Real-World 1-Year Retention Rate of Subcutaneous Tocilizumab Treatment in Patients with Moderate to Severe Active Rheumatoid Arthritis: TANDEM Study.

INTRODUCTION: Drug retention is particularly relevant to assess long-term treatments. This real-world study mainly aimed to describe 1-year retention rate (RR) of subcutaneously administered tocilizumab (TCZ-SC) in patients with moderate to severe active rheumatoid arthritis (RA). METHODS: This non-interventional, prospective, multicenter study (NCT02608112) was conducted in patients with RA initiating TCZ-SC treatment, with an 18-month follow-up. RR was estimated at month 12 in the overall population and baseline subgroups (combination with a conventional synthetic disease-modifying antirheumatic drug (csDMARD) or not, age, body mass index, methotrexate dose), using the Kaplan-Meier method. Patient compliance to TCZ-SC was described using the 5-item Compliance Questionnaire for Rheumatology (CQR5). RESULTS: At inclusion 75% of the 285 analyzed patients were women, mean RA duration was 9 ± 9 years, previous RA treatments included biological agents (63%) and/or csDMARDs (94%), mean Disease Activity Score 28 joints-Erythrocyte Sedimentation Rate (DAS28-ESR) was 4.8 ± 1.2. TCZ-SC RR at month 12 was estimated to be 64% (95% CI 58%-69%) with no statistical differences between subgroups. Clinical results improved with TCZ-SC; the proportion of patients treated with combined glucocorticoids decreased from 49% to 22% at month 12. At each follow-up time, at least 80% of patients were high adherers to TCZ-SC (at least 80% of theoretical injections). Among the 286 patients with at least one TCZ-SC injection, 25 patients (9%) experienced serious adverse events related to TCZ-SC with no differences according to patient age. CONCLUSIONS: This real-world study corroborates the RR at month 12 previously shown in interventional studies on TCZ-SC. Our data suggest there are no differences according to patient's profile (age, BMI), methotrexate doses, and TCZ-SC use. TRIAL REGISTRATION: NCT02608112.