SARS ANTIBODY SENT TO CHINA FOR PRECLINICAL TESTING

Fully human antibody developed by Medarex and the Massachusetts Biologic;   Laboratories may be part of China’s response to the recent outbreak of SARS in Beijing

April 26, 2004

Princeton, N.J. and Worcester, Mass.—Responding to a request from a Chinese biotechnology company working closely with officials in China,  Medarex, Inc.  (Nasdaq: MEDX) and the Massachusetts Biologic Laboratories (MBL) of the University of Massachusetts Medical School (UMMS) have shipped to Beijing a sample of the fully human antibody to SARS developed by Medarex and MBL/UMMS. The antibody was sent to Sinovac Biotech Ltd. (NASD OTC-BB: SNVBF) for preclinical testing against SARS strains used for their vaccine and the control strain from previous cases in China.

In response to the recent outbreak of SARS, and to assist with research on potential therapies, Beijing-based Sinovac submitted this idea to the Chinese State Food and Drug Administration and received support to test the Medarex/MBL/UMMS antibody before any further action.  Sinovac plans to conduct preclinical tests to determine the antibody’s effectiveness in neutralizing the strains of the SARS virus.  

“When faced with an outbreak of a deadly infectious disease like SARS, those with a public health mission need to move fast,” said Donna Ambrosino, MD, Director of the MBL and a Professor of Pediatrics at UMass Medical School.  “When the request was made to us, we were able to ship the antibody within hours.”

Donald L. Drakeman, President and CEO of Medarex, Inc., agreed, saying Medarex was ready to help.  “We hope that our fully human antibody technology can be useful in addressing this important public health issue,” he said. 

The antibody developed by scientists at MBL, Medarex and at UMass Medical School’s Worcester Campus, is the result of an accelerated research effort funded by the National Institute of Allergy and Infectious Diseases (part of the National Institutes of Health) that was launched in April of 2003 following the first global outbreak of SARS.

As previously announced, MBL/UMMS partnered with Medarex to use Medarex’s UltiMAb™ technology to generate fully human antibodies with the potential to treat SARS. Under the terms of the agreement, Medarex and MBL expect to share equally the full development costs of any antibody products as well as any future revenues arising from these products.

SARS, a viral respiratory illness caused by a coronavirus, was first reported in Asia in February 2003, and over the next few months, the illness spread to more than two dozen countries in North America, South America, Europe, and Asia.  According to the World Health Organization, during the SARS outbreak of 2003, a total of 8,098 people worldwide became sick with SARS; of these, 774 died. The SARS global outbreak of 2003 was contained; however, it is expected that the disease could re-emerge periodically in a cycle similar to the common flu.

About Sinovac

Sinovac is one of the leading emerging biotechnology companies in China. Working closely with Chinese public health officials, Sinovac focuses on manufacturing and marketing human-use vaccines and related products, and currently markets a vaccine for Hepatitis A. Sinovac is the first company in China, as well as the world, granted permission by the Chinese government to begin clinical trials for a vaccine to prevent SARS. The vaccine development effort was funded by the Chinese government. The project began in April 2003.

About UMass Medical School

The University of Massachusetts Medical School is one of the fastest growing academic health centers in the country and has built a reputation as a world-class research institution, consistently producing noteworthy advances in clinical and basic research. The Medical School attracts more than $153 million in extramural research funding annually, 80 percent of which comes from federal funding sources. Research dollars enable UMMS scientists to explore human disease from the molecular level to large-scale clinical trials. Basic and clinical research leads to new approaches for diagnosis, treatment and prevention of disease. Visit www.umassmed.edufor additional information.

About the Massachusetts Biologic Laboratories

The Massachusetts Biologic Laboratories is the only non-profit FDA-licensed manufacturer of vaccines and other biologic products in the United States. The laboratory was established in 1894; since then, the MBL's mission has been to improve public health through applied research, development and production of biologic products. MBL has been a part of the UMass Medical School since 1997.

About Medarex

Medarex is a biopharmaceutical company focused on the discovery and development of therapeutics to treat life-threatening and debilitating diseases. Medarex’s UltiMAb Human Antibody Development System® is a unique combination of human antibody technologies that Medarex believes enables the rapid creation and development of fully human antibodies to a wide range of potential disease targets for therapeutic antibody products, including products for the treatment of cancer, inflammation, autoimmune and infectious diseases.  Medarex’s   product pipeline is based on a variety of therapeutic antibody products developed through the use of its UltiMAb™ technology.  Medarex creates and develops fully human antibodies for itself and others, offering a full range of antibody related capabilities, including pre-clinical and clinical development supported by cGMP manufacturing services.  For more information about Medarex, visit its website at www.medarex.com.

Except for the historical information presented herein, matters discussed herein may constitute forward-looking statements that 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.  Statements that are not historical facts, including statements preceded by, followed by, or that include the words “potential”; “believe”; “anticipate”; “intend”; “plan”; “expect”; “estimate”; “could”; “may”; or similar statements are forward-looking statements. Medarex disclaims, however, any intent or obligation to update these forward-looking statements. Risks and uncertainties include risks associated with product discovery and development, uncertainties related to the outcome of preclinical testing, unforeseen safety issues, uncertainties associated with the collaborative process as well as risks detailed from time to time in Medarex’s public disclosure filings with the U.S. Securities and Exchange Commission (SEC), including its Annual Report on Form 10-K for the fiscal year ended December 31, 2003 and subsequent Quarterly Reports on Form 10-Q.  There can be no assurance that such development efforts will succeed, that such products will receive required regulatory clearance or that, even if such regulatory clearance were received, such products would ultimately achieve commercial success. Copies of Medarex’s public disclosure filings are available from its investor relations department.

Medarex®, the Medarex logo, and UltiMAb Human Antibody Development System® are registered trademarks of Medarex, Inc. UltiMAbTM is a trademark of Medarex, Inc. All rights are reserved.

Contacts: 

UMMS/MBL: Michael Cohen, 508-856-2000, michael.cohen@umassmed.edu

M edarex Inc.: Laura S. Choi, Investor Relations   609-430-2880, x2216;Jean Mantuano, Corporate Communications 609-430-2880, x222