Alexza Announces Preliminary Results from its AZ-104 (Staccato(R) Loxapine) Phase 2b Trial in Patients with Migraine Headache

Alexza Announces Preliminary Results from its AZ-104 (Staccato(R) Loxapine) Phase 2b Trial in Patients with Migraine Headache

Conference Call Scheduled for Today - Monday, September 14, 2009 at 9:00 a.m.
Eastern Time

MOUNTAIN VIEW, Calif., Sept. 14 /PRNewswire-FirstCall/ -- Alexza
Pharmaceuticals, Inc. (Nasdaq: ALXA) today announced preliminary results from
its 366 patient Phase 2b clinical trial of AZ-104 (Staccato(R) loxapine) in
patients with migraine headache.  Both AZ-104 dose groups trended towards
statistical significance, but the study did not meet its primary endpoint,
which was defined as pain-relief at the 2-hour time point, compared to
placebo.  There were no serious adverse events in the clinical trial, and
AZ-104 was generally safe and well tolerated in this patient population. 

"The failure to reach statistical significance on the primary endpoint is
disappointing, as we were not able to reproduce the positive clinical findings
from our AZ-104 Phase 2a proof-of-concept clinical trial," said James V.
Cassella, PhD, Senior Vice President, Research and Development at Alexza.
"Loxapine is a drug that had not been previously studied in migraine patients,
except for our earlier proof-of-concept study.  As part of our collaboration
with Symphony Allegro, we initiated this migraine program in 2007 to
investigate whether loxapine might be a viable product candidate for migraine,
due to the scientific rationale that loxapine's primary mechanism of action
(dopamine antagonism) has shown effectiveness in treating migraine."

"We continue to be impressed with Staccato's ability to safely and very
accurately deliver a portfolio of drugs in a simple, one-breath,
patient-controlled inhalation," said Thomas B. King, President and CEO of
Alexza.  "The uniqueness of our Staccato technology allows us to examine
medicines for both known and new indications, and we will continue to do so in
a patient setting.  Not every clinical trial will necessarily have positive
findings.  However, there is much value we can bring to patients through our
Staccato technology, as evidenced by our late-stage, pre-NDA program with
AZ-004 (Staccato loxapine, high dose) for the acute treatment of agitation."

AZ-104 Phase 2b Clinical Trial Design
The AZ-104 Phase 2b clinical trial was an outpatient, multi-center,
randomized, double-blind, single administration, placebo-controlled study.
The study was designed to evaluate the treatment of a single migraine attack
of moderate to severe intensity in each of approximately 360 migraine
patients, with or without aura.  Two doses of AZ-104 (1.25 mg and 2.5 mg) and
placebo were evaluated in the clinical trial.  The study enrolled a total of
366 patients: 125 patients in the placebo dose group, 121 patients in the 1.25
mg dose group, and 120 patients in the 2.5 mg dose group.

Patients rated their headache pain using the International Headache Society
(IHS) 4-point rating scale. The primary efficacy endpoint was headache pain
relief (headache pain rated as mild or none) at 2 hours post-dose.  Secondary
efficacy endpoints for the clinical trial included various additional
measurements of pain relief, as well as effects on nausea, vomiting,
phonophobia and photophobia.  All results were considered statistically
significant at the p < 0.05 level, as compared to placebo, and all analyses
were made on an intent-to-treat basis.  Safety evaluations were also made
throughout the clinical trial period.

Primary Efficacy Endpoint
AZ-104 was numerically superior to placebo in pain-relief at 2-hours
post-dose, but these differences were not statistically significant.  Pain
relief was observed in 56% of patients receiving the 2.5 mg dose (p=0.11) and
54% of patients receiving the 1.25 mg dose (p=0.12), as compared to 45% of
patients receiving placebo.

