WHO describes “biosimilars” as biological products that are designed to be similar in term of quality, safety, and efficacy to a registered biological products.
To understand the description above, it is important to understand what biotherapeutic medicine is and how it is originated. Biotherapeutic medicine is made from living organisms and is often used to treat complex and serious diseases e.g. cancer and diabetes. These living organisms are usually large protein and highly complex. Their structure is completely different from drug molecule that is synthesized from smaller and more simple chemical substances. Generally, new drugs involve years of research and sophisticated production that may take longer than the period protected by patent and thus provide an opportunity for other companies to offer biosimilars.
Since the property of biosimilars is specific and depends on its manufacturing process, it can be partially proved that biosimilars are rather ‘similar’ to its originator than identical. In 2006, European Medicines Agency was the first government agency that develop guideline and standard for the registration of biosimilars in Europe Union. This guideline and standard is widely accepted by many countries around the world and used as reference to develop their domestic regulations concerning the registration of biosimilars. Meanwhile, WHO published Guidelines on Evaluation of Similar Biotherapeutic Products in 2009 intended to serve as principles to evaluate biosimilars to ensure quality, safety, and efficacy when comparing it to the registered biotherapeutics.