MeiraGTx announced that the Offices of Orphan Products Development and Pediatric Therapeutics of the U.S. Food and Drug Administration (FDA) have granted rare pediatric disease designation to the company's gene therapy product candidate AAV2/5-OPTIRPE65 (A001) for the treatment of patients with Leber's Congenital Amaurosis due to mutations in the RPE65 gene (LCA2). A001 previously received orphan drug designation from the FDA for the treatment of LCA2 in 2016.
A001 is an adeno-associated virus (AAV2/5) investigational gene therapy designed to deliver a codon-optimized RPE65 cDNA under the control of a synthetic RPE-specific promoter to the back of the eye. A001 is delivered via subretinal injection of up to 1 ml to cover the largest possible area of viable retina.
"The FDA's decision to award rare pediatric disease designation to A001, along with the previously received orphan drug designation, underscores the urgency of developing effective therapies for rare pediatric diseases like LCA2," said Zandy Forbes, Ph.D., President and CEO of MeiraGTx. "We are pleased with the rapid progress in our LCA2 clinical study and we are excited to be including pediatric patients with this severe genetic disorder in both Europe and the U.S."
MeiraGTx is conducting an open label, multi-center Phase I/II dose escalation trial of A001 in up to 27 patients, aged 3 years and older, diagnosed with severe early onset LCA2. The primary endpoint of the study is to determine the safety of the treatment. Secondary endpoints include improvement in visual function including a mobility maze, retinal function, retinal structure and quality of life measures. MeiraGTx has completed the three dose escalation cohorts of adult patients in this study and in November 2017 the first pediatric patient was treated at the Moorfields Eye Hospital in London.
In October 2017, the FDA accepted the Investigational New Drug (IND) application for A001 opening the path for the treatment of pediatric patients in the U.S.
Leber's Congenital Amaurosis (LCA) is a group of autosomal recessive, early-onset retinal dystrophies that cause severe sight impairment in childhood. The underlying deficit in up to 16 percent of all LCA cases lies in the RPE65 gene, which plays a key role in the regeneration of visual pigment following exposure to light. There is currently no approved treatment available that can improve sight or protect against progressive sight impairment for people with LCA.