Roche Holding AG has appointed Sandra Horning as chief medical officer and head of global product development. Horning replaces Hal Barron, who left the company in November to join Google Inc.'s health care venture Calico. Horning joined Genentech in 2009.

She brings more than 35 years of experience, with a focus on oncology, to the company. Barron, one of the top executives to move from Genentech to Roche, left after being recruited by Calico Chief Executive Arthur Levinson.