SAN DIEGO, CA—The safety and efficacy of adalimumab in children 2—4 years of age were comparable to that observed in older children ages 4—17 with juvenile idiopathic arthritis (JIA), according to Daniel J. Kingsbury, MD, from Randall Children’s Hospital at Legacy Emanuel, Portland, OR, at the 2013 ACR/ARHP Annual Meeting.

Adalimumab is currently approved for use in moderate-to-severe JIA in patients ≥4 years of age. However, data regarding use in patients <4 years of age or patients ≥4 years of age weighing <15kg are limited. Dr. Kingsbury and colleagues aimed to assess the safety and efficacy of 1 year or more of adalimumab therapy in patients aged 2-<4 years or those ≥4 years old weighing <15kg with moderately to severely active polyarticular JIA.

In the ongoing Phase 3b, international, multicenter, open-label study, 32 patients with JIA were treated with adalimumab 24mg/m2 body surface area (max 20mg/dose) every other week with or without methotrexate for a minimum of 24 weeks and up to 96 weeks until they achieved the limit for age (≥4 years old) or weight (≥15kg).

Clinical endpoints included American College of Rheumatology pediatric (PedACR) 30/50/70/90 responses through Week 60, and JIA outcome parameters that included Physician’s Global Assessment of Disease (PhGA), Parent’s Global Assessment of Disease (PaGA), Child Health Assessment Questionnaire Disability Index (DI-CHAQ), Active Joint Count (AJC73), Limitation on Passive Motion (LOM69), C-reactive protein (CRP), tender joint count (TJC75), swollen joint count (SJC66), and Pain on Passive Motion (POM75).

Most patients were female and white; mean patient age at baseline was 3 years, with a mean disease duration of 12 months. “Baseline disease activity was consistent with moderately to severely active JIA, with a mean AJC of 9.8,” Dr. Kingsbury reported.

By Week 60, 90% of patients had achieved PedACR30, 80% had achieved PedACR50, 70% had achieved PedACR70, and 50% had achieved PedACR90. “High PedACR 50/70/90 response rates were achieved at Week 24 and maintained through Week 60,” he stated.

Statistically significant improvements in other JIA outcomes were also observed. At Week 60, mean change in PhGA of Disease Activity (VAS 0—100mm) was -42.7 (n=20, SD 28.17; P<0.001). Mean change in PaGA of Disease Activity (VAS 0—100mm) was -34.5 (n=20, SD 33.31; P<0.001).

Mean change in CRP was -0.3mg/dL (SD 1.83). Mean change in TJC75 was -4.5 (SD 5.85; P<0.05) and SJC66 reflected -8.4 (SD 7.15; P<0.001).

No adverse effects on height or weight were observed; however, data did reflect improvement in growth through Week 60 of the study, researchers concluded.