[The story of biosimilars--chance or threat?].

Patent protection on some key biologic drugs is going to expire soon. Therefore, chances are rising for biopharmaceutical manufacturers to develop and market biosimilars (follow-on biologics). These drugs are approved when similarity to reference biological medicine is proven: in terms of quality, safety or efficacy. In September 2013 European Medicines Agency authorized the first biosimilar monoclonal antibody-infliximab. Doubts considering follow-on biologics are related to their safety and efficacy. The majority of them are associated with the new phenomenon for biological products in clinical use and drug approval processes. These are: extrapolation of indications, immunogenicity and interchangeability. The case of interchangeability poses a threat that it would be impossible to determine which drug is responsible for adverse event, even if brand names and batch numbers of reference and biosimilar products are known. Biosimilar product is authorized if it has shown efficacy and safety in some of indications. When approved, its use will be extrapolated on other indications of the reference product. The aim of following article is to describe some current issues on biosimilars safety, approval procedures and legal solutions in Poland.