SAN FRANCISCO, CA—Abatacept demonstrated continued efficacy in patients with juvenile idiopathic arthritis (JIA), according to interim results from a longitudinal registry presented at the 2015 ACR/ARHP Annual Meeting.

Daniel J. Lovell, MD, from Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, and colleagues assessed the effectiveness and safety of abatacept in children with JIA.

The Pediatric Rheumatology Collaborative Study Group and Paediatric Rheumatology International Trial Organization (PRINTO) enrolled patients with JIA currently on or starting abatacept following a standardized protocol.  Duration of follow-up was set for 10 years, with visits every 3 months for Year 1, every 6 months for Years 2–5, and yearly for Years 6–10. Current data reflect follow-up duration of 2 years collected through March 26, 2015.

Of the 146 patients enrolled, 133 provided data for this analysis, for 79.4 total person-years of observation, 67.9 years on abatacept. About one-third of patients were newly initiated on abatacept and 28% were biologic-naïve. Specifically, 39% of patients had been treated with abatacept for 0–1 years and 28% for 1–2 years; abatacept was continued during follow-up in 113 patients (85%).

At baseline, JIA subtypes were as follows: systemic (2%), oligoarticular (21%), polyarticular RF- (54%), polyarticular RF+ (10%), psoriatic (5%), enthesitis-related (2%), and undifferentiated (6%).  Eighty-six percent of the patients were taking concomitant medication for JIA: methotrexate (64%), NSAIDs (49%), systemic steroids (17%), leflunomide (5%), hydroxychloroquine (5%), cyclosporine (1%), and sulfasalazine (1%). Study patients were given abatacept IV every 4 weeks in 83% and SC weekly in 17%.

At 2 years, persistent treatment efficacy was seen with low MD Global Disease Activity (VAS 0–10) and low number of active joints. Also, more than 30% of patients were in clinical inactive disease.

A total of 10 serious adverse events were reported in 9 patients. Rate of adverse events was 12.6 per 100 patient-years of exposure (95% CI: 6.9, 21.0). Two serious infections occurred, a methicillin-resistant Staphylococcus aureus wound infection and aseptic meningitis. One patient discontinued abatacept due to anaphylaxis.

Treatment with abatacept was “well tolerated and no new safety signals were seen,” Dr. Lovell concluded.