Safety Study of Recombinant Adeno-Associated Virus Acid Alpha-Glucosidase to Treat Pompe Disease

Pompe disease is an inherited condition of acid alpha-glucosidase (GAA) deficiency resulting in lysosomal accumulation of glycogen in all tissues. Glycogen accumulation leads to muscle dysfunction and profound muscle weakness. A wide spectrum of disease is characteristic and the most severe patients have cardiorespiratory failure, often fatal in the first two years of life. Researchers have developed a way to introduce the normal GAA gene into muscle cells with the expectation that the GAA protein will be produced at levels sufficient to reduce glycogen accumulation. This study will evaluate the safety of the experimental gene transfer procedure in individuals with GAA deficiency. The study will also determine what dose may be required to achieve improvement in measures of respiratory function.

The goal of the current study is to evaluate an experimental gene transfer procedure in which normal copies of the GAA gene are inserted into cells. In this study, a modified virus, adeno-associated virus (AAV), has been engineered to carry a normal copy of the GAA gene, known as rAAV1-CMV-hGAA, which is used to place normal copies of the GAA gene into diaphragm muscle cells. The purpose of this study is to evaluate the safety of rAAV1-CMV-hGAA delivery into individuals with GAA deficiency (Pompe Disease). Participants currently using enzyme replacement therapy will continue to receive their regular medical regimen during the 12 month duration of the study. Participants will first attend a screening study visit to confirm study eligibility. Participants will then attend a 3-5 day inpatient visit, during which they will receive a series of intradiaphragmatic injections consisting of the study agent (rAAV1-CMV-hGAA). Follow-up study visits will occur on Days 14, 90, 180, 270 and 365. Participants will have yearly follow-up evaluations by either telephone or mail for a total of 15 years, or as required by the FDA and other regulatory agencies.