Postponed MacTel Treatment Approval Could Lead to Delay of Needed Care

Macular telangiectasia (MacTel) type 2, a rare eye condition that affects the retina and central vision, will remain without any form of treatment for a little longer, as Neurotech Pharmaceuticals announced that the initial Prescription Drug User Fee Act (PDUFA) goal date for NT-501 of December 17, 2024, has been pushed back to March 18, 2025, in light of new data requested by the FDA to make a decision.¹ With no available treatment for MacTel currently existing, the delay in approval will require those with the condition to rely on other forms of mitigating the condition.

MacTel, most commonly seen in its type 2 form, is a rare eye condition that affects the macula and can cause the loss of central vision.² The condition, which affects men and women about equally, ultimately affects the blood vessels within the eye.

“Basically what happens [is] there’s changes in the center of the retina, in the macula, in the little blood vessels around the very center of the fovea,” said Aleksandra Rachitskaya, MD, associate professor of ophthalmology at Cleveland Clinic Cole Eye Institute. “And then, as time progresses, it causes changes in the retina itself…[including] loss of tissue within the retina.”

Macular telangiectasia is a rare condition that primarily affects middle-aged adults | Image credit: Home-stock - stock.adobe.com

Knowledge about MacTel is low, with the causes of the condition still primarily unknown, despite diabetes and hypertension being identified as possible conditions that increased risk.² The symptoms are also hard to distinguish, as patients may not always know that there is anything wrong with the back of their eye. Distortion of vision, blurring, and loss of central vision are all symptoms of MacTel but are not detectable in early stages of the disease. However, despite the relative lack of knowledge of the condition, it can affect patients in significant ways.

“This is a disease that develops in middle age. So, these patients are working adults and these issues, this vision distortion and blurry vision, can really affect the ability to do the work that they’re doing,” said Rachitskaya. “It can affect such essential tasks as reading, writing, doing any near work…So it is a disease that has a significant visual burden, especially as it progresses.”

There are currently no approved methods of treatment for MacTel, despite its significant burden on quality of life. Interdisciplinary care is the main suggested intervention, including making sure that the patient maintains a healthy lifestyle. This can include treating diabetes or hypertension, having the patient avoid smoking, encouraging the use of sunglasses, and advising on a healthy diet, said Rachitskaya.

“If somebody develops more advanced disease, in which case you might develop a choroidal neovascular membrane, which basically means that there’s an abnormal blood vessel in the center of the retina in the macular that can be treated with intravitreal injections to control the neovascular membrane,” said Rachitskaya.

Currently, however, there are no means of treating a patient with early stages of the condition, which has forced eye doctors to simply manage the complications of MacTel and help the patient get as much vision as they can. NT-501 presents a potential solution, as it would be the first treatment to specifically address MacTel Type 2 and slow the progression of the condition down.

NT-501 is an implant that is inserted into the eye during surgery. The implant is capable of delivering ciliary neurotrophic factor directly into the eye to help slow the progression of MacTel in the patient. Rachitskaya said that the treatment, if approved, should be given early, as patients younger than 65 years experienced better outcomes. The goal, she said, is to promote survival and maintenance of the functional photoreceptors.

“So it’s not necessarily something that is going to improve patients’ vision. Actually, in the studies, it didn’t show any improvement in vision. But it did show that some of the structures in the retina that were monitored with different imaging modalities…the patients who were on the treatment did better than the patients who were not,” said Rachitskaya.

Originally granted priority review in June 2024, the PDUFA date for NT-501 has been pushed back from December 17, 2024, to March 18, 2025, as a response to requests for additional data from the FDA. The delay in the decision could leave those who would benefit most from the treatment in a state of limbo. Until then, patients with MacTel will have to continue managing the accompanying symptoms.

Considering how the rare macular condition can affect working adults, an FDA-approved treatment can make a big difference in quality of life if it enters the market. Until then, treating the symptoms of MacTel will continue to be the primary approach to management.

References

1. Neurotech provides update on BLA for NT-501 as a treatment for macular telangiectasia type 2. News release. Eyewire; November 8, 2024. Accessed November 15, 2024. https://eyewire.news/news/neurotech-provides-update-on-bla-for-nt-501-as-a-treatment-for-macular-telangiectasia-type-2?c4src=article:infinite-scroll
2. Turbert D. What is macular telangiectasia? American Academy of Ophthalmology. September 23, 2024. Accessed November 15, 2024. https://www.aao.org/eye-health/diseases/macular-telangiectasia