Efficacy of Guanilib confirmed for inflammatory bowel disease

Apr 7 2007

Callisto Pharmaceuticals has announced additional data confirming efficacy of Guanilib, a first-in-class compound currently being developed for the treatment of inflammatory bowel disease (IBD), in two different standard animal models of experimental colitis.

Guanilib is an orally deliverable compound designed to mimic a naturally-occurring hormone called uroguanylin. The drug is currently in preclinical development and Callisto intends to move the drug into clinical trials in ulcerative colitis. Guanilib is a proprietary program that was developed in-house by Callisto scientists and the company owns 100% of the worldwide manufacturing and marketing rights.

The new animal data demonstrate that oral administration of Guanilib significantly reduces gastrointestinal (GI) inflammation, and confirm earlier evidence of down-regulation of interleukin-17 (IL-17), IL-23, and tumor necrosis factor (TNF), key cytokines that are known to be involved in etiology of IBD in humans. Guanilib treatment also improved stool consistency and removed intestinal blockage in treated animals.

"These are important findings and suggest a possible mechanism of action of Guanilib and implicate its therapeutic potential in GI inflammatory diseases such as IBD and IBS," said Dr. Kunwar Shailubhai, Senior Vice President, Discovery Research of Callisto, who is also the lead inventor of the issued patent covering therapeutic applications of Guanilib in GI inflammatory diseases and colon cancer.

Callisto believes that Guanilib is presently the best physiological ligand of guanylate cyclase receptor with the potential to provide a new way to treat gastrointestinal diseases, while exhibiting minimal side effects or toxicity. Treatment with Guanilib down-regulated production of IL-17 by 50%, IL-23 by 70% and TNF by 50% in addition to showing reduction of other cytokines including IL-4 and IL-5. Recent data on IBD suggest that proinflammatory IL-17 and IL-23 play major roles in the pathophysiology of this disease as well as irritable bowel syndrome [SCIENCE 314(5804):1461-1463, 2006].

Guanilib, also known as SP304, is an orally deliverable compound designed to mimic a naturally-occurring hormone called uroguanylin 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 Crone's disease.

The inflammatory bowel diseases Crohn's disease and ulcerative colitis are common, chronic disorders that cause abdominal pain, diarrhea, and gastrointestinal bleeding. Recent data also suggest that irritable bowel syndrome is a low-grade IBD. More than 500,000 Americans are afflicted with ulcerative colitis, a type of inflammatory bowel disease (IBD) that causes chronic inflammation of the digestive tract. Along with Crohn's disease, the other major form of IBD, ulcerative colitis can be painful and debilitating, and can lead to other serious and life-threatening complications. There is currently no medical cure for ulcerative colitis.