Corixa and the Australian Nuclear Science and Technology Organization Sign License and Supply Agreements for BEXXAR Rights in Australasia.

Business Editors/Health/Medical Writers

SEATTLE & SYDNEY, Australia--(BUSINESS WIRE)--May 19, 2004

New Collaboration to Broaden Potential Reach for Novel NHLTreatment

Corixa Corporation (Nasdaq:CRXA) today announced that it has signed a new, 12 year agreement with the Australian Nuclear Science and Technology Organization (ANSTO) trading as ARI (ANSTO Radiopharmaceuticals and Industrials) in which Corixa grants ANSTO exclusive rights to develop, market and sell BEXXAR (Tositumomab and iodine I 131 Tositumomab) therapeutic regimen in certain countries within Australasia, including Australia, New Zealand, Singapore, India, Indonesia and China. Corixa also grants ANSTO co-exclusive rights to supply BEXXAR to Japan, South Korea and Taiwan.

Under the terms of the agreement, ANSTO will pay Corixa an undisclosed upfront licensing fee and will pay Corixa milestone payments upon regulatory approval, obtaining reimbursement codes in Australia, approval for a second indication, as well as additional payments based on sales volume. In addition, ANSTO will pay Corixa royalties on all BEXXAR sales in the exclusive ANSTO territories. Corixa will supply the cold antibody (Tositumomab) to ANSTO and ANSTO will perform radiolabeling at its facility in Lucas Heights, New South Wales 

"Our collaboration with ANSTO marks an important milestone in the further development of BEXXAR as it will allow us to bring BEXXAR to patients in previously un-served markets," said Steve Gillis, Ph.D, chairman and chief executive officer of Corixa.

BEXXAR was developed by Corixa Corporation and is co-marketed in the United States by Corixa Corporation and GlaxoSmithKline for patients with non-Hodgkin's lymphoma. Additional information about the BEXXAR therapeutic regimen in the United States, including complete prescribing information, may be obtained by calling 1-877-4BEXXAR or visiting www.BEXXAR.com.

About ANSTO

ARI is the premier supplier of radioisotopes for medical and industrial application in the Asia-Pacific region. ARI is a business unit of The Australian Nuclear Science and Technology Organization (ANSTO). ARI supplies the full range of reactor and cyclotron produced isotopes commonly used in nuclear medicine. ANSTO is Australia's national nuclear research and development organization and the center of Australian nuclear expertise. The organization also operates the National Medical Cyclotron, an accelerator facility used to produce certain short-lived radioisotopes for nuclear medicine procedures

ANSTO's nuclear infrastructure includes the research reactor HIFAR (High Flux Australian Reactor), particle accelerators, radiopharmaceutical production facilities, and a range of other unique research facilities. HIFAR is Australia's only nuclear reactor. It is used to produce radioactive products for use in medicine, industry and the environment, as a source of neutron beams for scientific research and to irradiate silicon for semiconductor applications.

About Corixa

Corixa is a developer of immunotherapeutics with a commitment to treating and preventing cancer and infectious diseases by understanding and directing the immune system. 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 BEXXAR in Australasia, 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 March 31, 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.