Look back at pharma news to Sept 2

Shares of Novo Nordisk were in decline on Thursday as the Danish diabetes care giant announced that its chief executive Lars Rebien Sorensen will be  retiring at the end of 2016.

The move comes as Novo Nordisk is facing increased competition in the US market where it generates approximately half of its revenues, commented Reuters. The company is a major manufacturer of insulin and other medications used to treat diabetes. Last month, the company said it had lost a "sizable" contract for its top-selling insulin NovoLog, Bloomberg reports.

The news appears to be a departure from the company's previous plan, as Novo Nordisk had said Rebien Sorensen would leave when his contract expires at the end of 2019, Reuters noted. However, lower prices and rising competition from biosimilars, or cheaper versions of complex biologic drugs, have created challenges for Novo Nordisk. Concerns over the shifting market have caused it to lose almost a quarter of its value in 2016, according to Bloomberg.