A biological medicine is a medicine that contains an active substance made by a biological process or derived from a biological source. Examples include recombinant proteins such as insulin, monoclonal antibodies, blood derived medicines and vaccines. A biosimilar is a biological medicine that is highly similar to an originator biological medicine that has already been authorised for use.
Manufacturers of biosimilar medicines must perform an extensive head-to-head comparability exercise with the originator medicine and demonstrate to regulators that the biosimilar medicine has similar quality, safety and efficacy to the originator medicine such that there are no clinically meaningful differences between the two. A biosimilar medicine will have the same non-proprietary name as the originator medicine. However a biosimilar medicine is not a generic equivalent of the originator medicine. This is because the active substance in each medicine has been shown to be highly similar but not identical.
Biological medicines typically consist of complex heterogeneous protein molecules. As a result there is often a degree of variability in the molecules of the active substance, even between different batches of the same medicine. The extent of variability allowed is controlled within strict limits. The production process of a biological medicine is specific to each manufacturer and can shape the quality, safety and efficacy profile of the medicine. In addition, any changes to the production process may result in changes in immunogenicity which may be difficult to predict. In the case of therapeutic proteins, the consequences of an immune reaction ranges from the transient appearance of antibodies without any clinical significance, to severe and life-threatening conditions. For these reasons traceability to product and batch level is extremely important. All biological medicines including biosimilar medicines, should be prescribed, dispensed and sold in a way where the product supplied to the patient is clearly identifiable. EU and national legislation also requires that adverse reaction reports for biological medicines contain the brand name and batch number of the medicine.
There are specific considerations related to the pharmacovigilance of biological medicines (see Table 1).
Table 1: Considerations related to the pharmacovigilance of biological medicines
Reference: Draft Guide on Good Pharmacovigilance Practices (GVP), Product- or population- specific considerations II: Biological medicinal products
Within the EU there is a well-developed pharmacovigilance framework for the monitoring, evaluation and prevention of drug-related adverse events. The safety of all biological medicines including biosimilar medicines is monitored closely on an ongoing basis during the post-approval phase, including continued benefit-risk assessment.