Opus Genetics Launches Gene Therapy Clinical Trial for Best Disease

Opus Genetics, a biopharmaceutical company developing gene therapies for inherited retinal diseases, has dosed the first person in its BIRD-1 Phase 1/2 gene therapy clinical trial for people with Best vitelliform macular dystrophy (BVMD) or autosomal recessive Bestrophinopathy (ARB) caused by mutations in the gene Best1. BIRD-1 will enroll 10 patients and evaluate two doses of the gene therapy. The trial is being conducted by Mark Pennesi, MD, PhD, at the Retina Foundation of the Southwest and the surgical team of Kenneth Fan, MD, and Charles Wykoff, MD, PhD, at Retina Consultants of Texas. The company expects to report initial data from BIRD-1 in the first quarter of 2026.

Opus Genetics was established by the Foundation in 2021. The RD Fund, the Foundation’s venture philanthropy arm, is an investor in the company. The Foundation also provided nearly $2 million in funding for successful, proof-of-concept studies at the University of Pennsylvania for a Best1 gene therapy that reversed Best disease in canine models.

Known as OPGx-BEST1, the gene therapy is administered through a one-time subretinal injection. OPGx-BEST1 uses an adeno-associated virus (AAV), which works like a container system, to deliver healthy copies of the Best1 gene into retinal cells to augment the mutated copies. Researchers believe gene therapies such as OPGx-BEST1 may work for many years, perhaps the lifetime of the patient.

Best disease is a form of inherited macular degeneration, often leading to severe central vision loss. Lesions comprised of waste material accumulate in a layer of support cells known as the retinal pigment epithelium (RPE) and underneath the retina. The condition also causes micro detachments between the RPE and photoreceptors. The separation leads to loss of photoreceptors and vision.