SAN DIEGO, CA and Deerfield, IL - (October 22, 2009): Zogenix, Inc. (“Zogenix”), a privately held pharmaceutical company, and Astellas Pharma US, Inc. (“Astellas”) announced that positive results from two clinical studies of new SUMAVEL DosePro (sumatriptan injection) needle-free delivery system will be published in the November 2009 issue of Headache. SUMAVEL DosePro, was recently approved by the FDA to treat acute migraine, with or without aura, and cluster headache. SUMAVEL DosePro is a first-of-its-kind needle-free delivery system for subcutaneous sumatriptan, a treatment that provides migraine relief within 10 minutes for some patients.

The first clinical study evaluated the pharmacokinetics, bioequivalence and safety of administering subcutaneous sumatriptan via the new SUMAVEL DosePro needle-free delivery system as compared to a traditional needle-based autoinjector, IMITREX® STATdose®. The study showed that the unique needle-free delivery system offered by SUMAVEL DosePro delivered subcutaneous sumatriptan in a manner bioequivalent to traditional needle-based technology when administered to the thigh and the abdomen, the most common sites of self-injection. The drug was absorbed rapidly, resulting in peak plasma concentrations within approximately 12 minutes. This rate of absorption of subcutaneous sumatriptan has been previously shown to correlate with rapid and complete relief of migraine symptoms, including migraine relief within 10 minutes for some patients and almost 50% of patients within 30 minutes. Overall safety profiles were comparable for SUMAVEL DosePro and IMITREX STATdose.

The second study evaluated the ease-of-use of SUMAVEL DosePro needle-free delivery system in 52 patients who used the drug at home to treat their migraine headaches. Because SUMAVEL DosePro is a first-of-its-kind product, and was designed to be easily self-administered in three simple steps (snap, flip, press), the study assessed whether the patients, using instructions supplied, could correctly use SUMAVEL DosePro during their first use during a migraine episode. An overwhelming majority of patients in the study - 98 percent - successfully used the new needle-free system during a migraine attack on their first attempt. The study also demonstrated a similarly high level of correct use over the remainder of the trial period (3 migraine attacks or 30 days, whichever occurred sooner).

“Until now, relatively fewer patients have benefited from the unique profile of subcutaneous sumatriptan as compared to the many patients who have taken triptan tablets. These data demonstrate that SUMAVEL DosePro is a unique new product which delivers subcutaneous sumatriptan in a way that will make physicians confident their patients will both get the full benefits of the medication and be able use it correctly,” said Roger Hawley, chief executive officer and director of Zogenix. “We believe SUMAVEL DosePro with its simple, needle-free delivery system will open the doors for many more patients to try and experience the benefits of rapid migraine relief from subcutaneous sumatriptan. We are excited to launch SUMAVEL DosePro with our copromotion partner, Astellas, in January.”

About Migraine

Migraine affects nearly 30 million Americans and is considered the most common neurological condition in the developed world. It is typically characterized by severe, recurring head pain, usually located on one side of the head and one or more of the following associated symptoms: nausea; vomiting; and increased sensitivity to light, sound and/or smell. Oral and nasal treatment options are available but often do not work quickly enough for patients who experience migraine episodes associated with sudden onset, waking, nausea or vomiting. While needle-based treatment options are associated with faster onset of relief, some patients are deterred from use due to needle-aversion and complicated delivery systems.

About Sumavel DosePro

Zogenix and Astellas plan to launch SUMAVEL DosePro in January 2010 in the US. SUMAVEL DosePro (sumatriptan injection) is indicated for the acute treatment of migraine attacks, with or without aura, and the acute treatment of cluster headache episodes.

SUMAVEL DosePro should only be used where a clear diagnosis of migraine or cluster headache has been established. SUMAVEL DosePro is not intended for the prophylactic therapy of migraine or for use in the management of hemiplegic or basilar migraine and should not be administered intravenously. For a given attack, if a patient does not respond to the first dose of SUMAVEL DosePro, the diagnosis of migraine or cluster headache should be reconsidered before administration of a second dose.

