Biopharmaceuticals, or biologics, are pharmaceutical drug products that are made in, taken from, or semisynthesised from biological sources. They come in a wide range of forms, from vaccines to gene therapies. They are used to treat several pathologies, such as cancer (Zhou et al. 2014), autoimmune diseases (review by Rosman et al. 2013), and chronic inflammatory diseases (review by Gils et al. 2017). Although these new biologic therapies have now been prescribed to many patients, there remains a lack of routine clinical assessment of the drugs levels and immunogenicity in the serum.