Xeljanz (tofacitinib citrate) was approved by the US Food and Drug Administration (FDA) for the treatment of active ankylosing spondylitis in adults who have had an inadequate response or intolerance to one or more tumor necrosis factor (TNF) blockers in December 2021. It is the first janus kinase (JAK) inhibitor to be approved for use in ankylosing spondylitis.
Xelijanz is not recommended for use in combination with biologic disease-modifying antirheumatic drugs (DMARDs) or potent immunosuppressants such as azathioprine and cyclosporine in people with ankylosing spondylitis.
Xelijanz is also approved for use in patients with rheumatoid arthritis, psoriatic arthritis, ulcerative colitis and polyarticular course juvenile idiopathic arthritis.
Approval of Xeljanz for ankylosing spondylitis was delayed while the results from ORAL Surveillance were reviewed
In August 2020, Pfizer filed a supplemental New Drug Application (sNDA) for approval of Xeljanz in the US for ankylosing spondylitis and at that time a decision was expected from the FDA in the second quarter of 2021. However, the FDA delayed making a decision regarding the use of the drug for this new indication.
The FDA cited its ongoing review of data from ORAL Surveillance, a post-marketing safety study conducted in people with rheumatoid arthritis treated with Xeljanz, as a factor contributing to its delay in making a decision about the approval of Xeljanz for ankylosing spondylitis in July 2021.
After initial results from the ORAL Surveillance study were reviewed, the FDA warned in February 2021, that treatment with Xeljanz was associated with an increased risk of serious heart-related problems and cancer when compared with the tumor necrosis factor (TNF) inhibitors Enbrel (etanercept) and Humira (adalimumab).
Xeljanz approved for use in ankylosing spondylitis following positive phase 3 results
Xeljanz was approved for use in ankylosing spondylitis based on the results of a phase 3 trial comparing Xeljanz 5 mg twice daily with placebo. The trial was conducted in 269 adults with active disease.
A total of 56.4 percent of patients treated with Xeljanz achieved an Assessment in SpondyloArthritis International Society (ASAS) 20 response after 16 weeks of treatment, which was significantly more than the 29.4 percent of placebo recipients who achieved an ASAS20 response. Significantly more people treated with Xeljanz also achieved an ASAS40 response compared with those receiving placebo (40.6 versus 12.5 percent).
ASAS scores look for improvements across a range of parameters including pain, function and inflammation. Achieving ASAS20 and 40 represents an at least 20 percent and 40 percent improvement in symptoms, respectively.