To switch or not to switch after a poor response to a TNFα blocker? It is not only a matter of ACR20 OR ACR50.

The introduction in the therapeutic armamentarium of TNF inhibitors (TNFi) has greatly advanced the chance of obtaining a control of clinical manifestations and of structural damage progression in an important proportion of patients with rheumatoid arthritis (RA) Methotrexate (MTX)-poor responders. However not more than 50% of TNFi treated patients can reach relevant clinical benefits. Therefore the unmet medical question is: should we continue the therapeutic approach with a second or a third TNFi, or should we use other drugs, and change the mode of action of the second drug? These are practical issues that still do not have a definite answer. The real problem is that up to this moment no real biomarker is available to make the appropriate choice. The only clear-cut biomarker is represented by the positivity of rheumatoid factor (RF) or anti citrullinated peptide autoantibodies (ACPA). Seropositive patients seem to respond better than seronegative ones to B cell depletion therapy (Rituximab). This paper discusses the pros and cons of switching or swapping in RA patients poorly responder to the first TNFi.