Preliminary evidence on abatacept safety and efficacy in refractory juvenile localized scleroderma.

Objective: To evaluate the safety and efficacy of abatacept treatment for refractory juvenile localized scleroderma (jLS) in a retrospective study.

Methods: A multicentre cohort study was performed to evaluate jLS subjects treated with abatacept with follow-up for 12 months to maximum of 24 months. Assessments at 6-month intervals included skin activity measures and physician global assessment of activity (PGA-A). Descriptive statistical analysis was performed.

Results: Eighteen subjects were studied with median age of 13.4 years, the majority had linear scleroderma subtype, and musculoskeletal involvement. All had previously failed MTX and/or mycophenolate mofetil treatment and glucocorticoids. Abatacept was added to the subject's maintenance DMARD treatment; 13 also received glucocorticoids at start of abatacept. No serious adverse events occurred. Skin activity and PGA-A scores declined in nearly all by 6 months and continued to improve from 6 to 12 months. At 12 months, 15 (83%) subjects were considered responders, two (11%) treatment failures, and one dropped out for adverse event. Response was sustained for 11 (61%) subjects to 18 months and eight (44%) to 24 months. Overall, four (22%) subjects were treatment failures and three (16.7%) discontinued abatacept for adverse event. Active musculoskeletal problems improved in most affected subjects. Ten subjects were able to discontinue initial glucocorticoid and six concomitant DMARD treatment.

Conclusion: Abatacept was found to be safe and effective for jLS subjects refractory to standard of care treatment. Subjects experienced improvement in both skin and musculoskeletal activity. Prospective studies should be performed to more fully evaluate abatacept's efficacy.