Press release
Nov 26, 2008

Sosei Announces the Out-licensing of RS(+) Mefloquine to Treague Ltd for theTreatment and Prophylaxis of Malaria

Tokyo, Japan and Cambridge, UK– 26 November 2008: Sosei Group Corporation (“Sosei”; TSE Mothers Index: 4565), the biopharmaceutical company, today announced that it has outlicensed its IP and Know How relating to the RS(+) isomer of mefloquine to Treague Ltd. (“Treague”), a Cambridge, UK based pharma company, for the treatment and prophylaxis of malaria.

Mefloquine is a highly efficacious anti-malarial drug that is approved in its racemic form for both treatment (in combination with artesunate) and prophylaxis (as monotherapy) of malaria. Though its efficacy and long half-life make racemic mefloquine a particularly attractive antimalarial drug, its clinical utility has been compromised by CNS side effects. However, it is hypothesised, based on the stereoselective nature of mefloquine’s receptor binding that RS(+) mefloquine has the potential for substantially reduced CNS side effect liability. Treague is collaborating with Medicines for Malaria Venture (MMV), a Geneva-based not-for-profit organization dedicated to reducing the burden of malaria, to develop RS(+) mefloquine for the treatment of malaria in malaria endemic countries. In addition, Treague plans to develop RS(+) mefloquine for the prophylaxis of malaria for commercial sale.

Based on its cytokine modulatory activity, Sosei were developing RS(+) mefloquine as AD 452 for the treatment of rheumatoid arthritis. However, despite an excellent safety profile, clinical studies failed to demonstrate sufficient efficacy in this indication and the AD 452 programme was terminated in 2006.

“We are delighted to contribute to the development of a potentially safer and better tolerated anti-malarial,” said Shinichi Tamura, CEO of Sosei.

Dr Robert Tansley, Treague’s Development & Medical Director said, “By building on the preclinical and clinical work conducted by Sosei, we have the opportunity to rapidly develop an efficacious anti-malarial with potentially significant clinical advantages over existing treatment options.”