According to preliminary results from an on-going clinical trial, side effects of Xeljanz at higher doses may increase the risk of pulonary embolism problems by a factor of five when compared to other rheumatoid arthritis drug.
In February, the FDA issued a drug safety communication about the potential pulmonary embolism risks from Xeljanz, which was echoed late last month by European regulators as well, recommending that doctors closely monitor patients for signs of serious and potentially life-threatening blood clot problems.
Those assessments came following the recent release of results by Pfizer, which is conducting a clinical trial to assess the risk of cardiovascular problems from Xeljanz, but raised serious concerns about the off-label use of the drug at 10 mg twice daily doses.
Preliminary results of the study showed that the overall incidence of Xeljanz pulmonary embolism problems was five times higher among users taking higher doses when compared to individuals using other rheumatoid arthritis drugs that are part of a class known as TNF inhibitors, which includes blockbuster drugs like Humira, Enbrel and others. In addition, when comparing use of the 10mg twice daily dose to the 5mg twice daily dose, the results suggest that users still face a three-fold higher risk of pulmonary embolism.
Xeljanz (tofacitinib) is a drug that was first approved by the FDA in 2012 to treat adults with rheumatoid arthritis, which is an autoimmune disorder that causes inflammation of the joints in approximately one percent of the population. The drug was designed to block the activity of certain enzymes in the body that affect immune system function and is commonly used as an alternative for patients who have tried methotrexate and other medications without success.
In December of 2017, the FDA approved the use of Xeljanz and Xeljanz XR for the treatment of active psoriatic arthritis (PsA), and then approval was expanded again in May 2018 to include treatment of moderate to severe active ulcerative colitis, which includes the 10mg twice daily dose.
As part of the drugs approval process, the FDA required a post-marketing study to evaluate the safety of the drug in separate doses to assess the risk of cardiovascular events.
After evaluating data from the Xeljanz clinical trial results, the drug manufacturer Pfizer announced that patients receiving 10 mg doses of Xeljanz twice per day were found to have a significantly higher risk of experiencing pulmonary embolisms and had an overall higher rate of mortality when compared to patients taking 5 mg doses of Xeljanz.
European regulators further indicated that it appears the problem is when rheumatoid arthritis patients, typically given the 5 mg daily dose, are prescribed the 10 mg dose typically given to ulcerative colitis patients.
Additional concerns raised in the clinical trial found patients taking Xeljanz were at an increased risk for developing serious infections including tuberculosis, invasive fungal infections and bacterial and viral infections that resulted in hospitalizations and deaths. Pfizer announced if a patients develops an infection while using Xeljanz, treatment should be interrupted until the infection is controlled.
Pfizer, in conjunction with the FDA, announced they will begin reassessing dosage levels and infection warnings raised during the clinical trial. Healthcare professionals are being encouraged to follow the updated Xeljanz prescribing information and monitor all patients for symptoms of pulmonary embolism.
Patients are being asked to not change their dose of Xeljanz before consulting with their healthcare professional, as doing so could worsen their condition. Patients taking Xeljanz who begin to experience sudden shortness of breath, chest pain, difficulty breathing, coughing up blood, excessive sweating or clammy or bluish colored skin should seek immediate medical help.