On October 16, 2018, William J. Enright notified the Board of Directors of Altimmune, Inc. that he intends to resign as President and Chief Executive Officer (CEO) of the Company and as a member of the Board. The Board has begun a process to identify Mr. Enright's successor. The Company and Mr. Enright have agreed that Mr. Enright will remain the President and CEO of the Company until the earlier of the appointment of his successor or February 28, 2019.

Mr. Enright will also remain on the Board until his resignation as President and CEO is effective.