Another commonly used measure of efficacy in migraine studies is the
percentage of patients who are pain-free at 2 hours post-dose.  Again, AZ-104
was numerically superior to placebo in this measure, but the differences were
not statistically significant.  Pain-free responders were 31% of the patients
receiving the 2.5 mg dose and 27% of the patients receiving the 1.25 mg dose,
as compared to 23% of the patients receiving placebo.

Conference Call Information
Alexza will host a conference call today, Monday, September 14, 2009 at 9:00
a.m. Eastern Time.  A replay of the call will be available for two weeks
following the event.  The conference call and replay are open to all
interested parties. 

To access the conference call via the Internet, go to, under
the "Investor Relations" link.  Please join the call at least 15 minutes prior
to the start of the call to ensure time for any software downloads that may be
required.  Interested parties may also pre-register to avoid pre-call delays

To access the live conference call via phone, dial 888-680-0860.
International callers may access the live call by dialing 617-213-4852.  The
reference number to enter the call is 93505561. 

The replay of the conference call may be accessed via the Internet, at, or via phone at 888-286-8010 for domestic callers or
617-801-6888 for international callers.  The reference number for the replay
of the call is 16727234.

About Alexza Pharmaceuticals, Inc.
Alexza Pharmaceuticals is a pharmaceutical company focused on the research,
development and commercialization of novel, proprietary products for the acute
treatment of central nervous system conditions.  Alexza's technology, the
Staccato(R) system, vaporizes unformulated drug to form a condensation aerosol
that, when inhaled, allows for rapid systemic drug delivery through deep lung
inhalation.  The drug is quickly absorbed through the lungs into the
bloodstream, providing speed of therapeutic onset that is comparable to
intravenous administration, but with greater ease, patient comfort and

AZ-004 (Staccato loxapine) is Alexza's lead program, which is being developed
for the acute treatment of agitation in schizophrenic or bipolar disorder
patients.  Alexza has completed and announced positive results from both of
its AZ-004 Phase 3 clinical trials, and is projecting a New Drug Application
submission in early 2010. 

Alexza has completed an end-of-Phase 2 meeting with the FDA for AZ-001
(Staccato prochlorperazine) and has completed two Phase 2 studies with AZ-104
(Staccato loxapine, low-dose).  Both product candidates are being developed
for the acute treatment of migraine headache. 

AZ-002 (Staccato alprazolam) has completed Phase 1 testing and one Phase 2a
proof-of-concept clinical trial.  Product candidates that have completed Phase
1 testing are AZ-003 (Staccato fentanyl) for the treatment of breakthrough
pain and AZ-007 (Staccato zaleplon) for the treatment of insomnia.  More
information, including this and past press releases from Alexza, is available
online at

Safe Harbor Statement
This press release includes forward-looking statements regarding the
development, therapeutic potential and safety of AZ-104.  Any statement
describing a product candidate or Alexza's goals, expectations or beliefs is a
forward-looking statement, as defined in the Private Securities Litigation
Reform Act of 1995, and should be considered an at-risk statement.  Such
statements are subject to certain risks and uncertainties, particularly those
inherent in the process of developing and commercializing drugs.  Alexza's
forward-looking statements also involve assumptions that, if they prove
incorrect, would cause its results to differ materially from those expressed
or implied by such forward-looking statements.  These and other risks
concerning Alexza's business are described in additional detail in Alexza's
Annual Report on Form 10-K for the year ended December 31, 2008, and Alexza's
other Periodic and Current Reports filed with the Securities and Exchange
Commission, including the risks under the headings: "If our product candidates
fail to show a clinically significant benefit compared to placebo, they will
not be approved for marketing" and "If our product candidates do not meet
safety and efficacy endpoints in clinical trials, they will not receive
regulatory approval, and we will be unable to market them".  Forward-looking
statements contained in this announcement are made as of this date, and we
undertake no obligation to publicly update any forward-looking statement,
whether as a result of new information, future events or otherwise.

SOURCE  Alexza Pharmaceuticals, Inc.