Ligand Pharmaceuticals Incorporated announced that its subsidiary, Seragen Inc., has entered into an agreement with Hollister-Stier Laboratories LLC for the fill/finish of the approved cancer drug Ontak (deneleukin diftitox), under a new five-year contract that covers the existing commercial product as well as a new second-generation formulation in the advanced stages of development. The products will be fill/finished at the HollisterStier facility located in Spokane, Washington. Ontak bulk drug substance for fill/finish and labeling continues to be manufactured at the Cambrex Bio Science facility located in Hopkinton, Massachusetts.

Under the terms of the new agreement, Ligand and HollisterStier will work closely together in the qualification and validation of the facility. Following the successful technology transfer, expected to be completed in late 2004 or early 2005 and regulatory approval anticipated around mid 2005, production capability and supply of the currently marketed formulation of Ontak is expected to be maintained.

In order to facilitate supply continuity to our customers and patients of Ontak until regulatory approval of the new facility is complete, Ligand has recently invested in building strategic inventories of Ontak prior to the completion of the fill/finish contract with our previous supplier Eli Lilly and Company at the end of 2003.

"We are pleased to begin this new relationship with a seasoned manufacturing partner, HollisterStier, for Ontak, which has grown rapidly in recent quarters and is our best-selling oncology product," said Gian Aliprandi, senior vice president, technical supply and international operations. "We expect demand for Ontak to continue growing, and therefore look forward to working closely with them on fill/finish of the current formulation of Ontak and on our improved purity second generation formulation."

The initial term or the agreement is five years, with a provision for automatic renewal extension in additional two-year increments. Financial terms of the contract were not disclosed.

In February 1999, the US Food and Drug Administration granted Seragen, Inc., a wholly owned subsidiary of Ligand, accelerated approval for Ontak for the treatment of patients with persistent or recurrent cutaneous t-cell lymphoma whose malignant cells express the p55 (CD25) component of the IL-2 receptor. Ontak is currently available in deep-frozen formulation.