This was a two-phase study that involved a controlled in-office dose titration phase followed by a 6-month outpatient open-label treatment phase. During the in-patient dose titration phase, subjects were evaluated on separate days for the response to single doses of medication administered during an observed “Off” event (defined as first “Off” event that occurs at least one hour after administration of the normal morning dose of oral antiparkinson medication). Evaluation of the acute response to oral anti-PD medication (Baseline) and to apomorphine dose escalation between 2 and 10 mg (Titration Visits) was conducted under unblinded conditions. At the 0.4-mL titration level, placebo was randomly introduced under double-blind crossover conditions.