Adalimumab biosimilars now PBS-listed

• On 1 April 2021 adalimumab biosimilars became available on the PBS.
  In addition to the originator brand Humira, four biosimilar brands for adalimumab are now PBS-listed: Amgevita, Hadlima, Hyrimoz and Idacio.

• The adalimumab biosimilars are ‘a’ flagged with the originator brand Humira
  ‘a’ flagging allows substitution between the biosimilar and originator products according to authority level, strength and dosage form.

• New formulation and new strength for originator product
  From 1 April 2021, the adalimumab originator brand Humira will have new reduced-volume 20 mg and 40 mg formulations that are ‘a’ flagged to the existing formulations and new adalimumab biosimilar products. New 80 mg syringe and pen forms of Humira have also been listed on the PBS.

• Original Humira formulations are now ‘Supply Only’
  Prescriptions for the original formulation written before 1 April 2021 can be dispensed if available. The original formulation can no longer be newly prescribed and will be completely removed from the PBS on 1 April 2022.

Adalimumab biosimilars introduced

On 1 April 2021, four adalimumab biosimilars (Amgevita, Hadlima, Hyrimoz and Idacio) were added to the Pharmaceutical Benefits Scheme (PBS) General Schedule and Highly Specialised Drug (HSD) Program in the following strengths and forms:¹

• 20 mg/0.4 mL injection, prefilled syringe (Amgevita)
• 40 mg/0.8 mL injection, prefilled syringe (Amgevita, Hadlima, Hyrimoz and Idacio)
• 40 mg/0.8 mL injection pen device (Amgevita, Hadlima, Hyrimoz and Idacio)

Existing indications and clinical inclusion criteria for the use of adalimumab have not changed.^1,2

All adalimumab biosimilars are ‘a’ flagged to the adalimumab originator Humira and each other, according to authority level (written/digital or streamlined), form (ie, syringe or pen) and strength (ie, 20 mg or 40 mg).^1,2

Substitution is permitted between:

• ‘a’ flagged adalimumab originator and biosimilar brands of the same strength and dosage form, where written/digital authority has been obtained under the Initial 1, Initial 2, Initial 3, First Continuing or Subsequent Continuing treatment phases²
• ‘a’ flagged adalimumab biosimilars of the same strength and dosage form, where a streamlined authority prescription has been written under the Subsequent Continuing treatment phase.²

Prescribers should be aware of the different authority required restrictions for the different treatment phases:

• when writing prescriptions for the Subsequent Continuing treatment phase, the four adalimumab biosimilar brands may use an Authority Required (STREAMLINED) code, while the originator brand Humira remains available as Authority Required (written/digital)^2,3
• all listings, for all brands of adalimumab, remain Authority Required (written/digital) when prescribed for use in the treatment phases Initial 1, Initial 2, Initial 3, and First Continuing.^2,3

See the Schedule of pharmaceutical benefits 1 April (Addendum) for complete details for each item.

Reduced-volume formulations added

On 1 April, new reduced-volume formulations of adalimumab (Humira) were added to the PBS (General Schedule and HSD Program):^1,2

• 20 mg/0.2 mL injection, prefilled syringe
• 40 mg/0.4 mL injection, prefilled syringe
• 40 mg/0.4 mL injection pen device

The reduced-volume formulations deliver the active ingredient in equivalent doses to the existing 20 mg/0.4 mL and 40 mg/0.8 mL formulations of the originator brand.^2,4,5

The reduced-volume formulations are ‘a’ flagged to the adalimumab originator Humira and to the newly listed adalimumab biosimilars, according to authority level (written/digital or streamlined), form (ie, syringe or pen) and strength (ie, 20 mg or 40 mg).^1,2

Supply Only for original Humira formulations to 1 April 2022

With reduced-volume formulations for 20 mg and 40 mg Humira products now available on the PBS (General Schedule and HSD Program), the original formulations will become Supply Only for a 12-month period.^1,2 Supply Only items/brands are available on the Schedule for dispensing but not for prescribing.^1,6 Original Humira formulations will not be available for dispensing after 1 April 2022.²

