Clinical study planned for advanced or recurrent solid tumors

PRINCETON, NJ, USA | August 5, 2008 | Medarex, Inc. (Nasdaq: MEDX) announced today the allowance of an investigational new drug application (IND) filed with the U.S. Food & Drug Administration (FDA) for MDX-1105, for the treatment of patients with selected advanced or recurrent solid tumors, specifically renal cell carcinoma, melanoma, non-small cell lung cancer or epithelial ovarian cancer.  MDX-1105 is a fully human antibody that targets the PD-L1 pathway to promote enhanced T-cell immune responses against cancer and reverse T-cell inactivation in chronic  infectious disease.

The open-label, multi-dose, dose-escalation Phase 1 clinical trial is expected to enroll up to 46 patients with selected advanced or recurrent solid tumors. This trial is designed to establish and evaluate the safety, tolerability and maximum tolerated dose, as well as preliminary pharmacodynamics and efficacy, of MDX-1105.

"We are pleased that another product candidate from our proprietary pipeline has progressed into clinical trials," said Howard H. Pien, President and CEO of Medarex.  "We believe that our fully human anti-PD-1 and anti-PD-L1 antibodies represent the next stage in immunotherapy beyond the anti-CTLA-4 antibodies. We look forward to exploring the potential of MDX-1105 as a possible new treatment option for patients with cancer and infectious disease."

About Medarex

Medarex is a biopharmaceutical company focused on the discovery, development and potential commercialization of fully human antibody-based therapeutics to treat life-threatening and debilitating diseases, including cancer, inflammation, autoimmune disorders and infectious diseases. Medarex applies its UltiMAb(R) technology and product development and clinical manufacturing experience to generate, support and potentially commercialize a broad range of fully human antibody product candidates for itself and its partners. More than 40 of these therapeutic product candidates derived from Medarex technology are in human clinical testing or have had INDs submitted for such trials, with seven of the most advanced product candidates currently in Phase 3 clinical trials or the subject of regulatory applications for marketing authorization. Medarex is committed to building value by developing a diverse pipeline of antibody products to address the world’s unmet healthcare needs. For more information about Medarex, visit its website at www.medarex.com.

Medarex Statement on Cautionary Factors

Except for the historical information presented herein, matters discussed herein may constitute forward-looking statements, as defined in the Private Securities Litigation Reform Act of 1995, 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 "expected"; "potential"; "possible"; or "may"; or similar statements are forward-looking statements. Medarex disclaims, however, any intent or obligation to update these forward-looking statements. These risks and uncertainties include those 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, 2007 and its quarterly reports on Form 10-Q. There can be no assurance that such development efforts will succeed or that other developed 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(R), the Medarex logo and UltiMAb(R) are registered trademarks of Medarex, Inc. All rights are reserved.

SOURCE Medarex, Inc.