Open-label study of infliximab treatment for psoriatic arthritis: clinical and magnetic resonance imaging measurements of reduction of inflammation.

To evaluate infliximab efficacy and safety in disease-modifying antirheumatic drug-unresponsive psoriatic arthritis (PsA). In a 54-week, open-label, compassionate-use study, 10 patients received intravenous infliximab (5 mg/kg; weeks 0, 2, 6; individualized dosing after week 10). Patients continued their current therapy (stable dose) until week 10. Assessments were performed at weeks 2, 6, 10, and 54. Magnetic resonance imaging (MRI) objectively measured joint inflammation at weeks 0 and 10. Patients achieved a 20% improvement according to the American College of Rheumatology (ACR) criteria (ACR20) in all patients by week 2; 8 patients improved 70% (ACR70) at week 10; 6 patients maintained ACR70 after week 54. Week 10 MRI revealed an 82.5% mean reduction in inflammation from baseline, and psoriasis area and severity index scores were reduced by 71.3% +/- 16.7%. There were no significant adverse events, severe infections, or infusion reactions. Infliximab was effective, safe, and well tolerated in PsA. Arthritis and psoriasis improved in all patients during the 54-week evaluation. Further investigation of the use of infliximab for PsA and psoriasis is warranted.