IMPORTANT SAFETY INFORMATION

SUMAVEL DosePro is contraindicated in patients with uncontrolled hypertension, in patients with history, symptoms or signs of ischemic heart disease, coronary artery vasospasm, cerebrovascular or peripheral vascular disease including ischemic bowel disease and in patients with other significant underlying cardiovascular diseases or known sensitivity to sumatriptan. SUMAVEL DosePro should not be given to patients in whom unrecognized coronary artery disease is predicted by the presence of risk factors without a prior cardiovascular evaluation. Serious cardiovascular events, including death, have been reported when taking sumatriptan, including patients with no findings of cardiovascular disease. Considering the extent of use of sumatriptan in patients with migraine, the incidence of these events is extremely low. Cerebrovascular events, some fatal, have been reported in patients treated with sumatriptan. In a number of cases, it appears possible that the cerebrovascular events were primary, sumatriptan having been administered in the incorrect belief the symptoms experienced were a consequence of migraine when they were not. It is important to advise patients not to administer Sumavel DosePro if a headache being experienced is atypical. SUMAVEL DosePro should not be used within 24 hours of other ergotamine-containing or ergot-type medications or other 5-HT1 agonists and is not generally recommended for use with MAO-A inhibitors. The development of a potentially life-threatening serotonin syndrome may occur with triptans, including treatment with Sumavel DosePro, particularly during combined use with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). SUMAVEL DosePro should be used during pregnancy only if the potential benefit justifies the potential risk. In controlled clinical trials with sumatriptan injection, the most common adverse reactions were injection site reactions, tingling, warm/hot sensation, burning sensation, feeling of heaviness, pressure sensation, feeling of tightness, numbness, feeling strange, tight feeling in head, flushing, tightness in chest, discomfort in nasal cavity/sinuses, jaw discomfort, dizziness/vertigo, drowsiness/sedation and headache.

About DosePro technology

The DosePro technology is an easy-to-use, pre-filled drug delivery system designed to enable self-administration of single doses of liquid drug formulations, subcutaneously, without a needle. The DosePro technology has undergone more than ten years of design, process engineering, clinical evaluation and development work. DosePro is protected by more than 80 patents, issued and applied for, worldwide. Approximately 9,000 injections have been delivered in clinical trials in volunteers using the DosePro needle-free drug delivery system.

About Zogenix

Zogenix, Inc., with offices in Emeryville and San Diego, Calif., is a privately held pharmaceutical company focused on the development and commercialization of medicines to treat neuroscience disorders and pain. The company's initial focus is the commercialization of Sumavel DosePro. Zogenix submitted a New Drug Application with the U.S. Food and Drug Administration for Sumavel DosePro in December 2007, and received FDA approval in July 2009. The company’s pipeline also includes ZX002, a novel oral controlled-release formulation of hydrocodone without acetaminophen for the treatment of chronic pain, preparing to enter Phase 3 clinical trials. Zogenix also plans to license the patented DosePro needle-free drug delivery system to other companies. For additional information, visit www.zogenix.com.

About Astellas

Astellas Pharma US, Inc., located in Deerfield, Illinois, is a U.S. affiliate of Tokyo-based Astellas Pharma Inc. Astellas is a pharmaceutical company dedicated to improving the health of people around the world through the provision of innovative and reliable pharmaceutical products. The organization is committed to becoming a global category leader in focused areas by combining outstanding R&D and marketing capabilities. In the US, Astellas markets products in the areas of Immunology, Urology, Anti-Infectives, Cardiovascular and Dermatology. For more information about Astellas Pharma US, Inc., please visit our website at www.us.astellas.com.

Zogenix™, Sumavel™ and DosePro™ are trademarks of Zogenix, Inc.