Press release
Dec 26, 2008

Sosei Announces Buyback of the Commercialization Rights to AD 923 from Mundipharma

Tokyo, Japan – 26 December 2008: Sosei Group Corporation (“Sosei”; TSE Mothers Index: 4565), a biopharmaceutical company, today announces that it has reacquired the rights for commercialization of AD 923 from Mundipharma International Corporation Ltd. (“Mundipharma”).

AD 923 is an optimized, sublingual formulation of the strong opioid analgesic fentanyl for the treatment of cancer breakthrough pain. It has been specifically designed to provide rapid onset of analgesia in a device that is easy to use by either the patient or their care giver. An additional benefit is the lockout system that prevents inadvertent overdosing.

In June 2006, Sosei entered into a licence agreement with Mundipharma, under which Mundipharma were granted the right to commercialize AD 923 in Europe and other international markets, excluding North America and Japan.

In February 2008, the programme entered Phase III clinical trials in Europe. However, due to a problem concerning a supplied component in the device used to deliver the fentanyl spray, the trial was temporarily halted in March 2008.

A solution to the technical problem with the device has since been identified, but Sosei is no longer in a position financially to continue with the programme and a new partner is being sought to progress clinical development.

The buyback of the Mundipharma rights now provides Sosei with the possibility of offering commercialisation rights on a global basis. The Mundipharma rights will be re-acquired for a mutually agreed sum of £2m, plus an additional 20% (up to a maximum of £1.5m) of net receipts if Sosei enters into a new partnership agreement involving the Mundipharma territory.