Geographic Atrophy Overview

Ryan Haumschild, PharmD, MS, MBA, opens a discussion surrounding the disease landscape of geographic atrophy.

Ryan Haumschild, PharmD, MS, MBA: Hello, and welcome to this AJMC® Peer Exchange®program titled, “Emerging Treatments in Geographic Atrophy.” I am Dr Ryan Haumschild, director of pharmacy services at Emory Healthcare in the Winship Cancer Institute [Atlanta, Georgia]. Joining me today for this virtual discussion are my colleagues, Dr Arshad Khanani, director of clinical research at Sierra Eye Associates [Reno, Nevada]; Dr David Lally, director of Retina Research Institute at New England Retina Consultants [Springfield, Massachusetts]; and Dr Maria Lopes, former chief medical officer at MagellanRx [Cresskill, New Jersey]. Today our panel of experts will explore the clinical attributes and burden of geographic atrophy [GA], review the upcoming treatments and management strategies for geographic atrophy, and discuss payer considerations of emerging treatments. Thank you for joining us. Let’s being.

Let’s get started with an overview of geographic atrophy. Dr Khanani, if you could get us started, a lot of us are unfamiliar with geographic atrophy. What are some of the clinical attributes and burden of disease? If you could give us an overview talking a bit about the loss of the outer retinal cells and how people lose that central vision over time, that would be really helpful.

Arshad Khanani, MD: Thank you so much, Ryan. I’m looking forward to our discussion today. Geographic atrophy is a big problem for patients living in the United States and globally. We have about 1.5 million patients in the United States and 5 million or over globally. That number I think is higher because we don’t get to see these patients, and up until recently, we didn’t have any treatment options for these patients. If you think about geographic atrophy, let’s start with the disease itself, age-related macular degeneration [AMD]. It’s a disease that is the No. 1 cause of blindness in our elderly population, and it usually starts with drusen. These are spots or deposits under the retina, and they usually start at an earlier age, sometimes even [in patients in their] 40s or 50s. These drusen get bigger over time, and then you see pigmentary changes. The disease becomes moderate dry AMD, and then the moderate disease can advance to either neovascular [nAMD] or wet AMD, or it can go to geographic atrophy, which is the advanced form of dry AMD.

Essentially, what you said, you are starting to lose photoreceptors and RPE [retinal pigment epithelium] cells over time, and patients usually notice these scotomas or black spots in their vision, mainly in the periphery, and then around the center vision. Then over time, it creeps into the center, and that’s where they start to have major vision issues in terms of losing their driver’s license, losing their functional vision, not being able to write checks or read their books.

It’s not a small problem, and if you look at the rate it goes, in most of the patients with GA in the worse-seeing eye, they lose about 2 lines of vision in about 2 and a half years. And a third of them will lose 3 lines of vision in about 3 or 4 years. So, it progresses quite fast, with 40% losing 2 lines in 2 to 3 years, and 30% losing 3 lines in 3 to 4 years. That’s not the only problem. The problem is the decline in their better-seeing eye is even faster. The better-seeing eye loses vision over time with a line of vision every year, and then by 5 years they’re losing 4 lines of vision. This is a major problem we have. It’s something that takes independence away from our patients. So, I’m glad we are here discussing it.

Ryan Haumschild, PharmD, MS, MBA: You definitely described that there’s a big unmet need here. Especially when you think about patient-reported outcomes and quality of life and ability to function, it seems like this could drastically impact that. In addition to geographic atrophy, one of the things you mentioned was also nAMD. Dr Lally, if you could, how does GA compare to nAMD? Can you give us a bit of background and maybe compare and contrast a little further?

David Lally, MD: Absolutely, Ryan. Yes, thanks for having me. This is an important discussion, so I’m glad we’re having it today. The way we think about macular degeneration is, we think of it in different stages. It starts with the early stage, which is typically the presence of drusen, which is the hallmark feature of macular degeneration. From there it can progress to the intermediate stage of disease, where sometimes we see larger drusen and/or the presence of what we call pigment changes or abnormalities in the center of the retina. Then from there, it can sometimes progress to the advanced stage of macular degeneration. The advanced stage is defined as having either nAMD or the presence of geographic atrophy. Although they’re both under the same umbrella term of being the advanced stage of disease, they’re quite different entities, although they both can result in severe central vision loss for the patient.

nAMD is when there is a development of new blood vessel growth under the retina, something we term choroidal neovascularization. I often tell my patients in the clinics that if you think of your retina like a garden, these are weeds of new blood vessels growing under the garden of the retina. We don’t like those weeds of new vessels growing because those vessels are often immature, and they can leak fluid from the vessel into the retina and/or leak some hemorrhage into the retina. Those patients typically present with an acute sudden loss of their central vision in one of their eyes. Geographic atrophy, on the other hand, is not the presence of new blood vessel growth, but actually the death of the retina, where we see particularly the outer part of the retina and part of the retina we call the retinal pigment epithelium can start to degenerate and die over time. When I explain it to patients I say, if you think of your eye as being like a camera, and the retina is like film in the camera, GA is when the film starts to die, or the film starts to become missing near the center of the retina. Both of those conditions can cause loss of vision, but they do it in very different manners.

Traditionally speaking, we used to think of nAMD causing the type of advanced form of macular degeneration that causes acute sudden vision loss, while GA was traditionally thought to be the slowly progressive cause of profound vision loss in patients over time. However, as Arshad noted a minute ago, we’ve learned that patients with GA lose a lot of vision much faster than we traditionally thought. So, they both have the potential to cause severe central vision loss.

Ryan Haumschild, PharmD, MS, MBA: That was a great overview. I haven’t heard of the weeds under the eye, but I will definitely remember that moving forward. It was a good visual. Thanks for giving that overview.

Transcript edited for clarity.

Related Videos
James Howard, MD
Related Content
© 2023 MJH Life Sciences
All rights reserved.