CancerVax Presents Preclinical Data on Anti-Tumor Effects of Angiogenesis Inhibitors; Data Presented at AACR Annual Meeting.

Business Editors/Health/Medical Writers

BIOWIRE2K

AACR Annual Meeting

CARLSBAD, Calif.--(BUSINESS WIRE)--March 31, 2004

CancerVax Corporation (NASDAQ:CNVX) announced today results from preclinical studies demonstrating that humanized monoclonal antibodies and a synthetic peptide licensed to its wholly owned subsidiary, Cell-Matrix, Inc., suppress blood vessel formation (angiogenesis) and inhibit tumor growth in animal models of melanoma and breast cancer. The data were presented at the 95th Annual Meeting of the American Association for Cancer Research (AACR) in Orlando, Florida on March 28 and 30, 2004.

In a poster entitled "Humanized Monoclonal Antibodies Binding to Epitopes on Denatured Collagen Inhibit Tumor Growth In Vivo," CancerVax scientists and collaborators demonstrated that the Company's D93 and H8 humanized monoclonal antibodies reduced angiogenesis and inhibited tumor growth in in vivo models. These humanized monoclonal antibodies are directed at cryptic, or hidden, binding sites on collagen that become exposed during tumor growth and metastasis. In a murine model using human melanoma cells, antibodies D93 and H8 inhibited tumor growth by 56% and 63%, respectively. Most notably, the D93 antibody also inhibited human breast tumor growth by 84% using an "orthotopic" animal model, which is designed to more closely mimic breast cancer by generating human breast carcinomas in mouse mammary pads. These data suggest that antibodies targeting sites on denatured collagen may provide a novel approach to treating cancer.

"This approach to inhibit angiogenesis associated with tumor growth shows promise as a potentially viable approach to the treatment of cancer," said David F. Hale, President and CEO of CancerVax. "Considering the novelty of targets within the extracellular matrix, we believe CancerVax's monoclonal antibodies may have properties that are different from other anti-angiogenic approaches to treating cancer and have the potential to be used in combination with other treatments such as radiation, specific active immunotherapy and chemotherapy."

In a separate poster entitled "Inhibition of Angiogenesis and Tumor Metastasis by a Synthetic Peptide that Binds a Matrix Immobilized Cryptic ECM Epitope (MICEE) in Laminin," Peter C. Brooks, Ph.D., Director of Angiogenesis and Radiation Research at New York University School of Medicine, presented data showing that a novel peptide that has been licensed to CancerVax's subsidiary Cell-Matrix, Inc., binds to a cryptic, or hidden, epitope in laminin. Laminin is another protein component of the extracellular matrix that may denature during tumor growth and metastasis. In in vitro studies, the STQ peptide was shown to bind to denatured laminin while having little effect on normal laminin. Using an in vivo chick embryo model, the STQ peptide inhibited angiogenesis and melanoma metastasis by 90% and 70%, respectively. These results support further investigation of the anti-tumor effects of the STQ peptide.

The abstracts are available on the AACR web site (www.aacr.org) and on CancerVax's home page (www.cancervax.com) in the "Focus" section.

Background

The extracellular matrix is a molecular network that supports cells and tissues and regulates cellular processes such as adhesion, migration, gene expression and differentiation. Collagen and laminin proteins are found in the extracellular matrix of connective tissue and blood vessels. CancerVax's monoclonal antibodies and peptides bind specifically to hidden, or cryptic, binding sites within collagen and laminin, respectively, which become exposed when the proteins denature during tumor growth and metastasis. As a result of binding, tumor growth and metastasis are inhibited with little effect on normal collagen and laminin proteins.

About CancerVax Corporation (www.cancervax.com)

CancerVax Corporation is a biotechnology company focused on the research, development and commercialization of novel biological products for the treatment and control of cancer. The Company's lead product candidate, Canvaxin(TM), is one of a new class of products being developed in the area of specific active immunotherapy, also known as therapeutic cancer vaccines. Canvaxin(TM) is currently being studied in two international Phase 3 clinical trials for the treatment of patients with Stage III or Stage IV, or advanced-stage, melanoma. The Company is also finalizing the design of a Phase 2 clinical trial in patients with Stage III colon cancer. In addition to Canvaxin(TM), the Company plans to identify and develop new product candidates based on its proprietary specific active immunotherapy, anti-angiogenesis and T-oligonucelotide, or telomere homolog oligonucelotide, technology platforms, as well as on its human monoclonal antibody technology. CancerVax's corporate headquarters and research and development facility is located in Carlsbad, California and its biologics manufacturing facility is located in the Los Angeles, California area. Cell-Matrix, Inc., is a wholly owned subsidiary of CancerVax Corporation.

CancerVax cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by CancerVax that any of its plans will be achieved. Actual results may differ materially from those set forth in this release due to the risks and uncertainties inherent in CancerVax's business including, without limitation, statements about: difficulties or delays in research, development, testing, obtaining regulatory approval, producing and marketing its technologies and product candidates; unexpected adverse side effects or inadequate therapeutic efficacy of its product candidates that could delay or prevent product development or commercialization, or that could result in recalls or product liability claims; the scope and validity of patent protection for its product candidates; its ability to meet product candidate development objectives; competition from other pharmaceutical or biotechnology companies; its ability to obtain additional financing to support its operations; its ability to attract and retain experienced scientists and management; and other risks detailed in CancerVax's Securities and Exchange Commission filings, including CancerVax's Annual Report on Form 10-K for the fiscal year ended December 31, 2003. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement and CancerVax undertakes no obligation to revise or update this news release to reflect events or circumstances after the date hereof.

CancerVax(R) is a registered trademark of CancerVax Corporation.

Canvaxin(TM) is a trademark of CancerVax Corporation.