Psoriatic arthritis affects about 11 percent of patients with psoriasis.
Anti-tumor necrosis factor alpha (anti-TNFalpha) agents, which block signaling molecules that induce inflammation, improve the symptoms of psoriatic arthritis. Golimumab is a new human monoclonal antibody that works against TNFalpha and has been shown to be beneficial within two weeks of the first subcutaneous injection in a phase II rheumatoid arthritis trial. A new phase III, multicenter, randomized, double-blind, placebo-controlled trial, the largest of its kind to be completed with a biologic agent to treat psoriatic arthritis and the first placebo-controlled study evaluating the effect of a TNF inhibitor on nail psoriasis, found that golimumab significantly improved active psoriatic arthritis and associated skin and nail psoriasis. The study was published in the April issue of Arthritis & Rheumatism.
Led by Arthur Kavanaugh of the University of California San Diego in La Jolla, CA the study involved 405 patients with active psoriatic arthritis even after having taken disease-modifying antirheumatic drugs or nonsteroidal anti-inflammatory drugs. Patients were randomized to receive subcutaneous injections of placebo, golimumab 50 mg, or golimumab 100 mg every four weeks for 24 weeks. Patients with less than 10 percent improvement in swollen and tender joints at week 16 were switched from placebo to 50 mg golimumab or from 50 mg to 100 mg. The primary end point of the study was the proportion of patients who met the American College of Rheumatology 20 percent improvement criteria (ACR20 response) at week 14. This response included at least a 20 percent improvement in swollen and tender joint counts and other measures such as pain, disease activity, physical function, and C-reactive protein. ACR50 and ACR70 responses were defined by at least 50 percent and at least 70 percent improvement.