(Reuters) - Alexion Pharmaceuticals Inc (ALXN.O) said on Tuesday its chief financial officer and research head would leave in the latest top level exits, sending the company's shares down 11 percent to a more-than-three-and-half year low.
The company said Chief Financial Officer Dave Anderson will resign at the end of August, while head of research and development Martin Mackay would retire at the end of the year.
Chief Commercial Officer Carsten Thiel will also leave by the end of May, the company said, whose flagship Soliris specialty medication has a U.S. list price of about $480,000 per year.
The latest round of exits comes two weeks after Brazilian police searched the Sao Paulo offices of Alexion as part of a probe into its relationship with a patient advocacy group accused of filing fraudulent lawsuits to spur drug purchases.
"The move now to replace its second CFO in 6 months will not help waning confidence in Alexion shares," J.P. Morgan analyst Anupam Rama noted, downgrading the company to "neutral" from "overweight".
Alexion in December said its then chief executive officer and chief financial officer would resign, a month after the company said it was investigating allegations related to sales practices of Soliris.
However, some analysts saw the latest changes as part of new Chief Executive Officer Ludwig Hantson's, a former CEO at Baxalta, efforts to steady the ship.
Leerink Partners analyst Geoffrey Porges said the management changes appear to be recently appointed CEO's plan and signaled his intention to make a complete break with the company's past leadership.
Investor confidence in Alexion has whittled with Soliris, which treats two rare blood disorders, facing slowing sales growth and looming competition.
Alexion's shares, which had fallen about 6 percent this year through Monday's close, were down 7.77 percent at $106.45, wiping out about $2 billion in market value. The stock was the top drag on the S&P 500 index .SPX and the Nasdaq Biotech index .NBI.
The shares earlier touched a three-and-half year low of $102.47.
Reporting by Ankur Banerjee in Bengaluru; Editing by Sriraj Kalluvila