Research & Development

MeiraGTx is developing AAV-AQP1 as a potential treatment for xerostomia caused by Sjogren’s syndrome, a disease affecting more than two million people in the United States. Sjogren’s syndrome is an autoimmune disease in which a patient’s immune system may target the salivary glands. Chronic inflammation of the salivary glands results in long term damage and chronic xerostomia in many Sjogren’s patients.

AAV-GAD is an investigational genetic medicine designed to deliver the glutamic acid decarboxylase (GAD) gene to the subthalamic nucleus in order to increase production of GABA, the primary inhibitory neurotransmitter in the human brain. GAD is the rate-limiting enzyme in the synthesis of GABA, therefore it is believed that increasing subthalamic nucleus GAD expression through gene therapy will result in normalization of motor circuits and improve symptoms in Parkinson’s disease patients without affecting other brain regions that can be responsible for complications of existing therapies.

We have designed our product candidate, AAV-UPF1, with the aim of increasing UPF1 expression in the motor neurons of amyotrophic lateral sclerosis (ALS) patients. UPF1 plays an important role in nonsense mediated decay (NMD), a quality control system that regulates RNA processing in neurons. AAV-UPF1 is currently being investigated in preclinical studies.

Botaretigene sparoparvovec (bota-vec) is designed to treat the most common form of X-linked retinitis pigmentosa (XLRP) caused by mutations in the eye-specific form of the RPGR gene called RPGR open reading frame 15 (RPGR ORF15). Both rods and cones photoreceptors require RPGR ORF15 to function.

The Phase 1/2 clinical trial of bota-vec in adult and pediatric patients is complete, and the Phase 3 Lumeos clinical trial completed enrollment in 2023. Treatment with bota-vec was found to have an acceptable safety profile and efficacy assessments in this proof-of-concept study demonstrated improvements in retinal sensitivity, visual function and functional vision. These findings were presented in a late-breaking oral presentation at the Retina Subspecialty Day program of the American Academy of Ophthalmology (AAO) 2022 Annual Meeting (Abstract #30071754) by Professor Michel Michaelides

AAV-RPGR has received Fast Track and Orphan Drug designations from the FDA, as well as PRIME, ATMP and Orphan Medicinal Product designations from the EMA.

AAV-RPE65 is a gene therapy product candidate in which expression of a codon-optimized RPE65 gene is driven by a novel synthetic retinal pigment epithelium (a thin layer of cells at the back of the eye) cell-specific promoter. The RPE65 protein is essential for rod function because it recycles the light sensing machinery in rod photoreceptors. The codon and vector optimization resulted in a gene therapy that is 100 to 1,000 times more potent than the first generation therapy.

We are currently conducting a Phase 1/2 clinical trial of AAV-RPE65 in both adult and pediatric patients with RPE65-deficiency.

The FDA and EMA each granted orphan status to AAV-RPE65 for the treatment of Leber’s Congential Amaurosis (LCA). The FDA also granted AAV-RPE65 rare pediatric disease designation for the treatment of inherited retinal dystrophy due to biallelic RPE65 mutations.

AAV-CNGB3, a gene therapy treatment designed to restore cone function, is delivered via subretinal injection to the area of the eye where most of the cones in the retina are located. MeiraGTx is currently conducting a Phase 1/2 clinical trial of AAV-CNGB3 in both adult and pediatric patients with achromatopsia (ACHM) due to mutations in the CNGB3 gene.

AAV-CNGB3 was granted Orphan Drug, Rare Pediatric Disease and Fast Track designations by the FDA, and Orphan Drug and PRIME designations by the EMA, for the treatment of ACHM caused by mutations in the CNGB3 gene.

AAV-CNGA3, a gene therapy treatment designed to restore cone function, is delivered to the cone receptors at the back of the eye via subretinal injection. It was designed with a synthetic promoter associated with strong gene expression to account for the larger amount of protein needed to restore cone function in achromatopsia (ACHM) patients with a CNGA3 gene mutation.

MeiraGTx is conducting a Phase 1/2 clinical trial of AAV-CNGA3 in children aged 3-15 years old with ACHM caused by mutations in the CNGA3 gene.

AAV-CNGA3 was granted Orphan Drug designation by the FDA and EMA, as well as Rare Pediatric Disease designation and Fast Track designation by the FDA, for the treatment of ACHM caused by mutations in the CNGA3 gene.