CVS Health announced Friday it has appointed David Joyner as its new Chief Executive Officer, replacing Karen Lynch.

CVS Health on Friday replaced CEO Karen Lynch with David Joyner, a CVS veteran who retired before returning to the company last year, after investors including activist Glenview Capital pressured the company to improve its stagnant share price.

CVS Health Chief Executive Officer Karen Lynch has stepped down and will be replaced by David Joyner, who runs the company's pharmacy benefit firm, Caremark.