ELB139 Given Orally to Patients With Concurrent Panic Disorder, Challenged by CO2 Inhalation After a Single Dose and One Week of Treatment

International, Multicenter, Randomized, Double-Blind, Placebo Controlled, Two-Period, Cross-Over Study to Demonstrate Safety, Tolerability and Anxiolytic Effects of 600 mg ELB139 Given Orally t.i.d. to Patients With Concurrent Panic Disorder, Challenged by Inhalation of 35% CO2 After a Single Dose and One Week of Treatment

This study is designed to investigate if 600 mg ELB139 given orally t.i.d. to patients suffering from panic disorder is effective in reducing anxiety evoked by inhalation of 35% CO2 measured by a visual analogue scale after the first intake and after approximately one week of treatment as compared to placebo treatment.

Inclusion Criteria:

• Diagnosis of concurrent panic disorder
• At least 2 panic attacks within the 4 weeks before the screening visit
• Naïve to the CO2 challenge test
• Age 18-65 years (inclusive)
• Ability to comply with all procedures mandated by the study protocol
• Negative pregnancy test and adequate contraceptive measures

Exclusion Criteria:

• History of poly-pharmacotherapy for panic disorder or treatment resistance
• Any current psychiatric Axis I DSM-IV diagnosis other than panic disorder, except concurrent simple phobia
• History of abuse of benzodiazepines or tolerance to effects of benzodiazepine
• Any concomitant psychotropic medication
• Evidence of impaired hepatic, renal or cardiac functions
• Participation in any drug trial in the preceding 6 months