AVANIR Pharmaceuticals Awarded NIH Grant to Generate Antibodies to Cytomegalovirus

SAN DIEGO, May 6, 2003 /PRNewswire-FirstCall via COMTEX/ -- AVANIR Pharmaceuticals (Amex: AVN) today announced it has been awarded a grant from the National Institutes of Health (NIH) under its Phase I Small Business Innovation Research (SBIR) program. The $100,000 grant will fund the initial development of human monoclonal antibodies for the treatment of human cytomegalovirus (CMV) infection using AVANIR's Xenerex(TM) technology. The NIH grant provides funds to cover a portion of the costs of generating a panel of prospective monoclonal antibodies and characterizing them as to neutralizing activity, specificity and affinity to CMV.

"We believe there is considerable need for improvement in the treatment of CMV infections, and a human antibody that efficiently neutralizes CMV could result in a sizable commercial opportunity," said Dr. Phillip Morrow, the Principal Investigator on this grant and Director of Technology at AVANIR Pharmaceuticals. "We are pleased to receive this funding which provides additional validation of the breadth of our technology platform, following our success in discovery and early development of AVP-8C1, the anti-anthrax antibody,"

AVANIR's Xenerex technology is capable of generating fully human antibodies to target antigens, particularly infectious diseases, through the engraftment and immunization of human immune system cells in immunodeficient SCID (Severe Combined Immuno-Deficient) mice. AVANIR scientists have identified donors that already produce neutralizing antibodies to CMV by examining serum samples. When cells from screened donors are used, the likelihood of a successful outcome is increased. After identification and recovery of the specific CMV-neutralizing antibody-producing lymphocytes, recombinant antibody producing cell lines are created. Monoclonal antibodies are harvested from these lines and after evaluation for affinity, specificity and neutralization characteristics, become the basis for a potential therapeutic treatment of CMV infection.

The NIH awards SBIR grants for research on a competitive basis. Innovation and the potential for commercialization are among the important factors included in the review criteria used in the scientific and technical merit evaluation process. The Phase I SBIR grant is customarily utilized for proof of concept and can lead to a larger Phase II SBIR award that could be used to advance one or more antibodies candidates to the clinical testing phase.

Dr. Angray Kang of AVANIR Pharmaceuticals will be presenting an overview of the Xenerex platform technology at the 4th Annual Recombinant Antibodies Conference being held in Cambridge, Massachusetts on May 14, 2003. The presentation will provide demonstrations of the technology and its capabilities and strengths using recall antigens.

About Cytomegalovirus

CMV is a member of the herpes virus group, which includes herpes simplex virus types 1 and 2, varicella-zoster virus (which causes chickenpox), and Epstein-Barr virus (which causes infectious mononucleosis). Infection with CMV is a major cause of disease and death in immunocompromised patients, including organ transplant recipients, patients undergoing hemodialysis, patients with cancer, patients receiving immunosuppressive drugs, and HIV-infected patients. While drugs are available for treatment of these conditions, the primary drug choices carry significant side effects and warnings. Currently, there are no anti-CMV drugs indicated for treatment of primary CMV infection during pregnancy resulting in infections that can have catastrophic consequences to the newborn. Maternal-fetal transfer of CMV infection results in a fetal death rate of 12% and most survivors have permanent debilitating disorders, including mental retardation, vision loss, and sensorineural deafness.

About the Company

AVANIR Pharmaceuticals, based in San Diego, is a drug discovery and development company with a commercialized FDA-approved product (Abreva(R)) and products in clinical development for the treatment of pseudobulbar affect (Phase III), neuropathic pain (Phase II), and allergy and asthma (Phase I). AVANIR is engaged in small-molecule research to develop treatments for central nervous system disorders and inflammatory diseases. Through the use of its Xenerex(TM) technology, AVANIR also develops human monoclonal antibodies for infectious diseases and other therapeutic applications. 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 which are available from the company upon request. Such publicly available information sets forth many risks and uncertainties related to the Company's business and such statements, including risks and uncertainties related to drug development and clinical trials. The Company's receipt of an SBIR grant intended to establish proof of concept of a potential treatment for human cytomegalovirus (CMV) infection should not imply that the company's research will be successful or that a Phase II grant will be awarded. Final review decisions made by the NIH, FDA and other regulatory agencies concerning our research are unpredictable and outside of the influence and/or control of the Company.

SOURCE AVANIR Pharmaceuticals

Media, Vince Heald of Beck Ellman Heald, +1-858-453-9600, vheald@behmedia.com, for AVANIR Pharmaceuticals; or Patrice Saxon, Investor Relations of AVANIR Pharmaceuticals, +1-858-622-5202, psaxon@avanir.com (AVN)