Guillaume Pfefer, Ph.D.
Chief Executive Officer
Senda Biosciences
CEO Partner
Flagship Pioneering

Guillaume is the Chief Executive Officer of Senda Biosciences and is a Flagship Pioneering CEO-Partner. He has more than 25 years of experience in the pharmaceutical industry across R&D, manufacturing, strategy, commercial, business development, and operations.

Prior to joining Flagship, he was SVP, Global Vaccine Leader for Shingrix, GSK’s flagship biological against shingles. In this role, Guillaume had the accountability for the launch in the US. Under Guillaume’s leadership, his team delivered the best biopharma launch in North America over the past decade as independently assessed by IQVIA. Shingrix achieved multi-billion dollar revenue, 98% US market share, and received the Prix Galien for the best pharmaceutical product of 2019.

Prior to GSK, Guillaume was President and CEO of Kala Pharmaceuticals. As CEO, he transformed Kala from a pre-clinical technology platform start-up to a leading ophthalmology company with four Phase III/II clinical trials and the foundation for a successful IPO.

Prior to Kala, Guillaume held several ascending leadership positions over a nine-year career at Sanofi. In his last position, he served as General Manager of Sanofi Pasteur Mexico, one of the company’s largest worldwide affiliates. His previous positions included Vice President, Global Head of the Sanofi Pasteur’s Influenza and Pneumococcal Franchise and Global Head of Corporate Strategy. Guillaume holds a Master’s degree in Chemical Engineering from the National School for Chemical Engineering (Nancy, France), a PhD in Materials Science from Centre National de la Recherché Scientifique (CNRS), France, and a MBA from the Wharton School at the University of Pennsylvania.