Etanercept provided 4-year clinical efficacy in patients with polyarticular-course juvenile rheumatoid arthritis, and was well tolerated without an increase in the rate of serious infection, reported Dr. Daniel J. Lovell and colleagues.
The researchers had previously conducted a randomized, open-label trial that found that clinical efficacy could be sustained for at least 2 years. From this initial group of 69 patients, Dr. Lovell and colleagues enrolled 58 patients in a multicenter, open-label extension study to assess etanercept's long-term efficacy and safety (Arthritis Rheum. 2006;54:1987–94).
The study group had a mean age of 10 years, of which 39 (67%) were female. Five participants (9%) had pauciarticular JRA, 34 (59%) had polyarticular JRA, and 19 (33%) had systemic JRA. The mean duration of their disease was 5.9 years; 100% had previously used methotrexate (MTX), 97% had used NSAIDs, and 38% had previously used corticosteroids with a mean dose of 5.7 mg/day. At year 4, 32 of the 58 patients remained, with a similar demographic composition, disease history, and previous use of JRA therapies.
Dr. Lovell, of Cincinnati Children's Hospital Medical Center, and his colleagues calculated infection safety data from all 69 patients enrolled in the original study and the long-term extension. Results showed that eight patients (12%) “had serious infections, for a rate of 0.04 infections per patient-year. The exposure-adjusted rates of serious infection did not increase over time with continuing etanercept treatment,” the researchers reported.
When it came to long-term efficacy, data from the 58 patients in the extension study were assessed. Patient assessment of pain, on a 0–10 scale, was a median of 3.6 at baseline, 0.3 at 1 year, and 0.9 by the 4th year. The physician's global assessment on a 0–10 scale was a median 6.5 at baseline, 2.0 at 1 year, and 1.0 at year 4.
For total joints with active disease, the median at baseline was 28.5, 2.5 at 1 year, and 2.0 at 4 years. When participants scored the number of joints experiencing limitation of motion and painful/tender joints, it was a median of 9 at baseline, and 0 at both the 1-year and 4-year marks. The articular severity score for participants was a median 88 at baseline, 25 at year 1, and 18 at year 4.
By the second year of the extension study, 8 (17%) of the 47 remaining patients were receiving MTX at a mean dose of 13.4 mg/week, and by the 4th year 13 of 38 patients (34%) were receiving MTX at a mean dose of 15.8 mg/week. According to the researchers, 23 (40%) of the 58 patients were taking low-dose steroids at the start of the extension study, but 70% of these patients discontinued steroid use, while another 4 participants decreased their dosages. From the original 58 participants in the extension study, 6 withdrew due to lack of efficacy.
“Patients with JRA showed sustained improvements in disease activity measures in this extension study. ACR Pediatric 30 scores observed at year 1 were sustained through year 4 of treatment with etanercept,” said Dr. Lovell. Adding MTX to the treatment regimen may have contributed to the sustained improvements.
“Overall, etanercept offers significant clinical benefit with an acceptable safety profile,” the investigators concluded.