AVANIR Pharmaceuticals Presents Additional Data on Novel Anti-Cancer Compounds at AACR Meeting

SAN DIEGO--(BUSINESS WIRE)--March 29, 2004--AVANIR Pharmaceuticals (AMEX:AVN) presented preclinical data on its experimental compound AVP-893 and four related analogs at the 2004 Annual Meeting of the American Association for Cancer Research (AACR) in Orlando, Florida. In vitro, these compounds possess potent anti-proliferative activity and are most potent against melanoma, leukemia, breast, prostate, kidney, and central nervous system tumor types. The compounds appear to work through the Golgi apparatus to inhibit tumor growth.

AVANIR's anti-cancer compounds are active alone or in combination with established chemotherapy in several in vivo tumor models. The compounds have been tested in combination models with doxorubicin, cisplatin, or paclitaxel and have shown substantial activity over that observed with either agent alone. Preclinical tests also show that the compounds are active following daily intraperitoneal and intravenous injections. Three of the compounds demonstrate activity following daily oral dosing. In all of these studies, AVP-893 and other compounds of this series, show a favorable toxicity profile even when dosed daily for up to three months.

As reported at the 2003 AACR meeting, early compound screening by the National Cancer Institute (NCI) suggested that AVP-893 represents a new class of anti-cancer drugs. Data presented at the 2004 AACR meeting suggests that the mechanism by which these compounds act is also novel and not duplicated among anti-cancer drugs that are currently marketed or those known to be in development for cancer or other indications.

The abstract accepted for presentation at the 95th Anniversary AACR meeting will be published in the journal, Cancer Research.

AVANIR Pharmaceuticals is a drug discovery and development company focused on the development of treatments for chronic diseases. The Company's lead product candidate, Neurodex(TM), is in Phase III clinical development for the treatment of pseudobulbar affect, also known as emotional lability. Neurodex is also in Phase II clinical development for the treatment of neuropathic pain. An internally developed small molecule, AVP-13358, is in a Phase I clinical trial for the treatment of allergy and asthma. Using its proprietary Xenerex(TM) technology, AVANIR also develops human monoclonal antibodies for infectious diseases and other therapeutic applications. The Company's first commercialized product, Abreva(R), is marketed in North America by GlaxoSmithKline 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 anti-cancer program is only in the early stages of development and competes with other research approaches and compounds under development by large pharmaceutical and biotechnology companies with greater financial and other resources. Pre-clinical research findings are not always supported 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 are not within the control of the Company.

CONTACT: AVANIR Pharmaceuticals
Patrice Saxon, 858-622-5202 (Investor Relations)
psaxon@avanir.com

SOURCE: AVANIR Pharmaceuticals