UnitedHealth Group is promoting former GlaxoSmithKline leader Sir Andrew Witty to become the health insurance provider’s next CEO immediately. The company said Thursday that current CEO David Wichmann will retire, more than three years after being promoted from his role as company president. The 56-year-old Witty had served as CEO of UnitedHealth’s Optum segment and then became president of the parent company in November 2019. Before that, he ran British drugmaker GlaxoSmithKline for several years. The leadership changes come a few weeks after UnitedHealth reported fourth-quarter earnings that topped Wall Street expectations. UnitedHealth earned more than $15 billion last year.