Chief Financial Officer Matt Gline will replace Vivek Ramaswamy, who will step into the role of executive chairman.
The move would "separate my increasing public engagement from Roivant's day-to-day operations", Ramaswamy said in a letter to the company's shareholders.
Japan's Sumitomo Dainippon Pharma Co owns a 10% stake in Roivant.
(Reporting by Manas Mishra in Bengaluru; Editing by Maju Samuel)