Research on Stem Cell Transplants for Dry AMD
When you have a chronic condition with no treatment, it is natural to feel frustrated. Many people with dry age-related macular degeneration (AMD) wonder when a treatment will be available for them. Some may be interested in participating in a clinical trial to help find a solution.
If you feel frustrated by the lack of treatment options for your or your loved one's dry AMD, you are not alone! Keep reading to learn about the latest cell-therapy-based clinical trials. You might even be inspired to participate in the search for new cell-based dry AMD therapies.
What is dry AMD?
AMD is a form of progressive eyesight deterioration that leads to blindness. Dry AMD slowly affects the central vision needed for sharp, clear eyesight. It damages a specific tissue in the eye called the retinal pigment epithelium (RPE). RPE cells are a core part of what makes the eye able to detect light.1,2
Forms of AMD
AMD comes in 2 forms: wet and dry. Wet AMD occurs when an overgrowth of new, weak, leaky blood vessels causes fluid build up in the RPE. Dry AMD occurs when a part of the eye called the macula begins to thin and RPE cells are lost. The macula is where central vision is processed.1,3,4
There are therapies available for wet AMD, and it is the more severe form of AMD. But dry AMD affects more people than wet AMD. Dry AMD currently has no cure. It is the leading cause of blindness in those over the age of 65.5
The number of people affected by dry AMD is growing because the US population is aging. Almost 17.1 million people are projected to have dry AMD by 2050. This is nearly double the number diagnosed just over a decade ago, in 2010. For this reason, a lot of research is focused on finding therapies to either slow or reverse dry AMD.1
One of the most promising areas of research is stem cell transplant therapy.
What is stem cell transplant therapy?
Stem cell therapies replace damaged or diseased tissues in the body. The cells used in this therapy may come from either a healthy donor or the person with vision loss.6
About 15 years ago, scientists learned they could genetically program adult cells to become a type of cell called induced pluripotent stem cells (iPSCs). These cells have been changed to act like embryonic stem cells, which can change into any type of cell in the body. Reverse programming adult cells into iPSCs may allow researchers to design cell-based therapies to treat diseases like dry AMD.6.
Even better, iPSCs can be developed into RPE cells in a laboratory. Cells are collected from a person for this process. Next, they are reverse programmed into iPSCs, which are converted to RPE cells and transplanted into the eye. There, the new RPE cells replace the older ones damaged by dry AMD. This is called a stem cell transplant.6
Stem cell transplants are being investigated in clinical trials. Clinical trials are the most reliable way to develop safe and effective therapies for people.7,8
Clinical trials for dry AMD
Clinical trials are conducted in phases, from 1 to 4. Each phase enrolls more participants and narrows down the safest and most effective dose. After the final phase of a trial is completed, the therapy still has to be approved by the US Food and Drug Administration (FDA) for use in people.7
There are 2 clinical trials currently looking at stem cell-based therapies for dry AMD. Both focus on an advanced form of AMD called geographic atrophy (GA). People with GA have blind spots in their vision.8,9
Both trials are in an early stage, so more research that looks at a larger number of people is needed. But these studies may offer hope to those living with dry AMD.
This clinical trial uses human allogeneic stem cells that come from a healthy donor. The cells are then transplanted into the person with vision loss. The purpose of the trial is to see how well the transplanted cells survive and how participants tolerate the treatment. It will also track whether vision loss slows or changes after the cell transplant.8
The cell-based therapy being studied is called OpRegen. It is given to participants either as eye drops or as an injection to the eye.8
This phase 1/2 trial is no longer enrolling participants, and full results have not yet been published. But preliminary findings show that it is well tolerated in people. Participants who took OpRegen gained some vision. Researchers also found physical changes in their eyes after treatment.8,10
Autologous iPSC-derived RPE cell transplant for GA trial
A second trial is still recruiting participants with GA. This phase 1/2 trial also uses stem cells, but the donor cells come from the participant. This is called autologous stem cell therapy.9
The cells taken from the participant are changed in a laboratory into iPSCs, then into RPEs. These new RPE cells are then put back into the participant’s body to replace the older, damaged ones.9
Because this is a research trial, the cell transplant surgery is performed in 1 eye only. The RPE transplant cells are inserted into the retina through a small cut. Participants receive dilating eye drops and anesthesia for the procedure.9
This study will measure changes in the participants' vision over 1, 2, and 5 years. It will also look for changes in the structure of the treated eye.
The first participant to receive this therapy had autologous cells transplanted in late August 2022. It is too early for results, but this is a trial to watch closely.9,11
How to enroll in a clinical trial
If you are interested in participating in a clinical trial for dry AMD, talk to your doctor. Participants have the right to withdraw from a trial at any time, for any reason. You can also learn more about who is eligible and how to apply on ClinicalTrials.gov.
Editor's Note: As of August 2023, 2 drugs known as complement inhibitors — Syfovre® and Izervay™ — have been approved by the US Food and Drug Administration (FDA) to treat geographic atrophy (GA).
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