DuPont Acquires ImaRx Pharmaceutical Corp.

N. BILLERICA, Mass.--(BUSINESS WIRE)--Oct. 8, 1999--

Purchase Solidifies DuPont's Leadership Role in the Ultrasound

Contrast Industry

DuPont announced today it has acquired the worldwide marketing rights and patent estate for the ultrasound contrast agent Definity(TM) and its back-up compounds, through the purchase of all outstanding shares of ImaRx Pharmaceutical Corp. - a privately held research and development company based in Tucson, Ariz. Financial terms were not disclosed.

The acquisition is the third in a series of actions taken by DuPont recently to strengthen its pharmaceuticals business through alliances and acquisitions. The company announced a major research collaboration with Pharmasset on September 27, which will focus on research and development of proprietary HIV and hepatitis B virus antiviral compounds. On October 5, the company announced an agreement to acquire CombiChem, Inc., for $6.75 per share in cash, or approximately $95 million. Once completed, this acquisition is expected to drive DuPont's efforts in the discovery and development of new medicines.

In December 1998, the Medical Imaging Division of DuPont Pharmaceuticals submitted a new drug application to the U.S. Food and Drug Administration for Definity. If approved as submitted, Definity could become the first ultrasound contrast agent approved for heart, liver and kidney imaging in the United States. DuPont also has submitted applications for regulatory approval of Definity in Canada and Europe.

"This acquisition is yet another example of DuPont's commitment to develop and provide products that impact people's lives," said Kurt M. Landgraf, DuPont executive vice president and chief operating officer. "Once again we are taking a bold step in a high technology market and are in an excellent position to be a global leader in the field of ultrasound contrast imaging."

Under the terms of the acquisition, Evan Unger, M.D., the founder of the company will retain the ImaRx Pharmaceutical Corp. name. He also retains intellectual property rights to develop targeted drug and gene delivery technology.

DuPont Pharmaceuticals (at the time, DuPont Merck) and ImaRx Pharmaceutical began a collaboration in 1995 to develop and market Definity. Under the agreement, DuPont Pharmaceuticals held the rights to manufacture, market and sell Definity in North America, Latin America and Europe. Now, DuPont Pharmaceuticals assumes the complete patent estate and worldwide marketing rights for Definity.

Yamanouchi Pharmaceutical Co. Ltd., one of the largest pharmaceutical companies in Japan, has licensed the marketing rights for the ultrasound contrast agent, designated YM454, for Asia including Japan. DuPont now will receive milestone payments and royalties from Yamanouchi.

The Medical Imaging Division of DuPont Pharmaceuticals, a world leader in perfusion and function imaging, is committed to providing innovative and cost-effective solutions to enhance patient management. Building on the foundation of its extensive nuclear imaging portfolio, the company is seeking to expand the array of diagnostic imaging options available to physicians and their patients. The Medical Imaging Division is based in N. Billerica, Mass.

DuPont Pharmaceuticals is a worldwide business that focuses on research, development and delivery of pharmaceuticals to treat unmet medical needs in the fights against HIV, cardiovascular disease, central nervous systems disorders, cancer and arthritis-related disorders.

DuPont (NYSE:DD) is a science company, delivering science-based solutions that make a difference in people's lives in food and nutrition; health care; apparel; home and construction; electronics; and transportation. Founded in 1802, the company operates in 65 countries and has 97,000 employees.

Definity is a trademark of DuPont Pharmaceuticals