Press release
May 15, 2006

Sosei Discontinues Development of SOU-001

Tokyo, Japan/London, UK – 15 May 2006: Sosei Co. Ltd. (TSE Mothers Index: 4565) announced today the discontinuation of the development programme for its stress urinary incontinence (SUI) project SOU-001.

Sosei commenced Phase IIa clinical trials with patients suffering from SUI in June 2005 but has found the recruitment of patients much more difficult than anticipated. A subsequent review of this opportunity in the light of the future development requirements has led Sosei to its decision to discontinue the project.

Based on an ongoing review of the product pipeline, Sosei decided SOU-001 would no longer be a priority project for internal development resources.