Biosimilar medicines are medicines “similar” in quality, efficacy and safety to the reference biological medicines and are not subject to patent coverage. A biosimilar and its reference product, despite being the same biological substance, may have minor differences due to a certain degree of natural variability, to their complex nature and to production techniques.

A biosimilar medicine is approved by the European Medicines Agency (EMA) when it has been demonstrated, through a "comparability exercise", that this natural variability and the differences compared to the reference medicine do not affect its safety and efficacy. The comparability exercise is based on a robust "head to head" comparison that proceeds by stages and according to specific standards. Any differences between the biologic medicine and its biosimilar shall not be clinically relevant.

For this reason, the Italian Medicines Agency, as expressed in the second Position Paper on Biosimilar Medicines, considers biosimilars as interchangeable products with the corresponding originators (so-called "switch"), both for patients initiated for the first time to treatment (naïve) as well as for those already in therapy.

Unlike what happens for equivalent medicines, it is not allowed to automatically substitute a reference biological medicine with its biosimilar nor to switch between biosimilars, therefore the pharmacist should consider the abovementioned substitution only after consultation with the prescriber.

The choice of treatment remains in fact a clinical decision entrusted to the doctor and agreed with the patient who, in turn, cannot change the prescription received.

If compared to their originators, biosimilars represent an additional therapeutic option and allow the treatment of a greater number of patients, so guaranteeing more health with the same resources.

For these reasons it is essential to promote a constructive dialogue between doctors and patients on the therapeutic choices available, thus contributing to raising patients’ awareness and participation.

In this section, AIFA provides updated information for doctors and patients with an aim to promote the appropriate use of biological and biosimilar medicines.