Response to: Biosimilars for vasculitis: promise requires validation by quality studies

Excerpt

We thank Misra et al. for their interest in our paper on the role of similar biological rituximab in remission induction and maintenance in granulomatosis with polyangiitis [1, 2]. They reviewed the available published literature on the use of biosimilars in vasculitis, which nicely highlights the sparsity of such data. They used the Newcastle-Ottawa quality assessment scale for cohort studies to grade all the published studies. Three components of this scale are “selection,” “comparability,” and “outcome.” Since most of the published studies did not have a comparator arm, they proposed that the future observational studies should have a representative comparator group, and the issue of switching from innovator to biosimilar should also be addressed. While such studies have been done in rheumatoid arthritis and non-Hodgkin’s lymphoma, these would be very difficult to do in rare diseases like vasculitis [3]. …