The U.S. FDA has put five phase III studies of Sanofi SA’s potential multiple sclerosis and myasthenia gravis blockbuster tolebrutinib on partial clinical hold after several cases of liver injury were identified after exposure to the drug. Sanofi said new recruitment in the U.S. is paused and participants who have been part of the trial for fewer than 60 days should stop taking tolebrutinib, although those taking the drug for longer can continue.