AVANIR's Phase III Trial Results with Neurodex Published in Neurology

SAN DIEGO--(BUSINESS WIRE)--Oct. 27, 2004--AVANIR Pharmaceuticals (AMEX:AVN) announced today that results of its first Phase III clinical trial of Neurodex(TM) have been published in the October 26, 2004 issue of Neurology. The published report "Treatment of Pseudobulbar Affect in Amyotrophic Lateral Sclerosis Patients with Dextromethorphan/Quinidine (AVP-923)" was chosen as an Editor's Highlight of the issue. The report describes the results of a multi-center, double-blind, controlled study that examined the safety and efficacy of Neurodex, an orally administered combination of dextromethorphan and quinidine, in the treatment of pseudobulbar affect (PBA) in patients with Lou Gehrig's disease (amyotrophic lateral sclerosis or ALS).

Neurodex is the first drug product in clinical development specifically intended to treat PBA. Also known as emotional lability, PBA is a symptom complex that is often characterized by uncontrollable laughing or crying and is experienced by an estimated one million patients with neurological conditions such as ALS, Alzheimer's disease, multiple sclerosis (MS), stroke and traumatic brain injury. AVANIR intends to begin submission of a new drug application to the U.S. Food and Drug Administration this year seeking marketing approval for Neurodex for the treatment of PBA.

In the article, the manuscript's lead author Benjamin Rix Brooks, M.D., Professor of Neurology and Medical Microbiology/Immunology and Director of the University of Wisconsin Neurology ALS Clinic and the ALS Clinical Research Center, stated, "Neurodex represents a novel treatment option for pseudobulbar affect in ALS and is the first agent proven effective in a controlled, multi-center, randomized study. The results demonstrate that Neurodex effectively palliates pseudobulbar affect in ALS patients and is significantly more effective than either of its components. Further, this benefit significantly improved qualities of life and relationships for these patients with ALS."

Patients with ALS and PBA were enrolled at 17 leading ALS academic study sites throughout the U.S. A total of 140 patients were randomized to receive Neurodex or dextromethorphan or quinidine capsules twice daily for four weeks. Patients in the one-month study, which concluded in 2002, were assessed at screening and on the first, 15th and 29th day of the study.

Patients in the Neurodex arm of the study experienced 3.3-points greater improvement than those receiving only dextromethorphan (p=0.001) and 3.7-points greater improvement than patients receiving only quinidine (p less than 0.001) for the primary efficacy endpoint. Neurodex patients exhibited lower overall episode rates, improved quality of life scores, and improved quality of relationship scores (p less than 0.01 for all endpoints). Adverse events were mostly mild or moderate; treatment discontinuation was 24% for Neurodex patients, 6% for dextromethorphan, and 8% for quinidine.

Favorable results were also achieved in the second Phase III trial of Neurodex in the treatment of PBA in MS patients, which was completed June 20, 2004.

AVANIR Pharmaceuticals is a drug discovery and development company focused on treatments for chronic diseases. The Company's most advanced product candidate, Neurodex(TM), is in Phase III clinical development for pseudobulbar affect, and in Phase II clinical development for neuropathic pain. A potential treatment for allergy and asthma, AVP 13358, is in Phase I clinical development. The Company's first commercialized product, Abreva(R), is marketed in North America by GlaxoSmithKline Consumer Healthcare and is the leading over-the-counter product for the treatment of cold sores. Further information about AVANIR can be found at www.avanir.com.

Statements in this press release that are not historical facts, including statements that are preceded by, followed by, or that include such words as "estimate," "anticipate," "believe," "plan" or "expect" or similar statements, are forward-looking statements that are subject to certain risks and uncertainties that could cause actual results to differ materially from the future results expressed or implied by such statements. There can be no assurance that AVANIR will submit a new drug application for Neurodex(TM) in the anticipated time period, that the application, when and if filed, will be accepted by the FDA, that Neurodex will receive regulatory approval, or that even if such regulatory clearance is received, that AVANIR will be able to market Neurodex successfully. Risks and uncertainties also include the risks set forth in AVANIR's most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q and from time-to-time in other publicly available information regarding the Company. Copies of this information are available from AVANIR upon request. AVANIR disclaims any intent or obligation to update these forward-looking statements.

    CONTACT: AVANIR Pharmaceuticals
             Patrice Saxon, 858-622-5202

    SOURCE: AVANIR Pharmaceuticals