As the population continues to age, the need for medical advances targeted towards age-related diseases grows in tandem with no signs of slowing. The field of ophthalmology is no exception. Serious eye disorders that can cause blindness, including glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, diabetic macular edema (DME), and retinal vein occlusion represent just some of the areas that are the largest drivers of blindness among those 65 and older. These diseases can be deeply distressing for millions of impacted individuals, their loved ones, and caregivers. And as the number of people afflicted by these disorders increases along with the aging population, these diseases also have a growing impact on the overall healthcare system and our society.
AMD in particular impacts as many as 11 million Americans. About 15% of those affected have neovascular or wet AMD. It’s a devastating disease that can lead to irreversible vision loss. In fact, wet AMD is the leading cause of blindness in people 50 years of age and older in the United States.
Wet AMD occurs when abnormal blood vessels grow in the back of the eye and damage the macula, caused by abnormal increase in vascular endothelial growth factor (VEGF) in the retina. VEGF in the retina may be produced in response to a compromised blood supply causing poor oxygen supply to the cells within. As a result, these blood vessels leak fluid and sometimes whole blood in the retina, causing damage to the retinal structure and scarring of its layers. Without early and frequent treatment, a progressive reduction or complete loss of central vision over time can occur.
Symptoms of wet AMD may include blurriness in the center of one’s vision, straight lines that look wavy, colors that look dull and washed out, blind spots or patches as well as objects that seem further away than they really are. Complete blindness is rare, but there is a reduction or loss of central vision over time. Additionally, there’s a variety of factors that put individuals at greater risk for developing wet AMD, such as age, ethnicity (appearing to be more prevalent in Caucasians), genetics/family history, smoking, alcohol, and cardiovascular disease.
Trends, challenges & solutions in treating wet AMD
There is vast room for improvement in the existing treatment landscape for wet AMD. Currently, most patients with wet AMD are treated every month or two with eye injections. This intense treatment regimen represents an ongoing challenge for patients, caregivers, and physicians.
Although there are a number of available drugs deemed efficacious in this space — requiring regular, ongoing intra-ocular injections — they are often viewed as uncomfortable, intimidating, and inconvenient to the point that adherence can become an issue. And we know from large databases of information that have been studied that for many patients over time, their serious eye conditions continue to have their eyesight deteriorate — not because of therapeutic efficacy, but because of lack of treatment compliance.
For example, today’s most common approach to managing wet AMD involves anti-vascular endothelial growth factor (anti-VEGF) treatment that works by blocking the growth of abnormal blood vessels and decreasing leakage. Regular treatments of anti-VEGF therapy may help to lessen or stop the causes of vision loss associated with wet AMD. Presently, there are a variety of anti-VEGF treatments on the market. It is recommended that these treatments be administered by intravitreal (back of the eye) injection approximately every month for the first three months, followed by intravitreal injection once every eight weeks.
Current anti-VEGF treatments are effective and safe, but they are not as durable and long-acting as patients really need given the burden of having to visit their doctor as often as every month or two for injections into their eye for the rest of their lives. We know in the real world, a year or two into their disease, patients can lose much of the visual gains they receive from these drugs because they can’t make it back for visits as often as needed or treatment intervals have been extended beyond what they should be.
New treatments on the horizon
New solutions are in progress aimed at maintaining the gains anti-VEGF drugs are giving patients over the long-term. One potential therapy in development is EYP-1901, EyePoint Pharmaceuticals’ anti-VEGF investigational treatment being studied initially in wet AMD. This investigational therapy is sustained release, which means it may sustain the majority of wet AMD patients’ treatment interval up to six months or longer after a single injection. Another similar treatment therapy is OTX-TKI from Ocular Therapeutics. They use a hydrogel encapsulating anti-VEGF drug and are also aiming to sustain patients for up to six months.
Additionally, there are other therapeutics and drug delivery systems on the horizon with the potential for reduced treatment burden and improved outcomes. Gene therapies including Regenxbio’s RGX-314, an anti-VEGF treatment with the potential to block VEGF for years following a surgical procedure and Adverum Biotechnologies’ ADVM-022, which can be injected via an office procedure, show promise in clinical trials. Other treatments, including investigations into pan-VEGF inhibition (multiple VEGF targets) and other anti-VEGF therapies, represent the next wave of innovation in serious eye disorders focused on increasing the longevity of action and durability of treatment, thus relieving patients and their caregivers of the burden of visiting their doctor every month or two, all while maintaining their vision.
As we look towards the future, I’m energized by the many advancements being made across ophthalmology to tackle the most serious eye diseases that can cause blindness. As the prevalence of these diseases continues to grow along with our aging population, they represent an opportunity for the biopharmaceutical industry to continue to follow the science to demonstrate the value of these treatments to providers and the overall healthcare system. And most importantly, to impact the lives of patients and loved ones affected by these devastating diseases.
Photo: KAREN BLEIER/AFP, Getty Images