Ocugen's OCU400 Phase 3 in retinitis pigmentosa nears topline data, enrollment closed
The only Phase 3 gene therapy trial testing a gene-agnostic mechanism across broad RP mutations has finished enrolling, setting up a 12-month functional-vision readout expected in Q1 2027.
Executive Summary
- Ocugen has closed enrollment in its pivotal retinitis pigmentosa trial and locked the population that will read out topline results in the first quarter of 2027.
- The trial tests a single gene therapy across a broad range of RP-causing mutations rather than targeting one gene, a design with no direct precedent at this phase in the field.
- The sponsor has already secured orphan and regenerative-medicine designations and cleared the trial design with European regulators, positioning the readout to feed directly into a marketing application if it succeeds.
- Because no other program shares this mechanism or phase, the result will be read as a test case for whether a mutation-agnostic approach can work in an inherited retinal disease, not just for this asset alone.
The trial
The liMeliGhT trial (NCT06388200) enrolled 140 patients with retinitis pigmentosa, randomized 2:1 into a treatment arm receiving OCU400 by subretinal injection and an untreated control arm, spanning both patients with RHO mutations and those with other RP-associated mutations in a gene-agnostic design. The primary endpoint measures the change in functional vision from baseline to week 52, comparing treated study eyes to untreated control eyes using a luminance-dependent navigation assessment the company developed, a mobility test administered under controlled light levels. Ocugen said the trial is the first and largest gene therapy registrational trial for broad RP patients, and that topline data will follow the 12-month treatment period, expected in the first quarter of 2027. NCT06388200+1A Phase 3 Study Of OCU400 Gene Therapy for the Treatment Of Retinitis PigmentosaNCT06388200Ocugen Announces Phase 3 liMeliGhT Enrollment Completion for OCU400, a Novel Modifier Gene ...Mar 2, 2026
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The mechanism bet
"With enrollment complete for OCU400, we enter into a time as a Company," said Dr. Shankar Musunuri, Chairman, CEO, and Co-founder of Ocugen, describing the milestone as a step toward a one-time treatment for RP patients across a wide range of genetic causes. RP has more than one hundred known causative genes, and the only approved gene therapy in the disease targets a single gene. Ocugen's investigator on the trial, Dr. Victor Gonzalez of Valley Retina Institute, said the approach is meant to reach the roughly 98% of RP patients who are not candidates for that approved therapy because their mutation falls outside its target. That framing is the stake: a mutation-agnostic mechanism, if it works, would address a population the current standard of care does not reach. OcugenOcugen Announces Phase 3 liMeliGhT Enrollment Completion for OCU400, a Novel Modifier Gene ...Mar 2, 2026
Enrollment and timeline
The registry shows enrollment finalized at 140 patients, down from an earlier target of 150, a change the trial's own operational risk model classifies as within the routine band for design changes of this kind. The primary completion date has moved twice, from June 2025 to December 2026 in August 2025, and again to February 2027 in March 2026, alongside the enrollment update, as the trial's actual completion timeline firmed up. The sponsor's guided readout window, Q1 2027, has stayed consistent across four separate disclosures dated between March and May 2026, and it contains the registry's February 12, 2027 primary completion date. NCT06388200A Phase 3 Study Of OCU400 Gene Therapy for the Treatment Of Retinitis PigmentosaNCT06388200
The field
No other industry sponsor has advanced a Phase 3 program against the NR2E3 target, and OCU400 is the only Phase 3 asset in this indication tested for a gene-agnostic mutation approach. Ocugen's earlier Phase 1/2 study of OCU400 (NCT05203939) is the trial's own precedent, and the company has reported three-year durability data from that program showing a sustained visual-acuity gain of roughly two lines on a letter chart with no new treatment-related serious adverse events. Beyond Ocugen's own program, retinal gene therapy trials in adjacent diseases, including efforts from Novartis, GenSight Biologics, and Gyroscope Therapeutics, share the modality but target different genes, leaving OCU400 without a same-mechanism competitor to benchmark against in this indication. OcugenOcugen Announces Phase 3 liMeliGhT Enrollment Completion for OCU400, a Novel Modifier Gene ...Mar 2, 2026
Regulatory groundwork
OCU400 holds Regenerative Medicine Advanced Therapy designation and orphan drug designation from the FDA, and the European Medicines Agency has granted the program Advanced Therapy Medicinal Product classification and accepted the U.S.-based trial as the basis for a centralized marketing authorization application. Ocugen has said the Phase 3 data are intended to support a Biologics License Application in the U.S. and potential approval in 2027, meaning the readout, not a subsequent trial, is positioned as the pivotal evidence package for both regulators. OcugenOcugen Announces Phase 3 liMeliGhT Enrollment Completion for OCU400, a Novel Modifier Gene ...Mar 2, 2026
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.