Ligand's approved cancer drug Ontak (denileukin diftitox) will continue to be manufactured by Cambrex Bio Science Hopkinton Inc, a subsidiary of Cambrex Corporation, under a new 5-year contract that covers the existing commercial product as well as a new, second generation formulation in the advanced stages of development, the companies announced today. The products will be manufactured at the Cambrex Bio Science facility located in Hopkinton, Massachusetts.

Under the terms of the agreement, which extends through 2008, Cambrex will continue to be the primary supplier of the drug substance for Ontak and will also manufacture the drug substance for the second generation, improved purity, lyophilized formulation of the product. Ligand intends to file for regulatory approval of the second-generation product by early 2005.

"Cambrex has been a good manufacturing partner for Ontak, which has grown rapidly in recent quarters and is our best-selling oncology product," said David E. Robinson, Ligand's Chairman, President and CEO. "We expect demand for Ontak to continue accelerating, and therefore look forward to working closely with them on production of the current formulation of Ontak and on our improved purity, lyophilized formulation that will be less expensive to produce, suitable for global distribution and easier for clinicians to use. The new second generation product and expanding clinical data should facilitate globalization of the brand to Europe and Japan over the next several years."

Ligand's Ontak had net sales of $16.4 million in the first half of 2003, up 21% compared to the same period of 2002. Ontak's growth has been driven primarily by new clinical data and increasing use in diseases such as chronic lymphocytic leukemia, B- and T-cell non-Hodgkin's lymphomas, and graft-versus-host disease. Ongoing studies in solid tumors such as non-small cell lung cancer could further expand Ontak's clinical utility as the only FDA-approved fusion protein for use in oncology.