Introduction
Biological disease modifying antirheumatic drugs (bDMARDs) have a central role in the treatment of rheumatoid arthritis (RA). Tumour necrosis factor inhibitors (TNFis) are commonly used as first-line agents, while non-TNFis (tocilizumab, abatacept and rituximab) have shown to be non-inferior to TNFis in head-to-head trials. In case of TNFi inadequate response, using other mechanisms of action provides a better response than using an alternate TNFi. Which non-TNFi bDMARD administered subcutaneously to allow for ambulatory management to choose in case of first line TNFi inadequate response has not been tested in a randomised clinical trial, while observational data support a potential superiority of tocilizumab over abatacept.
Methods and analysis
The SUNSTAR (SUbcutaNeouS Tocilizumab vs Abatacept in TNF Alpha inadequate responders for the treatment of Rheumatoid arthritis) study is a 52-week prospective, randomised, multicentre, open-label, superiority phase IV trial comparing subcutaneous tocilizumab with abatacept in a 1:1 ratio. Patients with active RA (Disease Activity Score-erythrocyte sedimentation rate >3.2 and Clinical Disease Activity Index (CDAI) >10) and with inadequate 3-month response to a first or second TNFi are included in 25 centres in France. The primary outcome is the CDAI improvement at week 24. Intention-to-treat analysis will be applied primarily. The secondary outcome is a composite outcome of the percentage of responders defined as a CDAI