Update on Stem Cell Clinical Trials for Dry Macular Degeneration and Stargardt's Disease
by Maureen Duffy
On Tuesday, July 12, 2011, Advanced Cell Technology (ACT) announced the treatment of the first two patients in its two Phase I/II clinical trials for Stargardt's disease and dry macular degeneration (AMD), using retinal pigment epithelial (RPE) cells derived from human embryonic stem cells. The procedures were carried out by principal investigator Steven Schwartz, M.D., Ahmanson Professor of Ophthalmology at the David Geffen School of Medicine and retina division chief at the Jules Stein Eye Institute, both at UCLA.
The Stem Cell Procedure
In a press release from Medical News Today, Dr. Schwartz explains the procedures:
"One patient in each clinical trial, the Stargardt's trial and the dry AMD trial, has undergone surgical transplantation of a relatively small dose (50,000 cells) of ... retinal pigment epithelial (RPE) cells derived from human embryonic stem cells. Early indications are that the patients tolerated the surgical procedures well.
The primary objective of these Phase 1/2 studies is to assess the safety and tolerability of these stem cell-derived transplants. We will be carefully monitoring our patients over the course of the trials."
To better understand this latest development, here is background information from my prior blog posts about ACT's initial stem cell therapy clinical trial for Stargardt's disease and its subsequent stem cell therapy clinical trial for Dry Age-Related Macular Degeneration:
On November 22, 2010, the U.S. Food and Drug Administration (FDA) lifted a prior clinical hold on stem cell research to clear Advanced Cell Technology's (ACT) Investigational New Drug (IND) application and initiate a Phase I/II multicenter study, using retinal cells derived from human embryonic stem cells to treat patients with Stargardt's disease.
ACT's product is a human embryonic stem cell trained to become a retinal cell. ACT first requested approval from the FDA to conduct the clinical trial approximately one year ago.
About Macular Degeneration
VisionAware's Lylas G. Mogk, MD, a renowned expert on age-related macular degeneration (AMD), founding director of the Visual Rehabilitation and Research Center of Michigan, part of the Henry Ford Health System Eye Care Services, and co-author of Macular Degeneration: The Complete Guide to Saving and Maximizing Your Sight, explains more about the different types of AMD:
"There are two types of AMD: wet (neovascular) and dry (atrophic). It's possible to experience the wet type in one eye and the dry type in the other; in addition, the dry type can progress to wet in approximately 10-15% of cases.
The dry/atrophic type affects approximately 85-90% of individuals with AMD. Its cause is unknown, it tends to progress more slowly than the wet type, and there is not — as of yet — an approved treatment or cure. In dry AMD, small white or yellowish deposits, called drusen, form on the retina, beneath the macula, causing it to deteriorate or degenerate over time."
About Stargardt's Disease
As described in a press release from Advanced Cell Technology, Stargardt's disease, also called Stargardt macular dystrophy and fundus flavimaculatus,
… causes progressive vision loss, usually starting in children between 10 to 20 years of age. Eventually, blindness results from photoreceptor loss [i.e., cells that detect light, convert it into electrical signals, and relay those signals to the brain] associated with degeneration in the pigmented layer of the retina, called the retinal pigment epithelium (RPE).
"There is currently no treatment for Stargardt's disease," said Dr. Robert Lanza, ACT's Chief Scientific Officer. "Using stem cells, we can generate a virtually unlimited supply of healthy RPE cells, which are the first cells to die off in [Stargardt's] and other forms of macular degeneration."
VisionAware will provide research updates as they become available.
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