New treatments for macular degeneration may help preserve your eyesight for longer, without the need for frequent injections. Some of these treatments include retinal gene therapy and the "port" delivery system.
This article discusses some of the new treatments that are emerging to treat both wet and dry age-related macular degeneration (AMD).
Understanding the Different Types of Macular Degeneration
Emerging Treatment for Wet AMD
New treatments for wet AMD may help preserve your eyesight without the need for frequent injections into the back of the eye.
Just 20 years ago, if a person developed wet AMD, vision loss was imminent.But in 2004, a groundbreaking new treatment called anti-VEGF—including drugs such as Lucentis, Eylea, and Avastin—became available. These drugs work to stop the blood vessels from growing, subsequently controlling the leakage and slowing down the damage to the macula. Anti-VEGF is highly effective in preserving the central vision of people with wet AMD.
The primary drawback to anti-VEGF injections is that they must be given into the back of the eye every four to six weeks. Today, there’s hope for new types of anti-VEGF treatments that will not need to be administered as often as the current, four- to six-week regimen.Some experts say that a few treatments being developed today may possibly even cure the disease.
What Is Wet Macular Degeneration?
What Are Anti-VEGF Drugs?
The acronym VEGF—which stands for vascular endothelial growth factor—is an important protein in the growth and development of new blood vessels.When injected into the eye, anti-VEGF drugs help to stop the growth of these new, abnormal blood vessels.
How Age-Related Macular Degeneration Is Treated
Retinal Gene Therapy
One promising new treatment for wet AMD involves retinal gene therapy as an alternative to monthly eye injections.The goal of gene therapy is to employ the body to make its own anti-VEGF by inserting a harmless virus (called an adeno-associated virus/AAV) carrying the anti-VEGF gene into a person’s DNA.
More specifically, RGX-314 gene therapy only requires one injection, but it must be performed via a surgical procedure. This treatment is currently moving through clinical research trials.
Studies on RGX-314
Now that retinal gene therapy has been approved by the FDA for other retinal eye conditions (other than AMD), this type of treatment looks very promising for people with AMD.RGX-314 could potentially work to block VEGF for years after it is administered. This, in turn, would help to inhibit the development of the symptoms of wet AMD, namely, the immature blood vessels that leak blood into the retina.
In an early clinical trial involving 42 people, 9 out of 12 study participants did not require any further anti-VEGF injections for six months after one RGX-314 injection.
ADVM-022
Another potentially effective type of gene therapy can be administered in an outpatient setting (such as the doctor’s office). This therapy is called ADVM-022, and it is also moving through clinical trials.It’s estimated that both of these therapies (ADVM-022 as well as RGX-314) could be available to people with wet AMD in 2023.
The Port Delivery System
The Port Delivery System (PDS), is a very small (smaller than a grain of rice) apparatus that can store anti-VEGF medication.The PDS is implanted into the eye during a surgical procedure. It provides a continuous release of anti-VEFG medication into the eye.
The Port Delivery System could allow people with wet AMD to avoid eye injections altogether.The procedure enables people with wet AMD to go up to two years without needing a treatment.
Refilling the medication can be done via a doctor’s office visit. But, the procedure to refill the medication is a bit more complex than the anti-VEGF injections that are currently the standard treatment for wet AMD.
This innovative treatment could possibly be available for consumer use in 2023.
Study of Lucentis (Ranibizumab) Port Delivery System
A 2019early-phase clinical trial published by the American Academy of Ophthalmology evaluated the safety and effectiveness of the Port Delivery System with the anti-VEGF drug Lucentis (ranibizumab) for wet AMD treatment.
The study found that the PDS was well tolerated and that in people with age-related AMD, the PDS resulted in a response comparable with monthly intravitreal (inside the back of the eye) injections of anti-VEGF (ranibizumab) treatments.
"The PDS was found to be well tolerated with the potential to reduce the treatment burden [the workload of healthcare caused by a chronic condition] in nAMD [age-related AMD] while maintaining vision,” wrote the study authors.
