The Food and Drug Administration (FDA) on Thursday warned that early results from a safety trial on Pfizer’s arthritis and colitis drug, tofacitinib, revealed an increased risk of heart issues and cancer when compared to another medicine.
The drug, marketed under Xeljanz or Xeljanz XR, was tested against an arthritis drug called tumor necrosis factor (TNF) inhibitors. The FDA is still waiting for more information on blood clots and death.
"Patients should not stop taking tofacitinib without first consulting with your health care professionals, as doing so may worsen your condition. Talk to your health care professionals if you have any questions or concerns," the FDA said in a statement posted Thursday.
"Health care professionals should consider the benefits and risks of tofacitinib when deciding whether to prescribe or continue patients on the medicine. Continue to follow the recommendations in the tofacitinib prescribing information," the agency advised.
Fox News has requested additional comment from Pfizer.
The FDA previously approved this drug to treat rheumatoid and psoriatic arthritis in patients who weren’t responding to a medicine called methotrexate. More recently, in 2018, the drug saw FDA approval to treat a serious inflammatory condition called ulcerative colitis.
The drug lowers an otherwise overactive immune system causing harmful inflammation. The FDA required Pfizer to run a safety trial to monitor for heart issues, cancer and infections among patients taking the drug.
"The clinical trial is now complete and initial results show a higher occurrence of serious heart-related events and cancer in RA [rheumatoid arthritis] patients treated with both doses of tofacitinib compared to patients treated with a TNF inhibitor. FDA is awaiting additional results from the trial."
Side effects from tofacitinib should be reported to the FDA MedWatch program, the agency said.