Safety and Efficacy of AVP-923 in the Treatment of Levodopa-induced Dyskinesia in Parkinson's Disease Patients

Proof-of-concept phase 2a, double-blind, randomized, placebo-controlled, crossover study.

Inclusion Criteria:

- Males and females 30 to 80 years of age, inclusive.

- Diagnosis of idiopathic PD meeting the United Kingdom Parkinson's disease Society
Brain Bank criteria.

- Levodopa-induced dyskinesia present greater than 25% of the day as per MDS-UPDRS.

- Dyskinesia of at least moderate severity as per MDS-UPDRS

- Amantadine and Monoamine Oxidase (MAO) inhibitors must be discontinued at least three
weeks prior to randomization.

- Subjects currently receiving anti-parkinsonian medications, including all Levodopa
preparations are eligible provided they have been on a stable dose of these
medications for at least 1 month prior to randomization.

- Concomitant use of antidepressants such as selective serotonin reuptake inhibitors are
allowed, provided the dose has been stable for at least 1 month prior to
randomization.

Exclusion Criteria:

- Subject had a prior surgery for PD except Deep Brain Stimulation (Deep Brain
Stimulation must not have been performed within one year of screening)

- Hoehn and Yahr score of 5 when "off".

- Subject with Cognitive impairment and/or history of psychiatric manifestations or
active hallucinations.

- Subjects with any history of complete heart block, QTc prolongation, or torsades de
pointes.

- Subjects with any family history of congenital QT interval prolongation syndrome.

- Subjects with history of postural syncope, or any history of unexplained syncope
within the last 12 months.

- Subjects with a history of substance and/or alcohol abuse within the past 2 years.