Published on:

Xeljanz and Pulmonary Embolisms, Heart Disease, & Cancer er

In the past two years, the Food and Drug Administration (FDA) and Pfizer have made several announcements on the drug Xeljanz. None of them have been good.

The FDA has reported on Xeljanz’s association with pulmonary embolisms, severe heart issues, cancer, and death. This comes nine years after the FDA approved it to treat psoriatic arthritis, rheumatoid arthritis, and ulcerative colitis. Former Xeljanz patients have begun to file lawsuits against Pfizer. These Xelijanz lawsuits allege that the drug caused them to suffer severe side effects.


Tofacitinib, known by the brand name Xeljanz, is a Janus kinase inhibitor. Janus Kinase inhibitors are drugs that treat psoriatic arthritis, rheumatoid arthritis, and ulcerative colitis. They inhibit Janus Kinase (JAK) enzymes, which cause rheumatoid and psoriatic arthritis symptoms. Other JAK inhibitors include Jakafi and Rinvoq. Xeljanz comes in either 5 or 10 mg tablets. Patients take them twice a day. Xeljanz also comes in either 11 mg or 22 mg extended-release tablets named Xeljanz XR. Patients take these tablets once a day. Xeljanz can be used to either replace or complement methotrexates. The pharmaceutical giant and frequent flyer product defect defendant Pfizer manufactures and distributes the drug.  The FDA first approved Xeljanz in 2012. In 2020, Pfizer made over $1.7 billion from its sales.

Xeljanz Side Effects

Xeljanz may cause the following side effects:

  • Severe infections
  • Death in patients who are over 50+ years and at risk for heart disease
  • Cancer
  • Immune system issues
  • Pulmonary embolisms
  • Stomach and intestinal perforations
  • Severe allergic reactions

Post-marketing study on Xeljanz

As a condition for FDA approval, Pfizer was required to evaluate Xeljanz’s association with cardiovascular issues and cancer (excluding non-melanoma skin cancers). The study began on March 14, 2014. It was named Study A3921133. Pfizer researchers compared Xeljanz’s 5 mg and 10 mg doses among rheumatoid arthritis patients who were over 50 years old and at risk for cardiovascular diseases. This study comprised 4,362 patients. Each of them was over 50 and at risk for cardiovascular problems. They then compared those patients with tumor necrosis factor inhibitor (TNFis) patients. Between 2019 and 2021, Pfizer gradually announced the study’s results.

February 2019 Pfizer Xelijanz announcement

On February 19, 2019, Pfizer announced that they reduced the study patients’ dose from 10 mg twice a day to 5 mg twice a day. This came after the Xeljanz Rheumatology Data Safety Monitoring Board (DSMB) reviewed Study A3921133’s most recent analysis at the time. The board found that patients who took 10 mg doses twice a day were at higher risk for pulmonary embolisms or death compared to patients who took 5 mg doses or TNFis. At the time of the announcement, the FDA did not approve 10 mg tablets for rheumatoid arthritis patients. It only approved them for ulcerative colitis patients.

February 2019 FDA announcement on Xeljanz’s association with pulmonary embolism and death

The FDA’s February 25, 2019 Drug Safety Communication reported on Xeljanz’s associations with high doses of the drug and pulmonary embolisms and death. It also reported on Pfizer’s changing of the study patients’ dose. The FDA announced that they were working with the pharmaceutical giant to evaluate additional safety information for Xeljanz. It recommended that healthcare professionals follow the prescription recommendations for Xeljanz. The FDA also advised that they monitor patients for pulmonary embolisms. It recommended that Xeljanz patients speak to their healthcare provider before discontinuing the drug. The FDA advised them to immediately seek medical attention if they experience pulmonary embolism symptoms.

July 2019 Black box warning announcement

On July 26, 2019, the FDA announced their black box warning for Xeljanz. The warning stated that the drug was associated with pulmonary embolisms and death. The FDA also advised patients with a medical history of heart problems or blood clots to speak to their physician. It announced that it was limiting 10 mg tablets to ulcerative colitis patients who were not effectively treated with or suffered severe side effects from other drugs. The FDA advised Xeljanz patients to stop taking it if they experience blood clot symptoms. However, it reiterated that they speak to their healthcare professional before they stop taking the drug altogether. It also advised healthcare providers to stop prescribing Xeljanz and immediately evaluate patients with thrombosis symptoms.

January 2021 Pfizer announcement on Xeljanz study’s endpoint results

On January 27, 2021, Pfizer announced Study A3921133’s co-primary endpoint results. Its researchers found that 98 Xeljanz patients experienced a significant cardiovascular event compared to 37 TNFi patients. Heart attacks were the most frequently reported event. The researchers also found that 122 Xeljanz patients suffered cancer (excluding non-melanoma skin cancer) compared to 42 TNFi patients. Lung cancer was the most frequently reported cancer. This post-marketing study indicates that TNFis are safer than Xeljanz regarding cardiovascular events and cancer.

February 2021 FDA announcement on Xeljanz’s links with heart problems and cancer

On February 4, 2021, the FDA announced that Pfizer’s clinical trial found that Xeljanz was more likely to cause severe heart problems and cancer compared to TNFis. It also announced it had not received the trial’s final results yet. The FDA advised that patients speak to their healthcare provider before discontinuing Xeljanz. It also advised healthcare professionals to consider whether the drug’s risks outweigh its benefits. The FDA encouraged both patients and healthcare professionals to report Xeljanz’s adverse side effects to their MedWatch voluntary reporting program.