In patients with an inadequate response or intolerance to standard therapy used for the management of juvenile idiopathic arthritis, baricitinib was efficacious with an acceptable safety profile, a study shows. The phase 3 trial included participants with polyarticular juvenile idiopathic arthritis, extended oligoarticular juvenile idiopathic arthritis, enthesitis-related arthritis, and juvenile psoriatic arthritis.
At 75 centers in 20 countries, 220 children and adolescents aged 2 to less than 18 years with an inadequate response after 12 or more weeks of treatment or intolerance to conventional synthetic or biologic disease-modifying antirheumatic drugs (DMARDs) entered a 2-week safety and pharmacokinetic period and a 12-week open-label lead-in period (10 weeks for the safety and pharmacokinetic subcohort). Participants meeting Juvenile Idiopathic Arthritis-American College of Rheumatology (JIA-ACR) 30 criteria (JIA-ACR30 responders) continued to a 32-week placebo-controlled double-blind withdrawal period with age-based dosing of barcitinib.
Based on a primary endpoint of time to disease flare during the double-blind withdrawal period, the study showed the following: “Time to disease flare was significantly shorter with placebo versus baricitinib (hazard ratio 0.241 [95% CI 0.128–0.453], P <0.0001). Median time to flare was 27.14 weeks (95% CI 15.29–not estimable) in the placebo group, and not evaluable for patients in the baricitinib group (<50% had a flare event). Six (3%) of 220 patients had serious adverse events during the safety and pharmacokinetic period or open-label lead-in period. In the double-blind withdrawal period, serious adverse events were reported in four (5%) of 82 patients (incidence rate [IR] 9.7 [95% CI 2.7–24.9] per 100 patient-years at risk) in the baricitinib group and three (4%) of 81 (IR 10.2 [2.1–29.7]) in the placebo group. Treatment-emergent infections were reported during the safety and pharmacokinetic or open-label lead-in period in 55 (25%) of 220 patients, and during the double-blind withdrawal period in 31 (38%) of 82 (IR 102.1 [95% CI 69.3–144.9]) in the baricitinib group and 15 (19%) of 81 (IR 59.0 [33.0–97.3]) in the placebo group. Pulmonary embolism was reported as a serious adverse event in one patient (1%; IR 2.4 [95% CI 0.1–13.3]) in the baricitinib group in the double-blind withdrawal period, which was judged to be related to study treatment.”