An open-label pilot study of the efficacy and safety of anakinra in patients with psoriatic arthritis refractory to or intolerant of methotrexate (MTX).

Only limited data have been published about the therapeutic use of anakinra in patients with psoriatic arthritis. We undertook this study to evaluate the efficacy and safety of anakinra in patients with active psoriatic arthritis. In a prospective open-label single-center study, 20 patients were treated with 100 mg anakinra everyday either alone or in combination with ongoing methotrexate over 6 months. Safety and efficacy was evaluated using Psoriasis Arthritis Response Criteria (PsARC), Disease Activity Score (DAS) 28, American College of Rheumatology (ACR), European League Against Rheumatism (EULAR), Psoriasis Area and Severity Index Score, Dactylitis Score and Health Assessment Questionnaire (HAQ), and the C-reactive protein, and erythrocyte sedimentation rate. Of the 20 patients enrolled, six completed 24 weeks, 18 completed 12 weeks, and 19 completed 4 weeks of treatment. Early-treatment termination was mainly due to inefficacy (13 patients) and only one drop-out occurred because of an unrelated adverse event. Six patients fulfilled continuously the PsARC until week 24. A moderate EULAR response was achieved by four patients and a good EULAR response by three patients in week 24. Five patients reached ACR 20, four patients ACR 50, and two patients ACR 70 in week 24. HAQ improved slightly throughout the study (n = 19, mean (SD); baseline, 1.127 (0.671); week 24, 1.055 (0.812)) just as DAS 28 (n = 16; baseline, 4.7(1.5); week 24, 4.0(2.0)). Only nine patients showed skin manifestations affecting >3% of their body surface area which improved in two, worsened in four, stabilized in two patients, and newly evolved in one patient. Adverse events were mainly mild (95%). Fifteen (75%) patients showed injection site reactions. No serious infections occurred. Anakinra was well tolerated with no occurrence of serious drug-associated adverse events and lead to improvement of signs and symptoms in nine out of 19 patients, therefore providing a potential therapeutic option in patients with active psoriatic arthritis.