In another indication seeking new treatments, Parkinson’s disease, two other gene therapy companies are forging ahead. The first-ever trial of gene therapy in Parkinson’s has just been published, and the data appear promising (The Lancet 369, 2097-2105, 2007). In the trial, a recombinant adeno-associated virus (AAV)-expressing glutamic acid decarboxylase, an enzyme catalyzing the conversion of the excitatory neurotransmitter glutamate into the inhibitory neurotransmitter ¡-aminobutyric acid (GABA), was delivered to the subthalamic nucleus on one side of the brain in each of twelve patients, in an effort to switch off downstream signals that affect normal motor functions. As well as being safe, the therapy appeared to have a positive effect on the motor fluctuations associated with long-term use of levodopa (sold as Bendopa, Carbidopa, Levodopa, Dopar, Larodopa, Sinemet), which require patients to go on and off the therapy.

“It seems to reduce those fluctuations and improve function in the on-and-off state, and that is quite unusual,” says Matthew During, professor at Ohio State University School of Medicine in Columbus, and one of the principal investigators on the study. During and his collaborator, Michael Kaplitt of Cornell University’s Weill Medical College in New York, set up a small biotech firm in Fort Lee, New Jersey, called Neurologix, to commercialize their work. They plan to move the Parkinson’s therapy into a phase 2 trial later this year and to commence a phase 1 trial of neuropeptide ¡ in epilepsy. “That’s a disease where we can make a significant impact, as well,” During claims.