On June 25, 2019, Merrimack Pharmaceuticals, Inc. entered into a Transition, Separation and Release of Claims Agreement with Richard Peters, the President, Chief Executive Officer and a director of the Company, whereby he resigned from each such position as of June 28, 2019. On June 25, 2019, the Company entered into a Transition, Separation and Release of Claims Agreement with Jean Franchi, the Chief Financial Officer and Treasurer of the Company, whereby she resigned from each such position as of June 28, 2019. On June 28, 2019, the Board appointed Gary Crocker, the Chairman of the Board of the Company, as the President (principal executive officer) and Treasurer (principal financial and accounting officer) of the Company.

Mr. Crocker, age 67, has served as a member of the Board since 2004 and as Chairman of the Board since 2005. Mr. Crocker also served as the Interim President and Chief Executive Officer of the Company from October 2016 to February 2017. Since 2002, Mr. Crocker has served as President and Managing Director of Crocker Ventures, LLC.