Key Takeaways

  • Ocugen has completed enrollment of 140 patients in the Phase 3 liMeliGhT trial evaluating the gene therapy OCU400 for retinitis pigmentosa

  • The study is designed to test a gene-agnostic therapy across multiple RP mutations

  • Positive 3-year phase 1/2 data showing sustained visual function improvements support plans for a rolling BLA submission in 2026 and potential approval in 2027

Ocugen announced that it has completed patient enrollment for the phase 3 liMeliGhT clinical trial evaluating OCU400, an investigational gene therapy for retinitis pigmentosa (RP).

The 1-year study enrolled 140 patients with RP and will assess whether the therapy can improve visual function across multiple genetic mutations associated with the disease. Topline results are expected in the first quarter of 2027, and Ocugen said the findings could support a Biologics License Application (BLA) submission to the FDA, with a potential approval decision in 2027.

Regulatory progress may extend beyond the United States. The European Medicines Agency (EMA) has indicated that the US-based clinical trial would be acceptable for a Marketing Authorization Application (MAA) submission in Europe, according to Ocugen,

“With enrollment complete for OCU400, we enter into a very significant time as a company,” said Shankar Musunuri, PhD, chairman, CEO, and co-founder of Ocugen. “This milestone brings us even closer to potentially delivering our first novel modifier gene therapy candidate to market and providing a one-time treatment for life to hundreds of thousands of RP patients across the globe with unmet medical need.”

The liMeliGhT trial randomized participants in a 2:1 ratio to receive OCU400 treatment or remain in an untreated control group. The therapy was administered at a dose of 2.5×10¹⁰ vector genomes per eye (250 µL).

The study includes patients with both early- and late-stage RP, including pediatric participants aged 3 years and older, and spans multiple genetic mutation types. Trial arms include individuals with RHO mutations as well as a gene-agnostic cohort, reflecting the therapy’s intended ability to treat a wide range of genetic causes of RP.

The trial’s primary endpoint is the 12-month change in visual function, measured using luminance dependent navigation assessment (LDNA), a mobility test developed by Ocugen designed to evaluate functional vision changes by measuring improvements in the lowest light level at which patients can navigate a course.

“It is critical to work towards FDA-approved treatment options that address the significant gap that remains for the approximately 98% of people living with RP who are not candidates for the approved gene therapy for RP,” said Victor H. Gonzalez, MD, primary investigator of the trial at Valley Retina Institute and faculty at the University of Texas Rio Grande Valley.

The company also reported positive long-term results from its phase 1/2 trial, including 3-year follow-up data from evaluable participants.

In that study, 88% of treated patients (7 of 8) experienced improvement or preservation of visual function compared with untreated fellow eyes. Investigators observed an approximately 2-line improvement in low-luminance visual acuity (LLVA) across multiple mutation types in treated eyes.

OCU400 also maintained a favorable safety and tolerability profile, with no new treatment-related serious adverse events reported during the extended follow-up period.

Next Steps

With enrollment complete and supportive early-phase data available, Ocugen said it remains on track to begin a rolling BLA submission in the third quarter of 2026.

If approved, OCU400 could become the first gene-agnostic modifier gene therapy for RP, potentially expanding treatment options to a broader population of patients with the inherited condition.