Effects of Concomitant Conventional and Previous Biological Disease Modifying Anti-Rheumatic Drugs Treatment on the Efficacy of Tocilizumab to Induce Remission in Patients with Rheumatoid Arthritis – An Observational Real-Life Study

Abstract

Objectives: To investigate remission rates in rheumatoid arthritis patients exposed to tocilizumab treatment in real life clinical practice and to test whether concomitant conventional and previous biological disease modifying anti-rheumatic drugs treatment affects the efficacy of tocilizumab to reach remission. Methods: Between January 2009 and December 2012 disease activity was analyzed in 272 rheumatoid arthritis patients exposed to tocilizumab at the onset of treatment and sequentially thereafter, i.e. every four weeks at the time of infusion. Aside from demographic and disease-specific variables, previous and concomitant conventional and biologic disease modifying anti-rheumatic drugs therapy was documented in all patients. Multivariate logistic regression analyses were conducted to identify factors influencing Disease Activity Score 28 remission and attrition to tocilizumab treatment. Results: 219 (80.5%) of all patients were female. Mean Age was 55.48 ± 13.23 years and our patients had mean disease duration of 12.48 ± 9.30 years. Disease Activity Score 28 significantly decreased from 5.00 ± 1.52 at baseline to 3.09 ± 1.49 at the latest infusion. Mean treatment period was 58.28 ± 43.95 weeks. A total of 101 patients (42.8%) achieved Disease Activity Score 28 remission, which was significantly associated to the length of tocilizumab exposure. Achievement of Disease Activity Score 28 remission was independent from the concomitant use of conventional disease modifying anti-rheumatic drugs. Previous exposure to tumour necrosis factor inhibitors but not rituximab significantly reduced the likelihood to achieve Disease Activity Score 28 remission. Two logistic regression analyses revealed baseline disease activity and duration of tocilizumab therapy as independent factors for Disease Activity Score 28 remission, whereas age and concomitant methotrexate therapy were linked to attrition to tocilizumab treatment. Conclusion: Remission rates found in this observational study are comparable to those of randomized controlled trials and those of big post-marketing surveillance studies. Remission rates of rheumatoid arthritis patients treated with tocilizumab in clinical practice are not influenced by concomitant disease modifying anti-rheumatic drugs use. Previous exposure to tumour necrosis factor inhibitors but not to rituximab decreases the chance to reach remission with tocilizumab.