SP-333 is a synthetic analog of uroguanylin, a natriuretic hormone which is normally produced in the body's intestinal tract. Deficiency of this hormone is predicted to be one of the primary reasons for the formation of polyps that can lead to colon cancer, as well as debilitating and difficult-to-treat GI inflammatory disorders such as ulcerative colitis and Crohn's disease. Orally-administered SP-333 binds to and activates GC-C expressed on epithelial cells lining the GI mucosa, producing anti-inflammatory activity. In animal models, oral administration of SP-333 ameliorates GI inflammation by suppressing production of certain pro-inflammatory cytokines.
Plecanatide is a member of a new class of essentially non-systemic drugs, referred to as guanylate cyclase C (GC-C) agonists, that are currently in development to treat CIC and IBS-C, which includes a first-in-class drug being developed by Ironwood (Nasdaq: IRWD) and Forest Labs (NYSE: FRX). Plecanatide is a synthetic analog of uroguanylin, a natriuretic hormone that regulates ion and fluid transport in the GI tract. Orally-administered plecanatide binds to and activates GC-C receptors expressed on epithelial cells lining the GI mucosa, resulting in activation of the cystic fibrosis transmembrane conductance regulator (CFTR), and leading to augmented flow of chloride and water into the lumen of the gut. Activation of the GC-C receptor pathway is believed to facilitate bowel movement as well as producing other beneficial physiological responses including improvement in abdominal pain and inflammation. In animal models, oral administration of plecanatide promotes intestinal secretion and also ameliorates GI inflammation.About Ulcerative Colitis More than 500,000 Americans are afflicted with ulcerative colitis, a type of IBD that causes chronic inflammation of the colon. Along with Crohn's disease, the other major form of IBD, ulcerative colitis is painful and debilitating, and can lead to other serious and life-threatening complications such as increased incidence of colon cancer. There is currently no medical cure for ulcerative colitis. A considerable medical need exists for the control and treatment of ulcerative colitis.