Press release
Mar 26, 2008

Sosei Announces Temporary Halt to AD 923 CBP Phase III Studies in Europe

Tokyo, Japan – 26 March 2008: Sosei Group Corporation (“Sosei”; TSE Mothers Index: 4565), a biopharmaceutical company, today announces that it has notified the UK Medicines and Healthcare products Regulatory Agency (MHRA) and other relevant EU Competent Authorities that it has suspended further patient recruitment into the Phase III clinical trial programme for its fentanyl sublingual spray (AD 923), in CBP (Cancer Breakthrough Pain) pending resolution of a technical issue.

The problem concerns a supplied component in the device used to deliver the fentanyl spray which may result in patients receiving a sub-optimal dose of medication. A detailed investigation is underway but, as a precautionary measure to ensure patient safety, a temporary halt to the study has been implemented and all affected clinical trial supplies will be recalled.