About Zohydro ERZohydro ER is an oral, novel extended-release formulation of hydrocodone without acetaminophen for the management of moderate to severe chronic pain in patients requiring continuous, around-the-clock opioid therapy for an extended period of time. If approved, Zohydro ER could be the first extended-release novel formulation hydrocodone therapy without acetaminophen for the management of chronic pain, avoiding the potential for liver injury associated with the use of acetaminophen in high doses or over long periods of time. Zohydro ER uses Alkermes Pharma Ireland Limited's patented Spheroidal Oral Drug Absorption System (SODAS®) drug delivery technology, which serves to enhance the release profile of hydrocodone to provide extended-release pain relief relative to existing immediate-release combination products. About Chronic Pain Chronic pain is defined as ongoing or recurrent pain that adversely affects an individual's well-being. An estimated 100 million people in the United States are burdened with chronic pain, at an estimated national economic cost of $560 billion to $635 billion annually. Chronic pain can be managed with both immediate-release and extended-release opioids. Currently marketed hydrocodone products are only immediate-release and contain an analgesic combination ingredient, primarily acetaminophen. Acetaminophen may cause liver injury when used in high dosages, over long periods of time or in accidental overdoses due to multiple acetaminophen products being taken at once. About Zogenix Zogenix, Inc. (Nasdaq:ZGNX), with offices in San Diego and Emeryville, California, is a pharmaceutical company commercializing and developing products for the treatment of central nervous system disorders and pain. Zogenix's first commercial product, SUMAVEL® DosePro® (sumatriptan injection) Needle-free Delivery System, was launched in January 2010 for the acute treatment of migraine and cluster headache. Zogenix's lead investigational product candidate, Zohydro™ ER (hydrocodone bitartrate), is an oral, extended-release formulation of various strengths of hydrocodone, without acetaminophen, intended for administration every 12 hours for around the clock management of moderate to severe chronic pain. In May 2012, Zogenix submitted to the FDA a New Drug Application for Zohydro ER. Zogenix's second investigational product candidate, Relday™, is a proprietary, long-acting injectable formulation of risperidone for the treatment of schizophrenia; an investigational new drug application was submitted to the FDA in May 2012.