Vincent F. Simmon, Ph.D. became CEO in November, 2006. Prior to joining Xytis, Dr Simmon was employed by Merrimack Pharmaceuticals as Chief Operating Officer since February 2004.Before joining Merrimack, Dr. Simmon served as the President and CEO of Cortex Pharmaceuticals, Inc. At Cortex, Dr. Simmon was responsible for initiating six Phase 2 clinical trials, obtaining federal, private, and corporate funding for pre-clinical and clinical research, and entering three corporate collaborations. Prior to Cortex, Dr. Simmon served as CEO of Prototek, Inc., Alpha 1 Biomedicals, Inc., and Viral Technologies, Inc. He has also served as Vice President of Research and Development at W.R. Grace & Co and Genex Corp.