Prometheus Biosciences, Inc. completed the previously announced merger of Splash Merger Sub, Inc. (Merger Sub) and a wholly owned subsidiary of Merck & Co., Inc. (Merck), with and into Prometheus (the Merger), with Prometheus surviving the Merger as a wholly owned subsidiary of Merck. Pursuant to the Merger Agreement, as of the Effective Time, each of the directors of Prometheus, Mark C. McKenna, Helen C. Adams, Fred Hassan, Martin Hendrix, Ph.D., James Laur, Joseph C. Papa, Judith L. Swain, M.D. and Mary Szela resigned from the board of directors of Prometheus. At the Effective Time, Jon Filderman, Rita Karachun and Aaron Rosenberg, each a director of Merger Sub immediately prior to the Effective Time, became directors of Prometheus.

In connection with the Merger, at the Effective Time, Mark C. McKenna, Keith W. Marshall, Ph.D. and Mark Stenhouse ceased to be executive officers of Prometheus. In accordance with the terms of the Merger Agreement, at the Effective Time, the officers of Merger Sub became the officers of Prometheus.