(Bloomberg) -- Nearly nine years ago, when Emma Walmsley was preparing to take over as CEO of GSK Plc, she wrote in her diary that Luke Miels — then an executive at rival AstraZeneca Plc — would be “a dream appointment for this adventure.”Now, as Walmsley’s own adventure atop the British pharmaceutical group winds down, Miels has been named to replace her. The 50-year-old, who joined Walmsley at GSK in 2017, will take the reins as chief executive officer at the start of next year. His main challenges will b ...