Interchangeability of biologicals and biosimilars

Interchangeability means the possibility of replacing a particular medicinal product with another medicinal product which has the expected same clinical effect. The replacement can be done by switching when the prescriber decides to exchange one medicine for another medicine with the same therapeutic intent, or with a substitution under special conditions when one medicine is dispensed instead of another equivalent medicine at the pharmacy level without consulting the prescriber.

The data from real world experience and from switching studies accumulated by now show that changing reference biological medicinal product to its biosimilar, biosimilar to another biosimilar of the same reference product and biosimilar to its reference product is safe. Therefore, the European Medicines Agency (EMA) recognizes that from the scientific point of view the biosimilars are interchangeable (“Biosimilar medicines can be interchanged”). The decision, however, on whether to allow interchangeable use and substitution at the pharmacy level of the reference biological medicine and the biosimilar falls under the responsibility of EU Member States, which have the necessary legal framework in place and issue regulations, guidelines, and advice in their areas of competence.

JAZMP does not include biologicals and biosimilars on the list of interchangeable medicinal products, as it classifies certain generic medicinal products (Rules defining interchangeable medicines). In Slovenia, as in several other European countries, biological medicines are not allowed to be substituted at the pharmacy level without consulting a doctor. Nevertheless, at the beginning of the treatment, the doctor has an option to choose a biosimilar.

The JAZMP’s position is that a physician-led switching between authorized versions of a given biologic medicine at treatment initiation or during ongoing treatment is safe. Switching can apply to the following situations:

  • switching from reference medicine to biosimilar medicine
  • switching from biosimilar medicine to reference medicine
  • switching from a biosimilar medicine to another biosimilar medicine, based on the same reference product.

The decision to prescribe a biological medicine for an individual patient, whether it is a reference product or a biosimilar, is limited to performed in the clinical environment and is subject to the clinician’s medical consultation with the patient. As with all biologic medicines, adequate clinical monitoring in line with clinical guidelines should be envisaged.

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