Sustained Effectiveness and Safety of Subcutaneous Tocilizumab over Two Years in the ARATA Observational Study

OBJECTIVES:To investigate long-term effectiveness and safety of subcutaneous tocilizumab (TCZ-SC) in the routine clinical care of patients with rheumatoid arthritis (RA).METHODS:ARATA (ML29087) was a prospective, multicentre, observational study of adult patients with active RA initiating therapy with TCZ-SC. The primary effectiveness outcome was the proportion of patients achieving DAS28-ESR <2.6 at week 104. Additional efficacy outcomes included individual DAS28-dcrit responses (improvement of ≥1.8 from baseline), CDAI remission (≤2.8), and patient-reported outcomes (PROs), including Work Productivity and Activity Impairment scores. Adverse event rates were used to evaluate safety and tolerability.RESULTS:Between May 2014 and July 2018, 114 study centres in Germany enrolled 1,300 patients with RA who received at least one dose of TCZ-SC (mean age 57.3 [SD 12.5] years, mean DAS28-ESR of 4.9 [SD 1.3]). At week 104, 58.7% (365/622) patients achieved DAS28-ESR <2.6, 64.0% had an individual DAS28-dcrit response, and 31.4% (241/767) achieved CDAI remission. PROs, including patient global assessment, pain, and fatigue, showed marked improvements from baseline. Work outcomes, including absenteeism (missed work) and presenteeism (productivity while at work), also improved. Injection reactions were rare and no new safety signals occurred. Patients expressed a high level of satisfaction with treatment. Baseline patient characteristics and outcomes were similar for ARATA and ICHIBAN (an observational study of TCZ-IV in Germany), despite different formulations and time periods.CONCLUSIONS:The safety and effectiveness of TCZ-SC is maintained over 2 years during routine clinical care. TCZ-SC represents a convenient and effective option for RA patients who prefer SC administration.