jCyte has announced the dosing of the first patients in the JC02-88 study, marking a significant milestone in the development of famzeretcel (jCell) as a potential treatment for retinitis pigmentosa (RP). The investigational therapy consists of allogeneic retinal progenitor cells administered via intravitreal injection.
"The initiation of the patient dosing in this trial marks an important milestone in our mission to bring a breakthrough treatment to the majority of RP patients who currently have limited treatment options," said John Sholar, chief executive officer of jCyte, in a press release.
Trial Design and Dosing Strategy
JC02-88 is a phase 2 trial designed to evaluate the safety, tolerability, and efficacy of a single 8.8 million cell injection of famzeretcel. This dose represents approximately 50% higher than the highest dose administered in previous jCyte clinical trials. The study employs a controlled design where patients will receive either one famzeretcel dose or a sham treatment, with safety and vision changes assessed over 6 months.
The trial is supported by multiple institutions including the Gavin Herbert Eye Institute, the UCI GMP Facility, Lexitas, and the California Institute for Regenerative Medicine. A subsequent extension study is anticipated following the conclusion of the JC02-88 trial.
Mechanism of Action and Patient Requirements
The therapeutic approach is based on the neurotrophic mechanism of famzeretcel. Previous phase 2b study findings hypothesized that patients with RP need sufficient living photoreceptors to enable restoration of visual function. Since photoreceptors cannot divide and replace dead adjacent photoreceptors, the therapy requires that photoreceptors have lost function but remain alive to benefit from neurotrophic factors.
More specifically, sufficient living cone photoreceptors are needed to achieve a best-corrected visual acuity (BCVA) response to the famzeretcel injection. This requirement underscores the importance of patient selection and timing of intervention in the disease progression.
Disease Burden and Unmet Need
Retinitis pigmentosa affects an estimated 2 million people worldwide, with 100,000 cases in the United States. This rare genetic disorder leads to progressive loss of rod and cone photoreceptors in the retina. The condition is typically diagnosed in adolescence, and many patients become legally blind by middle age, highlighting the significant unmet medical need for effective treatments.
"This is an exciting development for the RP community, and I am eager to see how this promising therapy advances toward providing a novel cell-therapy treatment for a patient population with vast unmet need," said Paul Sieving, MD, PhD, Neil and MJ Kelly Professor of Ophthalmology at UC Davis School of Medicine and immediate past-Director of the National Eye Institute at NIH.
