Abstract:

Over the past decade, nine separate gene therapy clinical trials for advanced Parkinson’s disease (PD) have been launched and completed, involving the dosing of nearly 12-dozen PD volunteers who incurred significant risks to hopefully reduce symptoms and gain a better life. Each attempted to directly or indirectly correct or compensate for the dysfunction and death of dopamine neurons that originate in the substantia nigra (located in the brain stem), projecting their axon terminals to the putamen (centrally located within each cerebrum). All told, incalculable hours were spent planning and executing these clinical trials, collectively costing hundreds of millions of dollars. After all is said and done- what has been gained? It would be understandable if one answered that question by pointing out that treatments for PD have not improved following these efforts, for advanced patients are left with the same choices- and the same disappointing prognosis- faced a decade ago. However, as with any nascent and highly complicated endeavor, especially one also applying highly innovative and unproven technology, initial progress is often better measured by how much new information has been gained to guide further efforts, rather than how closely the ultimate goals may have been met.