AbstractBiosimilars are new biological medicines that are highly similar but not identical to their reference biological medicines. As biosimilars are produced from living organisms by genetic engineering, even a small difference in their production process has the potential to alter their efficacy and safety. Therefore, prior to their approval, biosimilars are assessed to confirm therapeutic equivalence and comparable safety and efficacy to their biological reference medicines. Once approved, adverse effects of biosimilars are continuously monitored by regulatory bodies. The lower cost of biosimilars improves affordability and access to new therapies for patients with serious diseases and these medicines are increasingly being prescribed in Australia. Hence, pharmacy professionals need to be aware of the structural complexity and important aspects of the regulatory approval process, immunogenicity and safety profiling, extrapolation of indication, nomenclature and labelling, interchangeability and substitution for these novel therapies.