Secondary failure to treatment with recombinant human interleukin-1 receptor antagonist in Chinese patients with rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To assess the efficacy of intedeukin (IL)-1Ra,a recombinant human IL-1receptor antagonist,plus methotrexate ( MTX ) in patients with active rheumatoid arthritis ( RA ) refractory to MTX therapy.Methods A total of 54 patients with active RA,who had been taking MTX at a stable dosage,were randomized to receive daily subcutaneous injections of IL-1Ra (80 mg) or placebo.The proportion of patients who had a response as assessed by ACR20,ACR50 and ACR70 was analyzed using Chi-square test measures.Baseline variables and DAS28 were analyzed using Student's t-test (parametric) or Wilcoxon's rank sum test (nonparametric) as appropriate.Results After 24 weeks,more patients achieved clinical benefits treated with IL-1Ra plus MTX compared with MTX alone (64％ vs 17％,P=-0.004) as determined by the ACR20 improvement.In the IL-1Ra group,an ACR50 response was observed in 38％ and an ACR70 response in 17％.None of the patients treated with MTX alone achieved ACR50 or ACR 70 improvement.However,9 of 42 (21％) patients in the IL-1Ra group,who showed therapeutic response initially,had secondary drug failure to IL-1Ra therapy thereafter.A significant increase in mean DAS28 from baseline was found in the nonresponders to IL-1Ra,compared with placebo.Conclusion IL-IRa is effective for the treatment of patients with active RA by blocking IL-1.However,the efficacy of IL-1Ra is lost soon in about one-fifth of patients in soite of initial good resoonse.