A Study of AAV-hAADC-2 in Subjects With Parkinson's Disease

Safety Study in subjects with Parkinson's Disease

In a patient with Parkinson's disease, the part of the brain called the substantia nigra progressively loses the ability to send dopamine signals to the striatum. To compensate for the loss of striatal dopamine, most patients take L-dopa, an approved drug which is converted to dopamine by an essential enzyme - AADC. With time, however, the brain loses its remaining ability to convert L-dopa to dopamine and thus the drug becomes progressively less effective. In the therapy being studied, the gene coding for the enzyme that converts L-dopa to dopamine (AADC) is inserted into a common, non-pathogenic virus (AAV) to which \> 90% of humans have been exposed. The AAV will help to transport the AADC into the brain cells. AAV-hAADC-2, the investigational drug being studied, is injected into the striatum during a surgical procedure. Patients who undergo the procedure would continue to take L-dopa; AAV-hAADC-2 is intended to provide, directly to the brain, the missing enzyme needed to convert L-dopa to dopamine.