FDA Worried Jakafi May Have Cancer, Heart Risks Similar to Xeljanz

Federal drug regulators have stalled on making a decision about whether to expand approval of a drug known as Jakafi, because of fears it may carry similar cancer and heart risks as Xeljanz, a Pfizer rheumatoid arthritis drug which is part of the same class of medications.

In a press release issued on June 8, the drug maker Incyte announced the FDA has extended the review period of Jakafi (ruxolitinib), which is meant to be a new treatment for steroid-refractory chronic graft-versus-host disease (GVHD).

Jakafi belongs to the same class of medications as Xeljanz, which are known as Janus Kinase inhibitors, or JAK inhibitors, and is already approved for the treatment of myelofibrosis; a bone marrow disease.

Xeljanz (tofacitinib) was the first medication approved as a JAK inhibitor, and is authorized for treatment of rheumatoid arthritis, psoriatic arthritis and ulcerative colitis. When it was first introduced by Pfizer in 2012, it joined a lucrative market for rheumatoid arthritis drugs, which already included long-standing treatment options like Humira, Enbrel and other similar medications, known as tumor necrosis factor (TNF) inhibitors.

Amid aggressive marketing over the past eight years, Pfizer grew Xeljanz into a blockbuster medication, generating annual sales in excess of $2 billion worldwide, with more than 200,000 prescriptions. However, data from a recently completed study raised questions about serious side effects of Xeljanz, which are not disclosed on the drug’s warning label.

In February 2021, the FDA issued a safety communication about the potential Xeljanz cancer and heart risks, indicating data from a recently completed post-marketing study found users may be more likely to be diagnosed with cancer or experience major cardiovascular events.

Since then, the FDA has delayed a number of requests for approval involving JAK inhibitors, including both expanded use of Xeljanz and indications for newer medications from the same class, including Rinvoq and Olumiant.

Jakafi appears to be the latest JAK inhibitor delayed over FDA concerns, though Incyte only vaguely references an FDA request for additional data. The company expects the drug’s approval to be delayed until at least September 22.

Jakafi has been on the market since 2011. It is given to patients with GVHD in twice-daily doses at different strengths. The approval by the FDA would allow the company to produce a once-daily formulation specifically targeted at patients with GVHD.

Xeljanz Heart and Cancer Lawsuits

The study behind the FDA concerns was initially launched in January 2012, and given the long latency period for many cancers, many users now face concerns they require on-going medical monitoring to detect and diagnose cases in the future.

Although the drug maker disclosed that lung cancer on Xeljanz was the most frequently reported malignancy identified in the study, no information has been provided about other types of cancer identified, or potential signs and symptoms for which former users should be monitored. In addition, it remains unclear how the Xeljanz cancer cases were distributed in time and across different doses of the medication, as well as how long users were monitored.

While awaiting access to the full data, rheumatologists and other experts have raised serious concerns about how the medication should be prescribed and question whether the FDA will be required to further restrict user of the medication, or even potentially recommend a Xeljanz recall. However, health experts caution that users should not stop taking the medication without first consulting with their own healthcare provider.

Former users are now contacting lawyers who are investigating Xeljanz lawsuits and class action claims, to seek additional information which has not been disclosed and compensation for treatments they may now require.