Amgen's decision to block reinstatement of GDNF is faulted by a leading Parkinson's advocacy group


New York, February 11 The following statement is being released by the Parkinson's Disease Foundation, located at 710 West 168th Street, New York City. It follows the announcement, earlier today, of a decision by Amgen Incorporated, manufacturer of GDNF, an experimental neural growth factor, to forgo the offer of reinstatement of GDNF to patients who were involved in recent clinical trials of the treatment. The authors of the PDF statement are Stanley Fahn, M.D., the Foundation's Scientific Director, and Robin Anthony Elliott, its Executive Director.

"The Amgen announcement, which followed a resolution by the PDF Board of Directors urging the company to permit patients who participated in the company's clinical trials the option of continued access to GDNF, is deeply disappointing to PDF, to the Parkinson's community, and to the participating patients," the statement reads. "However well-intentioned the company may have been in wrestling with this issue, we believe it has reached the wrong decision whether judged in terms of science, or the desires of the people who participated in the clinical trials, or the issues of safety."

"In terms of the science, we would argue that the reinstatement of GDNF, if accompanied by the continuing collection of efficacy and safety data, would enable scientists and regulatory authorities to monitor the long-term aspects of safety and efficacy of the treatment. Furthermore, the observation of increased fluorodopa uptake in PET scans needs to be carefully followed over time to determine if this will eventually translate into clinical improvement. Giving up this opportunity to learn is, in our view, a mistake."

"In good faith, the 48 patients who participated in the clinical trials invested their time and indeed their lives in helping to test the efficacy and safety of GDNF. This trophic factor has long been viewed by scientists as a potentially beneficial treatment to slow and possibly reverse the effects of Parkinson's disease. Since the trial was halted last summer, many of these people, supported by organizations and thousands of well-wishers from around the Parkinson's community, have pleaded with Amgen to reinstate those subjects who wish to continue with the treatment and are willing to be carefully followed to generate ongoing data. We understand and fully accept that such reinstatement of treatment should take place only with appropriate waivers that would hold the company harmless in event of any complications, whether foreseen or unforeseen, and with the approval of the relevant Institutional Review Boards."

"The safety issues of neutralizing antibodies (found in some of the human subjects) and of cerebellar degeneration involving high-dosage GDNF (in some non-human primate subjects) need to be investigated and understood. If subjects are willing to offer themselves for continuing GDNF infusion with all of these safety concerns fully explained and understood by the subjects, then the Parkinson community science as well as patients can gain much new information related to the safety of GDNF infusions."

"In summary, the decision is a mistake because it denies the patients and their doctors the opportunity to continue with a potentially useful, albeit yet unproven, treatment, and it denies us all the opportunity to gather more scientific data about the long-term effects of GDNF. We hope very much that this company, which has long held a position of high respect in the business and health communities, will consider reversing its decision, and soon. In the meantime, the coalition of patient-voluntary groups which besides PDF includes the Parkinson's Action Network and the Parkinson's Pipeline Project -- will continue fighting for patients' interests as long as it takes."

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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