AVANIR's Novel Orally Active Asthma/Allergy Drug Candidate Subject of Journal Article

SAN DIEGO--(BUSINESS WIRE)--Dec. 16, 2004--AVANIR Pharmaceuticals (AMEX:AVN) announced that an article profiling its orally active experimental drug, AVP 13358, was published today in the Journal of Medicinal Chemistry (J Med Chem V-47 #26: pp.6451-6454). The article, entitled "Novel 2-(Substituted phenyl) Benzimidazole Derivatives with Potent Activity Against IgE, Cytokines, and CD23 for the Treatment of Allergy and Asthma," describes the novel compound and its activity against critical targets in the allergy cascade.

AVANIR's allergy/asthma research resulted in a series of orally active compounds that suppress experimental asthma in animal models, while mitigating biomarkers of the disease such as serum IgE, airway levels of IL-4, IL-5, eosinophils, and lymphocytes, and the expression of CD23 on leukocytes. The compounds are unique in structure and apparent mechanism and appear to act on a target critical to the function of several intermediaries in the allergic response.

"Identification of AVP 13358 and its analogs started with the premise that IgE is the hallmark of allergy and asthma. Therefore, a compound that down-regulates the IgE response should be beneficial in treating these conditions," stated Jagadish Sircar, Ph.D., Vice President of Drug Discovery at AVANIR Pharmaceuticals. "The reported efficacy of the injectable anti-IgE antibody omalizumab (Xolair) has validated IgE as an important target for the treatment of allergic diseases."

AVANIR successfully completed an initial Phase I clinical trial with AVP 13358 earlier this year. Results of the trial reported in May 2004 indicate that AVP 13358 was well-tolerated at all single rising doses administered to healthy volunteers in the study.

AVANIR Pharmaceuticals is a drug discovery and development company focused on treatments for chronic diseases. Our product candidates address therapeutic markets that include central nervous system and cardiovascular disorders, inflammation, and infectious disease. 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.

The information contained in this press release, including any forward-looking statements contained herein, should be reviewed in conjunction with the Company's most recent Annual Report on Form 10-K and other publicly available information regarding the Company. Copies of such information are available from the Company upon request. Such publicly available information sets forth many risks and uncertainties related to the Company's business and technology. Forward-looking statements often contain such words like "estimate," "anticipate," "believe," "plan," or "expect". Our IgE modulation program competes with other research approaches and compounds under development by large pharmaceutical and biotechnology companies and is subject to risks and uncertainties including the unpredictable nature of clinical trials and the regulatory environment, and the impact of competitive products. Pre-clinical research findings are not always supportable by evidence obtained from subsequent clinical trials. Final review decisions made by the FDA and other regulatory agencies concerning clinical trial results are unpredictable and outside the influence and/or control of the Company. The Company disclaims any intent or obligations to update these forward-looking statements.

    CONTACT: AVANIR Pharmaceuticals
             Patrice Saxon, 858-622-5202 (Investor Relations)

    SOURCE: AVANIR Pharmaceuticals