Opus Genetics Announces Initial Clinical Data from Phase 1/2 OPGx-BEST1 Gene Therapy Study

Early signals of functional and structural improvement observed in sentinel participant with BEST1-related retinal disease

Published on Feb. 27, 2026

Got story updates? Submit your updates here. ›

Opus Genetics, a clinical-stage biopharmaceutical company, announced new clinical data from its ongoing Phase 1/2 study of OPGx-BEST1 gene therapy, presented at the Macula Society Annual Meeting. The data showed the sentinel participant, a 63-year-old female with Autosomal-Recessive Bestrophinopathy (ARB), experienced no ocular inflammation, treatment-related adverse events, or dose-limiting toxicities at three months. Early signals of functional and structural improvement were observed, including a 12-letter gain in Best Corrected Visual Acuity and a 23% decrease in central subfield thickness in the treated eye.

Why it matters

BEST1-related retinal diseases represent a significant unmet medical need, with no approved treatments currently available. The preliminary results from this study, including the early favorable safety profile and initial signals of functional and structural improvement, are encouraging and support continued evaluation of OPGx-BEST1 as a gene augmentation approach for patients with BEST1-associated disease.

The details

The ongoing adaptive, open-label Phase 1/2 study is evaluating single-eye subretinal administration of OPGx-BEST1 up to two dose levels in adult participants with Best Vitelliform Macular Dystrophy (BVMD) or Autosomal-Recessive Bestrophinopathy (ARB). The primary objective is to assess safety and tolerability and identify the most appropriate dose for further clinical development, with participants followed longitudinally for long-term outcomes. The trial will also explore biological activity through functional and anatomical endpoints, including changes in visual function and retinal structure.

  • The sentinel participant was treated and followed for 3 months.
  • Full cohort data is expected in mid-year 2026.

The players

Opus Genetics, Inc.

A clinical-stage biopharmaceutical company developing gene therapies to restore vision and prevent blindness in patients with inherited retinal diseases (IRDs).

George Magrath, M.D.

Chief Executive Officer of Opus Genetics.

Mark Pennesi, M.D., Ph.D.

Study investigator at the Retina Foundation of the Southwest in Dallas, Texas.

Got photos? Submit your photos here. ›

What they’re saying

“We are encouraged by these results from our sentinel participant, showing OPGx-BEST1 was well-tolerated and demonstrated promising initial efficacy at three months.”

— George Magrath, Chief Executive Officer, Opus Genetics

“BEST1-related retinal diseases represent a significant unmet medical need, with no approved treatments currently available. The preliminary results from this study, including the early favorable safety profile and initial signals of functional and structural improvement, are encouraging and support continued evaluation of OPGx-BEST1 as a gene augmentation approach for patients with BEST1-associated disease.”

— Mark Pennesi, Study investigator at the Retina Foundation of the Southwest

What’s next

Recruitment in the Phase 1/2 study is ongoing at two clinical sites in the U.S., with additional sites expected to open in Florida, Cincinnati and New York. Two participants have been enrolled to date, with 3-month results from the full Cohort 1 expected in mid-year 2026.

The takeaway

The early positive safety and efficacy signals from the sentinel participant in Opus Genetics' OPGx-BEST1 gene therapy study represent an important milestone in the development of a potential treatment for patients with BEST1-related retinal diseases, an area with significant unmet medical need.