On October 23, 2019, Ryan Lynch, the Corporate Controller and Principal Accounting Officer of Concert Pharmaceuticals, Inc. (the “Company”), provided notice of his resignation, effective as of November 27, 2019. Mr. Lynch is leaving the Company to pursue another opportunity and is not departing due to any disagreements with the Company regarding its financial statements or practices. Mr. Lynch will continue to consult for the Company for a period of time. In connection with Mr. Lynch’s resignation, on November 27, 2019, Marc A. Becker, the Company’s Chief Financial Officer and Principal Financial Officer, will also become the Company’s Principal Accounting Officer. Mr. Becker, age 47, has served as the Company’s Chief Financial Officer and Principal Financial Officer since January 2018. Prior to joining the Company, Mr. Becker served as the Chief Financial Officer of CRISPR Therapeutics AG, a publicly traded biotechnology company, from February 2016 to September 2017. From January 2012 to February 2016, Mr. Becker was the Chief Financial Officer of rEVO Biologics, Inc., a biotechnology company. Prior to rEVO Biologics, Mr. Becker held roles of increasing responsibility at Genzyme Corporation, a biotechnology company subsequently acquired by Sanofi S.A., from August 2001 to October 2011, culminating in Vice President, Finance.