OPi is an integrated biopharmaceutical company whose mission is to develop and market pharmaceuticals aimed at treating patients suffering from rare and severe diseases. OPi’s primary focus is onco-haematology, with Kidrolase® (Escherichia coli-derived L-asparaginase), and Erwinase® (Erwinia chrysanthemi-derived L-asparaginase), and with a R&D portfolio of monoclonal antibodies at various stages of preclinical and clinical development.

OPi SA, Pharmaceuticals for Rare Diseases and EUSA Pharma Inc. announced on the 1st of March 2007 that the shareholders of OPi and EUSA Pharma have executed a binding share purchase agreement whereby EUSA Pharma will acquire 100% of the shares of OPi SA. The closing of this all-cash transaction occured in March 2007.