Ropinirole Slows Loss of Dopaminergic Marker (AAN 2002)

Subject: Ropinirole Slows Loss of Dopaminergic Marker (AAN 2002)

Date: 4/21/2002

E-MOVE reports from the 54th Annual Meeting of the American Academy of Neurology, April 13-20, in Denver Colorado. Poster numbers, session numbers, and pages are from Neurology 2002;58(supplement 7).

1. The REAL-PET study: Slower progression in early Parkinson's disease treated with ropinirole compared with L-dopa
AL Whone, P Remy, MR Davis, M Sabolek, C Nahmias, J Stoessl, RL Watts, DJ Brooks
S11.006, A 82

Initial treatment of PD with ropinirole slows the loss of a marker for dopaminergic cells compared to levodopa, according to this study.

One hundred eighty-six de novo PD patients were randomized to receive ropinirole or levodopa, with open-label levodopa added as needed to control symptoms. Patients were a subset of the 056 study previously reported by E-MOVE (http://www.wemove.org/ema/em_pd_01.html). At two-year follow-up, 73-74% of each group remained in the study. As measured by PET, putaminal fluorodopa uptake had declined by 13% in ropinirole-treated patients, compared to 20% in levodopa-treated patients (p=0.022). As shown in the parent study, dyskinesias were significantly lower in ropinirole-treated patients, while UPDRS scores were better in levodopa-treated patients, despite the availability of supplemental levodopa to agonist-treated patients.

Based on the imaging results, the authors conclude that ropinirole as initial therapy slows nigral degeneration by 30% compared to levodopa.

E-MOVE's report on a similar study of pramipexole, reported last month in JAMA, is archived at http://www.wemove.org/emove/article.asp?ID=426. As quantified with a different imaging technique, pramipexole treatment produced similar results, which were also presented in this session.

Several neurologists attending the session cautioned that the significance of these results depends on how well loss of these markers tracks cell death, versus simple loss of the relevant transporter activity in still-living nigral cells. Animal studies tend to support the cell-death interpretation; the evidence in humans is scant and somewhat contradictory. Kenneth Marek, who presented the pramipexole imaging data at this session, said afterward he thinks the case for these imaging techniques as reliable markers of neurodegeneration is very strong, but not yet conclusive. Klaus Leenders, a neuroimaging specialist involved in a similar trial with pergolide, was more skeptical. He said afterward, the in vivo evidence only shows a difference in biochemical adaptation of nigral cells to dopamine agonists versus levodopa, and there is not yet any basis for claiming dopamine agonists are neuroprotective.
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2002 E-MOVE conference reports are made possible in part through unrestricted educational grants from Elan Pharmaceuticals, Glaxo SmithKline, and Pharmacia Corporation.

E-MOVE Editor: Richard Robinson, NASW, WE MOVE

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