Clinical trials with a trophic factor called GDNF, where GDNF is injected directly in the brain by pumps, have not been completely successful. Many scientists believe that the delivery method is part of the problem and have been calling for gene transfer as the most viable delivery method. We further contend that GDNF will only function properly as a therapeutic when used with early stage patients. In order to perform gene therapy in early stage patients, extreme safety of the gene therapy must be demonstrated prior to use in humans. This project is part of a program to produce a viral vector to deliver GDNF but with the added safety that it can be turned off by a harmless antibiotic if side-effects appear.
First, we need to know if our regulated vector makes therapeutic amounts of GDNF in the brain. So, we will test our regulated vector in two animal models of PD. Second, there is some controversy as to whether part of the regulated vector is immunogenic in the brain. The second experiment will test whether there is any added immunogenicity for the regulated vector as compared to vectors that do not have the suspect components.
We hope that the results of this project will provide enough data to start the final phase of animal research needed to prove our regulated GDNF viral vector is suitable to test in a phase I clinical trial.