Efficacy and Safety Study of Inhaled CVT 301 in Parkinson's Disease Patients for Treatment of OFF Episodes

Inclusion Criteria: * Idiopathic Parkinson's Disease (PD) diagnosed between the ages of 30 and 80 years; * Hoehn and Yahr Stage 1-3 in an "on" state; * Require levodopa-containing medication regimen at least 4 times during the waking day; * Experience motor fluctuations with a minimum of 2 hours of average daily "off" time per waking day (excluding early morning "off" time) and demonstrate levodopa responsiveness; * Are on stable PD medication regimen. Exclusion Criteria: * Pregnant or lactating females; * Previous surgery for PD or plan to have stereotactic surgery during the study period; * History of psychotic symptoms requiring treatment, or suicide ideation or attempt within last year; * Adequate lung function as measured by spirometry; * Any significant condition, severe concurrent disease, abnormality or finding that would make patients unsuitable or may compromise patient safety.