Duchenne is a severe, progressive, degenerative muscle disease caused by mutations in the DMD gene, which encodes dystrophin, a protein involved in muscle cell structure and function. Without functional dystrophin protein, muscles throughout the body degenerate and become weak. Individuals with Duchenne experience progressive muscle weakness and eventually lose the ability to walk. Respiratory and heart muscles are also impacted, leading to the need for ventilator-assisted breathing along with the development of cardiomyopathy. There is presently no cure for Duchenne.
RGX-202 is designed to deliver a transgene for a novel microdystrophin that includes the functional elements of the C-Terminal (CT) domain found in naturally occurring dystrophin. Presence of the CT domain has been shown in preclinical studies to recruit several key proteins to the muscle cell membrane, leading to improved muscle resistance to contraction-induced muscle damage in dystrophic mice. Additional design features, including codon optimization and reduction of CpG content, may potentially improve gene expression, increase translational efficiency and reduce immunogenicity.
RGX-202 is designed to support the delivery and targeted expression of genes throughout skeletal and heart muscle using the NAV® AAV8 vector, a vector used in numerous clinical trials, and a well-characterized muscle-specific promoter (Spc5-12).
One-time administration of RGX-202 aims to address the underlying cause of Duchenne by potentially enabling production of microdystrophin in muscle cells to protect them from damage and ultimately preserve muscle function.
RGX-202 has received Orphan Drug Orphan Drug Designation and Rare Pediatric Disease Designation from the FDA.
The AFFINITY DUCHENNE™ Phase 1/2, first-in-human trial of RGX-202 is active and recruiting patients. Learn more about the trial: NCT05693142
The AFFINITY BEYOND™ observational screening study to evaluate the prevalence of AAV8 antibodies in patients with Duchenne up to 12 years of age is also active and recruiting patients. Learn more about the trial: NCT05683379