Heaven help those perseverant souls who pursue translational research on neurodegnerative disorders. New interventions in this area have just about the highest failure rate of any area of medical research. And last week, yet another promising strategy was shown ineffective in a phase II study.
The trial in question was testing Ceregene’s gene transfer strategy against Parkinson’s Disease (PD). Ceregene was second out of the gate testing gene transfer against PD (the first was Neurologix). In April 2008, I wrote about their phase 1 study results, which on the one hand seemed to suggest safety, while on the other hand did not show signs of a dose-effect nor a change in dopamine metabolism by imaging. For me, the most troubling aspect of this protocol was its aggressiveness: researchers delivered vector along eight needle tracks to deep brain structures. Based on surgical complication rates in the published literature, the risk of causing permanent neurological deficits from cerebral hemorrhage was on the order of 7% in this study- and that’s not including the additional risk associated with the vector itself.
On November 26, Ceregene announced results of its sham controlled phase II study of CERE-120. First the good news: the press release described CERE-120 as “safe and well tolerated.” The bad news is that the investigators saw no difference in outcomes between the sham and active arms. The press release does not say whether any adverse events were reported; nor does it say anything about surgical complications. In the next few weeks, expect to see data on why, precisely, the strategy might have failed. (photo credit: bebob717 2006).