Cephalon says that it has signed a deal with Cell Therapeutics to acquire the leukaemia therapy, Trisenox (arsenic trioxide), for up to $170 million dollars, in a bid to get its foot in the door of the increasingly lucrative oncology market.

Under the terms of the deal, Cephalon will assume the worldwide marketing, sales and development of Trisenox, for $70 million in cash, and possible future milestones of up to $100 million. The purchase remains subject to regulatory approval, and is expected to close in the third quarter of 2005. Cephalon anticipates the transaction will be neutral to its 2005 earnings.

Trisenox was approved for marketing in the US and Europe in 2000 and 2002, respectively, for the treatment of patients with relapsed or refractory acute promyelocytic luekaemia, a life-threatening haematologic cancer. It generated $26.6 million in 2004 sales.