CLEVELAND (AP) — Athersys Inc. said Monday it signed a development deal with Pfizer Inc. worth $6 million upfront and potentially up to $105 million for an experimental stem cell therapy. Under the deal Athersys will receive the upfront cash payment, along with research funding for its MultiStem, a potential stem cell-based treatment for inflammatory bowel disease. The company is also eligible to receive milestone payments of up to $105 million, along with tiered royalty payments on worldwide sales. In lieu of royalties and some other payments, Athersys could choose to codevelop the drug with Pfizer when the drug candidate reaches late-stage development. That option would include sharing development and sales costs, along with profit. Inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease, affects the colon and small intestine, with symptoms including abdominal pain, weight loss, and diarrhea.