Etanercept Well Tolerated in Various Pediatric JIA Subtypes

SAN DIEGO, CA—At the 2013 ACR/ARHP Annual Meeting, study investigators presented that etanercept treatment for 96 weeks was well tolerated and effective in pediatric patients with various juvenile idiopathic arthritis (JIA) subtypes – extended oligoarticular idiopathic arthritis, enthesitis-related arthritis, or psoriatic arthritis.

Etanercept is a tumor necrosis factor (TNF) blocker currently approved for the treatment of pediatric patients with the polyarticular subtype of JIA.

CLIPPER was a Phase 3b, 96-week, open-label, multicenter study.  Patients with extended oligoarticular JIA (n=60), enthesitis relaed arthritis (n=38), or psoriatic arthritis (n=29) received etanercept 0.8mg/kg once weekly (max dose 50mg) for 96 weeks. Safety was assessed by reporting treatment-emergent adverse events (TEAE) throughout the study. Study endpoints included the proportions of subjects achieving JIA American College of Rheumatology 30/50/90 responses and inactive disease criteria at Week 96.

The recent interim 12-week data from the CLIPPER study supported the approval for the treatment of pediatric patients with extended oligoarticular, enthesitis-related, and psoriatic JIA subtypes in Europe. In this second part of the CLIPPER study, Tamás Constantin, MD, from Semmelweis University, Budapest, Hungary, and colleagues set out to assess the long-term safety and clinical benefit of etanercept in pediatric patients with these JIA subtypes. 

Regarding safety data, the most frequently reported TEAEs were (number of events, events per patient year [EPPY]): headache (23, 0.107), pyrexia (12, 0.056), diarrhea (10, 0.046), leukopenia (8, 0.037), increased alanine aminotransferase (8, 0.037), and arthralgia (8, 0.037). 

In the overall population, the percentage of patients who achieved JIA ACR 30/50/70/90/100 responses at Week 12 were 88.6%, 81.1%,61.5%, 29.8%, and 23.0%, respectively. By Week 96, the overall proportions (95% CI) of subjects achieving JIA ACR 30/50/90/inactive disease criteria were 99.1% (94.9, 100), 98.1% (93.5, 99.8), 65.4% (55.6, 74.4), and 34.0% (25.0, 43.8), respectively. 

Dr. Constantin noted there was “approximately a 2-fold and 3-fold increase in the percentage of JIA ACR 90 and inactive disease responders from Week 12 to Week 96.” Overall, as expected from the previous data on polyarticular JIA, 96-week treatment of etanercept was well tolerated and effective in patients with these particular JIA subtypes, researchers concluded.