Advanced Cell Technology recently announced the beginning of their landmark trial where stem cells are transplanted into patients with Stargardt’s Macular Dystrophy (aka Stargardt’s Disease) and dry macular degeneration.
The company announced that their phase I/II clinical trials started in mid-July with one patient each of either Stargardt’s or macular degeneration. Each patient received a relatively small dose of cells and subsequent patients will receive larger amounts of cells. The first patients received about 50,000 cells.
The goal of the study, at this phase, is to test the safety and tolerability of the stem cell treatment over a 12 month period, that is, phase I/II will answer the question as to “how safe is the procedure?” and will also asses if this is a viable way to transplant stem cells.
The cells to be replaced are called RPE (retinal pigment epithelial) cells and are located underneath the top layer of the retina. If you liken the retina to be an open faced sandwich with a slice of ham with cheese on top, the RPE cells are the slice of ham. The “rods and cones” (otherwise known as photoreceptors) are located on the underside of the cheese. The RPE cells nourish the photorecptors.
In cases of Stargardt’s disease and dry macular degeneration, the faulty RPE cells can no longer nurture, or feed, the photoreceptors, hence, the loss of vision. It is hoped that by replacing the sick retinal pigment epithielial cells with stem cells, the vision can return.
What Does This Mean? This is really promising and exciting news. On the horizon is the potential for a true “fix” for two of the most common forms of “blindness” in the world. Actually, most of these patients are legally blind as you remember that the macula gives us central vision. Thus, RPE transplantation should improve the central vision.
In my view, there are two large variables or areas of concern. First, the actual technique of implanting the cells must be refined and perfected and at the same time, we need to see how long the stem cells can live or remain healthy.
While this is very promising, this may still be years away from becoming a viable treatment option.