FDA Approves First Treatment for Macular Telangiectasia Type 2, With Houston Methodist Among Top Trial Sites

A Houston Methodist Hospital ophthalmologist who helped conduct the trial that led to the FDA's recent approval of the first-ever treatment for macular telangiectasia type 2 (MacTel) says the therapy is a game changer for patients.

The treatment, commonly called NT-501, uses a pioneering encapsulated cell therapy (ECT) platform to deliver sustained levels of ciliary neurotrophic factor (CTNF) directly to the retina, where the disease has caused central vision loss.

"For patients with macular telangiectasia, this is a tremendous step forward," said Dr. Charles Wykoff, a professor of Clinical Ophthalmology at Houston Methodist and leading enroller in the Phase 3 trial. "It is the first approved therapy and offers a meaningful way to slow the progression of a disease that until now had no effective treatments."

Dr. Wykoff called ECT, developed by Neurotech Pharmaceuticals, "a fascinating platform with the potential to transform treatment for a variety of retinal diseases."

MacTel type 2 is a relatively rare but not insignificant retinal disorder, affecting an estimated 100 in every 100,000 people. It leads to the progressive degeneration of the central retina, often resulting in distortion, blurriness and small blind spots that enlarge over time. The disease is believed to involve dysfunction of Müller cells, which are critical for maintaining retinal structure and metabolism.

The new therapy, the product of two decades of research, uses a surgically implanted device the size of a grain of rice to deliver the CNTF. The device contains approximately 300,000 genetically modified retinal pigment epithelial (RPE) cells that continuously secrete CNTF through a semi-permeable membrane.

It is surgically placed into the vitreous cavity and anchored to the sclera, where it can function for more than a decade, possibly indefinitely.

In two pivotal Phase 3 studies, NT-501 met its primary endpoint of reducing the rate of photoreceptor loss, as measured by ellipsoid zone area on optical coherence tomography (OCT). This marks the first time the FDA has used an OCT-based anatomic endpoint to approve a treatment for a retinal disease — a precedent that is influencing future trials.

In Phase 3 Study A, conducted at the University of Iowa and Houston Methodist, the implant reduced the rate of photoreceptor loss by 54.8% over two years compared to sham controls. Study B showed a 30.6% reduction. Secondary endpoints also favored the treatment, with improvements in reading speed and retinal sensitivity. In one study, NT-501 reduced reading speed loss by up to 69% and retinal sensitivity decline by 48.5%.

Dr. Wykoff emphasized the durability of the treatment: "We have explants from patients that show the cells continue producing therapeutic levels of the protein more than 10 years post-implantation. This is not only effective, but also long-lasting."

Although NT-501 does not reverse or halt the disease, it significantly slows its progression, potentially preserving patients' ability to perform everyday tasks such as reading and driving for longer periods.

The treatment was approved in March and is expected to be available to U.S. patients in June.

The broader scientific community has taken note of the platform's promise. The encapsulated cell therapy used in NT-501 could be adapted to deliver other therapeutic proteins for a range of retinal conditions.

Dr. Wykoff's role in the NT-501 trial reflects Houston Methodist's ongoing commitment to advancing ophthalmic research and innovation. The hospital has been engaged in MacTel research for more than a decade and continues to enroll patients in follow-up studies.

"This is a big win for patients," Dr. Wykoff said. "We're proud to have helped bring a safe, durable and effective treatment option to a community that has long been underserved."