Opus Genetics reaches FDA alignment on phase 3 registrational design for OPGx-LCA5 gene therapy

Opus Genetics, Inc has reached alignment with the US Food and Drug Administration (FDA) on the design of its registrational phase 3 clinical trial of OPGx-LCA5, an investigational gene therapy for LCA5-associated inherited retinal disease (IRD), the company announced.¹ The agreement followed a Type B Rare Disease Evidence Principles (RDEP) meeting, and the company reported it has since received meeting minutes confirming several key elements of the study.

OPGx-LCA5 is designed to address a form of Leber congenital amaurosis (LCA) that results from biallelic mutations in the LCA5 gene, which encodes the lebercilin protein.¹ The disease is an early-onset, severe inherited retinal dystrophy and one of the most profound forms of childhood blindness, with affected patients experiencing significant vision loss at an early age and no approved treatment options. The therapy uses an adeno-associated virus 8 (AAV8) vector to deliver a functional LCA5 gene to the outer retina.¹

A pathway built for an ultra-rare population

The confirmed phase 3 design reflects the small patient population characteristic of LCA5-associated IRD. The study is expected to enroll 8 participants who are able to complete microperimetry testing, with both eyes treated, and to incorporate a 6-month run-in period, allowing each participant to serve as their own natural history control prior to treatment.¹ Seven of the 8 planned participants have already been enrolled and are completing the run-in period.¹

The single-arm, adaptive structure builds directly on guidance the company received earlier in its regulatory dialogue. Following a Type B Regenerative Medicine Advanced Therapy (RMAT) meeting in late 2025, Opus indicated it would advance an adaptive design incorporating a phase 3 portion—enrolling as few as eight participants and using a run-in period to establish each patient's natural history—rather than conducting a separate registrational trial.²

Perhaps most consequentially, the FDA indicated that Opus may submit a BLA based on compelling efficacy at the 6-month primary endpoint, with 12-month durability data submitted during the review process.¹ The primary efficacy endpoint is a mean improvement of at least 7 decibels (dB) in retinal sensitivity across the central 16 test loci, a measure of visual function for which the study is designed with greater than 90% statistical power.¹

Phase 1/2 data underpin the endpoint

Confidence in the 7-dB threshold draws on results from the ongoing phase 1/2 trial (NCT05616793) at the University of Pennsylvania, in which participants able to complete microperimetry demonstrated an average improvement of approximately 10.5 dB.¹ The program has previously reported durable functional gains in treated adults sustained to 1 year, along with measurable gains in cone-mediated vision among treated teenagers.^3,4 Across participants treated to date, OPGx-LCA5 has been well tolerated, with no ocular serious adverse events or dose-limiting toxicities reported.¹

"We believe this alignment with the FDA provides a clear roadmap toward a potential BLA submission and, most importantly, brings us one step closer to delivering a treatment for patients living with LCA5-associated blindness," George Magrath, MD, chief executive officer of Opus Genetics, said in the news release.¹ He added that the company anticipates initiating dosing in the phase 3 study during the fourth quarter of 2026 and noted that OPGx-LCA5 may qualify for a priority review voucher, "representing a potentially significant strategic asset."¹

Jean Bennett, MD, PhD, co-founder and board member of Opus Genetics, emphasized the unmet need in the population. LCA5-associated IRD ranks among the most severe forms of childhood blindness, she noted, with patients facing profound early vision loss and no approved therapies.¹

OPGx-LCA5 has received Rare Pediatric Disease, Orphan Drug, and RMAT designations from the FDA and has been accepted into the agency's RDEP program.¹ The Rare Pediatric Disease designation makes the candidate eligible for a Priority Review Voucher upon approval, an incentive the company has previously highlighted as part of its development strategy.⁵ The therapy is the lead program in an Opus pipeline that spans seven AAV-based candidates targeting inherited retinal diseases.¹

References:

1. Opus Genetics announces FDA alignment on phase 3 registrational trial design for OPGx-LCA5 in LCA5-associated inherited retinal disease. Opus Genetics, Inc. Published July 6, 2026. Accessed July 7, 2026. https://ir.opusgtx.com/press-releases/detail/537/opus-genetics-announces-fda-alignment-on-phase-3-registrational-trial-design-for-opgx-lca5-in-lca5-associated-inherited-retinal-disease

2. Harp MD. Opus Genetics has Type B RMAT meeting with FDA for its gene therapy candidate, OPGx-LCA5. Ophthalmology Times. Published November 7, 2025. Accessed July 7, 2026. https://www.ophthalmologytimes.com/view/opus-genetics-has-type-b-rmat-meeting-with-fda-for-its-gene-therapy-candidate-opgx-lca5

3. OPGx-LCA5 gene therapy phase 1/2 data support potential to restore meaningful vision. Ophthalmology Times. Published May 29, 2026. Accessed July 7, 2026. https://www.ophthalmologytimes.com/view/opgx-lca5-gene-therapy-phase-1-2-data-support-potential-to-restore-meaningful-vision

4. Charters L. Positive pediatric data emerge from the OPGx-LCA5 phase 1/2 trial of Leber congenital amaurosis type 5. Ophthalmology Times. Published October 1, 2025. Accessed July 7, 2026. https://www.ophthalmologytimes.com/view/positive-pediatric-data-emerge-from-the-opgx-lca5-phase-1-2-trial-of-leber-congenital-amaurosis-type-5

5. Opus Genetics receives Pediatric Disease Designation from FDA for OPGx-LCA5 to treat rare inherited retinal disease LCA5. Ophthalmology Times. Published October 11, 2025. Accessed July 7, 2026. https://www.ophthalmologytimes.com/view/opus-genetics-receives-pediatric-disease-designation-from-fda-for-opgx-lca5-to-treat-rare-inherited-retinal-disease-lca5