Risk of gastrointestinal perforation in patients with rheumatic diseases exposed to janus kinase inhibitors versus adalimumab: nationwide cohort study.

OBJECTIVE: To compare the risk of gastrointestinal perforation (GIP), a rare but serious adverse event, in patients initiating a Janus kinase inhibitor (JAKi; tofacitinib, baricitinib, upadacitinib or filgotinib) versus adalimumab (tumor necrosis factor inhibitor) among a comprehensive real-world population of patients with rheumatic diseases.

METHODS: We conducted a nationwide population-based cohort study of the French national health data system, the exposed group initiating a JAKi and the comparison group adalimumab. We included all individuals with a rheumatic disease who had their first dispensation of these treatments from July 2017 to December 2021. The primary endpoint was the occurrence of GIP (end of follow-up May 2022). Weighted hazard ratios (wHRs) were estimated with the inverse probability of treatment weighting method to account for confounding factors. Concomitant administration of systemic corticosteroids, non-steroidal anti-inflammatory drugs and proton pump inhibitors were time-varying variables.

RESULTS: The cohort included 39,758 patients: 12,335 and 27,423 in the JAKi and adalimumab groups (mean age 58.2 and 47.3 years; female 76% and 58%; rheumatoid arthritis 85.3% and 27.3%, and psoriatic arthritis/axial spondyloarthritis 14.7% and 72.7%). During follow-up, 38 and 42 GIPs occurred in the JAKi and adalimumab groups, incidence rates were 2.1 (95% CI 1.5-2.8) and 1.1 (0.8-1.5) per 1000 person-years respectively. Rates of GIP did not differ between JAKi and adalimumab groups : wHR 1.1 (95% CI 0.7-1.9) (p=0.65). Despite lack of power in some subgroup analyses, results were consistent whatever the JAKi or rheumatic disease subgroup.

CONCLUSION: In this nationwide cohort study, the rates of GIP did not differ between groups of patients initiating JAKi and adalimumab treatment. These results need to be confirmed in other observational studies.