Eyedrops
Anti-VEGF eye drops for wet AMD is another new treatment modality for AMD that is in the initial stages of clinical trials—but hasn't yet been used on humans.The treatment has been tested on animals.
Once the medicated eye drops are considered safe enough for human use, clinical trials will begin. It may take until the year 2030 for anti-VEGF eye drops for wet AMD to be available for consumer use.
Oral Tablets
An anti-VEGF pill, to be taken orally (by mouth) may be available to the public by 2025. The pill form of the medication will enable people with wet AMD to eliminate or reduce the frequency of anti-VEGF injections.
Now in clinical trials, developers of oral medication for wet AMD are trying to work out the bugs. The medication has many side effects right now, such as nausea, leg cramps and liver changes.
Once the medication can be considered safe, and dangerous side effects can be eliminated,it can be considered for consumer consumption.
Longer-Lasting Anti-VEGF Injections
Several new anti-VEGF medications—aimed at reducing the frequency of injections—are being developed by the drug industry.These include drugs such as sunitinib.
Another new drug,Beovu has already been approved for use in the U.S. Beovu injections can last as long as three months and the innovative medication is said to be more effective at drying fluid that has accumulated in the retina due to wet AMD.
Combination Drug Treatments
New combination medications for AMD include a combination of drugs that are already on the market, for treatment of AMD.The goal is a multi-faceted treatment approach aimed at increasing the benefit of the drugs and making the injections last longer.
One such combination is an eye drop to treat glaucoma, called Cosopt (dorzolamide-timolol), being tested in combination with anti-VEGF injections. Studies indicate that these two drugs, when given together, may help to lower retinal fluid better than just anti-VEGF injections can accomplish alone.
Emerging Treatment for Dry AMD
The majority of the cases of AMD involve the slow-developing type of AMD, called dry AMD.Currently there are no treatment options available for dry AMD, but some promising new therapies are in the pipeline.
Stem Cell Therapies
Stem cell therapy is gaining momentum for all types of treatment today, including many forms of cancer, as well as for dry AMD.The goal of stem cell therapy for AMD is that the new stem cells will be able to replace retinal cells that have been damaged or destroyed by symptoms of AMD.
Stem cells are often introduced into the body’s blood circulation, via IV infusion. But, researchers are working on how to transplant the stem cells directly into the eyes. One strategy involves placing the stem cells into a fluid suspension that can be injected under the retina.
Although stem cell therapy for AMD has only been studied in small clinical trials, the experts say this treatment regime shows great promise. The drawback is that stem cell therapy may not be proven safe for consumers until 2030 to 2035.
Study of Stem Cell Therapy for AMD
A small study, involving people with wet AMD,published by the New England Journal of Medicine, found that using a person’s own stem cells to replace damaged retinal cells, resulted in maintaining visual acuity for one year after the procedure.
The study authors wrote, “This seems to indicate the surgery helped to halt the progression of the disease.” Although this study does not indicate that stem cell therapy is effective for dry AMD, many scientists are confident that upcoming studies on stem cell therapy for dry AMD will be promising.
Injections for Dry AMD
Apl-2 is a drug that can be injected intravitreally (directly into the back of the eye) to help slow the progress of dry AMD, protecting the retinal cells from being destroyed.This treatment is in clinical trials and is expected to be available around 2023 to 2025.
Other Potential New Dry AMD Treatments
There are several other potentially effective new treatment modalities on the horizon for dry AMD, these include:
- Oracea: An oral antibiotic with anti-inflammatory properties, it may be available for people in the late-stage of dry AMD.Oracea is currently in clinical trials.
- Metformin: A drug commonly given to people who have diabetes, it was found to lower the risk of development of AMD. This may be due to metformin’s anti-inflammatory properties.Metformin is in clinical trials.
A Word From Verywell
With the advent of the mRNA vaccines making antibodies to protect us from COVID-19, the treatments in gene therapy are very exciting. Using your body's antibody factories with new gene instructions for anti-VEGF antibodies is right around the corner and can be game changing for AMD treatment.
— ANDREW GREENBERG, MD, MEDICAL EXPERT BOARD