Optimer Pharmaceuticals, Inc. (Optimer) is a biopharmaceutical company focused on developing and commercializing hospital specialty products. The Company’s development is focused on products that treat gastrointestinal infections and related diseases. Its two products OPT-822/821 and CEM-101 (OP-1068) are in clinical development. Optimer’s products include Fidaxomicin and Solithromycin under anti-infectives, and OPT-822/821 under other therapeutic areas. In January 2011, its majority owned subsidiary, Optimer Biotechnology, Inc. (OBI) conducted a Phase 2/3 clinical, trial to evaluate OPT-822/821for the treatment of metastatic breast cancer. On May 27, 2011, the United States Food and Drug Administration (FDA) approved DIFICID(fidaxomicin) tablets, its antibacterial drug for the treatment of adult patients with Clostridium difficile-associated diarrhea (CDAD). In October 2013, Cubist Pharmaceuticals, Inc announced that it has completed its acquisition of Optimer Pharmaceuticals, Inc.