Parkinson Pipeline Project-treatment development database, research, FDA drug approval, PD clinical trials and sponsors, patient involvement

GDNF and Amgen in the News


	The halt of the Phase 2 GDNF trials and the struggles of the trial participants to convince biotech giant Amgen to reinstate treatment was initially reported mainly in cities where the participants reside (New York, Bristol UK, Lexington Kentucky), or Amgen is well- known (Los Angeles, Ventura County (Ca). However, in July, reports on the autopsy study in Bristol showing proof of the growth of neurons in a phase I trial participant, has captured the interest of the national, local and international news media and the public. Further down on this page are selected news articles, research reports and web sites on GDNF for Parkinson’s.

Breaking News

The autopsy of the brain of one of the Bristol study participants, who died of an unrelated heart attack, revealed that dopamine-containing nerve fibers lost in Parkinson’s disease had sprouted back in the region where GDNF had been infused.

Because the GDNF had been infused into one side of the brain only, the effects of the treatment could be assessed by comparing the two sides.

“This is the first neuropathological evidence that infusion of GDNF in humans causes sprouting of dopamine fibers, in association with a reduction in the severity of Parkinson’s.” stated Dr. Seth Love, who studied the tissue.⁽¹⁾

This is also the first time any potential treatment has been shown to halt disease progression and possibly reverse the loss of nerve fibers in Parkinson’s.

In August 2005, the University of Kentucky researchers reported on a primate study that concluded that in parkinsonian monkeys, GDNF was effective in promoting recovery of dopamine producing neurons and improved motor functions, and that optimal distribution of GDNF into the brain increased the efficacy of the treatment . Multiport catheters using pulse delivery to distribute GDNF in the brain were the most effective. ⁽²⁾

The successful human Phase I trials at the University of Kentucky had also utilized multiport catheters. The successful human Phase I trial at Frenchay Hospital in Bristol, UK utilized the smallest catheter and pulse delivery of the GDNF. However, in Amgen’s phase II human trial, they used instead a single port, constant delivery system. ⁽³⁾

“The varying results in the phase I and phase II trials are the best argument for why further testing is warranted, using methods similar to those employed in the successful UK’s Phase I human trial,” states Dr. Gash. ⁽⁴⁾

“GDNF acted on the patients' remaining neurons like a tonic on a wilting plant: GDNF restores the neurons, makes them sprout, and suddenly they look healthy and happy.” (5) states Dr. Clive Svendsen, a member of the Bristol research team.

Experimental treatment shown to reverse the loss of nerve fibres in Parkinson's Disease. Retrieved online. News-Medical.Net, July 6, 2005.
http://www.news-medical.net/?id=11514
Gash DM, Zhang Z, Ai Y, Grondin R, Coffey R, Gerhardt GA. Trophic factor distribution predicts functional recovery in parkinsonian monkeys. Annals of Neurology. 2005. Vol.8, Issue 2, pp.224-233.
Notes on conference call with Katie Hood and Dr. Todd Sherer, Michael J. Fox Foundation , Jan. 4, 2005. http://pdpipeline.org/PAN_GDNF_calls.htm
Reaction to withdrawal of GDNF Treatment. University of Kentucky news release, February 11, 2005. Retrieved online. www.uky.edu/PR/News/Archives/2005/Feb2005/050211_parkinsons_treatment.hm
Wade, Nicholas. Promising Results Are Seen in Small Parkinson's Trial. New York Times, April 8, 2003.