Recombinant human erythropoietins, biosimilars and immunogenicity

Biopharmaceutical agents have revolutionised the treatment and management of medical conditions such as diabetes, Gaucher disease, cancer and infertility. From the introduction of the first products of nonhuman origin some 100 years ago, to the more recent addition within the last 2 decades of human recombinant DNA products (e.g., recombinant human erythropoietin and growth hormone), millions of patients have benefited from treatment using these complex medicinal products. With many of the developed biopharmaceuticals reaching their patent expiry, increasing interest has been expressed in the almost inevitable introduction of biosimilars, or follow-on biopharmaceuticals. In particular, concerns have been raised regarding the safety of biosimilars in light of the complex production methods necessary for the generation of biopharmaceutical products. This review explores some of the safety issues applicable to biosimilars, with a focus on immunogenicity.