The special protocol assessment (SPA) from the FDA documents agreement on the protocol under which Avanir will conduct and analyze the data from a pivotal trial evaluating the safety and efficacy of Neurodex in the treatment of painful diabetic neuropathy. "In the SPA communication, the FDA advised that the clinical design and analysis plan of our submitted protocol are suitable to provide evidence of safety and efficacy to support a new drug application for Neurodex in the treatment of diabetic neuropathic pain," said James Berg, vice president of clinical and regulatory affairs at Avanir. "We look forward to starting this phase III trial in the first half of 2005." Neurodex is comprised of dextromethorphan and an enzyme inhibitor that slows the rapid metabolism of dextromethorphan in the liver. Slowing the metabolism of dextromethorphan with the inhibitor makes it possible to maintain therapeutic levels for a longer period of time. Neurodex has an anti-excitatory effect by reducing glutamate through the combined actions of sigma-1 agonist activity and NMDA receptor antagonism, suggesting utility in treating certain central nervous system disorders, including neuropathic pain.