A new treatment that could restore vision to people with a rare form of blindness may soon become the first-of-its-kind gene therapy to be approved by the U.S. Food and Drug Administration (FDA).
An advisory committee for the FDA voted unanimously last week to recommend the new gene therapy designed to help people with a rare degenerative condition that leads to blindness.
The committee recommended that the FDA approve LUXTURNA, manufactured by Spark Therapeutics.
The FDA does not have to follow the committee’s recommendation, but the agency often does.
The drug is a gene therapy designed to help patients with a condition called RPE65-mediated inherited retinal disease (IRD), which gradually leads to blindness.
The RPE65 gene “provides instructions for making a protein that is essential for normal vision,” according to the National Institutes of Health.
It creates a “thin layer of cells” at the back of the eye that nourishes the retina. A mutation on that gene can result in damage to the eye that over time results in total blindness.
Clinical trial success
The gene therapy drug targets this mutation by using a virus to deposit the RPE65 gene into the tissue via an injection, so the protein can be made.
Patients taking LUXTURNA reported regaining aspects of their vision after they started to receive the therapy, according to studies released by Spark Therapeutics and published in the Lancet medical journal.
Approximately 93 percent of all treated Phase 3 trial participants who had received LUXTURNA, or 27 of 29 participants, had a gain of functional vision during the yearlong follow-up period, according to the data.
This doesn’t necessarily mean these patients can see perfectly or even read small text, but they can better discern lights, shapes, and spaces.
New treatment frontier
If it becomes FDA approved, LUXTURNA would be the first gene therapy approved by the FDA that would affect an inherited genetic trait.
"This is potentially game-changing," officials from the American Academy of Ophthalmology told Healthline in a statement. "There are currently no treatments available for inherited retinal diseases. So, if the FDA approves this treatment, it will offer new hope for patients who have an incurable disease that causes severe vision loss or blindness."
The association also explained the drug's FDA approval could help lead to other similar therapies.
"It could open the door for use in other inherited and acquired forms of retinal disease," they said. "The potential applications within ophthalmology are broad."
Overall, LUXTURNA would be the third gene therapy treatment approved by the FDA.
Earlier this year, the agency approved an immunotherapy treatment called Kymriah to fight forms of leukemia.
This week, the FDA approved another CAR-T cell therapy for treatment in adults with certain types of large B-cell lymphoma.
“There currently are no pharmacologic treatment options for people living with RPE65-mediated IRD, who in most cases progress to complete blindness,” Dr. Albert M. Maguire, professor of ophthalmology at the Scheie Eye Institute at the University of Pennsylvania’s Perelman School of Medicine and a principal investigator for the study, said in a statement released by Spark Therapeutics.
Dr. Yasha Modi, assistant professor of ophthalmology at NYU Langone Health, said the studies that Spark Therapeutics has released have been promising for those with this disorder.
“This particular gene therapy offers them a glimmer of hope,” he said.
Modi said that about 1,000 to 2,000 people in the United States are affected by this condition every year.
But he also said the progressive, inhereted condition greatly impacts a patient’s life.
“Patients who have RPE65 will progressively lose their photoreceptors,” Modi told Healthline. “That will put them in a world of darkness that is true lights out blindness by the age of 40 or so.”
An improvement of “functional vision” can be a huge benefit in their lives, Modi explained.
Patients that spoke to the FDA said they had “improved light sensitivity, improved color; a very small minority said they could even read large print, which is pretty spectacular,” Modi said.
Potential future uses
While this treatment targets a small population, Modi said this type of therapy may be able to help many others with similar conditions in the future.
Modi said that the therapy could potentially be used as a template for other treatments of similar conditions.
“Could we have similar results? I think the answer is probably yes,” Modi said about other conditions with mutations on specific genes.
However, he said that people should not count on this treatment as a silver bullet.
There is a lot about the treatment that remains unknown. It’s unclear how much the drug will cost. The other FDA-approved gene-therapy — Kymriah — was reported to cost hundreds of thousands of dollars per patient.
In addition, scientists will have to see what happens to patients in the long term. It’s possible that these seemingly impressive results might start to fade over time.
“We don’t know if this is going to be stable long term,” Modi said.
He explained that past research of similar gene therapy indicated it may stop working after a few years.
“They may need repeat treatment,” or a new vehicle or “vector” to get the gene therapy to continue to work to protect photoreceptors, Modi explained. Additionally, he said, “The long-term side effect profile is something we don’t really know.”