LGMD2D is a severe, debilitating condition caused by a defect in the gene that produces the alpha-sarcoglycan protein.
Experimental gene therapy treatment aims to deliver alpha-sarcoglycan genes to permanently restore protein expression, which could significantly improve symptoms and functional ability for patients.
Early clinical studies of MYO-102 have demonstrated safety and expression of alpha-sarcoglycan protein using the gene therapy candidate.
"We have had success in the clinic using AAV gene therapy with limb girdle muscular dystrophy type 2D, which is caused by mutations in the alpha-sarcoglycan gene," Louise Rodino-Klapac, PhD, principal investigator in the Center for Gene Therapy at The Research Institute of Nationwide Children's Hospital, said.
"However, the dysferlin gene is very large, about six times larger than the alpha-sarcoglycan gene and can't fit into a traditional AAV vector."
Injections of the alphasarcoglycan gene in the foot muscles of three patients with limb-girdle muscular dystrophy type 2D produced 4-5 times the amount of the
alpha-sarcoglycan protein, compared with saline injections.
For example, one form may be called
alpha-sarcoglycan deficiency and another is known as beta-sarcoglycan deficiency.
The researchers point out that limb-girdle muscular dystrophy actually describes more than 19 disorders that occur because patients have a faulty
alpha-sarcoglycan gene.