Who currently oversees keytruda's patent applications?

Merck & Co. (MSD outside the United States) owns the Keytruda (pembrolizumab) patent portfolio. The day-to-day oversight of patent applications is handled by Merck’s Global Intellectual Property Organization within the Legal department, usually with assistance from outside patent counsel as needed.

If you want, I can help you locate specific Keytruda/pembrolizumab patent application numbers or show you how to look up their status in patent databases (USPTO, EPO, WIPO).