Arena Pharmaceuticals, Inc., a biopharmaceutical company, focuses on providing novel medicines with pharmacology and pharmacokinetics to patients worldwide. Its investigational clinical programs include Etrasimod (APD334) that is in Phase III clinical trial for ulcerative colitis, Phase IIb/III clinical trial for Crohn's disease, Phase II clinical trial for alopecia areata, Phase III clinical trial for atopic dermatitis, and Phase IIb clinical trial for eosinophilic esophagitis; Olorinab (APD371), which is in Phase IIb clinical trial for the treatment of abdominal pain associated with irritable bowel syndrome; APD418 that is in Phase I clinical trial for acute heart failure; and Temanogrel for coronary microvascular obstruction is in Phase II clinical trial. It also develops ralinepag (APD811), which is in Phase III clinical trial for pulmonary arterial hypertension. The company has collaboration agreements with Second Genome, Inc.; United Therapeutics Corporation; Everest Medicines Limited; Beacon Discovery; Boehringer Ingelheim International GmbH; Eisai Co., Ltd.; Eisai Inc.; and Aristea Therapeutics, Inc. for the development of RIST4721 for treatment of serious immune-mediated inflammatory diseases. Arena Pharmaceuticals, Inc. was incorporated in 1997 and is based in Park City, Utah.