Michael P. Bailey, senior vice president of commercial operations at ImClone Systems, has resigned effective August 1, 2008. Mr. Bailey has accepted a senior level commercial position with Synta Pharmaceuticals, a New England-based biopharmaceutical company.     ImClone has appointed Joseph I. DePinto as vice president of commercial operations, effective July 14, 2008. He will assume responsibility for the company’s commercial operations department upon Mr. Bailey’s departure. Mr. DePin...