About half of the children with juvenile idiopathic arthritis who are treated with etanercept achieve inactive disease status, and those who experience early disease onset and lack of involvement of the wrist joint at baseline are more likely to do so, according to data presented by Dr. Nicoletta Solari during the pediatric rheumatology session of the annual European Congress of Rheumatology.
Dr. Solari presented findings from a chart review of 187 consecutive children with JIA who were treated with etanercept between 2002 and 2011 and then were followed for at least 6 months after treatment initiation.
Based on Wallace criteria for disease inactivity (J. Rheum. 2004;31:2290-4), 50.3% of patients had disease inactivity at their last follow-up, and the time to disease inactivity ranged from 2 months to 6.3 years, with a median of just 0.7 years, according to Dr. Solari of the University of Genoa, Italy.
The chart review showed that the strongest predictors of achieving inactive disease status at the last follow-up were age at onset of less than 3.6 years and lack of wrist joint involvement (adjusted odds ratio, 1.8 and 2.1, respectively).
"The patients included in the study had disease duration ranging from 3 months to 21 years, with a median duration of 5 years. Treatment duration from baseline to follow-up among the 173 patients who were treated for at least 6 months was up to 10.5 years, with a median of 2.4 years," Dr. Solari said in an interview.
All patients were treated with the standard 0.8 mg/kg per week dose of etanercept during the study period.
The increasing use of biologic agents, along with the results that have been seen with these agents, has raised the bar when it comes to expectations for remission in patients with juvenile idiopathic arthritis, but clinical studies of these agents typically fail to include assessment of remission, Dr. Solari said, noting that even less is known about the predictors of achieving remission.
Dr. Nicoletta Solari
"These findings indicate that about half of the children with JIA who are treated with etanercept in real-life clinical settings are able to attain a state of complete disease quiescence," according to Dr. Solari.
The findings are consistent with those reported from German and Dutch national registries, as well as from two previous studies that also aimed to evaluate the prevalence of inactive disease in patients whose JIA was treated with etanercept.
"Notably, these results refer to all JIA subtypes, including systemic patients," Dr. Solari said, explaining that several prior studies have shown that the systemic subtype of JIA responds less to etanercept than do the other disease categories.
The findings of the current study may have important implications for clinical practice.
"In our study, the lack of involvement of the wrist joint was the strongest predictor of both achievement of inactive disease at last follow-up visit and a shorter time to attainment of inactive disease after etanercept initiation," Dr. Solari said. This observation implies that wrist disease is a marker of poorer therapeutic outcome in children with JIA treated with etanercept, she noted.
"Thus, the presence of arthritis in the wrist joint might identify a subgroup of JIA patients with poorer outcome and who subsequently may have an indication for earlier introduction of etanercept during their disease course or the administration of etanercept in combination with methotrexate. This finding might help to improve the rate of remission," she said.
Session chair Dr. Nico Wulffraat of the University of Utrecht (the Netherlands) commented: "Many of us feel that involvement of the hips and neck are poor prognostic features."
Dr. Solari replied that she and her coinvestigators looked at that specifically, but they did not find a significant difference in response to etanercept with involvement of the joints.