Immunogenicity, the ability of a substance to provoke an immune response23, was a key concern of regulators and healthcare professionals when the first biosimilars were approved over a decade ago. Verifying that the proposed biosimilar and reference product have comparable immunogenicity profiles, via a head-to-head comparison, is a critical component in defining the safety profile of the biosimilar and its overall similarity to the reference product1,4. Data collected through both post launch monitoring and clinical trials has not validated these original concerns and the incidence of immunogenicity for biosimilar medicines has been shown to be no higher than for the reference product21,24.