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

A Phase 2a, Double-blind, Randomized, Placebo-controlled, Crossover Study to Evaluate the Safety and Efficacy of AVP-923 (Dextromethorphan/Quinidine) in the Treatment of Levodopa-induced Dyskinesia in Parkinson's Disease Patients.

To evaluate the efficacy, safety, and tolerability of AVP-923 capsules containing 45 mg dextromethorphan and 10 mg quinidine (AVP-923-45) compared to placebo for the treatment of levodopa-induced dyskinesia (LID) in patients with Parkinson's disease (PD).

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.