June 6, 2006

Alexza Pharmaceuticals has announced today that it has initiated a Phase IIb clinical trial with AZ-001 (Staccato prochlorperazine) in patients with migraine headaches. AZ-001 is an inhalation product candidate being developed for the acute treatment of migraine headaches.

The Phase IIb clinical trial is an outpatient, multicenter, randomized, double-blind, single-dose, placebo-controlled study in approximately 400 migraine patients with or without aura. Four doses will be evaluated in the clinical trial, placebo and three doses of AZ-001 (5, 7.5 and 10 mg). Using the International Headache Society (IHS) 4-point rating scale, the primary efficacy endpoint for the trial is headache pain relief at 2 hours post-dose. Secondary efficacy endpoints for the trial include pain relief and other symptom assessments at various time points. Safety evaluations will also be made throughout the clinical trial period.