INTRODUCTION: Tocilizumab (TCZ) monotherapy has been proven as an effective treatment for rheumatoid arthritis (RA) in clinical trials. However, there are limited data available regarding the effectiveness of TCZ monotherapy in real-world clinical settings in the United States. The objective of this study was to evaluate the impact of TCZ monotherapy on disease activity and patient-reported outcomes (PROs) in a US-based observational cohort of patients with RA seen in routine clinical practice.

METHODS: Eligible patients had active RA, no prior use of TCZ, and initiated TCZ as monotherapy. Changes in disease activity and PROs were assessed 1 year after TCZ initiation for the overall cohort and stratified by number of prior tumor necrosis factor inhibitors (TNFis; 0, 1, or > /=2). Primary outcomes were change in Clinical Disease Activity Index (CDAI); change in patient global disease activity, pain, fatigue; and the proportions of patients with improvement in modified Health Assessment Questionnaire (mHAQ), morning stiffness, and EQ-5D.

RESULTS: Of 255 eligible TCZ monotherapy initiators, 9.4% were TNFi naive, 36.5% had one prior TNFi, and 54.1% had > /=2 prior TNFis. Clinical and PRO measures indicated that patients were substantially impacted by their disease at baseline. The median decrease in CDAI from baseline to 1 year was 9.8 and median patient global and pain scores improved by 10 mm, indicative of clinically meaningful improvement; the median fatigue score improved by 5 mm. Approximately 26% of patients reported clinically meaningful improvement in mHAQ, 54% experienced improvement in morning stiffness, and 20% to 36% experienced improvement in EQ-5D domains (walking, self-care, usual activities, pain/discomfort, and anxiety/depression). Improvements were similar across TNFi groups.

CONCLUSIONS: Patients with active, refractory RA who initiated TCZ monotherapy experienced improvements in both composite disease activity scores and PROs at 1 year, regardless of prior TNFi exposure.

FUNDING: Corrona, LLC and Genentech.