SAN DIEGO, Calif. and Deerfield, Ill., December 21, 2011 — Zogenix, Inc. (NASDAQ: ZGNX), a pharmaceutical company commercializing and developing products for the treatment of central nervous system disorders and pain, and Astellas Pharma US, Inc. (Astellas),a U.S. subsidiary of Tokyo-based Astellas Pharma Inc.(Tokyo:4503) announced today that the co-promotion of SUMAVEL DosePro (sumatriptan injection) Needle-free Delivery System will end on March 31, 2012. SUMAVEL DosePro is Zogenix's first commercial product and was launched with Astellas in January 2010 for the acute treatment of migraine and cluster headache.  

Beginning in the second quarter of 2012, Zogenix will assume full responsibility for the continued commercialization of the brand, with a focus on headache specialists, neurologists and primary care physicians who treat a significant number of migraine patients. The companies plan to agree on a detailed customer transition plan by February 1, 2012, with a goal of uninterrupted access and service to physicians within the Astellas segment.

Under the amended co-promotion agreement, neither company will incur any penalty payments related to the early termination of the agreement which was originally slated to expire June 30, 2013. Astellas will contribute its agreed portion of marketing expenses through March 31, 2012, and will continue to earn a service fee based on product sales to its physician segment during that period. Zogenix will no longer pay service fees to Astellas for sales of SUMAVEL DosePro beginning with the second quarter of 2012. 

Zogenix will be issuing a separate announcement commenting on the strategic direction for SUMAVEL DosePro in 2012.