Xeljanz Cancer Risks Highlighted In Study Data

Harvey Kirk

By Harvey Kirk
Posted February 8, 2021


Updated April 2024: Saiontz & Kirk, P.A. is no longer investigating new Xeljanz cancer lawsuits.
The content on this page is for informational purposes only.

Serious Xeljanz cancer risks that have not been adequately disclosed by the drug makers have been recently uncovered in a completed study conducted by Pfizer. If earlier information and warnings had been provided for users about the Xeljanz cancer side effects, many individuals may have avoided a diagnosis by using an alternative treatment or monitoring for signs of specific types of cancer caused by Xeljanz.

Does Xeljanz Cause Cancer?

The FDA has issued a warning for healthcare providers and patients about the risk that Xeljanz causes cancer, after a review of preliminary data from a post-marketing study found a more than 42% increased incidence of cancer following Xeljanz or Xeljanz XR use, compared to older TNF inhibitors used for treatment of rheumatoid arthritis.

Out of 4,362 participants in this study, about 4.19% of Xeljanz users were diagnosed with cancer (122 events), compared to 2.89% of users receiving a TNF inhibitor, like Humira or Enbrel.

While the full data on Xeljanz cancer risks have not yet been released, the lawyers at Saiontz & Kirk, P.A. are investigating potential Xeljanz lawsuits involving individuals who developed any type of cancer. Potential cases are also being investigated for certain Xeljanz heart problems, as well as users who suffered a pulmonary embolism or blood clot injury following high doses of the arthritis and ulcerative colitis drug.

What Types of Cancer is Xeljanz Linked To?

Until the complete results of this study conducted by Pfizer are made available to independent experts and Xeljanz lawyers, it remains unclear what specific types of cancer Xeljanz causes.

According to a press release issued by Pfizer, lung cancer caused by Xeljanz was the most frequently reported cancer in the study, occurring at rates higher than would be expected. However, the drug maker has not yet updated the Xeljanz FDA label to include information about the link between side effects of Xeljanz and cancer, or added warnings for patients about symptoms of specific types of cancer Xeljanz is linked to.

Based on adverse event reports and other information, it appears that some of the most common cancers caused by Xeljanz may include:

  • Lung Cancer (non-smokers)
  • Breast Cancer
  • Colon Cancer
  • Prostate Cancer
  • Pancreatic Cancer
  • Non-Hodgkin’s Lymphoma

Xeljanz and Skin Cancer

This new study data does not appear to provide any new insight into the link between Xeljanz and skin cancer. The reported increased incidence of cancer from Xeljanz specifically excluded non-melanoma skin cancer (NMSC) from the study results.

A prior study presented in 2015 examined the Xeljanz skin cancer risk and found that the incidence rates among individuals with rheumatoid arthritis treated with the medication “appeared to be stable”.

At this time, our Xeljanz cancer lawyers are not investigating or pursuing cases involving non-melanoma skin cancer. However, we will continue to monitor the evolving data on this potential risk.

Failure to Warn About Xeljanz Cancer Risks

Xeljanz (tofacitinib) was introduced in 2012, as the first member of a new class of medications known as Janus kinase (JAK) inhibitors, which work in a unique way deep inside the cell to disrupt cellular activities.

Since the medication was approved, it has been aggressively marketed by the drug maker, and quickly grew to become a blockbuster treatment for rheumatoid arthritis, psoriatic arthritis and ulcerative colitis. However, there is increasing evidence that the drug makers failed to adequately warn about serious Xeljanz cancer risks.

Pfizer has yet to update the Xeljanz FDA warning label warnings to any information on the types of cancer seen, or the cancer symptoms users should monitor for.

The History of the Xeljanz FDA Warning Label

The Xeljanz warning label was updated in 2019, after early data from the same study that highlighted the Xeljanz cancer risk found that higher doses may cause serious and potentially life-threatening blood clots in the lungs, known as pulmonary embolism. However, it now appears that problems with Xeljanz extend beyond blood clots and could impact lower doses as well.

On February 4, 2021, the FDA issued a new drug safety communication, announcing that preliminary results from a clinical trial showed an increased risk of serious heart-related problems and cancer from Xeljanz and Xeljanz XR when compared to use of another type of medication, known as a TNF (tumor necrosis factor) inhibitor:

When FDA first approved [Xeljanz], we required the manufacturer, Pfizer, to conduct a safety clinical trial in patients with RA who were taking methotrexate to evaluate the risk of serious heart-related events, cancer, and infections. The trial studied two doses of [Xeljanz] (5 mg twice daily, which is the approved dosage for RA, and a higher 10 mg twice daily dosage) in comparison to another type of RA medicine called a TNF inhibitor. Patients in the trial were required to be at least 50 years old and have at least one cardiovascular risk factor.

In February 2019 and July 2019, we warned that interim trial results showed an increased risk of blood clots and death with the higher 10 mg twice daily dosage, and as a result, approved a Boxed Warning to the [Xeljanz] prescribing information. The clinical trial is now complete and initial results show a higher occurrence of serious heart-related events and cancer in RA patients treated with both doses of [Xeljanz] compared to patients treated with a TNF inhibitor. FDA is awaiting additional results from the trial.

2 Comments • Add Your Comments

  • Richard says:

    I would not use it now.

    Posted on June 14, 2021 at 5:37 am

  • Jill says:

    I took xeljanz for almost a year and now I am fighting pancreatic cancer.

    Posted on June 4, 2022 at 12:03 pm

Add Your Comments

  • Have Your Comments Reviewed by a Lawyer

    Provide contact information below and additional private comments if you want an attorney to contact you to review a potential case.

    The information below will not be published to this page.

  • NOTE: Providing information for review by an attorney does not form an attorney-client relationship.

  • This field is for validation purposes and should be left unchanged.