Newly published safety study results have shown heart and cancer risks associated with Xeljanz, a common treatment for rheumatoid arthritis (RA) and ulcerative colitis. The long-term study, a condition for the drug’s initial approval, was recently completed.

What is Xeljanz?

“XELJANZ is a Janus Kinase (JAK) inhibitor that helps disrupt JAK pathways from inside cells that are thought to play a role in inflammation,” said Pfizer, the drug’s company . Xeljanz’s anti-inflammatory effects made it the first treatment for various ailments. Pfizer is promoting the “most widely prescribed JAK inhibitor” based on calculations with IQVIA data.

Xeljanz, also known as tofacitinib, was approved as a treatment for RA in 2012 and is available as a twice-daily pill or in its daily XR formula. In 2017, Xeljanz received approval for active psoriatic arthritis. The following year, approval was granted for adults with moderate to severe ulcerative colitis. Late last year, the Food and Drug Administration approved its use in polyarticular juvenile idiopathic arthritis.

The process

When Xeljanz was first approved by the FDA, the agency ordered an ongoing clinical trial to assess the risk of heart problems, cancer, infection, and other problems over time. The study compared patients taking Xeljanz for RA with patients taking an alternative type of medication called tumor necrosis factor (TNF) inhibitors. According to a release from Pfizer, 4,362 participants took part in the study – 2,911 received tofacitinib and 1,451 TNFi. 1,455 of participants who took tofacitinib received the standard dose of 5 mg, while 1,456 received a double dose of 10 mg.

Interim results from long-term studies published in 2019 showed a risk of blood clots and possible death. This prompted the FDA to issue a warning box – a message printed on packaging and prescribing materials that warns of possible serious side effects.

Upon completion of the clinical trial, the FDA announced that “initial results show a higher incidence of serious cardiac events and cancers in RA patients treated with both doses of tofacitinib than in patients treated with a TNF inhibitor.”

According to Pfizer, 135 major cardiovascular events were recorded and 164 participants developed malignant cancers during the risk period. Of the cardiovascular problems, 98 subjects took Xeljanz and 37 received TNFI. Of the cancer patients, 122 took Xeljanz, while only 42 in the group received TNFi.

The FDA will continue to evaluate the trial data as it becomes available. Pfizer has indicated that additional information will include information on effectiveness as well as additional data on outcomes such as death and pulmonary embolism.

What should I do if I take Xeljanz?

The FDA urges patients to consult their doctor before stopping medication. Suddenly stopping use of Xeljanz may make your condition worse. Your doctor will help you weigh the benefits and risks of the medicine against the prescribing information from the NIH.

Sean Marsala is a Philadelphia, Pennsylvania-based health journalist. He loves technology, usually reads, surfs the internet, and explores virtual worlds.

Article medically reviewed by Yvonne Stolworthy, MSN, RN