The wind of change is blowing in rheumatology. Rheumatologists may soon be exposed to ‘biosimilars’ of the medicines they routinely use as the European Medicines Agency (EMA) has recently issued its final guideline on biosimilar monoclonal antibodies (mAbs)1—a product class of utmost importance for rheumatologists—and a biosimilar infliximab is currently under evaluation for marketing authorisation in Europe,2 and more will come. Rheumatologists, as it appears, are especially challenged these days as many of their patients are already successfully put on long term treatment with individualised drug regimens, including biologicals such as tumour necrosis factor α inhibitors. Apparently, introduction of ‘copy’ versions of the medicines they already know may be seen as a critical issue, although economic considerations suggest major cost savings in healthcare.3 ‘Concerns’, ‘challenges’ and ‘critical issues’: these are terms with which the term ‘biosimilar’ is often combined in papers written by clinicians and discussions at conferences.4–6 We read about the ‘complexity’ of biological medicines, and that it is difficult to replicate their exact structure. Also in clinical literature in rheumatology, we read about ‘small variations’ that can impact the activity and function of a biosimilar, and ‘major safety and efficacy concerns’ that have to be addressed before clinicians can use biosimilars.7

In their review in this issue, Dörner et al report on a roundtable discussion on the advent of biosimilars in rheumatology recently held at the Charité in Berlin (Germany).8 I note at least one aspect in this review that is worth emphasising—the paper puts scientific facts into perspective. For example, it reports about the complexities and microheterogeneity of mAbs/cepts but also puts it into perspective with the so-called ‘originator’ mAbs/cepts that are likewise complex. As a regulator, I have been deeply involved in the design of guidelines around biosimilars (including …