Better AMD Drugs On The Horizon

It seems as if medical science is continually scrambling for new drugs to treat age-related macular degeneration (AMD). When it comes to this incurable disorder, other than slowing the disease, these drugs often fall short and eventually lose effectiveness and the afflicted can eventually go blind. This is one of the main reasons optical researchers persists at tirelessly working to not only slow AMD but finding a way to cure it. 

With better AMD drugs on the horizon medical science is getting closer than ever with many professionals in the field predicting hope for the first time in a long time. 

Current Treatment

There are a variety of conventional pharmaceuticals as well as invasive treatments currently used to treat AMD. 

Some of these, as reported by All About Vision, include:

• Lucentis (ranibizumab) – A form of the colorectal cancer treatment drug, Avastin. Inhibits proteins called vascular endothelial growth factor (VEGF), thought to contribute to development of macular degeneration by promoting the growth of abnormal blood vessels in the retina. Lucentis is injected into the eye.
• Macugen – Also injected into the eye, Macugen is a therapeutic molecule able to attack and slow VEGF.
• Eylea – Eylea, another injectable medication, is designed to inhibit the action of VEGF in wet (neovascular) AMD.
• Implantable Miniature Telescope (IMT) – A tiny, implantable device that magnifies images onto the retina to improve central vision damaged by AMD 
• Visudyne  (Photodynamic Therapy or PDT) – The doctor injects Visudyne into your arm, then activates the drug as it passes through the retinal blood vessels by shining a low-energy laser beam into your eye. Visudyne is activated by the laser light, which produces a chemical reaction that destroys abnormal blood vessels. The procedure is virtually painless.
• AREDS I & II – This is a natural vitamin and mineral supplement formula that has shown some success in preventing or slowing AMD. The formula is named after the Age-Related Eye Disease Studies that included: vitamin C – 500 milligrams (mg); vitamin E – 400 International Units (IU); beta-carotene – 15 mg; zinc – 80 mg; copper – 2 mg.

Re-Purposed Meds

In the lab many unexpected results can occur. When it comes to the effectiveness of various pharmaceuticals, some have had dual (or more) applications. We have seen this with the erectile dysfunction drug Viagra (sildenafil citrate) which was originally developed to combat high blood pressure; Botox (botulinum toxin), created to assist those with muscle disease, migraines, and as a popular anti-aging treatment; and the aforementioned Lucentis (ranibizumab) used to treat colorectal cancer as well as macular degeneration. 

Recently life saving drugs used to treat HIV for over three decades have been found to correlate with being able to inhibit macular degeneration in much of the same way. Known as nucleoside reverse transcriptase inhibitors (NRTIs), these drugs are described by the University of Kentucky College of Medicine Ophthalmology,

“NRTIs are thought to be therapeutic in HIV/AIDS patients because they target the enzyme reverse transcriptase, which is critical for replication of HIV. Previous work from the Ambati lab found that a type of toxic molecule called Alu RNA accumulate in the retina to cause dry AMD; interestingly, Alu RNA and HIV are similar in that they both require reverse transcriptase to fulfill their life cycle.”

NRTI’s have been around since the 1960’s to treat cancer and then were found to inhibit the HIV/AIDS virus in the 1980’s. Today NRTI’s may offer this third application for macular degeneration. 

According to Benjamin Fowler, the lead author and a postdoctoral fellow in the Ambati lab,

“Repurposing of NRTIs could be advantageous, for one, because they are very inexpensive. Moreover, through decades of clinical experience, we know that some of the drugs we tested are incredibly safe. Since these NRTIs are already FDA-approved, they could be rapidly and inexpensively translated into therapies for a variety of untreatable or poorly treatable conditions,”

Dr. Fowler added, 

“We are excited at the prospect of testing whether NRTIs could be effective in halting the progression of AMD in patients.”

As drugs such as NRTIs are repurposed to treat macular degeneration, many other drugs and natural remedies alike are currently forging the way as AMD maintenance/prevention until a cure is found. 

Further Drug Research 

The application of NRTIs for combating macular degeneration is a palpable hope that many in the industry feel will soon be a valid treatment. In the meantime, there are several other research projects and mainstream usage underway applying even more pharmaceutical opportunities for AMD management. 

Some of these (reported by Bright Focus) include:

AXT107

Researchers at Johns Hopkins University in Baltimore have developed a drug called AXT107. This drug may surpass other vascular endothelial growth factor (VEGF) inhibitors which prevent excessive blood vessel development, a major contributor to macular degeneration. In addition to acting as an anti-VEGF, the advantages of AXT107 also include targeting three other factors that promote blood vessel growth. 

The best part about AXT107 is that it requires fewer injections than conventional applications as it forms a medicated gel within the eye that releases over a period of months. As a result there are fewer eye doctor visits and less invasive injections which leads to more patients conveying willingness to continue treatment. 

Brolucizumab, Sunitinib, and Abicipar are similar drugs in the pipeline offering approximated twelve-week intervals between injections that some patients currently endure weekly. 

RGX-314

“RGX-314 is an anti-VEGF treatment delivered by gene therapy. It has the potential to block VEGF for years following a surgical procedure in which a harmless virus, called adeno-associated virus (AAV), carrying the anti-VEGF gene, is injected under the retina. This approach is more promising now that retinal AAV gene therapy has been approved by the FDA for another disease called Leber’s congenital amaurosis.”

Alpha-Lipoic Acid

A natural remedy amongst the Big Pharma fixes is the antioxidant/iron chelator called alpha-lipoic acid. In current rodent lab studies, funded by Bright Focus, lipoic acid has been found to protect mice from degeneration of the retina which is the major devastating result of AMD. It may be possible that this easy to find acid could help prevent or slow AMD progression.

In addition to alpha-lipoic acid daily dietary supplements, foods high in this essential antioxidant include: spinach, broccoli, yams, tomatoes, Brussel sprouts, carrots and beets. 

It’s nice to know that science is paying attention to macular degeneration and bringing attempt after attempt to stop it in its tracks. In the meantime, paying attention to your diet and leaning toward a more plant-based approach just may keep you ahead of the curve. Studies continue to show the benefits of eating low on the food chain, especially how it could strengthen your visual health, so take heed and eat clean.