MeiraGTx (Nasdaq: MGTX), has announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its AAV-CNGA3 gene therapy for the treatment of achromatopsia (ACHM) caused by mutations in the CNGA3 gene. MeiraGTx and Janssen Pharmaceuticals, Inc. (Janssen / Johnson & Johnson) will jointly develop their gene therapy candidate (AAV-CNGA3) “as part of a broader collaboration to develop and commercialize gene therapies for the treatment of inherited retinal diseases”. MeiraGTx is conducting an open-label, dose-escalation Phase 1/2 clinical trial of AAV-CNGA3 in patients with ACHM due to mutations in the CNGA3 gene. (listed in ClinicalTrials.gov NCT03758404).
Achromatopsia (ACHM) is a rare disorder with an estimated prevalence of 1:30,000 to 40,000, characterized by reduced central visual acuity (<20/200), pendular nystagmus, photophobia, eccentric fixation and reduced or complete lack of colour discrimination. The disorder is an autosomal recessive condition caused by mutations in one of six genes: CNGB3, CNGA3, GNAT2, PDE6C, PDE6H and ATF6. CNGA3 and CNGB3 (the cone-specification channel cyclic nucleotide gated channel α and β 3) are estimated to account 75-80% of all cases. The diagnosis is made on electrophysiology (ERG) where cone cell function is absent, while in contrast, rod function is normal. The disease is essentially stable. The glare and photophobia can be ameliorated with either a brown or red tint in glasses and currently there is no treatment. In the current clinical trial, the study uses an open label, multi-centre, Phase I/II dose escalation trial using an AAV2/8-hG1.7p.coCNGA3 treatment among paediatric and adults due to defects in the CNGA3 gene. The primary outcome will records the incidence of adverse events and safety while secondary outcome measures include improvements in visual function, visual acuity, retinal function, microperimetry, perimetry and improvements in Quality of life (QoL).
Commenting on the achievement, Alexandria Forbes, Ph.D., president and chief executive officer of MeiraGTx stated, that, “we are very pleased to have received Fast Track designation for AAV-CNGA3 and that the FDA has recognized a significant need exists to quickly advance new therapies for those with ACHM. ACHM is a serious and debilitating disease and we look forward to communicating closely with the FDA as we continue the clinical advancement of AAV-CNGA3.” According to the company, this accomplishment is the third Fast Track designation received for additional inherited retinal disease product candidates with AAV-RPGR and AAV-CNGB3.