Merck KGaA (MRK) plans to close the Geneva headquarters of its Serono unit, five years after buying Europe’s biggest biotechnology company for about $13.3 billion to expand a drug business that has since faced development and regulatory setbacks. Merck plans to transfer 750 positions to other locations, the Darmstadt, Germany-based company said in a statement today. Merck expects to cut 500 jobs in Geneva as well as 80 positions across three manufacturing sites in Switzerland, according to the statement.