Do you take L-Dopa to treat your Parkinson's disease but feel like your medication does not work sometimes?

What is the purpose of this study?

This study is being done to see if Preladenent, a study medication, is safe and can help increase the amount of time that you do not have symptoms of Parkinson's disease.

Can I participate in this study?

You may be eligible for this study if you meet the following criteria:

• Conditions:Parkinson's Disease
• Age: Between 30 - 85 Years
• Gender: Male or Female
• Inclusion Criteria:

  If you answer YES to the following questions you may be eligible to participate in this study:
  
      1. Do you have Parkinsons disease?
      2. Have you been using levodopa for more than one year?
      3. Do you have times when your medication does not work as long as you would like?
          *A member of the research team will discuss all the criteria with you.
• Exclusion Criteria:

  If you answer YES to any of the following questions you may not be eligible to participate in this study:
  
      1. Do you have any uncontrolled medical conditions?
      2. Do you have uncontrolled depression?
      3. Have you had a heart attack in the last 6 months?
          *A member of the research team will discuss all the criteria with you.

Detail Study Description

This study is for Parkinson's disease patients who are already taking L-Dopa to treat their symptoms of Parkinson's disease.

During the study you will either be given Preladenent or a placebo (a lookalike pill without any drugs or medicine).

No one involved in your care will know if you are taking the study medicaiton or the placebo.

Study Treatments

Preladenant, Placebo to preladenant