Merck has named Frank Clyburn as chief commercial officer and Michael Nally as chief marketing officer.

The appointments were made after head of the global human health unit, Adam Schechter, said he plans to step down at the end of December. Merck has decided to shake up its executive committee and add the two roles, chief commercial and chief marketing officers. Schechter will move into an advisory position to the CEO.

Nally previously led Merck’s vaccines unit. He has worked at Merck since 2003, with roles spanning financial, investor relations, business development, strategic initiatives, and operations. Over his career at Merck, Nally has worked in its U.S. business and in two locations in Europe, Sweden, and the U.K. In his new role, Nally will oversee global marketing and long-term franchise strategy across the portfolio.

Clyburn was previously president of the global oncology business, a role he’s held since 2013. He first joined the company in 2009, and has held roles in market access, primary care, and women’s health divisions. He will be responsible for global operations across Merck’s human health commercial portfolio.

Both Clyburn and Nally will report to CEO Ken Frazier.

In October, Merck appointed Jim Scholefield as chief information and digital officer after 24-year chief information officer Clark Golestani retired from the company in April. Scholefield joined the company from Nike to lead its digital and tech strategy.

Merck also rescinded its mandatory CEO retirement policy this year, allowing Frazier to stay in the role after he turns 65 next year. Frazier also said he plans to stay with the company beyond December 2019.