Agreement Includes Manufacture of Antibodies and Antibody Drug Conjugates

PRINCETON, NJ, USA & BASEL, Switzerland | July 09, 2009 | Lonza and Medarex, Inc. (NASDAQ:MEDX) today announced that they have  signed an agreement giving Medarex the option to work with Lonza as a  collaboration partner to provide manufacturing services in support of  the development and commercialization of Medarex’s pipeline of  therapeutic proteins and antibody drug conjugates (ADCs). As part of the  agreement, Lonza may provide process development services for certain  Medarex programs and may reserve manufacturing capacity for Medarex antibody and antibody drug conjugate programs at Lonza’s  biopharmaceutical facilities around the world. Further details of the  agreement were not disclosed.

"We are pleased to be working with such a successful mid-size biotech  company to advance and strengthen their robust portfolio of innovative  therapies," said Dr. Stephan Kutzer, Head of Lonza Biopharmaceuticals.  "Supporting Medarex’s immediate and long-term needs with our expertise  in mammalian cell culture and antibody drug conjugates is both exciting  and rewarding."

This collaboration agreement represents the continued extension of  Lonza’s contract manufacturing business model, evolving from a  short-term product-by-product development and manufacturing arrangement  toward more strategic long-term collaboration on a pipeline of products.  The Medarex agreement leverages Lonza’s expertise and asset base in  biologics manufacturing and its new state-of-the-art facilities to  produce antibody drug conjugates in milligram to multiple kilogram  quantities for both clinical and commercial supply.

Medarex’s biologics portfolio is focused on treating oncology and  immunology therapeutic indications with ten antibody programs in Phase 3  to Phase 1 clinical development. Medarex is a leader in therapeutic  antibody development, and there are over forty therapeutic product  candidates derived from its UltiMAb(R) technology in  development or at the IND submission stage for clinical trials, either  through its internal efforts or through partnerships. Under the terms of  the agreement, Lonza may be supporting a portion of the Medarex product  pipeline.

About Lonza

Lonza is one of the world’s leading suppliers to the pharmaceutical,  healthcare and life science industries. Its products and services span  its customers’ needs from research to final product manufacture. Lonza  is the global leader in the production and support of active  pharmaceutical ingredients both chemically as well as  biotechnologically. Biopharmaceuticals are one of the key growth drivers  of the pharmaceutical and biotechnology industries. Lonza has strong  capabilities in large and small molecules, peptides, amino acids and  niche bioproducts which play an important role in the development of  novel medicines and healthcare products. Lonza is a leader in cell-based  research, endotoxin detection and cell therapy manufacturing. Lonza is  also a leading provider of value chemical and biotech ingredients to the  nutrition, hygiene, preservation, agro and personal care markets.

Lonza is headquartered in Basel, Switzerland and is listed on the SWX  Swiss Exchange. In 2008, Lonza had sales of CHF 2.937 billion. Further  information can be found at www.lonza.com.

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. Over  forty of these therapeutic product candidates derived from Medarex  technology are in human clinical testing or have had INDs submitted for  such trials, with the most advanced product candidates currently  approved for commercial sale, the subject of regulatory applications for  marketing authorization or in Phase 3 clinical trials. 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.

SOURCE: Medarex, Inc.