Researchers found olokizumab led to prolonged improvement for patients with rheumatoid arthritis.
Dr. Patrick Durez, of the Catholic University of Louvain in Brussels, Belgium, and colleagues at multiple sites worldwide analyzed patient-reported outcomes (PROs) in patients who were enrolled in a phase II randomized, controlled trial and its open-label extension.
Study participants had active, moderate to severe rheumatoid arthritis (RA) and had been receiving a stable dose of methotrexate (12.5-25 milligrams a week for at least 6 weeks). They were also intolerant to or had a previous inadequate response to at least one tumor necrosis factor (TNF) inhibitor.
Olokizumab is an investigational, humanized monoclonal antibody that is specific for the cytokine interleukin-6. Interleukin-6 is an important mediator of inflammation and is involved in key immunologic processes that underlie the pathology of RA.
While TNF inhibitors are frequently prescribed to patients who have an inadequate response to disease-modifying, anti-rheumatic drugs and are typically combined with methotrexate (MTX), roughly 40-50 percent of patients receiving TNF inhibitors respond inadequately to this treatment.
Improvements with olokizumab were maintained for 48 weeks
Patients enrolled in the randomized study received one of nine treatments:
- Subcutaneous (SC) administration of placebo every 4 weeks or every 2 weeks, plus MTX
- Intravenous administration of tocilizumab (8 milligrams per kilogram) every 4 weeks, plus MTX
- SC olokizumab (60, 120 or 240 milligrams) every 2 or 4 weeks, plus MTX.
Overall, 190 patients who completed the 12-week study subsequently entered the extension phase, during which all of them received SC okolizumab at a dose of 120 milligrams every 2 weeks, plus MTX.
For their analysis, the researchers analyzed changes in PROs from baseline using widely validated tools, including the Health Assessment Questionnaire-Disability Index, Patient's Global Assessment of Disease Activity, Patient's Assessment of Arthritis Pain, Patient's Acceptable Symptom State, Patient's Global Impression of Change, the Bristol Rheumatoid Arthritis Fatigue-Multi-Dimensional Questionnaire, and the EuroQol Five Domain Visual Analogue Scale.
By week 12, olokizumab-treated patients had improvements in PROs that were larger than those observed in placebo-treated patients and on a par with those seen in tocilizumab-treated patients.
In addition, the improvements observed with olokizumab were maintained to week 48 of the extension in patients who received okolizumab in the original trial and its extension, as well as in patients who were initially randomized to tocilizumab and switched to okolizumab during the extension phase.
Finally, patients who switched from placebo to olokizumab also had improvements in PROs.
The study was sponsored by R-Pharm - a pharmaceutical company specializing in the development of treatments for cancer and chronic autoimmune diseases.