Adult Stem Cell Therapy Shows Promise for Advanced Dry AMD

A groundbreaking clinical study led by researchers at the University of Michigan reports encouraging results from a Phase 1/2a trial evaluating adult-derived stem cell therapy for advanced dry age-related macular degeneration (AMD). The findings, published in Cell Stem Cell, highlight both the safety and potential efficacy of using retinal pigment epithelial (RPE) stem cells derived from postmortem human eye tissue.

Addressing a Critical Unmet Need in Dry AMD

Dry AMD accounts for more than 90% of macular degeneration cases yet remains without approved therapies that restore lost vision. The condition arises from dysfunction and eventual death of retinal pigment epithelial cells, essential for supporting photoreceptors in the macula. As these RPE cells deteriorate, patients experience progressive central vision loss that currently cannot be reversed.

First-in-Human Study Evaluates Adult RPE Stem Cell Transplants

The trial used adult RPE stem cells isolated from donated eye-bank tissues. These cells are specialized to develop only into retinal pigment epithelial cells, avoiding the pluripotency-related safety concerns of embryonic or induced pluripotent stem cells. The first six participants received a low dose (50,000 cells) via a subretinal surgical procedure in the affected eye.

Key Findings:

• No serious inflammation or tumor formation was observed.

• The treated eyes showed vision improvement, while the untreated eyes did not.

• On average, patients gained +21 letters on a standard eye chart over 12 months.

“Although we were pleased with the safety data, the exciting part was that their vision was also improving,” said Dr. Rajesh C. Rao, Leonard G. Miller Professor of Ophthalmology & Visual Sciences.
“This level of vision gain has not been seen in this group of patients with advanced dry AMD.”

Next Steps: Mid and High-Dose Cohorts Underway

Twelve additional patients have received medium (150,000 cells) and high (250,000 cells) doses. The research team is currently monitoring these participants for safety and efficacy outcomes. If no concerns arise, the trial will advance to later stages of development.

“We are grateful to all our participants who are allowing us to better understand whether this intervention is safe enough to be a future therapy,” Dr. Rao added.
“These kinds of studies can help us offer advanced treatments in regenerative medicine, and we are happy to lead this first-in-human, cutting-edge clinical trial at the University of Michigan.”

Reference:

Rajesh C. Rao et al, Safety and tolerability of RPESC-RPE transplantation in patients with dry age-related macular degeneration: Low-dose clinical outcomes, Cell Stem Cell (2025). DOI: 10.1016/j.stem.2025.08.012