Board of Directors

Barbara S. Fox, Ph.D.

Barbara S. Fox, Ph.D.

Chief Executive Officer

As Chief Executive Officer, Barbara brings more than 25 years of biopharmaceutical leadership expertise. She joined Rheos from Tilos Therapeutics, a biotech company developing antibody therapies designed to selectively block TGFβ activation for use in oncology and immune-mediated diseases. As founding CEO of Tilos, she established a strong IP position and compelling pre-clinical data package, resulting in an acquisition of the company by Merck for $773 million within three years of initial seed financing. Prior to her role at Tilos, Barbara was the first Entrepreneur-in-Residence at Partners Innovation Fund, hired to evaluate Partners-based technologies suitable for company formation. Earlier, Barbara was founding CEO of Avaxia Biologics, raising more than $24 million in equity financing, and successfully completing a Phase 1b clinical trial of an oral anti-TNF antibody for ulcerative colitis, validating the concept of oral delivery of gut targeted antibodies. Other leadership roles include Founder and Chief Scientific Officer of Recovery Pharmaceuticals and VP, Discovery and Immunology at ImmuLogic Pharmaceutical Corp., where she directed research programs in vaccine development for allergy, autoimmune and substance abuse.

Barbara has been honored as a Mass High Tech Women to Watch Awardee, was a finalist in the Ernst & Young Entrepreneur of the Year New England® Award and currently serves as a Director of the Massachusetts Biotechnology Council and a member of their DEI subcommittee. She is an Executive Coach for Massachusetts Life Science Center’s MassNextGen Initiative, and has been a reviewer and advisor to Springboard Enterprises, both initiatives which support greater gender parity and entrepreneurial opportunities for women working in the life sciences industry. Earlier in her career, Barbara was a tenured Associate Professor in the Division of Rheumatology and Clinical Immunology at the University of Maryland School of Medicine.

Barbara earned her A.B. in Chemistry from Bryn Mawr College, her Ph.D. in Chemistry from the Massachusetts Institute of Technology and completed a Post-Doctoral Fellowship with the National Institutes of Health in Cellular Immunology.