Less than two weeks before the listing of the first biosimilar infliximab - Pfizer's INFLECTRA - and some questions remain over the operation of pharmacy-level substitution.
The Pharmaceutical Benefits Advisory Committee (PBAC) recommended the listing of INFLECTRA at its July meeting, applying an 'a' flag and authorising pharmacy-level substitution across the eight inflammatory conditions for which it was approved by the TGA.
The operation of an 'a' flag is not normally an issue that generates any questions or controversy. It is a policy that has been in place for several decades and, by any measure, has been very successful.
However, the PBAC's approach to the 'a' flagging of biosimilars has generated significant controversy. Clinicians and consumers have expressed concern and it became the single biggest factor in the decision of Medicines Australia to walk away from a strategic agreement with government earlier this year.
Pfizer confirmed in a statement last week that it had accepted the 'a' flag and INFLECTRA will be listed on the PBS on 1 December.
The company also confirmed its understanding the Department of Health was developing infliximab focused information to support the INFLECTRA listing, in addition to the biosimilars awareness initiative, although any specifics remain unclear.
In recommending the first 'a' flag for a monoclonal antibody, the PBAC largely dismissed any concerns over the risk of multiple switching between brands and emphasised the right of prescribers to prevent substitution.
The Committee said multiple switching was unlikely because infliximab is mainly dispensed and inflused in a hospital setting. Yet a significant proportion is actually dispensed by retail pharmacy.
PharmaDispatch understands that around 30 per cent of Janssen's originator biologic, REMICADE, is dispensed via retail pharmacy, with the remainder dispensed and administered through hospitals.
According to market intelligence firm NostraData, retail pharmacy currently dispenses over 1,700 prescriptions of REMICADE monthly, with patients then going to hospitals or clinics to have the therapy administered intravenously.
On brand substitution, the PBAC said: "For any individual prescription, a prescriber may choose to not permit brand substitution."
In a statement yesterday, Janssen expressed concern over these two assumptions - that multiple switching is unlikely and prescribers can readily prevent substitution.
"It is clear that a number of patients have their infliximab dispensed by a retail pharmacy which could lead to patients being switched without clinician oversight," it said. "Secondly, the PBAC noted that substitution was not automatic as a prescriber, in consultation with their patient, could specify that the brand was not to be substituted. However a number of hospitals do not provide the 'Do Not Substitute' box on their prescription pads. State Health Departments are also issuing tender requests seeking sole supply agreements. This removes clinician and patient choice by only providing one infliximab brand."
These issues would not normally be of any concern with an 'a' flag. Yet the PBAC itself directly addressed them in its recommendation arguably based on questionable assumptions regarding the dispensing and prescribing of infliximab. Its recommendation that the Department of Health develop an implementation plan specifically to support the introduction of ‘a’ flagged biosimilar infliximab also suggests the Committee at least tacitly acknowledged the unusual nature of the listing.
Janssen confirmed that it has communicated its concerns over these two assumptions to the Department of Health and PBAC Chair, Professor Andrew Wilson.
The substance of that communication and any direct contact remains unclear.
Janssen said it remains "committed" to assisting the PBAC and Department of Health in "any way possible, and believe it is important and necessary that all stakeholders are involved and consulted on any implementation plan, including communications, related to infliximab.”
"Janssen has long supported the introduction of biosimilars into Australia. However we want to ensure this occurs in a way which ensures patient safety and is done consistently," it added.
