On April 23, 2019, pursuant to the Agreement and Plan of Merger and Reorganization (the Merger Agreement), dated as of December 5, 2018, by and among Mereo BioPharma Group plc (Mereo), Mereo US Holdings Inc., (HoldCo), Mereo MergerCo One Inc., and OncoMed Pharmaceuticals, Inc., (OncoMed), Merger Sub merged with and into OncoMed, with OncoMed continuing as the surviving corporation (the Merger). As a result of the Merger, OncoMed became an indirect wholly-owned subsidiary of Mereo. In connection with the Merger, on April 23, 2019, Perry Karsen, John Lewicki, Jack W. Lasersohn, Deepa R. Pakianathan, Jonathan D. Root, Rick E Winningham and Michael S. Wyzga each tendered their respective resignations from the board of directors of OncoMed and any committee thereof, with such resignations effective as of the Effective Time. In addition, in connection with the Merger, on April 23, 2019, the following individuals resigned as officers of OncoMed, effective as of immediately prior to the Effective Time: John Lewicki, Alicia J. Hager, Robert Stagg and Yvonne Li.