Prescribers and dispensers should let their patients know of this change. Some patients may be concerned about how the change could affect current management of their condition. Discuss active ingredients with them and explain that the reduced-volume Humira formulations are considered clinically equivalent to the original formulations for the purposes of substitution.^2,4,5

New strength for Humira added

A higher strength dose (80 mg/0.8 mL) of adalimumab (Humira) is now listed on the PBS General Schedule as Authority required for the treatment of people living with severe Crohn disease (Tables 1a and 1b), fistulising Crohn disease (Table 2), moderate to severe ulcerative colitis (Table 3), moderate to severe hidradenitis suppurativa (Table 4) or chronic severe plaque psoriasis (Table 5).¹

Adalimumab (Humira) in 80 mg/0.8 mL forms is not equivalent or ‘a’ flagged to any other adalimumab products.²

Information about the treatment and clinical criteria for prescribing this dose to the patient groups described above can be found in the Schedule of pharmaceutical benefits 1 April (Addendum).

Table 1a. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for severe Crohn disease – adult

Table 1b. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for severe Crohn disease – paediatric patients with refractory disease

Table 2. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for complex refractory fistulising Crohn disease

Table 3. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for moderate to severe ulcerative colitis

Table 4. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for the treatment of moderate to severe hidradenitis suppurativa

Table 5. PBS listings for 80 mg/0.8 mL adalimumab (Humira) for the treatment of chronic severe plaque psoriasis

Adalimumab is a disease-modifying biological medicine. It is a recombinant, fully human immunoglobulin (IgG1) monoclonal antibody that recognises and binds to the cytokine protein tumour necrosis factor (TNF-alpha), which is present at higher levels in some inflammatory diseases.^7,8

The originator brand Humira was TGA-approved for use in Australia in 2003, initially for the treatment of patients with rheumatoid arthritis.^7,8 Since 2017, four new adalimumab medicines have also been TGA-approved and determined to be biosimilars to the originator brand Humira.^9-12

In alignment with the Government’s commitment to the uptake of biosimilars, prescribers are encouraged to prescribe a biosimilar brand for treatment-naïve patients where appropriate.³

Biological medicines are medicines derived from a living source.¹³

These medicines now contribute to the management of several chronic diseases, including a range of autoimmune and inflammatory conditions.¹³ In recent years, primary care practitioners will have noted increasing numbers of patients with more severe forms of rheumatoid arthritis, ulcerative colitis, Crohn’s disease, psoriasis and other inflammatory conditions who are using these medicines, usually prescribed by specialists.

Biological medicines are, however, expensive to develop and manufacture. As patents on these products expire, competing manufacturers are able to develop highly similar versions of originator biological medicines, referred to as biosimilar medicines, or simply, ‘biosimilars’. The introduction of biosimilar medicines into the market prompts price reductions and potential savings for the PBS.¹³

A biosimilar has demonstrable similarity to the originator in physicochemical, biological and immunological characteristics, efficacy and safety, based on comprehensive comparability studies.^14,15

The current practice of ‘a’ flagging in the Schedule of Pharmaceutical Benefits denotes that brand substitution may be undertaken by pharmacists at the point of dispensing without differences in clinical effect. When dispensing, attention must be paid to the selection of the correct PBS item code to ensure the correct product is claimed. Applying incorrect item codes may result in a rejection warning message from Services Australia.²

As with all ‘a’ flagged medicines, if prescribers are concerned that patient safety may be at risk from medicine substitution at the pharmacy, they can mark ‘substitution not permitted’ on the prescription.

Pharmacovigilance is important to establish the long-term safety and efficacy of all medicines, including biosimilars. No safety signals have emerged following a single switch from reference to biosimilar medicines.¹⁶ Data on repeat switching for any biosimilar, including adalimumab, are currently limited.¹⁷

Patients should be educated on brand substitution and informed of any potential differences in appearance or use of ‘a’ flagged medicines eg, different injector devices.

Changes to Humira pack sizes

Pharmacists are advised that pack sizes for adalimumab (Humira) have changed to better match pack sizes available for adalimumab biosimilar products.²

The changes affect 11 PBS item codes.

Find details of the changes and a table summarising the impacted codes (p 3).²

For information about reporting adverse reactions to the TGA, or to report suspected adverse reactions online, see the TGA website.