The monoclonal antibody olokizumab showed promise in patients with rheumatoid arthritis (RA) who had an inadequate response to antitumor necrosis factor therapies, according to the results of a study published in the Annals of the Rheumatic Diseases.
Olokizumab is a newer type of RA drug known as a biologic. Biologics interfere with specific parts of the immune system that drive inflammation. Olokizumab is a humanized monoclonal antibody specific for the protein interleukin-6 cytokine (IL-6). IL-6 plays a role in inflammation and can contribute to the signs and symptoms of RA by prompting white blood cells to attack certain tissues in the body.
Researchers conducted a randomized, double-blind, placebo-controlled trial that included 221 patients with RA. Patients were randomly assigned to one of nine treatment arms: they received either an injection of olokizumab or placebo every two weeks or every four weeks in dosages of 60 mg, 120 mg, or 240 mg, or an 8 mg/kg infusion of Actemra® (tocilizumab) every four weeks.
At week 12, the results indicated that regardless of the dose tested, olokizumab produced greater reductions in baseline DAS28-CRP scores than did placebo. ACR20 and ACR50 responses were numerically higher in the test group than in placebo. The researchers recorded ACR20 responses in 32.5%-60.7% of olokizumab-treated patients and in 17.1%-29.9% of placebo-treated patients. ACR50 responses occurred in 11.5%-33.2% of patients who received olokizumab, compared with 1.3%-4.9% of placebo patients.
Regardless of dose, olokizumab was shown to be comparable to Actemra. Treatment-related adverse events were mild to moderate and were consistent with those seen in other IL-6 targeted therapies. Adverse events did not vary significantly between the two drug treatment groups.
Genovese MC, Fleischmann R, Furst D, et al: Efficacy and safety of olokizumab in patients with rheumatoid arthritis with an inadequate response to TNF inhibitor therapy: outcomes of a randomised Phase IIb study. Annals of the Rheumatic Diseases. Published early online March 18, 2014. doi:10.1136/annrheumdis-2013-204760.