Theodore Leng, MD: Characterizing the Definition, Rates of Intermediate Dry AMD

Dr. Leng discusses the progression of dry AMD patients in the IRIS registry from early stages to potential GA, as well as the benefit in narrowing the clinical definition of intermediate dry AMD.

In an interview with HCPLive, Theodore Leng, MD, Department of Ophthalmology, Stanford University, discussed his presentation on the natural history disease progression among adults with dry age-related macular degeneration (AMD) in the IRIS registry.

His talk entitled "A Real-World Study of Prevalence and Natural History Disease Progression Among Adults With Dry AMD in the IRIS® Registry," was presented at the American Academy of Ophthalmology 2021 Meeting.

Leng highlighted the benefit of the IRIS registry in this investigation, with longitudinal data from over 70 million unique patients and 412 million patient visits in the registry, encompassing 70 - 75% of all ophthalmology and retina visits in the United States.

"We wanted to see what the patient journey was for dry AMD patients when they showed up as a mild or intermediate, dry AMD patient,” he said. “Did they progress to advance disease with geographic atrophy or neovascular AMD and how long did that take?”

Then, Leng discussed the findings of the data set, analyzing 645,000 dry AMD patients where 90% of patients had mild to intermediate dry AMD. He noted this data shows that a large proportion of patients with AMD have early stages, which is not a main focus of current therapeutic treatments.

“I think the other major findings are that the probability of maintaining a dry AMD stage, so if you started out as a mild dry or intermediate dry, the probability of staying in that stage on an annual basis was about 80 to 90%, across all the disease stages,” he said.

However, Leng noted that the conversion from mild to intermediate, the rate was over 3 times higher for patients who are intermediate to an advanced stage. At a rate of per 100 person-years of progression to geographic atrophy, data show it was 3 times higher among those with intermediate dry AMD compared to mild dry AMD.

Then, he discussed the visual acuity component of the study, explaining that visual acuity was shown to get worse faster if you had a more progressive stage of dry AMD.

“If you had geographic atrophy, those patients progress, as far as vision is concerned, more rapidly than those with mild, dry AMD,'' Leng said. “And dry AMD progression to geographic atrophy and wet AMD were also faster once you reach the intermediate dry AMD stage.”

As a result, Leng noted that one of the key takeaways that he took from the study included a specific focus on intermediate AMD, as an area of huge unmet need.

“I think addressing the intermediate AMD population is going to be a key target next for us as a specialty, to really develop therapies that can prevent progression or stop progression, maybe even reverse disease in that population, because this study has shown that those intermediate AMD patients are at the highest risk of progressing to worse vision states, as well as more advanced disease states in AMD,” Leng said.

Additionally, Leng spoke on the impact of port delivery systems (PDS) on the future of care and how it will reduce both the treatment burden of patients with monthly injection visits. He also noted it may aid retinal physicians in addressing vision threatening diseases, particularly as the population ages and the bandwidth of clinicians is stretched thin.

“I think having a sustained delivery device, like the port delivery system, is really going to help kind of unload our schedules a little bit so we can care for patients, with other indications and also new therapies that are coming to market,” Leng said.

When looking forward, Leng once more pointed to better characterizing intermediate AMD and narrowing the definition from mild AMD to geographic atrophy by determining those in-between stages.

“I think better characterizing this population will then lead to better studies, both for natural history and for potential therapeutics that are hopefully being worked on by our industry partners,” he said.