In a surprise move, the drugmaker has shifted ceo Matt Emmens to the role of non-executive chair to replace the retiring James Cavanaugh in June. In turn, Angus Russell, the cfo, is being promoted to become ceo.

In its statement, the Shire board says the changes were discussed in advance with major shareholders, although some were caught off guard. WestLB analyst Irina Stratan, tells MarketWatch said that while she was surprised by the management changes, although she adds that Russell is very well known in the market and views this is a positive move for Shire.

Shire is the UK’s third-largest drugmaker and Emmens, 56, joined in 2003. Before joining Shire as cfo in 1999, Russell worked for Imperial Chemical Industries as well as AstraZeneca.