Otsuka Pharmaceutical Co., Ltd. (OPC) and PDL BioPharma, Inc. announced closing of the previously announced transaction under which Otsuka has acquired PDL's rights to IV Busulfex (busulfan), including trademarks, patents, intellectual property and related assets, for $200 million plus inventory value.

IV Busulfex is an oncologic product marketed and sold in the United States and Canada, and through distributors in a number of other countries.

Now that this transaction has closed, OPC will oversee the outsourced manufacturing of the product, while its US affiliate, Otsuka Pharmaceutical Development and Commercialisation, Inc. (OPDC), will investigate clinical studies for potential new indications for IV Busulfex. Another OPC affiliate, Otsuka America Pharmaceutical, Inc. (OAPI), will market the product for its current indication in the United States. OPDC was established in 2007 and OAPI in 1989 by Otsuka America, Inc. (OAI). Both OPDC and OAPI are wholly owned by OAI, which is the holding company for OPC's interests in the US. OAI is wholly owned by OPC.

IV Busulfex (busulfan) is indicated for use in combination with cyclophosphamide as a conditioning regimen prior to allogeneic haematopoietic progenitor cell transplantation (also referred to as blood or bone marrow transplantation or BMT) for chronic myelogenous leukaemia (CML).

Busulfex (busulfan) Injection is a potent cytotoxic drug that causes profound myelosuppression at the recommended dosage. At the recommended dosage, IV Busulfex produced profound myelosuppression in all patients (i.e., severe granulocytopenia, thrombocytopenia, anaemia, or a combination thereof).