Regenerative Patch Technologies, a company developing stem-cell-derived treatments for people with retinal diseases, has reported encouraging results for the first five patients with advanced, dry age-related macular degeneration (AMD) participating in a Phase 1/2a clinical trial for its therapy – a patch comprised of a layer of retinal pigment epithelial (RPE) cells on a synthetic scaffold. The treatment is known as the California Project to Cure Blindness–Retinal Pigment Epithelium 1 (CPCB-RPE1).
One patient in the trial had visual acuity improvement of 17 letters (about 3 lines on an eye chart) in her treated eye. Three patients had vision maintained in their treated eyes. Two had improved fixation. One patient did not receive the patch due to debris underneath the retina. No evidence of safety issues with the treatment was observed.
The study investigators also reported anatomic improvements in the treated eyes. Imaging showed that the transplanted RPE cells integrated with photoreceptors, the cells that make vision possible.
In people with advanced AMD, RPE cells degenerate leading to loss of photoreceptors. RPE cells provide critical support functions – including nutrition and waste management – for photoreceptors. The RPE cells used in Regenerative Patch’s emerging therapy are derived from human embryonic stem cells.
The treatment’s scaffold mimics Bruch’s membrane, which breaks down in people with AMD. Also known as the blood-retina barrier, Bruch’s membrane works like a sieve to transport waste debris to, and nutrients from, the retina’s vasculature.
“People with advanced dry AMD have very limited options for saving or restoring their vision,” says Stephen Rose, PhD, chief scientific officer at the Foundation Fighting Blindness. “These early results from the California Project to Cure Blindness are good news for these patients. We look forward to learning more about the therapy as the trial moves forward.”
Initial results of the clinical trial were published online in the journal Science Translational Medicine. Authors of the paper include Mark Humayun, MD, PhD, at the University of Southern California (USC), developer of the Argus bionic retina; Amir Kashani, MD, PhD, surgeon at USC; and Dennis Clegg, PhD, at the University of California, Santa Barbara, who has been funded by the Foundation Fighting Blindness to develop scaffolding for a therapeutic retinal patch in development at the University of Wisconsin-Madison.