Etanercept safe, efficacious and tolerable for juvenile idiopathic arthritis: CLIPPER study.

New research revealed that Etanercept medication for up to 10 years was well tolerated, consistent with the established safety profile, and resulted in a lasting response in individuals who were still on active treatment. Etanercept's benefit-risk profile in juvenile idiopathic arthritis groups remained good. The trial results were published in the journal Rheumatology. 

Juvenile idiopathic arthritis (JIA) is the most common type of chronic arthritis that affects children before the age of 16 years and lasts for a few months or years or a lifetime. Joint pain, swelling, warmth, and stiffness that last at least 6 weeks are some of the symptoms of JIA. CLIPPER2 was an 8-year, open-label extension of the phase 3 b, 2-year CLIPPER study on the safety and efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), categorized as extended oligoarticular arthritis (eoJIA), enthesitis-related arthritis (ERA), or psoriatic arthritis (PsA). 

Participants with eoJIA aged 2-17 years old, ERA, or PsA each 12-17 years old and who received ≥1 etanercept dose at 0.8 mg/kg weekly reaching a maximum of 50 mg in CLIPPER trial could enter CLIPPER2 trial. The occurrence of malignancy was considered the primary end point of measurement. Efficacy assessments included proportions achieving JIA American College of Rheumatology (ACR) 30/50/70/90/100 criteria and ACR inactive disease criteria, and clinical remission (ACR criteria) or Juvenile Arthritis Disease Activity Score (JADAS) ≤1. 

Key findings: 

•  In total about 109/127 (86%) CLIPPER participants entered the CLIPPER2 trial.
• There were 55 of eoJIA, 31 of ERA, and 23 who had PsA; (99 in total [78%]) who were on active treatment.
• Of these 84 (66%) on active treatment completed 120 months of follow-up (32 [25%]). 
• There was one malignancy reported in the eoJIA group but there were no cases of active tuberculosis or deaths.
• Numbers and incidence rates [events per 100 patient-years] of TEAEs (excluding infections/ISRs) decreased from 193 [173.81] in Year 1-9 [27.15] in Year 10; TE infections and serious infections also decreased. 
• Over 45% of participants (N = 127) achieved JIA ACR50 responses from the second month onwards; 42 (33%) and 17 34 (27%) participants achieved JADAS and ACR clinical remission, respectively.

Thus, long-term etanercept treatment for up to 10 years was safe, tolerable, and beneficial in patients with JIA. 

Further reading: Vojinović J, Foeldvari I, Dehoorne J, et al. Ten-year safety and clinical benefit from open-label etanercept treatment in children and young adults with juvenile idiopathic arthritis [published online ahead of print, 2023 May 4]. Rheumatology (Oxford). 2023;kead183. doi: 10.1093/rheumatology/kead183