Sustained Clinical Response in Psoriatic Arthritis Patients Treated with Anti-TNF Agents: A 5-year Open-Label Observational Cohort Study

Abstract

To investigate the efficacy, toxicity, and drug discontinuation in patients with psoriatic arthritis treated with anti-tumor necrosis factor agents. Sixty-five patients with active disease were included in this open-label study. They had tender or swollen joint count ≥5, Psoriatic Arthritis Severity Index (PASI) score ≥10, and erythrocyte sedimentation rate ≥28 mm Hg/1st hour and/or C-reactive protein ≥10 mg/L. All were refractory to at least 2 disease-modifying antirheumatic drugs. Thirty were treated with infliximab, 25 with etanercept, and 10 with adalimumab. Infliximab (5 mg/kg body weight) was given intravenously at weeks 0, 2, 6, and every 8 weeks thereafter; etanercept was given subcutaneously (25 mg twice a week), while adalimumab was given subcutaneously (40 mg every other week) for a period of 5 years. Data concerning anti-tumor necrosis factor efficacy tolerability, adverse events, and drug discontinuation were recorded. The percentage of patients who achieved the Psoriatic Arthritis Response Criteria (PSARC), the improvement of PASI, the improvement according to the American College of Rheumatology (ACR) criteria, and the disease activity for 28 joint indices score (DAS-28) were recorded. After 5 years, PSARC was 60%, PASI 70 was 66.7%, PASI 90 was 63.3%, while ACR 50 was 56.7% for the patients treated with infliximab. Moreover, PsARC was 64%, PASI 70 and PASI 90 were 68%, while ACR 50 was 56% for those treated with etanercept. Furthermore, in the adalimumab group PsARC was 56%, PASI 70 and PASI 90 were 58% and 50%, respectively, while ACR 50 was 50%. Additionally, DAS-28 scores were significantly improved. Thirteen patients treated with infliximab, 6 with etanercept, and 5 patients with adalimumab were withdrawn. At the end of treatment, the survival of infliximab was 56.7%, for etanercept 76%, and for adalimumab 50%. All drugs were effective, safe, and well-tolerated. The clinical improvement was maintained through the 5 years with satisfying infliximab and adalimumab survival and high etanercept survival.