FDA Approves First-Ever Cell Therapy Treatment for Rare Progressive Eye Disease

The FDA has approved the first – and only – treatment, a cell therapy, for macular telangiectasia type 2 (MacTel), a rare neurodegenerative disease that causes irreversible vision loss.

The treatment, Encelto (revakinagene taroretcel-lwey), is an encapsulated cell therapy, developed by Neurotech Pharmaceuticals, that continually delivers therapeutic doses of ciliary neurotrophic factor to the retina, significantly slowing the loss of macular photoreceptors. In clinical trials, patients receiving the treatment had 31% less progression of neurodegeneration over 24 months, compared with patients who had received a sham treatment.

“This is a historic moment for the MacTel community,” said Thomas M. Aaberg Jr., M.D., chief medical officer at Neurotech, in a news release. “For those who have been affected by MacTel and for all who have supported this journey, today we look forward to a future where vision loss from MacTel may be slowed.

The approval was based on results from two phase 3 trials, which demonstrated that after placement of the implant, Encelto slowed the loss of macular photoreceptors in MacTel patients over 24 months. Trial data showed functional benefits beyond preserving photoreceptors. The treatment group maintained reading speed while the control group experienced a decline of 14 words per minute. Retinal sensitivity measurements showed that loss in the sham group was 45% greater than in the treated group, closely correlating with photoreceptor preservation.

MacTel is caused by the dilation of the tiny blood vessels around the fovea in the center of the macula. It causes gradual central vision loss, blurriness and distortion, although peripheral vision remains intact. It typically emerges after age 40 and affects both eyes.

The exact cause is unknown, but it is linked to neurodegeneration, with potential risk factors including aging, smoking, diabetes and hypertension. One study from August 2023 found that MacTel is linked to diabetes. The Beaver Dam Eye Study found a prevalence of 0.1% in people between the ages of 43 and 86 years.

Diagnosis relies on imaging techniques like fluorescein angiography and optical coherence tomography.

Encelto uses a small, semi-permeable capsule containing allogeneic retinal pigment epithelium (RPE) cells genetically engineered to produce specific therapeutic proteins for targeted disease treatment.

Charles C. Wykoff, M.D., Ph.D.

The capsule is surgically implanted in the eye by an ophthalmologist. Once in place, the membrane allows nutrients to enter while permitting therapeutic proteins to travel to the retina, protected from the body's immune system.

The most common adverse reactions in trials included conjunctival hemorrhage, delayed dark adaptation, foreign body sensation and eye pain.

“Now with an FDA-approved treatment, I am confident that Encelto will be able to meaningfully slow disease progression for many patients affected by MacTel, allowing them the opportunity to preserve more functional vision over time,” said Charles C. Wykoff, M.D., Ph.D., of Retinal Consultants of Texas and a clinical investigator in the trials, in the news release.

Neurotech expects Encelto to be available to U.S. patients starting in June 2025.