapy Clinical Trial for Best Disease. Published November 13, 2025. Accessed November 17, 2025. https://ir.opusgtx.com/press-releases/detail/509/opus-genetics-announces-dosing-of-first-participant-in-opgx-best1-phase-12-gene-therapy-clinical-trial-for-best-disease

2. Harp MD. Opus Genetics has Type B RMAT meeting with FDA for its gene therapy candidate, OPGx-LCA5. Published November 7, 2025. Accessed November 17, 2025. https://www.ophthalmologytimes.com/view/opus-genetics-has-type-b-rmat-meeting-with-fda-for-its-gene-therapy-candidate-opgx-lca5