Sustained clinical response and high infliximab survival in psoriatic arthritis patients: a 3-year long-term study

OBJECTIVE: To investigate the efficacy, toxicity, and survival of infliximab in patients with psoriatic arthritis (PsA). METHODS: Thirty-two patients with PsA, refractory to at least 2 disease-modifying antirheumatic drugs, were included in this prospective, open-label, uncontrolled study. All had active disease, defined as having a tender or swollen joint count > or =6, Psoriasis Area and Severity Index (PASI) scores > or =10, and erythrocyte sedimentation rate > or =28 mm Hg/h, or C-reactive protein > or =10 mg/L. The primary endpoints were the percentage of patients who achieved the Psoriatic Arthritis Response criteria (PsARC) and the improvement of PASI. Patients were treated with infliximab (5 mg/kg) at weeks 0, 2, 6, and every 8 weeks thereafter for a period of 3 years. Data concerning infliximab efficacy, tolerability, concomitant therapy, adverse events, and drug discontinuation were recorded. The clinical response according to the American College of Rheumatology (ACR) criteria as well as the disease activity for 28 joint indices score (DAS-28) were also recorded. RESULTS: After the third year of treatment, PsARC was achieved by 23/32 of patients, PASI 70 by 24/32, and PASI 90 by 23/32. A significant improvement of ACR and DAS-28 was noted. Clinical improvement was associated with a reduction of acute phase reactants. Eight patients withdrew from the study primarily for acute allergic reactions. After the first year, infliximab survival was 84%, while after the second year, it was 75%, which was maintained throughout the third year of treatment. CONCLUSION: Infliximab was effective, safe, and well tolerated in patients with PsA. The clinical response was maintained for a period of 3 years with high infliximab survival.