CVS Health (CVS) on Friday named company veteran David Joyner as recent CEO, succeeding Karen Lynch who stepped down from the helm of the struggling healthcare giant after an agreement with the board.

Shares of the company tumbled 11% to $57 in premarket trading.

Joyner, who’s the president of the company’s pharmacy profit manager CVS Caremark, takes over as president and CEO from Friday, the company said.

The change comes on the back of repeated profit forecast cuts this 12 months as the company’s insurance segment has struggled with rising medical costs.

“The board believes that’s the fitting time to make a change, and we’re confident that David is the fitting person to steer our company,” said Chairman Roger Farah.

The healthcare giant can be exiting its core infusion services business and plans to either close or sell 29 related regional pharmacies within the approaching months, Reuters reported earlier this week.

The Wall Street Journal had first reported the news of Joyner’s appointment on Friday.

(Reporting by Leroy Leo in Bengaluru; Editing by Maju Samuel)