Clinical trial finds an increased risk of blood clots in the lungs and of death in rheumatoid arthritis patients taking high dose of tofacitinib (sold as Xeljanz or Xeljanz XR)

Health Canada is conducting a safety review after issues were discovered during a clinical trial involving rheumatoid arthritis patients being treated with the drug tofacitinib (sold in Canada under the brand names Xeljanz and Xeljanz XR).

Tofacitinib is a prescription drug used to treat adults with moderate to severely active rheumatoid arthritis, active psoriatic arthritis, or moderate to severely active ulcerative colitis in people who do not respond well to other medications. It is generally prescribed in combination with other drugs, such as methotrexate.

The ongoing clinical trial, run by Pfizer, found an increased risk of blood clots in the lungs and of death when the drug was taken at a high dose of 10 mg, twice a day. Patients who were taking 10 mg of tofacitinib twice a day are now transitioning to the lower, currently authorized dose of 5 mg twice a day.

The purpose of this clinical trial is to further evaluate the safety of tofacitinib at two doses (5 mg twice a day and 10 mg twice a day) when taken with another drug (methotrexate). The trial is designed specifically to assess the risk of cardiovascular events, cancer and opportunistic infections in rheumatoid arthritis patients.

Pfizer is conducting the trial in multiple countries, including Canada. The trial involves patients who are at least 50 years of age and have at least one cardiovascular risk factor.

Pfizer is conducting other clinical trials in Canada that involve tofacitinib at 10 mg twice a day. Health Canada has requested the postponement of recruitment in a pediatric trial using this dose, and has asked investigators of other trials to inform participants and to secure their agreement to continue in the study. Health Canada is working with Pfizer to monitor the situation closely and continues to assess these clinical trials.

Health Canada has not authorized the high dose of 10 mg twice a day for rheumatoid arthritis or psoriatic arthritis; this dose is authorized only for patients with ulcerative colitis in people who do not respond well to other medications. For patients with ulcerative colitis, the Canadian prescribing information recommends that patients use the lowest effective dose possible for maintenance therapy, to lower the risk of adverse reactions.

Health Canada is working with Pfizer to evaluate the available safety information for tofacitinib and will inform the public of any new safety findings as needed, once the review is complete.

If you are a patient taking tofacitinib:

• Do not stop or change your dose of tofacitinib without first talking to your health care professional.
• Seek medical attention immediately if you experience symptoms of a blood clot in your lungs, such as sudden unexplained chest pain or shortness of breath, coughing up blood, excessive sweating, clammy or bluish coloured skin, or any other unusual symptoms.

If you are a health care professional:

• Follow the recommendations in the tofacitinib product monograph for the specific condition you are treating.
• Monitor patients for the signs and symptoms of pulmonary embolism, and advise them to seek medical attention immediately if they experience them.

To report a side effect to a health product to Health Canada:

• Call toll-free at 1-866-234-2345.
• Visit Health Canada’s Web page on Adverse Reaction Reporting for information on how to report online, by mail or by fax.