Conditions: Parkinson's Disease
Keywords: Parkinson's disease
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 450
Healthy volunteers: no

Brief summary:
This study is to evaluate the efficacy of a range of preladenant doses compared with placebo in participants with moderate to severe Parkinson's disease (PD) experiencing motor fluctuations and receiving a stable dose of levodopa (L-dopa), as measured by "off" time. Participants will continue to receive their stable regimen of L-dopa plus any adjunct medications during the study as prescribed by their physician. Several classes of adjunct medications may be used, including Amantadine, anticholinergics, dopa decarboxylase inhibitors, and dopamine agonists.

Primary Hypothesis: At least the 10 mg twice daily dose of preladenant is superior to placebo as measured by the change from Baseline to Week 12 in the mean "off" time.

Detailed description:

Arms:
arm 1: Participants will receive preladenant 2 mg taken orally twice daily (BID), one tablet in the morning and one tablet in the evening, for 12 weeks. arm 2: Participants will receive preladenant 5 mg taken orally BID, one tablet in the morning and one tablet in the evening, for 12 weeks. arm 3: Participants will receive preladenant 10 mg taken orally BID, one tablet in the morning and one tablet in the evening, for 12 weeks. arm 4: Participants will receive a placebo to preladenant tablet taken orally BID, one tablet in the morning and one tablet in the evening, for 12 weeks.

Interventions: intervention 1: Preladenant intervention 2: Placebo tablet to match Preladenant
Intervention descriptions: intervention 1: 2, 5, or 10 mg tablets taken orally twice daily (BID) intervention 2: tablets taken orally BID

Protocol document: