Corixa Announces Positive Opinion from EMEA for GlaxoSmithKline Biologicals' Hepatitis B Vaccine Containing Corixa's MPL Adjuvant.

SEATTLE -- Demonstrates Positive Momentum for Corixa's Vaccine Adjuvant 

Corixa Corporation (Nasdaq:CRXA), a developer of immunotherapeutics, today announced that the Committee For Medicinal Products for Human Use (CHMP) the scientific body of the European Medicines Evaluation Agency (EMEA), has issued a positive opinion for Fendrix(R), GlaxoSmithKline Biologicals' (GSK Bio) vaccine for the prevention of hepatitis B in specific high-risk groups. Fendrix is a novel vaccine, containing Corixa's MPL(R) adjuvant, that is designed to help prevent infection from hepatitis B in specific high-risk groups such as pre-haemodialysis and haemodialysis patients. This positive opinion represents an important step in the continuing commercial development of Corixa's MPL adjuvant, which is included in several late stage GSK Bio specific vaccine product candidates.

The opinions of the CHMP generally serve as the basis for European Commission approvals. European Commission approvals are typically issued three months after the CHMP opinions are issued. However, Fendrix is not yet approved.

"We are pleased to announce today's progress toward commercialization of our MPL adjuvant," said Steven Gillis, Ph.D., chairman and chief executive officer of Corixa. "Given that MPL adjuvant is a component of several additional GSK Bio vaccines now in late stage clinical trials, we look forward to the growth of our adjuvant business and its potential contribution to Corixa's future product sales and royalty income."

Adjuvants are formulated compounds or additives that help to boost the body's immune response when combined with vaccine antigens. In addition to GSK Biologicals' Fendrix vaccine, MPL is present in a number of GSK Bio vaccines now in late stage clinical development, including a vaccine under investigation for the prevention of cervical cancer, and another vaccine under investigation for the prevention of genital herpes.

About Corixa's Adjuvant Business and MPL

An adjuvant is a formulated compound or additive that, when combined with a vaccine, boosts the body's immune response to the antigen(s). Corixa's adjuvant technology is based on the fact that certain microbial products have long been recognized as potent immune system regulators and have been shown to induce a broad range of known cytokines, a class of substances that are produced by cells of the immune system and can affect the immune response. Modifications of these microbial products and their physical and biological delivery to the immune system can influence the way cytokines are expressed, as well as the recipient's own physiological responses. Such responses mimic the normal, protective responses that are initiated during microbial infection or injury. With its partners, Corixa is evaluating its adjuvants in adult and pediatric vaccines that are designed to be safe and more effective in protecting against a broad range of diseases.

Corixa's flagship adjuvant, MPL, is a derivative of the lipid A molecule found in gram-negative bacteria, one of the most potent immune system stimulants. Corixa also owns patented technology for extracting MPL adjuvant from bacterial cell walls. Several of Corixa's partners are evaluating MPL adjuvant in vaccines for development in allergy, cancer and infectious disease targets.

About Hepatitis B

Hepatitis B is the most common serious liver infection in the world. It is caused by the hepatitis B virus that attacks the liver. The virus is transmitted through blood and infected bodily fluids. This can occur through direct blood-to-blood contact, unprotected sex, use of unsterile needles, and from an infected woman to her newborn during the delivery process. According to the Hepatitis B Foundation, hepatitis B can be 100 times more infectious than the AIDS virus. There is a vaccine currently available to help prevent Hepatitis B. More information is available at http://www.hepb.org.

About Corixa

Corixa is a biopharmaceutical company developing oncology and immunology products that manage human diseases. On June 30, 2003, Corixa announced that the FDA approved BEXXAR for the treatment of patients with CD20 positive, follicular, NHL, with and without transformation, whose disease is refractory to Rituximab and has relapsed following chemotherapy.

Corixa is focused on immunotherapeutic products and has a broad technology platform enabling both fully integrated vaccine design and the use of its separate, proprietary product components on a standalone basis. In addition to BEXXAR, Corixa currently has multiple programs in clinical development, including several product candidates that have advanced to and through late stage clinical trials. The company partners with numerous developers and marketers of pharmaceuticals, targeting products that are Powered by Corixa(TM) technology with the goal of making its potential products available to patients around the world. Corixa was founded in 1994 and is headquartered in Seattle, with additional operations in Hamilton, Mont., and South San Francisco. For more information, please visit Corixa's Web site at www.corixa.com.

Corixa Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding the commercial potential for MPL adjuvant, the contribution of recent accomplishments to our long term success, and our plans, objectives, intentions and expectations. Forward-looking statements are based on the opinions and estimates of management at the time the statements are made. They are subject to certain risks and uncertainties that could cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Factors that could affect Corixa's actual results include, but are not limited to, the "Factors Affecting Our Operating Results, Our Business and Our Stock Price," described in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2004, copies of which are available from our investor relations department. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release.