David Simmons has been appointed chairman and chief executive officer of PPD. Mr. Simmons joins the company from Pfizer, where he served as president and general manager of the emerging markets and established products business units. Mr. Simmons will be based in PPD’s headquarters in Wilmington, NC.   “We are pleased to welcome David to PPD,” said Stephen H. Wise, managing director of The Carlyle Group and PPD board member. “David is a proven leader whose deep industry knowledge and vision will...