The Food and Drug Administration has alerted the public to an increased risk of serious heart-related problems and cancer risk associated with the Janus kinase inhibitor tofacitinib (Xeljanz, Xeljanz XR), based on early results from a safety clinical trial comparing tofacitinib and tumor necrosis factor inhibitors in patients with rheumatoid arthritis (RA).
The FDA is awaiting further results from the trial, but in a safety communication issued on Feb. 4, the agency advised patients not to discontinue tofacitinib without consulting their health care providers and advised health care professionals to weigh the risks and benefits when prescribing the drug and continue to follow the current prescribing information.
Tofacitinib was approved for treatment of RA in 2012 at a 5-mg dose. After this approval, the FDA required drug manufacturer Pfizer to conduct a safety clinical trial that included the 5-mg twice-daily dose and a 10-mg twice-daily dose that is currently approved only for ulcerative colitis. In addition to RA and ulcerative colitis, tofacitinib is approved for adults with active psoriatic arthritis and patients aged 2 years or older with active polyarticular course juvenile idiopathic arthritis.
Pfizer announced partial results of the study, known as the ORAL Surveillance trial, in a press release on Jan. 27. The randomized trial included 4,362 RA patients aged 50 years and older who received either 5-mg or 10-mg doses of tofacitinib or a TNF inhibitor (adalimumab or etanercept).
The full results have yet to be released, but based on data from approximately 10,000 person-years for the combined tofacitinib groups and approximately 5,000 person-years for the TNF inhibitor group, the rate of major cardiovascular adverse events was significantly higher in the combined tofacitinib group, compared with the TNF inhibitor group (0.98 vs. 0.73 per 100 person-years; hazard ratio, 1.33). In addition, the rate of adjudicated malignancies was significantly higher in the tofacitinib group, compared with the TNF inhibitor group (1.13 vs. 0.77 per 100 person-years; HR, 1.48).
In February 2019, the FDA issued a warning stating an increased risk of pulmonary embolism and death associated with the 10-mg twice-daily dose of tofacitinib, following interims results from the safety study.
In July 2019, the FDA added a boxed warning to tofacitinib advising of the increased risk for pulmonary embolism and death associated with the 10-mg twice-daily dose.
The FDA encouraged health care professionals and patients to report any side effects from tofacitinib or other medications through the FDA MedWatch program online or by phone at 1-800-332-1088.
Until nuances revealed, no change in practice
The preliminary study findings contain some nuances that are a bit complicated from a statistical standpoint, according to Daniel Furst, MD, professor emeritus of medicine at the University of California, Los Angeles; adjunct professor at the University of Washington, Seattle; and research professor at the University of Florence (Italy).
Dr. Daniel E. Furst
This is supposed to be a noninferiority study, so something might not be noninferior, “but that doesn’t mean it is inferior,” explained Dr. Furst, who is also a member of the MDedge Rheumatology Editorial Advisory Board.
Dr. Furst said he was surprised by the study findings, because “I didn’t expect there to be any differences, and in fact it is not clear how great the differences are” among the groups in the study, he said.
When the complete findings are released, in one of the instances, “the statistics may show a very small statistical difference that indicates we may have to be more careful in this particularly high-risk group,” Dr. Furst noted.
“When we understand the data more closely, we may find that there are some nuances we need to be careful about,” he said. However, “until those data are out, I would not make any changes in my practice.”
Whether the current study findings represent a class effect is “impossible to say,” since tofacitinib affects three enzymes, while other JAK inhibitors affect only one or two, he noted.
Dr. Furst disclosed receiving grant/research support from and/or consulting for AbbVie, Actelion, Amgen, Bristol-Myers Squibb, Corbus, the National Institutes of Health, Novartis, Pfizer, and Roche/Genentech.
Updated on 2/8/2021.