Eleven children who were legally blind at birth all gained visual acuity after receiving MeiraGTx's investigational gene therapy, data that are prompting the biotech to seek accelerated approval in AIPL1-associated severe retinal dystrophy.
Results from four of the 11 children were published in The Lancet Feb. 21.
Visual acuity—measured with a child-friendly, game-like touchscreen test—in treated eyes improved after four or more weeks, while the acuity in untreated eyes became unmeasurable, according to the published results.
The effects of treatment “extended outside the meaningful effects on vision and result in life-changing benefits in all areas of development including communication, behavior, schooling, mood, psychological benefits and social integration,” MeiraGTx's CEO Alexandria Forbes, Ph.D., said in the biotech's accompanying release.
One child developed cystoid macular edema, a build-up of fluid, in their treated eye due to the therapy, researchers wrote in the article, which partially improved over time and didn’t prevent the child’s vision from improving. There were no other safety concerns, the scientists said.
Evercore ISI analysts described the findings as “strong clinical data with clear evidence of efficacy in a huge unmet need pediatric population.”
“As should be expected from a subretinal approach, safety was clean,” the analysts added in a Feb. 21 note.
After positive conversations with the U.K.’s medicines watchdog, the firm now plans to submit the gene therapy, called rAAV8.hRKp.AIPL1, for expedited approval in that country, according to the release.
MeiraGTx, which is headquartered in New York and has R&D and manufacturing in England, has also been in discussions with the FDA on how to pursue accelerated approval in the U.S., the company added.
The therapy uses an adeno-associated virus to deliver functional copies of the AIPL1 gene and is injected once directly into the eye.
The study began with four children between the ages of one and three who were born with severe retinal dystrophy associated with mutated copies of the AIPL1 gene. These children were each treated in one eye. After the researchers saw the treatment was safe and seemed to be working, they gave the gene therapy in both eyes of a further seven children.