Ocugen has achieved a significant regulatory milestone with the U.S. FDA's clearance of its Investigational New Drug (IND) amendment to initiate a Phase 3 clinical trial for OCU400, a modifier gene therapy candidate for retinitis pigmentosa (RP). This marks the first gene therapy program to enter Phase 3 with a broad RP indication, potentially addressing a critical gap in treatment options for patients with this rare genetic disorder.
"The initiation of the OCU400 Phase 3 clinical trial is a significant milestone for patients with RP and a pivotal event for Ocugen as a company," said Dr. Shankar Musunuri, Chairman, CEO and Co-Founder of Ocugen. "OCU400 is the first gene therapy program to enter Phase 3 with a broad RP indication. Until now, there has been only one marketed product to treat one of the 100 gene mutations associated with RP. Now there is real hope for all RP patients who haven't had a treatment option."
Phase 3 Trial Design and Patient Population
The Phase 3 study will enroll 150 participants divided into two distinct arms: 75 participants with the RHO gene mutation and 75 participants in a gene-agnostic cohort. Within each arm, participants will be randomized 2:1 to receive either the treatment (2.5 x 10^10 vg/eye of OCU400) or serve as untreated controls.
The trial represents a significant advancement in RP treatment approach, as current therapies are limited to addressing single gene mutations. According to the company, approximately 110,000 patients in the United States have RP, with 1.6 million patients affected globally. More than 10% of these patients carry the RHO genetic mutation.
Novel Assessment Method for Broader Patient Inclusion
For the Phase 3 trial, Ocugen has developed an updated mobility assessment called the Luminance Dependent Navigation Assessment (LDNA), replacing the Multi-Luminance Mobility Testing (MLMT) scale used in the Phase 1/2 trial. The LDNA incorporates a wider range of light intensity (0.04-500 Lux) and Lux Levels (0-9) with uniform correlation between Lux level and intensity.
"A sensitive mobility course, LDNA, was developed by Ocugen in collaboration with FDA for the Phase 3 clinical trial to allow enrollment of patients with early to advanced stages of disease," said Dr. Arun Upadhyay, Chief Scientific Officer at Ocugen. "We are extremely encouraged that with this Phase 3 study design more than 50% of intent to treat RHO patients would meet the responder criteria, which is demonstrating 2 or greater Lux level of improvement after one year of treatment based on Phase 1/2 study results."
Gene-Agnostic Therapeutic Approach
OCU400 represents a novel modifier gene therapy based on the NHR gene, NR2E3, which regulates diverse physiological functions within the retina including photoreceptor development and maintenance, metabolism, phototransduction, inflammation, and cell survival networks. The therapy aims to reset altered cellular gene networks and establish homeostasis, potentially improving retinal health and function in patients with inherited retinal diseases.
"We believe that the gene-agnostic clinical trial design provides an appropriate therapeutic option to include patients who have greater potential of benefiting from treatment," said Dr. Huma Qamar, Chief Medical Officer at Ocugen. "We are looking forward to working with our selected trial sites and leading retinal surgeons to deliver this novel modifier gene therapy to potentially address unmet medical needs."
Addressing Critical Unmet Medical Need
RP encompasses a group of rare genetic disorders involving breakdown and loss of retinal cells, leading to vision loss and blindness. The condition is associated with mutations in more than 100 genes, presenting significant therapeutic challenges. Currently, no approved treatment options exist that can slow or stop the progression of multiple forms of RP.
Existing gene-replacement therapies, while promising, are limited to treating single mutations and may not eliminate underlying genetic defects that continue to cause cellular stress and toxic effects. The development of gene-specific replacement therapies becomes particularly challenging when multiple or unknown genes are involved, making novel therapeutic approaches targeting broader RP disease in a gene-agnostic manner particularly valuable for patients.
Regulatory Status and Timeline
OCU400 has previously received both orphan drug and Regenerative Medicine Advanced Therapy (RMAT) designations from the FDA. With the initiation of the Phase 3 clinical trial, the company maintains its target timeline for BLA approval in 2026, representing a potential breakthrough for the substantial population of RP patients currently without effective treatment options.
