Biotech giant Amgen has appointed Paul Burton chief medical officer, effective June 26, luring the veteran executive away from Moderna, where he has held the CMO role for nearly two years, according to an internal memo sent to Amgen staff by R&D Executive VP David Reese and received by FierceBiotech.

Burton will replace senior VP of global medical, Darryl Sleep, who has been acting CMO since Amgen announced a restructuring and hundreds of layoffs earlier this year.

Amgen said in a LinkedIn post that Burton, who previously spent 16 years at Johnson & Johnson, including several years as chief global medical affairs officer at its Janssen division, will oversee a newly created chief medical officer position with expanded responsibilities.

He will report to Reese in his new post, where he will supervise medical, global regulatory affairs and strategy, and global patient safety, as well as R&D strategy and operations.

Burton is returning to Amgen after previously working for the company as a worldwide development leader earlier in his career.

He joins Amgen at a time when the company is fighting to complete a purchase of Horizon Therapeutics in the face of opposition from the Federal Trade Commission.