On September 18, 2023, in connection with the approval by the board of directors of Histogen Inc. of the plan of liquidation and dissolution of the Company (the ?Plan of Dissolution?), each of Steven J. Mento, Ph.D., the Company?s President, Chief Executive Officer and principal executive officer, Alfred P. Spada, Ph.D., the Company?s Executive Vice President and Chief Scientific Officer, and Joyce Reyes, the Company?s Senior Vice President Regulatory, Quality, Clinical and Technical Operations, was terminated from all positions of employment with the Company, effective as of September 30, 2023 (the ?Separation Date?). Dr. Mento also resigned as a member of the Board effective September 18, 2023. Dr. Mento?s decision to step down as a member of the Board was not the result of any disagreement with the Company.

On September 18, 2023, Susan A. Knudson, the Company?s Executive Vice President, Chief Operating Officer, Chief Financial Officer, Secretary, and principal financial officer, was appointed to the additional positions of President and was designated as the Company?s principal executive officer, in each case effective as of October 1, 2023 (the ?Executive Employment Date?). Ms. Knudson will continue to serve as the Company?s Chief Financial Officer, Secretary and principal financial officer. Ms. Knudson, 59, has served as the Company?s Executive Vice President, Chief Operations Officer and Chief Financial Officer since March 2023.

Ms. Knudson served as the Company?s Executive Vice President and Chief Financial Officer from May 2020 to March 2023. Previously, Ms. Knudson served as Senior Vice President, Chief Financial Officer at Pfenex Inc., a biopharmaceutical company, from February 2018 until November 2019. From 2009 to 2017, Ms. Knudson held various roles at Neothetics Inc., a specialty pharmaceutical company, including Chief Financial Officer from 2014 to 2017 and Vice President of Finance and Administration from 2009 to 2014.

Prior to joining Neothetics, Ms. Knudson served as Senior Director of Finance and Administration at Avera Pharmaceuticals, a pharmaceutical company, from May 2002 to January 2009. Prior to May 2002. Ms. Knudson served as Director of Finance and Administration at MD Edge Inc., a medical communications company, from October 2000 to April 2002.

Prior to joining MD Edge, Ms. Knudson served as Assistant Director of Accounting at Isis Pharmaceuticals, a pharmaceutical company, from April 2000 to October 2000. Ms. Knudson has also held senior positions at CombiChem, General Atomics and Deloitte & Touche. Ms. Knudson holds a B.A. in Accounting from the University of San Diego.