The current study is part of a large, collaborative effort at Duke University Medical Center to find an effective treatment for Pompe disease. The Duke team earlier developed enzyme replacement therapy, in which a normal version of the faulty enzyme in those with the disease is infused weekly. In clinical trials of the replacement therapy, the infusions have already prolonged the lives of many babies with Pompe disease, Koeberl said.
"A number of babies have been receiving enzyme replacement therapy for several years," said Koeberl. "They are walking, living longer, and meeting developmental milestones."
Despite the early success of enzyme replacement therapy for some children with Pompe disease, a need for gene therapy remains, he added. In gene therapy, a therapeutic gene is delivered to patient cells, often using a modified virus.
Gene therapy might offer an alternative treatment for those children who fail to respond to enzyme replacement therapy, he said. Even for those that respond well to enzyme infusions, treatment requires weekly injection of a large amount of the enzyme.
"Gene therapy has the potential to reverse the course of the disease with a single treatment," Koeberl said.
The researchers delivered the glycogen-degrading enzyme with an adeno-associated virus (AAV) vector. AAV is not associated with any known human disease. The DNA coding for the enzyme was linked to a specialized DNA "promoter" region that restricted its activity to muscle. The investigators either injected the viral particles into t
Source:Duke University Medical Center