Luxa Reports Vision Improvements in Clinical Trial of its RPE Stem Cell Therapy for Dry AMD
Research News
Patients with worse vision at trial enrollment had greatest vision improvements.
Luxa Biotechnology reported encouraging results for six patients with dry age-related macular degeneration (AMD) receiving a low dose (50,000 cells) of RPESC-RPE-4W, its proprietary retinal pigment epithelial stem cell therapy, in a Phase 1/2a clinical trial. Thanks to these results, the company has begun dosing patients with a higher dose of 150,000 cells.
The three patients with worse vision in the clinical trial responded best to Luxa’s emerging RPE stem cell treatment. Their average best corrected visual acuity (BCVA) was approximately 32 letters (slightly better than 20/250) upon enrollment. At 12 months after receiving RPESC-RPE-4W, their vision improved an average of 21.67 letters to about 20/80.
The three patients with better vision had an average BCVA of approximately 52 letters (slightly better than 20/100) upon enrollment. At 3 months after receiving RPESC-RPE-4W, their BCVA improved 3.3 letters to about 20/80.
No serious adverse events were reported for the six patients.
Luxa’s collaborators for the trial included: the clinical team at the University of Michigan Kellogg Eye Center, the manufacturing team at the Cedars Sinai Biomanufacturing Center, Emmes Corporation, the California Institute for Regenerative Medicine, and the National Institutes of Health and the National Eye Institute.
RPE cells provide critical support functions, including nutrition and waste management, for the photoreceptor cells that initiate vision in the retina. In macular conditions such as AMD, the dysfunction and degeneration of RPE cells leads to loss of photoreceptor cells and central vision that can progress to legal blindness.
Sally Temple, PhD, and Jeff Stern, PhD, MD, scientific co-founders of Luxa and the Neural Stem Cell Institute (NSCI), said that the RPESC-RPE-4W cell product used in the trial consists of progenitor stage cells obtained after 4 weeks of differentiation, not mature RPE cells. The decision to use progenitor stage cells reflected years of study in the NSCI research labs that demonstrated progenitor cells derived from the adult human RPESC are more effective at rescuing vision in animal models than fully mature RPE cells.
The RPESC-RPE-4W cell product is derived from adult human RPESC that haven’t quite become mature RPE cells but whose fate is determined to produce RPE. These committed progenitor cells destined to produce RPE progeny show no evidence of unwanted cell growth or tumor formation. The RPESC-RPE-4W cells used in the Luxa trial were obtained from donated eyes deposited in eye banks. Cells obtained within 36 hours of the donors’ passing are expanded to manufacture cell banks that are frozen for subsequent transplantation.
