MeiraGTx Holdings Plc announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its AAV-CNGA3 gene therapy product candidate for the treatment of achromatopsia (ACHM) caused by mutations in the CNGA3 gene. ACHM is an inherited retinal disease that severely limits a person's sight by preventing cone photoreceptors in the eye from functioning. Individuals with ACHM are often legally blind from birth and have extremely debilitating sensitivity to light. AAV-CNGA3 is an investigational gene therapy treatment designed to restore cone function, delivered to the cone receptors at the back of the eye via subretinal injection.