Biosimilar substitution on the table in Australia
This article was originally published in Scrip
Australia's Pharmaceutical Benefits Advisory Committee (PBAC) is considering whether biosimilars could be marked as equivalent to their reference drug in the Schedule of Pharmaceutical Benefits – a move that would allow biosimilar substitution at the pharmacy level.
At its March meeting, the PBAC, which recommends new medicines for listing on the Pharmaceutical Benefits Scheme (PBS), said it would consider the "a"-flagging, or marking as equivalent, of biosimilars and their reference medicine on a case-by-case basis, "taking into account the evidence presented in each submission to list a biosimilar medicine".
At present, only bioequivalent generic drugs can be "a"-flagged, meaning that they can be substituted for the prescribed brand by the pharmacist without notifying the prescribing physician. Applying the equivalence principle to biosimilars would mean they could be substituted too, potentially giving a sharp boost to the slowly growing Australian biosimilars market.
The Australian generic industry body, the GMiA, welcomed the PBAC's decision to consider "a"-flagging of biosimilars on a case-by-case basis, saying this would "enable a pharmacist to substitute the biosimilar for the reference biological medicine in exactly the same way as generic medicines".
However, it is not yet clear what criteria would be applied in deciding whether a specific biosimilar could be dispensed in place of the originator medicine. The GMiA's CEO, Belinda Wood, told Scrip that this had still to be clarified: "As the full minutes from the PBAC meeting have not been publicized, we don't have a good picture into their requirements," she said.
Nor is it clear whether substitution would need to be circumscribed by special conditions, such as informing the prescriber. Ms Wood said that under the current generic substitution rules, pharmacists do not have to notify the prescriber of a generic substitution, but they do have to ask the patient if they would like a more affordable medicine if one is available. But whether this would also apply in the case of biosimilars remains to be seen.
Another unknown is what stance will be taken by Australia's drug regulatory agency, the Therapeutic Goods Administration. The TGA's current position is that "it is not currently possible to determine a degree of similarity between a biosimilar and an already registered biological medicine sufficient to support a designation by the TGA of 'bioequivalence'." It has said that a branded biologic should be replaced by a biosimilar only "under the supervision of the prescribing medical practitioner".
Presumably all these questions will have been addressed in the PBAC's March meeting, as well as at a special meeting on 17 April at which the committee said it "further considered PBS subsidy of biosimilar medicines". The outcomes of that meeting will be published separately.
If Australia does opt for biosimilar substitution, it is likely to be the first country with a biosimilars pathway to do so. One other country has made a formal foray into this perilous territory: at the end of 2014, the French parliament passed a law that would allow biosimilar substitution, but only under very strict conditions. The doctor would have to be notified, and could write "not substitutable" on the prescription form, and the patient would have to be kept on the same product throughout their course of treatment. However, the implementing decree that would put this law into effect has still not been published.
Boosting sluggish market growth
In the meantime, the GMiA wants to speed up growth in the biosimilars market. "It is fair to say that clinical experience with biosimilars in Australia has taken time to develop, but is gaining momentum," Ms Wood remarked.
"The availability, and PBS listing, of biosimilars means more patients can be treated within the same budget," the GMiA said. "However, savings can only be realised if more affordable biosimilars are listed on the PBS, prescribed by doctors and dispensed by pharmacists."
Ms Wood said that at present there are only three biosimilars on the PBS – epoetin, filgrastim and insulin glargine. The last of these is Lilly's Basaglar, a biosimilar version of Sanofi's Lantus, which was recommended for subsidy by the PBAC at its March meeting.
Another obvious way of boosting the market is to get doctors to switch patients from the originator drug to a biosimilar. In common with many other countries with a biosimilars pathway, Australia has no clear guidelines regarding the switching of patients from one biological to another. The decision is left up to the prescriber, Ms Wood said, but in general "biosimilar use is mainly influenced by whichever brand (originator or biosimilar) is available through a hospital formulary as a result of tendering".
TGA reviewing biosimilar guideline
In a related move, the TGA has just announced that it is reviewing its biosimilar evaluation guideline, which is intended to help sponsors identify the data needed to support biosimilar approval and to clarify the scientific and regulatory principles the TGA uses to evaluate applications.
The agency said that the "understanding of biosimilar medicines is evolving and as a result the current guideline 'Evaluation of Biosimilars' may need to be updated". It gave no more detail, and did not immediately respond to a request for comment.
This review comes on top of the one that is already being carried out on the TGA's policy on naming conventions for biosimilars. In July 2013, the agency published guidance on biosimilar naming under which the Australian Biological Name (ABN) would be combined with a biosimilar identifier consisting of the prefix sim(a) and a three-letter code issued by the World Health Organization's international non-proprietary name (INN) expert group.
However, in January this year the TGA announced that, following the July 2014 publication of the WHO's proposal for a "biological qualifier", it had decided not to pursue this approach and would be reviewing the policy. In the meantime, biosimilars in Australia will use the ABN without an additional identifier.
The WHO has just announced that it will press on with the biological qualifier proposal, having secured enough support from stakeholders including regulatory agencies.