Efficacy and Safety of Tocilizumab for Polyarticular-Course Juvenile Idiopathic Arthritis in the Open-Label Two-Year Extension of a Phase III Trial.

OBJECTIVE: To report the 2-year efficacy and safety of tocilizumab (TCZ) in patients with polyarticular-course juvenile idiopathic arthritis (JIA). METHODS: Patients ages 2-17 years with active polyarticular-course JIA, in whom treatment with methotrexate was unsuccessful, received 16 weeks of open-label intravenous TCZ in part 1 (once every 4 weeks: 8 mg/kg or 10 mg/kg for body weight [BW] <30 kg; 8 mg/kg for BW ≥30 kg). Assessments were based on the JIA-American College of Rheumatology (ACR) response (defined as percentage of improvement in ≥3 of the 6 JIA core response variables [CRVs]). Patients with at least a JIA-ACR30 response (defined as ≥30% improvement in ≥3 of the 6 JIA CRVs without worsening in >1 of the remaining JIA CRVs by >30%) at week 16 were randomly assigned (1:1) to receive TCZ or placebo in part 2. Patients remained in part 2 until either week 40 or the occurrence of JIA flare. Upon starting part 3, all patients received open-label TCZ. At week 104 of the study, efficacy was assessed using JIA-ACR50/70/90 response rates (defined as 50%, 70%, or 90% improvement, respectively), achievement of inactive disease, and the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71). Safety was assessed in the all-exposure population per 100 patient-years of exposure. RESULTS: Overall, 188 patients entered part 1, 166 patients entered part 2, and 160 patients entered part 3. By week 104, among the 188 patients in the modified intent-to-treat group who received TCZ, JIA-ACR50/70/90 response rates were 80.3%/77.1%/59.6%, respectively, the median JADAS-71 score decreased from 3.6 at week 40 to 0.7 at week 104, 51.1% of patients had achieved inactive disease, and 31 of 66 patients who had been receiving glucocorticoids discontinued them. Adverse event (AE) and serious AE rates were 406.5 per 100 patient-years and 11.1 per 100 patient-years, respectively. The infection rate was 151.4 per 100 patient-years, and the serious infection rate was 5.2 per 100 patient-years. CONCLUSION: Patients treated with TCZ for polyarticular-course JIA showed high-level disease control for up to 2 years. The TCZ safety profile was consistent with that previously reported.

Neutropenia During Tocilizumab Treatment Is Not Associated with Infection Risk in Systemic or Polyarticular-course Juvenile Idiopathic Arthritis.

OBJECTIVE: To determine whether neutropenia is associated with increased risk for infection in patients with systemic juvenile idiopathic arthritis (sJIA) and polyarticular-course juvenile idiopathic arthritis (pcJIA) treated with tocilizumab (TCZ). METHODS: Data up to Week 104 from 2 phase III trials of intravenous TCZ in sJIA (n = 112; ClinicalTrials.gov, NCT00642460) and pcJIA (n = 188; ClinicalTrials.gov, NCT00988221) were pooled. Worst common toxicity criteria grade and lowest observed absolute neutrophil count (ANC) were identified for each patient. Associations between patient characteristics and lowest observed ANC were tested using univariate regression analysis. Infection and serious infection rates per 100 patient-years (PY) in periods associated with grades 1/2 and 3/4 neutrophil counts were compared with rates associated with normal neutrophil counts. RESULTS: ANC decreased to grade ≥ 3 in 25.0% and 5.9% of sJIA and pcJIA patients, respectively, and decreases were transient. Young age (p = 0.047) and methotrexate use (p = 0.012) were positively associated with neutropenia in patients with sJIA but not in patients with pcJIA. The rate of serious infections in patients with sJIA (10.9/100 PY; 95% CI 6.8-16.5) tended to be higher than in patients with pcJIA (5.2/100 PY; 95% CI 3-8.5). No increase in rates of serious or nonserious infections was observed during periods of neutropenia in either trial. CONCLUSION: Patients with JIA treated with TCZ experienced transient neutropenia that was not associated with an increased number of infections.

Growth During Tocilizumab Therapy for Polyarticular-course Juvenile Idiopathic Arthritis: 2-year Data from a Phase III Clinical Trial.

