medwireNews: Infliximab appears efficacious for patients with juvenile-onset spondyloarthritis (JoSpA) who have failed to respond to conventional treatment, phase 3 study findings show.
The researchers comment that “to date, the efficacy of [biologic] DMARDs in children with JoSpA has not been established.”
They continue, however, that “their effect in polyarticular [juvenile idiopathic arthritis] and adults with axial SpA supports their use in children and adolescents with JoSpA and enthesitis-related arthritis.”
Indeed, they found that among 12 patients aged an average of 15 years who were randomly assigned to receive infliximab 5 mg/kg at weeks 0, 2, 6, and 12, the number of active joints affected by swelling, limited range of motion, and pain or tenderness decreased from 4.5 at baseline to 1.4 at 12 weeks.
This improvement in the study’s primary endpoint was significantly superior to the reduction seen among the 14 patients assigned to placebo, whose active joint count fell from 6.1 to 4.1.
“We selected the number of active joints as our primary outcome, due to its clinical implications, which strongly indicates the disease severity in this population,” Adalberto Loyola-Sanchez (University of Alberta, Edmonton, Canada) and colleagues explain.
“In addition, our results demonstrate that this outcome is sensitive to change, and clinically important differences can be found even in small samples.”
Similar 12-week benefits were also seen with infliximab over placebo for the mean number of swollen joints (1.5 vs 4.5), tender joints (1.0 vs 7.8), and tender entheses (1.4 vs 7.1), as well as high-sensitivity C-reactive protein levels (3.1 vs 19.7 mg/dL).
And the proportion of patients achieving the ACR-Pedi (JIA ACR) 30, 50, 70, and 90 response criteria at 12 weeks was significantly higher among the infliximab group, at 83% to 50% versus 36% to 0% among those taking placebo. Loyola-Sanchez and colleagues note in Arthritis Research & Therapy that while 33% of patients in the infliximab group achieved ACR-Pedi 100 responses compared with none of those in the placebo group, the small number of patients meant the difference was not statistically different.
At the end of the 12 weeks, the participants continued to take infliximab (5 mg/kg every 6 weeks) or placebo during a 42-week open label extension phase.
“The repeated mixed model analyses showed sustained efficacy of infliximab on the primary and most secondary outcomes during the open-label phase,” the researchers report.
They confirm that there were no serious adverse events during the study. The overall rates of adverse events were 75% in the infliximab group and 57% in the placebo group, with infections and infusion reactions occurring more frequently among patients taking infliximab than placebo, at 41% versus 28% and 41% versus 7%, respectively.
“Although the prevalence of JoSpA in Paediatric Rheumatology clinics is relatively low, the disease seems more active and severe than other JIA categories and adult-onset SpA,” comment Loyola-Sanchez et al.
They conclude that “infliximab is efficacious and is a good treatment alternative for JoSpA.”
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