Frequently Asked Questions


How does RP cause blindness?

Retinitis pigmentosa is caused by mutations in the rhodopsin gene. These genetic changes destroy retinal cells called rods, which are responsible for night and peripheral vision. Eventually, as the rods die, cones are also affected. These cells help us see faces, colors, etc. As rods and cones die off, RP patients continue to lose sight and eventually become legally blind.

How is RP currently treated?

At present, there are no effective treatments for RP. Patients must rely on visual aids, such as magnifiers, to address their vision loss. Eventually, these measures become ineffective.

What are retinal progenitor cells?

These cells are more mature stem cells that have committed to a retinal lineage. As a result, they are more precise, as they can only become retinal cells.

How do the progenitor cells in jCell treat RP?

These cells release growth factors that rescue photoreceptor cells from the degeneration associated with RP. Retinal progenitor cells also have regenerative capacity and can differentiate into rods and cones, which has the potential to reverse retinitis pigmentosa’s degenerative effects.

How is jCell administered to patients?

The retinal progenitor cells are implanted with a single intravitreal injection. This simple process has many advantages. First, since no surgery is required, they can be implanted in an ophthalmologist’s office. In addition, should more cells be needed, the procedure can be safely performed again.

Since these are transplanted cells, do patients need to be immune suppressed?

Because the eye is “immune-privileged,” it does not react to transplanted cells like other tissues. As a result, no immunosuppression is required

When will this treatment become available?

This therapy is currently in a phase I/IIa clinical trial to test safety. We are now planning an efficacy trial, which we hope to begin sometime in 2017. Because jCell has been granted orphan drug status by the FDA, approval should be accelerated.

How do I join a clinical trial?

If you have retinitis pigmentosa, are over 18 and your vision is between 20/63 and 20/200 in your worst-seeing eye, please visit our clinical trials page.