April 21, 2006

Alexza Pharmaceuticals has initiated a Phase IIa clinical trial with AZ-002 (Staccato alprazolam) in patients with panic disorder. AZ-002 is an inhalation product candidate being developed for the acute treatment of panic attacks associated with panic disorder.

The Phase IIa clinical trial is an in-clinic proof-of-concept study. It is a single-center, randomized, double-blind, placebo-controlled evaluation of 36 patients with panic disorder. The primary aim of the clinical trial is to assess the safety and efficacy of a single dose of AZ-002 in treating a pharmacologically-induced panic attack. Changes in the intensity and the duration of a panic attack using psychological and physiological measurements will be evaluated at multiple time points during the study.