Sanofi has made a sudden leadership change, ousting CEO Paul Hudson and appointing Belén Garijo, the former head of Merck KGaA, as his successor. This decision comes amid concerns over stalled research and development efforts within the company. Following the announcement, Sanofi’s shares tumbled over 6%, prompting BofA to downgrade the stock rating to Neutral. Garijo, the first woman to lead Sanofi, faces significant challenges ahead as the pharmaceutical giant seeks to reignite its R&D engine and address ongoing vaccine-related obstacles. The board has expressed hopes that Garijo will bring much-needed rigor and direction to the company during this critical transition.