Have Dry AMD and Wonder When There Will Be a Treatment?
In my article 'Have Wet AMD and Hoping for Something Other Than Injections?' I talk about how I’m entering my fourth year working with those who have macular degeneration (most have AMD) in a Facebook group that I manage.
Most people have dry AMD
If you were to visit my group, you would think that everyone sooner or later develops wet AMD because it’s one of the main topics. Actually, 85-90% of people with AMD have the dry form, either the early or intermediate stage. That means that 10-15% progress to either advanced dry AMD called geographic atrophy or wet AMD. If you have early dry AMD, your chance of progressing to wet is 10%. If you have intermediate AMD, your chance is 10-15%.1
Research in dry AMD
With so many people who have early and intermediate dry AMD, research is needed to slow down or stop it from progressing to the advanced forms of AMD. There are 2 advanced forms: wet AMD and advanced dry AMD which is called geographic atrophy (GA). Much of the research for dry AMD is working on slowing down the progression of GA which can cause severe vision loss.
Dan Roberts, an author and AMD advocate who has AMD, publishes a 'Summary of Research and Developments' each year.2 He also published a 'A Guide to Research in Dry AMD.' The date at the top says 2013, but you'll see that it was updated in December 2019.3 I'm using it here as well as 'Update on the Age-Related Macular Degeneration Drug Pipeline' for the details below.4
The complement system
The complement system (notice how it is spelled; it is different than compliment with an 'i'), also known as complement cascade, is part of the immune system and protects us from viruses and bacteria. It's made up of a series of more than 30 proteins called complement factors. These complement factors cause inflammation which is a good thing to battle viruses and bacteria but harmful if they are attacking our retinas and causing inflammation. These complement factors are designated by CF followed by a number. For example, CF5 is one often discussed.
Deactivating complement factors causing AMD
Some of the research is focused on deactivating the complement factors that may be causing AMD and also encouraging the progression of geographic atrophy. You can find these medications used in clinical trials: ARC1905/Zumira®, eculizumab, GEM103, and LFG316.
Another one is called APL-2. It is a current Phase 3 clinical trial whose purpose is to block complement factor CF3. Sue, an advocate for MacularDegeneration.net and my long-time friend, is enrolled in the study which will end in March 2021.
Similar to the Port Delivery System (PDS) for wet AMD, an implant with the FDA-approved glaucoma medication brimonidine is being studied. It's showing promise in slowing down the vision loss from AMD.
Encapsulated Cell Technology (ECT) is a way of delivering medication to the retina on a time-release basis. The device is called Renexus (formerly NT-501) and the medication is ciliary neurotrophic factor (CNTF).
There are 2 medications in topical form/eye drops being researched: MC-1101 (to stop early dry AMD from progressing to wet AMD) and OT-551 which is an antioxidant eye drop for the treatment of geographic atrophy.
Several oral drugs are also being tested for GA. These include Oracea®, which is the antibiotic doxycycline as well as another antibiotic minocyline. The theory is that they can reduce inflammation which is tied to AMD. Both are in Phase 2 clinical trials (Oracea® to wrap up the end of 2020; minocyline in 2024).
There are 2 investigational procedures that start with the word 'photo': Photothermal Laser Therapy (clinical trial to end in December 2020) and Photobiomodulation (clinical trial in the US to end in August 2020; in the European Union to end in September 2021). The purpose of both is reduce the volume of drusen in those with intermediate dry AMD. Photothermal Laser Therapy uses heat to do that ('thermal') and Photobiomodulation uses light. You will see the words 'PASCAL laser with Endpoint Management' associated with Photothermal Laser Therapy and 'Lumithera' associated with Photobiomodulation.
There are a few others sometimes called 'novel' therapies:
- A phase 2 study of risuteganib (Luminate®) that ended in 2019 showed vision improvement in vision for those with intermediate dry AMD. Risuteganib acts to block oxidative stress which contributes to the progression of AMD.
- Genentech (part of Roche) initiated a Phase 2 clinical trial with a medication delivered by injection that they call RO7171009 for those with GA. The 'mechanism of action' is unknown. I only found out about this one because one of the members of my Facebook group is enrolled in it. It will end in March 2022.
There is also research going on around the word with animals and in the labs. That is considered preclinical research. Clinical research means it is with humans.
Gene therapy for dry AMD
The goal of gene therapy for dry AMD is to identify and target faulty genes that contribute to the progression of the disease. Gene therapy won’t be able to repair any damage. Stem cell therapy will hopefully be able to do that.
I've written more about it in my article 'Gene Therapy Research for AMD' so I won't go into detail here.
Stem cell therapy
Stem cell therapy is one of those "It's complicated!" topics. Briefly, the purpose of stem cell therapy is to replace damaged RPE cells into the macula. If RPEs are damaged, the photoreceptors are at risk of dying which causes vision loss. These new RPEs can revive failing photoreceptors to restore vision. There is promising stem cell research going on around the world.
Want to participate?
Your eye specialist can advise you as to whether there are clinical trials in your area that you might be qualified for. You can read more about this in 'Clinical Trial Participation.'
I hope that you are as optimistic as I am about the future. If you want to read more about research that is working on a CURE, you might read my article '2020: Not Only a Date – A Deadline! A Cure for AMD in Our Lifetime?' For those of you with wet AMD, I there's an article with research 'Have Wet AMD and Hoping for Something Other Than Injections.'
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