Ocugen is advancing its gene-agnostic therapy, OCU400, through a Phase III clinical trial for retinitis pigmentosa (RP), a heterogeneous group of inherited retinal diseases. This innovative approach targets multiple genetic mutations, offering potential benefits to a broader patient population.
Gene-Agnostic Approach to Retinal Disease
Traditional gene therapies often focus on correcting specific genetic defects, which can be limiting given the vast number of genes associated with inherited retinal disorders. With over 100 genes implicated in RP alone, Ocugen is pioneering a gene-agnostic approach using OCU400, a modifier gene therapy.
Arun Upadhyay, PhD, Chief Scientific Officer at Ocugen, explained the rationale behind this approach: "Even though they are genetic disease, [genetics are] not the only factor which really determines the onset of disease, severity of disease or progression of the disease. There are other factors which contribute to the overall pathogenesis."
OCU400 works by delivering a molecule that restores homeostasis in the retina, preserving photoreceptor function and structure, irrespective of the underlying genetic mutation. This is achieved through the NR2E3 gene, a nuclear hormone receptor that regulates key pathways essential for retinal health.
Phase III Trial Design and Endpoints
The ongoing Phase III study involves 150 patients with retinitis pigmentosa, divided into two arms: a rhodopsin arm and a gene-agnostic arm. Patients are randomized in a 2:1 ratio to receive either OCU400 or remain as untreated controls. The trial includes both pediatric and adult participants, with a single dose administered via subretinal injection.
The primary endpoint is the change in luminance-dependent navigation assessment (LDNA), measuring mobility improvements at 12 months. A responder is defined as a patient showing an improvement of two Lux levels or more on the mobility course.
Regulatory Milestones and Future Plans
OCU400 has achieved significant regulatory milestones, including orphan drug designation from both the FDA and EMA for RP and Leber congenital amaurosis (LCA). It has also received Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA, reflecting its potential to address unmet medical needs in patients with RP.
Ocugen has also received FDA approval for an Expanded Access Program for RP patients, allowing access to OCU400 outside of the clinical trial protocol. The company anticipates completing Phase III enrollment by early next year and plans to submit the Biological License Application (BLA) and marketing authorization application in 2026.
Expanding the Pipeline: OCU410 for Geographic Atrophy and Stargardt Disease
Ocugen is also exploring the potential of other modifier genes, such as RORA, for treating other retinal diseases. OCU410 is being developed for geographic atrophy (GA), a complex, multifactorial condition. Preclinical studies have shown that RORA targets multiple pathways linked to GA pathophysiology, including complement, pro-inflammatory, and oxidative pathways.
Another program, OCU410ST, is in development for Stargardt disease, an ABCA4 gene mutation disease. Preclinical data suggest that RORA can control lesion growth and drusen deposits in Stargardt disease models. Both OCU410 and OCU410ST are currently in Phase I/II clinical development.
