In late August 2025, jCyte announced encouraging news for people living with retinitis pigmentosa (RP), including those in the Usher syndrome community. The company published results from its first major clinical study, which tested its cell-based therapy, called jCell. This therapy uses special “retinal progenitor cells” that are placed into the eye with a small injection. The hope is that these cells can support and protect the light-sensing cells in the retina, slowing down or even improving vision loss.
In the early study, 28 adults with RP each received a single dose of jCell. The main goal was to see if the treatment was safe, and the results were positive. No one experienced serious safety problems, and the cells did not cause rejection. Most side effects were mild, such as eye irritation, and went away on their own. Even though the focus was on safety, doctors also measured vision. People who received the highest dose—three million cells—saw an average improvement of about nine extra letters on an eye chart after one year.
Although not everyone improved, this early signal gave hope that jCell could have real benefits for vision.
Because of these results, jCyte has moved forward into a Phase 2 clinical trial, called JC02-88. This new study is a big step forward. It is testing a larger dose—8.8 million cells, which is about 50% more than the highest dose given before. Up to 60 adults with RP, ages 18 to 60, will take part. Some participants will receive jCell, while others will get a sham procedure (a fake treatment), so researchers can carefully compare results. After six months, those in the sham group will have a chance to receive the actual treatment as well.
What this means for the Usher syndrome community: Unlike some therapies that target just one gene, jCell is designed to work regardless of the genetic change that caused RP. That means it has the potential to help people with many different types of RP, including USH-related RP.
