Opus Genetics Reports Positive OPGx-BEST1 Phase 1/2 Data, Targets Potential Phase 3 Dosing in 2027

Opus Genetics (NASDAQ:IRD) reported positive low-dose Cohort 1 data from its Phase 1/2 BIRD-1 trial of OPGx-BEST1, alongside FDA alignment on potential pivotal endpoints and a development path that could lead to Phase 3 participant dosing in 2027.

Key Investor Takeaways

• All five low-dose participants showed clinically meaningful improvement in at least one measure of visual function, while four of five showed structural retinal improvements.
• Opus Genetics (NASDAQ:IRD) reported no serious adverse events, dose-limiting toxicities or intraocular inflammation in Cohort 1.
• The company aligned with the FDA on a potential Phase 3 endpoint involving microperimetry improvement alongside a patient-reported outcome in a randomized, controlled trial.
• Higher-dose Cohort 2 has been expanded from five to eight participants, with dosing expected to finish in Q4 2026 and three-month topline data targeted for Q2 2027.
• New epidemiology research estimates about 23,600 symptomatic BEST1 patients in the U.S. and 45,400 globally, suggesting a larger potential addressable population than the company previously believed.

Why IRD Stock Is in Focus

The Phase 1/2 data provide the first low-dose proof-of-concept results highlighted by Opus Genetics as it works toward potential pivotal development of OPGx-BEST1 for BEST1-related retinal diseases.

Cohort 1 included five participants receiving 1.5 x 10⁹ vg/eye: three with Best vitelliform macular dystrophy, or BVMD, followed for three months, and two with autosomal recessive bestrophinopathy, or ARB, followed for six months.

All five demonstrated clinically meaningful improvement in at least one visual-function measure. Best-corrected visual acuity improved in three of five participants, low-luminance visual acuity in two of five and contrast sensitivity in two of five. Among four evaluable participants, three showed clinically meaningful improvement in retinal sensitivity measured by microperimetry.

Structural changes were reported in four participants. Vitelliform material was reduced in two of three participants with BVMD, while both participants with ARB showed reductions in intraretinal fluid.

The strongest functional improvements occurred in participants with less advanced disease and viable retinal tissue, a finding the company said is helping inform patient selection and subsequent clinical development.

Safety data were also supportive at the low dose. Opus reported no serious adverse events, dose-limiting toxicities or intraocular inflammation, while all treatment-related adverse events were mild or moderate.

Why This Matters for Investors

For investors, the clinical results are only one part of the catalyst. The FDA interaction gives Opus greater clarity around what a potential pivotal programme could look like.

Following an August 2026 Type C meeting, the company said it aligned with the FDA on a potential pivotal endpoint based on an improvement of at least 3 dB in microperimetry across at least five prespecified loci, combined with a patient-reported outcome in a randomized, controlled trial. Other visual measures may also be acceptable endpoints.

Opus also said it reached alignment on Phase 3 and commercial manufacturing requirements, which it expects to complete in early 2027. The company plans to begin Phase 3 preparations immediately, with potential participant dosing during 2027.

This regulatory progress may reduce some uncertainty around the next stage of development, but meaningful clinical risk remains. Cohort 1 included only five participants, and the follow-up periods differ between the BVMD and ARB groups. Larger and controlled studies will therefore be important in determining whether the functional and structural improvements can be reproduced.

The updated patient estimates could also affect the longer-term commercial narrative. Research commissioned by the company estimates roughly 23,600 symptomatic BEST1 patients in the U.S., including 13,000 diagnosed and 10,600 undiagnosed patients, and around 45,400 symptomatic patients globally. There are currently no approved therapies addressing the underlying genetic cause of BEST1-related diseases.

What to Watch Next

The immediate clinical focus shifts to the 4.5 x 10⁹ vg/eye Cohort 2, which has been over-enrolled with eight participants versus the five originally planned. Dosing is expected to finish in Q4 2026, followed by topline three-month results in Q2 2027.

That quarter could carry multiple readouts for the programme, as Opus also expects six-month data from the three Cohort 1 participants with BVMD in Q2 2027.

Investors can additionally watch for completion of Phase 3 and commercial manufacturing requirements in early 2027 and further details on the planned pivotal trial ahead of potential dosing later that year.

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