On October 12, Chugai Pharmaceutical Co. filed a suit against Daiichi Sankyo Co., Ltd. and Pfizer based on a use patent related to #HERCEPTIN (Trastuzumab) for treating breast cancer. The patentee is actually Genetech and Chugai has its exclusive licensee. Genentech and Chugai will be the co-plaintiff.
Daiichi-Sankyo and Pfizer got approval regarding HERCEPTIN BS, which is directed to breast cancer and stomach cancer treatment, and Chugai claims that the use for the treatment of breast cancer only would infringe the patent at issue.