Optimer Pharmaceuticals was founded in 1998 and is based in San Diego, California. Optimer Pharmaceuticals, Inc., a biopharmaceutical company, focuses on discovering, developing, and commercializing anti-infective products worldwide. The company develops products that treat gastrointestinal infections and related diseases. Its two late-stage anti-infective product candidates include Fidaxomicin, the lead product candidate and an antibiotic that is in second Phase III registration trial for the treatment of clostridium difficile-infections; and Prulifloxacin, a prodrug in the fluoroquinolone class of antibiotics, which completed second Phase III trials for the treatment of infectious diarrhea in travelers. It also develops OP-1068/CEM-101, an antibiotic for the treatment of upper and lower respiratory tract infections; OPT-88, a disease-modifying intra-articular, or within the cavity of a joint, therapy for osteoarthritis; OPT-822, a carbohydrate-based cancer immunotherapy for the treatment of metastatic breast cancer; and an OPopS drug discovery platform. The company has a collaborative research and development, and license agreement with Cempra Pharmaceuticals, Inc. to discover, develop, and commercialize drugs based on macrolide and ketolide compounds.