EMD Serono, Inc., a subsidiary of Merck KGaA, Darmstadt, Germany, has appointed Gary Zieziula as chief commercial officer, Allene Diaz as senior vice president of Managed Markets, Lisa Buffington as vice president of U.S. Communications, Alexander Kuta as vice president and head of U.S. Regulatory Affairs, and Michael Ruggiero as vice president of U.S. Government Affairs and Policy.   Mr. Zieziula is responsible for maximizing the growth of the U.S. organization by driving the performance of the...