Opus Genetics announced that the first participant has been dosed in its phase 1/2 clinical trial evaluating OPGx-BEST1 for Best disease (BEST1). The milestone marks the first human administration of the company’s investigational gene therapy for this rare, vision-threatening condition.
Best disease, also known as vitelliform macular dystrophy, is an inherited form of macular degeneration caused by mutations in the BEST1 gene. These mutations disrupt the function of the retinal pigment epithelium (RPE), leading to progressive central vision loss and, in severe cases, blindness. OPGx-BEST1 is designed as a one-time subretinal injection aimed at restoring BEST1 function in affected RPE cells.
The first dose in the trial was administered through a collaboration between Mark Pennesi, MD, of the Retina Foundation of the Southwest and surgical retina specialists Kenneth Fan, MD, and Charles Wykoff, MD, of Retina Consultants of Texas.
“Dosing the first participant in our OPGx-BEST1 program is a historic moment for the Best disease community and for our team at Opus,” said George Magrath, MD, Chief Executive Officer of Opus Genetics. “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.”
“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,” said Dr. Pennesi, Director of the Inherited Retinal Degeneration Clinic at the Retina Foundation of the Southwest. “For patients with Best disease, this represents an important step toward potentially preserving and restoring vision.”
Dr. Charles Wykoff, a surgical retina specialist and ophthalmologist at Retina Consultants of Texas, added, “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.”
About OPGx-BEST1 and the BIRD-1 Clinical Trial
OPGx-BEST1 utilizes Opus Genetics’ proprietary AAV-based gene therapy platform to deliver a functional BEST1 gene directly to the RPE, enabling proper production of the bestrophin protein. Preclinical studies have shown restored BEST1 expression and improved retinal activity in disease models.
The phase 1/2 clinical trial, known as BIRD-1, is a multicenter, adaptive, open-label, dose-exploring study evaluating safety, tolerability, and preliminary efficacy of OPGx-BEST1 in patients with Best Vitelliform Macular Dystrophy (BVMD) or Autosomal-Recessive Bestrophinopathy (ARB). Each participant will receive a single subretinal injection in one eye across two dosing cohorts.
Investigators will assess biological activity through both functional and anatomical measures, including changes in visual function and retinal structure. Initial clinical data is expected in the first quarter of 2026.
