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FDA Issues Safety Alert for a JAK Inhibitor

March 04, 2019

A post-marketing safety trial showed an increased risk of blood clots and death among participants with rheumatoid arthritis (RA) receiving a 10 mg dose of tofacitinib (Xeljanz). The FDA issued a safety alert and recommended health care professionals follow the prescribing information for the specific condition they are treating with the Janus kinase (JAK) inhibitor.

Currently, only the twice-daily 5 mg dose of tofacitinib is approved for RA. However, the twice-daily 10 mg dose is approved for ulcerative colitis. 

The clinical trial, required by the FDA after approving tofacitinib, was designed to evaluate the risk of heart-related events, cancer, and opportunistic infections associated with the twice-daily 5-mg and 10-mg dose of the JAK inhibitor in combination with methotrexate compared with a tumor necrosis factor (TNF) inhibitor. Participants with RA were at least 50 years of age and had at least 1 cardiovascular risk factor. An external data safety monitoring committee found an increased occurrence of blood clots in the lungs and death among participants receiving 10 mg of tofacitinib compared with those treated with a 5 mg dose or the TNF inhibitor.

In addition to following the prescribing label, the FDA recommended providers monitor patients with RA for signs and symptoms of pulmonary embolism and advise patients to seek medical attention If they experience them. The FDA encourages providers and patients to report adverse effects to the FDA MedWatch Safety Information and Adverse Event Reporting Program:

Melissa Weiss


FDA. Xeljanz, Xeljanz XR (tofacitinib): Safety communication-safety trial finds increased risk of blood clots in the lungs and death with higher dose in rheumatoid arthritis patients. Published February 25, 2019. Accessed February 28, 2019.

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