On January 28, 2020, Beagle Merger Sub, Inc., a Delaware corporation (Merger Sub) and a wholly-owned subsidiary of Alexion Pharmaceuticals, Inc., a Delaware corporation (Parent), completed its merger (the Merger) with and into Achillion Pharmaceuticals, Inc., a Delaware corporation (the Company), pursuant to the terms of the Agreement and Plan of Merger, dated October 15, 2019 (the Merger Agreement), among Parent, Merger Sub and the Company. The Company was the surviving corporation in the Merger and, as a result, is now a wholly-owned subsidiary of Parent. In connection with the consummation of the Merger and as contemplated by the Merger Agreement (and not because of any disagreement with the Company), all of the directors of the Company ceased to be directors of the Company as of the Effective Time. In accordance with the terms of the Merger Agreement, at the Effective Time, the directors of Merger Sub became directors of the Company. Immediately following the Effective Time, the Company’s board of directors consisted of Aradhana Sarin, Michael Elloian, and Douglas Barry. Also in connection with the consummation of the Merger and as contemplated by the Merger Agreement (and not because of any disagreement with the Company), all of the officers of the Company ceased to be officers of the Company as of the Effective Time. In accordance with the terms of the Merger Agreement, at the Effective Time, the officers of Merger Sub became officers of the Company. Immediately following the Effective Time, the Company’s officers consisted of Aradhana Sarin (as President), Michael Elloian (as Treasurer), and Douglas Barry (as Secretary).