Generics and Biosimilars
2.1. General features
Biosimilars should not be confused with traditional generic medicines (the follow-on versions or copies of chemical medicines), which are considered to be identical to the original medicine (see the generics section for more details). Although the active substance is essentially the same, biosimilars may differ slightly from the original biologic medicine because they are often derived from a different biological (i.e. natural) source and produced using slightly different manufacturing processes. Importantly, before biosimilars are approved for use, it is necessary for manufacturers to show by way of clinical trials that, despite any minor differences that may exist, they are as effective at treating the target disease as the original biologic medicine, and do not cause any additional unwanted side effects.
Although biosimilars are similar to existing approved biologic medicines, they cannot necessarily be used interchangeably, as is the case with traditional generic medicines. In many countries, automatic generic substitution by the pharmacist (i.e., selecting a generic medicine in place of the original medicine) is often mandatory because it leads to substantial cost savings. Automatic substitution is not recommended for biosimilars because they are not identical to the original biologic medicine. In fact, several European countries, including the UK, Spain, France, Germany, the Netherlands, Italy and Sweden, do not allow biosimilars to be substituted automatically for the original biologic medicine. The decision whether to treat a patient with a biosimilar or the original biologic medicine must be made by a qualified doctor based on the available scientific evidence and the patient’s medical circumstances.