Comparison of outcomes using the rituximab originator MabThera with the biosimilar Truxima in patients with ANCA-associated vasculitis

Abstract

Objectives The use of rituximab (MabThera®), an anti-CD20 monoclonal antibody, is the most significant development in the management of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) since the introduction of cytotoxic therapy in 1950. Truxima® is the first anti-CD20 biosimilar approved for the same indications, and has been available in the UK since 2017. Significant cost savings have been reported when switching to biosimilars, which could lead to greater patient access to such treatment. Therefore, it is important to know whether patients’ clinical and laboratory parameters respond equally well to biosimilars as to reference medicines, tested in clinical trials. Method We retrospectively reviewed the clinical outcomes and laboratory parameters in 257 consecutive patients treated with anti-CD20 depletion therapy using MabThera or Truxima, for induction and maintenance of remission, in two tertiary renal centres between 2010 and 2019. Results We demonstrated no difference between patients treated with MabThera or Truxima in rates of remission, relapse, and hospitalization with infection when used for either induction or maintenance of remission of AAV. In one hospital subgroup analysis, we showed comparable levels of hypogammaglobulinaemia, B-cell depletion, and frequency of infusion reactions, with no significant differences. Conclusion The efficacy and safety of the rituximab biosimilar Truxima are not inferior to the originator MabThera in patients with AAV. Truxima represents a cheaper and safe therapeutic alternative that could increase patient access to rituximab.