LDP-341 Press release and fact sheet on multiple myeloma:

-Clinical and preclinical data presented at American Society for Hematology Meeting-

-Additional clinical trials planned with National Cancer Institute -

San Francisco, Dec. 4, 2000 -- Millennium Pharmaceuticals, Inc. (Nasdaq: MLNM) today announced the presentation of preclinical and clinical study results demonstrating that an investigational proteasome inhibitor, LDP-341 (formerly PS-341), the first in a new class of anti-cancer agents, is active against multiple myeloma. The latest findings were presented at the 42nd Annual Meeting of the American Society of Hematology (ASH) meeting in San Francisco.

The first presentation, entitled "The Proteasome Inhibitor PS-341 Inhibits Growth, Induces Apoptosis and Overcomes Drug Resistance in Human Multiple Myeloma (MM) Cells," was based on research conducted by Teru Hideshima, M.D., Ph.D., and colleagues at Dana-Farber Cancer Institute and Harvard Medical School in collaboration with Millennium. In the preclinical study, LDP-341, a proprietary small molecule compound, showed in vitro activity against multiple myeloma cells, resulting in the inhibition of cancer cell growth and reproduction, and the inducement of cell suicide (apoptosis), in animals. The potent anti-tumor action of LDP-341 on multiple myeloma cells in these preclinical studies appears to involve both direct (apoptosis) and indirect inhibition of growth factors that promote tumor growth. In addition, in animals LDP-341 appears to increase the effectiveness of other anti-cancer drugs by overcoming cellular resistance, which in humans is a major cause of chemotherapy failure.

Clinical research was presented at the meeting by Thomas Stinchcombe, M.D., and principal investigator Robert Orlowski, M.D., Ph.D., in a report entitled "PS-341 is Active in Multiple Myeloma: Preliminary Report of a Phase I Trial of the Proteasome
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Contact: Lynn Smiledge, Millennium
617-761-4700
Porter Novelli
4-Dec-2000