Zogenix completes enrollment in ZX002 Phase 3 study for moderate to severe pain

Zogenix, Inc. (Nasdaq:ZGNX) today announced completion of enrollment in its open-label Phase 3 safety study (Study 802) of ZX002. ZX002 is a novel, oral, single-entity, controlled-release formulation of hydrocodone for the treatment of moderate to severe pain in patients requiring around-the-clock opioid therapy for an extended period of time. The goal of this 12-month study of ZX002 is to evaluate overall safety in at least 300 patients for six months and at least 100 patients for one year. With successful conclusion of the enrollment of 450 patients for this study, the top-line long-term safety results are anticipated to be available in the second half of 2011.

Zogenix is concurrently conducting a pivotal Phase 3 efficacy study (Study 801) of ZX002. Study 801 is a randomized, 12-week, double-blind, placebo-controlled trial that is continuing to enroll opioid-experienced adult subjects with moderate to severe chronic lower back pain. The primary efficacy endpoint is the mean change in average daily pain intensity scores between ZX002 and placebo. Study 801 is expected to be fully enrolled in early 2011. Initial top-line data from Study 801 are also anticipated in the second half of 2011.

Pending positive Phase 3 clinical results, Zogenix expects to submit an NDA for ZX002 with U.S. Food and Drug Administration (FDA) by early 2012. If approved, ZX002 has the potential to be the first controlled-release version of hydrocodone and also the first hydrocodone product that is not combined with another analgesic.

Stephen J. Farr, Ph.D., President and Chief Operating Officer said, "With the completion of enrollment in our Phase 3 safety study, we believe ZX002 is on track to be the first potential single-entity, controlled-release hydrocodone formulation. Most marketed hydrocodone products contain acetaminophen, an analgesic which can cause liver toxicity at high doses over time. ZX002 is not combined with any other analgesic, and may be suitable for both patients who are using immediate-release opioid products on a chronic basis and patients already using extended-release opioids."

The American Pain Society estimated in 1999 that 9% of the U.S. adult population suffers from moderate to severe non-cancer related chronic pain. Chronic pain can be treated with both immediate-release and extended-release opioids. Marketed hydrocodone products are the most commonly prescribed pharmaceuticals in the United States, generating $3.1 billion in U.S. sales during the 12 months ended June 2010 (Wolters Kluwer Pharma Solutions, Source^®: PHAST Retail). Most of these products contain the analgesic combination ingredient acetaminophen. When used in high dosages over time, acetaminophen can cause liver toxicity.