Found on the Alzheimer's Forum dated Jan 9, 2009 under PD news (scroll down to middle of page--
"In the meantime, the JAMA study may help soften the blow from the disappointing Phase 2 trial of CERE-120, a PD gene therapy approach. Unlike DBS, which can relieve symptoms but does nothing to slow neuronal death, gene therapy strategies aim to rescue dying neurons by delivering growth factors to brain regions affected by disease. Such methods have shown some success in AD (see ARF related conference story"

"CERE-120, an adeno-associated viral vector developed by San Diego, California-based Ceregene, Inc., carries the growth factor neurturin to dopamine-producing nigral neurons that degenerate in PD. In a November news release, the company announced that CERE-120 showed no clinical benefit in a Phase 2 study of 58 patients with advanced PD. The trial did have a silver lining. “We saw no product-related side effects at all,” said Ray Bartus, the company’s chief scientific officer, in an interview with ARF.

Based on autopsy data his team has analyzed from two patients in the recent trial, he thinks the gene delivery procedure could be at fault. While it appeared that neurturin DNA was taken up at the injection site—the terminal fields of nigral neurons—the researchers saw no evidence of the target protein in nigral cell bodies. To work in advanced PD patients, Bartus said the therapy should target both terminal fields and cell bodies. Based on this working hypothesis, he hopes the company can launch a trial that includes those adjustments later this year."

http://www.alzforum.org/new/detail.asp?id=2012

This is the first i've read about this explanation. Has anyone else?