Press release
Mar 5, 2007

AD 923 Commences Phase I Clinical Development in the USA

Tokyo, Japan – 5 March 2007: Sosei Group Corporation (“Sosei”; TSE Mothers Index: 4565), a biopharmaceutical company, today announces that AD 923, a novel sublingual fentanyl spray for the treatment of cancer breakthrough pain, has entered into a Phase I comparative pharmacokinetic study in the USA under an IND regulatory submission.

The trial is a single centre, open-label, single dose, cross-over study to investigate the comparative pharmacokinetics of AD923 against intravenous and oral transmucosal formulations of fentanyl in 24 healthy human volunteers.

Mr Shinichi Tamura, President & CEO of Sosei, said: "I am delighted that we have been able to announce the progression of the AD 923 development programme into the USA. There is a major requirement for a simple and manageable method of providing immediate-release fentanyl for the rapid relief of breakthrough pain which AD 923 has been optimised to deliver.”