Drugmaker AstraZeneca has poached Alexion Pharmaceutical’s chief financial officer ahead of its acquisition, as the pharma firms shuffle their senior staff.

Joining with an £850,000 base salary, Aradhana Sarin will join when the deal closes as both an executive director and chief financial officer if the pharmaceutical firm’s deal for Alexion Pharmaceuticals goes to plan.

The famed vaccine maker’s $39bn deal for Alexion, which is expected to take place in the third quarter of this year, will be AstraZeneca’s largest-ever deal and marks a bet on the rare disease immunology market.  

Sarin’s appointment is still subject to certain regulatory approvals but will see her relocate from the US to the UK, reporting to AstraZeneca’s CEO Pascal Soriot.

The former CFO, Marc Dunoyer, will step down from the board at some point after 1 August, after holding down the financial fort for seven years.

Dunoyer will then take over the helm of Alexion as CEO and chief strategy officer of AstraZenca.

“I’m looking forward to working with him in his new role as CEO, Alexion, the Rare Disease Unit of AstraZeneca, and to his continued strategic input to AstraZeneca’s success,” CEO Soriot said. 

Earlier this week, the UK’s Competition and Markets Authority and EU antitrust watchdogs were eyeing the billion-dollar deal, a European Commission filing revealed.

They will be reviewing the deal until 5 July, looking at whether to approve the Anglo-Swedish drugmaker’s $39bn bid for biopharmaceutical company Alexion.