FDA slaps blockbuster JAK inhibitors with new safety warnings

The FDA has added new restrictions to the use of JAK inhibitors — made Pfizer, AbbVie and Eli Lilly — over serious safety concerns.

This week, the regulator announced that the class of drugs should now come with boxed warnings about the increased risk of blood clots, heart problems, cancer and death. Awareness over potential serious health risks associated with the drug emerged years ago during follow-up studies of Pfizer’s Xeljanz, a JAK inhibitor aimed at treating a number of inflammatory diseases including rheumatoid arthritis and ulcerative colitis. 

The issues with Xeljanz have since trickled down to AbbVie’s ambitions with Rinvoq. The drug was first approved in 2019 for rheumatoid arthritis, but AbbVie had submitted a supplemental NDA for psoriatic arthritis and ankylosing spondylitis — two indications that would help propel the drug to blockbuster levels. But the FDA has postponed approval for the new indications, pending more safety reviews.

News of the new FDA warnings sent shares for AbbVie tumbling and shaved about $20 billion off the company’s market value.

Although Bristol-Myers Squibb and Incyte Corp also have a JAK inhibitor, the FDA said it would not need the warning because it’s not used to treat inflammatory conditions.