jCyte Reports Promising Results for Phase 2b Clinical Trial of its Cellular Therapy for RP
The emerging therapy is designed to work independent of the mutated gene causing vision loss
jCyte, a biotech company based in Newport Beach, California, announced that its emerging cellular therapy for people with retinitis pigmentosa (RP) and related diseases has performed encouragingly in a Phase 2b clinical trial. The company plans to launch a Phase 3 clinical trial for the treatment in 2021.
jCyte’s treatment is an injection of human retinal progenitor cells (hRPC) into the vitreous, the soft gel in the middle of the eye. The goal of the therapy is to preserve or potentially restore some vision in people with RP and related conditions, independent of the mutated gene causing the disease. The hRPC are stem cells that have almost developed into photoreceptors, the cells that make vision possible. The hRPC produce growth factors that can slow or halt degeneration of the recipients’ remaining photoreceptors.
“The Phase 2b results for jCyte’s emerging cellular therapy are promising and we look forward to further results from the company’s Phase 3 trial,” says Brian Mansfield, PhD, executive vice president of research and interim chief scientific officer at the Foundation Fighting Blindness. “The Phase 2b results are helping the company understand which patients might benefit most from the therapy. That information is invaluable in designing the Phase 3 trial.”
In the Phase 2b study, patients received 3 million cells, 6 million cells, or a sham treatment. Patients had only one eye treated. The company reported results for 74 patients at 12 months after treatment. Those receiving 6 million cells had a mean improvement in best-corrected visual acuity (BCVA) of 7.43 letters. Those receiving 3 million cells and the sham procedure had mean BCVA improvements of 2.96 and 2.81 letters, respectively. (An eye chart has 5 letters per line.)
The company also performed an analysis of a targeted subgroup of 37 patients in the 2b trial — those who had reliable fixation (their eyes didn’t move much during testing) and whose study eyes and untreated eyes were similar in visual ability. Those in the targeted subgroup receiving 6 million cells in one eye had a mean improvement in BCVA of 16.27 letters. Those receiving 3 million cells in one eye and the sham procedure, had mean BCVA changes of -0.15 and 1.85 letters, respectively.
The company noted that those patients in the targeted subgroup receiving 6 million cells also had improvements in secondary endpoints, which included low light mobility, contrast sensitivity, visual fields, and a visual function questionnaire.
In May 2020, jCyte announced a $252 million licensing agreement with Santen Pharmaceutical.