Merck (NYSE:MRK), known as MSD outside the U.S. and Canada, announced a significant restructuring of its Human Health division on Monday, February 23, 2026.
The move splits its primary business into two specialized units: Oncology and Specialty, Pharma & Infectious Diseases.
The reorganization is designed to protect the company’s dominant lead in cancer care while accelerating a wave of new launches across its diversifying drug pipeline.
The structural shift comes as Merck manages the lifecycle of its blockbuster immunotherapy, Keytruda, which accounted for nearly 46% of the company's revenue in 2024.
By creating a dedicated Oncology Business Unit, Merck aims to streamline the commercial execution of approximately 80 ongoing Phase 3 studies and prepare for what it projects will be more than 20 new growth drivers over the next several years.
To head the new units, Merck has elevated a long-time veteran and recruited a heavyweight from a primary competitor.
Jannie Oosthuizen has been named Executive Vice President and President, Oncology and MSD International.
Oosthuizen previously led Merck’s U.S. Human Health business and has been instrumental in the global commercialization of the company’s oncology portfolio for over a decade.