Despite Australia’s relatively pro-biosimilar regulatory framework, the uptake of biosimilars in Australia continues to lag behind that observed in Europe and the USA.
Changes to the prescribing landscape over the last four years that were designed to herald an increase in biosimilar uptake have not had the anticipated effect.
What are biosimilars?
Biological medicines (biologics) are agents derived from living organisms. They are complex molecules and tend to be expensive to manufacture. Biosimilars are follow-on medicines that are highly similar to the reference (original) product in terms of biological activity, safety and efficacy; but are not bioequivalent to the reference biologic. Biosimilars do not follow the same regulatory pathways as generic small molecules, and there is significant controversy both nationally and internationally around appropriate data threshold requirements for their regulatory approval and interchangeability with the reference product in the absence of prescriber supervision (for example, at pharmacy).
The current state of biosimilar use in Australia
The high costs associated with biologics are anticipated to place an increasing burden on public healthcare spending in Australia unless processes are implemented to effectively facilitate increased uptake. In the 2017-18 financial year, five of the top 10 drugs by cost to the Australian Government were biologic medicines.
The Australian regulatory framework is comparatively facilitative to the adoption of biosimilars - biosimilars that are ‘a-flagged’ can be substituted for their reference products by a pharmacist without supervision by the prescribing doctor.
In 2015, the Australian government committed $20 million over three years for an awareness and educational campaign intended to increase biosimilar uptake and reduce PBS expenditure. Further, the 2018-19 Budget included measures to increase the uptake of generic and biosimilar medicines, including the provision of over $5 million to the Generic Biosimilar Medicines Association (GBMA), the representative body of generic and biosimilar medicines suppliers in Australia, over three years to continue the biosimilar medicines awareness campaign established as part of the Pharmaceutical Benefits Scheme Access and Sustainability Package announced in May 2015. The Biosimilar Awareness Initiative was intended to increase uptake by promoting awareness of, and confidence in, the use of biosimilar medicines in healthcare professionals and consumers.
Despite these measures, biosimilar uptake in Australia has been limited. The first a-flagged biosimilar in Australia, Inflectra (infliximab), used to treat rheumatoid and psoriatic arthritis, was listed on the PBS in December 2015, followed by MSD’s infliximab biosimilar Renflexis, listed in August 2017. However, scripts for the two biosimilars secured just 11.7% of the market in 2018 when compared with the reference biologic, Janssen’s Remicade. This data is not an anomaly, but a trend – in the 2018 calendar year, MSD’s etanercept biosimilar Brenzys accounted for just 7.5% of ‘subsequent continuing’ treatment (the reference product, Pfizer’s Enbrel, occupying the remaining 92.5% of the market).
Despite the limited biosimilar uptake in Australia however, manufacturers appear to remain interested in the Australian market. For example, Korean biosimilar manufacturer Celltrion, which previously marketed its biosimilar ‘Remsima’ with Pfizer’s ‘Inflectra’ under a licensing agreement, launched solo operations in Australia in early May 2019.
The challenges facing biosimilars
It is clear that the adoption of biosimilars can be substantially influenced by the regulatory landscape. In Australia however, despite regulatory attempts to actively promote the uptake of biosimilars, Australian doctors appear to be reluctant to promote substitution of patients to biosimilar medicines. Australia ranked last in a GlobalData survey of physicians in four jurisdictions relating to the prescription of biosimilars to at least 50% of rheumatoid arthritis patients, behind the EU, the US, and Japan.
Concerns persist among Australian prescribers about switching a patient from a biologic to a biosimilar, or from one biosimilar to another at the pharmacist level, without prescriber supervision. The most recent UTS Pharmacy Barometer conducted in October 2018 found that only 33% of the 361 Australian community pharmacists surveyed felt comfortable providing information to patients on the use of biosimilars, and only 29% said that they were confident substituting them. The GBMA also found a low level of confidence in relation to prescribing biosimilars after speaking with hundreds of specialists in advance of ‘Biosimilar Week’.
Prescriber concerns have been compounded by patient reluctance to switch to a biosimilar – which, clinicians from the University of Auckland recently reported, is highly influenced by whether their doctor frames the change positively (that is, focussing on the similarities between the biosimilar and its reference biologic) or negatively (focussing on differences). That study reported 67 per cent of patients with rheumatic diseases were willing to switch when their doctor adopted positive framing, compared with 46% of patients given a negatively framed explanation.
The cautious approach by doctors and pharmacists to the use of biosimilar drugs has no doubt surprised regulators who had hoped regulatory changes would increase Australia’s biosimilar uptake. We expect to see the introduction of further regulatory changes to promote the uptake of biosimilars in Australia.