OBJECTIVE: Evaluate growth in patients with polyarticular-course juvenile idiopathic arthritis (pcJIA) treated with tocilizumab (TCZ) for up to 2 years in a phase III trial. METHODS: Patients with pcJIA lasting at least 6 months and inadequate response to methotrexate received open-label TCZ intravenously every 4 weeks (randomly assigned to 8 or 10 mg/kg if they weighed < 30 kg; received 8 mg/kg if they weighed ≥ 30 kg) for 16 weeks. Patients with JIA American College of Rheumatology 30 response at Week 16 were randomly assigned to TCZ or placebo for 24 weeks, with an open-label extension through Week 104. Mean ± SD height velocity (cm/yr) and World Health Organization (WHO) height SD score (SDS) were measured in patients receiving ≥ 1 dose of TCZ who did not receive growth hormone and in patients whose baseline Tanner stage was ≤ 3. RESULTS: The study included 187 of 188 patients (99.5%) with mean WHO height SDS -0.5 ± 1.2, which was unrelated to age or disease duration (Spearman rank correlations r = 0.08 and r = -0.12, respectively). There were 123 patients at Tanner stage ≤ 3 at baseline, among whom 103 completed the study with 2 years of height SDS data. Mean height SDS increased from baseline to year 2 (+0.40, p < 0.0001). In 74 of 103 patients (72%), height SDS was greater than at baseline, and mean height velocity was 6.7 ± 2.0 cm/year. CONCLUSION: Among patients with pcJIA at Tanner stage ≤ 3 at baseline, 72% (74/103) had increased height SDS at the end of the study.

Catch-up growth during tocilizumab therapy for systemic juvenile idiopathic arthritis: results from a phase III trial.

OBJECTIVE: To investigate the impact of tocilizumab treatment on growth and growth-related laboratory parameters in patients with systemic juvenile idiopathic arthritis (JIA) enrolled in a phase III clinical trial. METHODS: Patients with systemic JIA ages 2-17 years (n = 112) received tocilizumab in a 12-week, randomized, placebo-controlled period and a long-term open-label extension. Height velocity and standard deviation (SD) score; levels of insulin-like growth factor 1 (IGF-1), osteocalcin (OC), and C-telopeptide of type I collagen (CTX-I); and Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71) were measured in a post hoc analysis of 83 patients who never received growth hormone and did not reach Tanner stage 5 by the end of the first year of treatment. RESULTS: Patients had stunted growth at baseline (mean height SD score -2.2). During tocilizumab treatment, males (73%) and females (83%) experienced above-normal mean height velocities of 6.6 cm/year (P < 0.0001 versus World Health Organization norms). Mean height SD score increases during year 1 (0.29) and year 2 (0.31) were significant (both P < 0.0001). The mean SD score for IGF-1 levels increased significantly (-0.2 for year 1 and -0.1 for year 2 versus -1.0 at baseline; both P < 0.0001). Mean OC and CTX-I levels (both P < 0.0001) and the OC:CTX-I ratio (P = 0.014) significantly increased from baseline to year 2. In multiple regression analysis, first-year height velocity had a significant inverse relationship to JADAS-71 at year 1, age, mean glucocorticoid dosage during the year, and height SD score at baseline. CONCLUSION: Our findings indicate that during treatment with tocilizumab, patients with systemic JIA experience significant catch-up growth, normalization of IGF-1 levels, and bone balance improvement favoring bone formation.

The epicurean fly: using Drosophila melanogaster to study metabolism.

In this review, the utility of Drosophila melanogaster as a model organism for research in metabolism will be demonstrated. Importantly, many metabolic pathways are conserved in both man and the fly. Recent work has highlighted that these conserved molecular pathways have the potential to give rise to similar phenotypes. For example, it has proven possible to generate obese and diabetic Drosophila; conversely, genetic manipulation can also generate lean and hypoglycemic phenotypes. From conserved circulating hormones to key enzymes, the fly is host to a variety of homologous, metabolically active signaling mechanisms. The world of Drosophila research has not only a rich history of developing techniques for exquisite genetic manipulation, but also continues to develop genetic methodologies at an exciting rate. Many of these techniques add to the cadre of experimental tools available for the use of the fly as a model organism for studying carbohydrate and lipid homeostasis. This review is written for the pediatric-scientist with little background in Drosophila, with the goal of relaying the potential of this model organism for contributing to a better understanding of diseases affecting today's children.