Who chooses whether the biosimilar medicine or the reference biological medicine is used?

Page last updated: 22 February 2019

The medicine used is a choice that is made by doctors in consultation with their patients.

In the community setting, doctors have the option to decide whether to prescribe a particular brand. If the doctor does not choose a brand, the pharmacist can offer the patient the choice. If doctors want to ensure that the patient receives only the reference biological medicine or a particular biosimilar medicine, they can tick the ‘brand substitution not permitted’ box when writing a prescription. If this box is ticked, by law the pharmacist cannot dispense a brand other than that prescribed.

In the public hospital setting, the choice is made by clinician-led committees and is based on the safety, efficacy and cost-effectiveness of the medicine. (See the recently revised publication from the Council of Australian Therapeutic Advisory Groups, which provides guiding principles for the governance of biological and biosimilar medicines in Australian hospitals.)

When you are considering prescribing a biosimilar medicine, or giving your patient the option of using a biosimilar medicine, it is important to talk them through the recommendation. You can explain:

  • what biosimilar medicines are and how they relate to biological medicines
  • why you think a particular reference biological medicine or biosimilar medicine may be appropriate for their treatment
  • how biosimilar medicines can help to support the Australian health care system
  • what they can expect when they go to the pharmacy
  • how the appearance of their medicine may change
  • that the dose and dosage regimen of their medicine will not change, because biosimilars are designed to be given at the same dose and dosage regimen as their reference biological medicine
  • the importance of maintaining an up-to-date medication list (such as NPS MedicineWise Medicines List).

The Biosimilar medicines: the basics brochure will help to answer common questions.

If one medicine can be exchanged for another by the pharmacist, they are known as ‘substitutable’. Generic medicines can be substituted for the reference chemical medicine, and biosimilar medicines can be substituted for the reference biological medicine.

The pharmacist can substitute these medicines in consultation with the patient, but without needing to go back to the doctor.

Pharmaceutical Society of Australia guidelines for pharmacists state that brand substitution may only occur after consultation with and agreement from, the patient or carer. Pharmacists should also be consistent in the selection of brands for patients on long-term therapy, to avoid confusion.

Brands that can be substituted by the pharmacist are indicated in the Schedule of Pharmaceutical Benefits by an ‘a-flag’ (a small ‘a’). Only a-flagged medicines can be substituted by the pharmacist.

PBAC recommendations are made on a case-by-case basis and TGA registration of a biosimilar does not mean that a biosimilar is automatically recommended for a-flagging. For example, a biosimilar of follitropin alpha (Bemfola®) was recommended at the March 2016 PBAC meeting and was listed on the PBS on 1 August 2016. The PBAC did not recommend that this biosimilar be marked as equivalent on the PBS (a-flagged) for substitution at the pharmacy level because of the differences in the strengths, number of pens per pack and maximum quantities between brands. Substitution at the pharmacy level would have been difficult from a practical perspective.

To establish that a biosimilar product might be a-flagged with the reference biological medicine, the PBAC will consider the following:

  • Whether the TGA has determined that the product is a biosimilar of the reference medicine as evidenced by ARTG registration documentation;
  • Availability of supportive data relating to the effects of switching between the reference product and the biosimilar product/s; and
  • Practical considerations relating to substitution by the pharmacist at the point of dispensing. This includes strength of formulation, number of units per pack and maximum quantities between the brands, which may make substitution at the pharmacy level difficult from a practical perspective.

Substitutability varies between countries. The European Medicines Agency has left decisions on substitution to each European Union member country. In some countries (e.g. Belgium, France), regulatory authorities do not recommend substitution, whereas in others (e.g. Germany), substitution is recommended only for specific groups of medicines. Countries such as Italy, Norway and the United Kingdom have left the decision to the prescribing doctor or specialist.

The United States has adopted a dual-licensing pathway for biosimilar medicines—a simplified pathway for biosimilar medicines deemed not substitutable, and a more demanding pathway for substitutable biosimilar medicines.

Substitution. If two or more medicines are considered substitutable, the pharmacist may dispense either of these medicines from the script, provided the prescriber has not indicated ‘brand substitution not permitted’, and they have permission from the patient. This applies most often to generic medicines and biological medicines with a biosimilar that has been recommended by the Pharmaceutical Benefits Advisory Committee (PBAC) as substitutable. Substitutable medicines are marked in the Schedule of Pharmaceutical Benefits with an ‘a’ (a-flagged).

Interchangeability. If two or more medicines are considered interchangeable, the prescriber may choose to prescribe either of the medicines for a patient to treat the same condition; however, the pharmacist must dispense as prescribed. This generally occurs between two different medicines, rather than brands or biosimilars of the same medicine.

Switching between medicine brands could occur in either case. One would be at the direction of the prescriber (prescribing an interchangeable medicine), the other would occur at the pharmacy level (brand substitution).

In Australia, there is no mandated requirement for doctors, pharmacists or patients to use biosimilar medicines.

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