Neuroprotective agents for clinical trials in Parkinson's disease: a systematic assessment.

Background: Current therapies for PD ameliorate symptoms in the early phases of disease but become less effective over time, as the underlying disease progresses. Therapies that slow the progression of PD are needed. However, there have been relatively few clinical trials aimed at demonstrating neuroprotection. The authors sought to identify potential neuroprotective agents for testing in clinical trials. Methods: First a broad array of compounds were identified by working with clinicians and researchers in academics and industry. Specific criteria were drafted for drug evaluation, including scientific rationale, blood–brain barrier penetration, safety and tolerability, and evidence of efficacy in animal models or humans. Agents were prioritized based on these criteria. Results: The authors identified 59 potential neuroprotective compounds, proposed by 42 clinicians and scientists from 13 countries. After systematic reviews using the specified criteria they found 12 compounds to be attractive candidates for further clinical trials in PD. Conclusions: Several potential neuroprotective compounds, representing a wide range of mechanisms, are available and merit further investigation in PD.