Corixa announces European approval for Fendrix®, GlaxoSmithKline Biologicals' hepatitis B vaccine containing Corixa's MPL® adjuvant
02/08/2005

SEATTLE, February 8, 2005 – Corixa Corporation (Nasdaq: CRXA), a developer of immunotherapeutics, today announced that GlaxoSmithKline Biologicals (GSK Bio) has received European approval for its hepatitis B vaccine, Fendrix®, containing Corixa’s MPL® adjuvant.
Fendrix, GSK Bio’s novel vaccine containing Corixa’s MPL adjuvant, is designed to prevent hepatitis B in patients with renal insufficiency, including specific high-risk groups such as pre-haemodialysis and haemodialysis patients from 15 years of age onwards. Haemodialysis patients’ immune response is typically lower than in healthy individuals, therefore a need exists for a vaccine with an improved immunogenicity profile to ensure that patients are protected against hepatitis B infections.

Fendrix builds on GSK Bio’s more than 15 years of experience with the hepatitis B vaccine, Engerix B®, of which more than 1 billion doses have been distributed worldwide.

"Today’s product approval marks another significant commercialization milestone for our adjuvant business," said Steven Gillis, Ph.D., chairman and chief executive officer of Corixa. "Given that our MPL adjuvant is a component of several additional GSK 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, when combined with vaccine antigens, help to either direct or boost the body’s immune system. GSK Bio, one of the world’s leading vaccine developers, is developing a portfolio of novel and proprietary adjuvant systems capable of either directing the most appropriate immune response or increasing the immune response in order to increase the effectiveness of a vaccine to prevent a particular disease.

Corixa’s MPL adjuvant is a component in many of GSK’s proprietary and novel adjuvant systems contained in multiple GSK Bio vaccines, including:

GSK Bio’s vaccine for human papilloma virus/cervical cancer that recently showed 100 percent efficacy against persistent infection with HPV types 16 and 18 (Lancet 2004;364:1757 – 65);
GSK Bio’s malaria vaccine, which also recently reported breakthrough results in clinical trials in the field (Lancet 2004;364:1411 – 20);
GSK Bio’s genital herpes vaccine, which demonstrated significant efficacy against genital herpes in women in a phase III trial published in 2002 (Stanberry LR, Sprunance SL, Cunningham AL et al, N. Engl; Med 347(21), 1652-1661); and,
GSK Bio’s vaccine in Phase I clinical trials for the prevention of tuberculosis.
About Corixa’s Adjuvant Business and MPL
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 regulators of immune response. Corixa also owns patented technology for extracting MPL adjuvant from bacterial cell walls. Several of Corixa’s partners are evaluating MPL adjuvant for development of allergy, cancer and infectious disease vaccines.

MPL Manufacturing and Supply Agreement
Corixa entered into a new manufacturing and supply agreement with GSK in July 2004 covering the production of its MPL adjuvant. The agreement, which runs through 2012, guarantees payment to Corixa for supplying GSK with increasing annual quantities of MPL peaking in 2008 at the current maximum output of Corixa’s Hamilton, Montana, MPL manufacturing facility (approximately 2 kilograms/year). Under the terms of the agreement, Corixa agreed to expand cGMP compliant MPL production capacity in association with anticipated approvals of GSK vaccines that contain MPL adjuvant. Other elements of the agreement include increased base pricing and annual price increases for MPL, and payment of royalties to Corixa by GSK on all GSK vaccines containing MPL adjuvant until 10 years after market introduction of GSK’s human papilloma virus vaccine.

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. More information is available at www.hepb.org.

About Corixa
Corixa is a biopharmaceutical company developing vaccine adjuvants and immunology based products that manage human diseases. Corixa’s products are currently in multiple clinical development programs, including several 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™ 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, Montana. 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 September 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.