Last month, the FDA added a boxed warning to Xeljanz’ label for increased risk of potentially fatal blood clots, while Olumiant has been held back by approval only for a lower, less effective ...

JAK inhibitor Xeljanz is one of Pfizer’s top-selling drugs, despite a ‘black box’ warning for blood clots and cancers added to its label in 2019. Now, a study designed to prove its safety ...