The PBAC’s commitment to evidence demonstrated at a biosimilar stakeholder meeting this week is reassuring but the potential for patients to be switched between drugs multiple times remains a concern, the ARA says.

ARA President Mona Marabani attended the meeting on Tuesday along with other groups including the Gastroenterological Society of Australia, the Royal Australasian College of Physicians, Arthritis Australia and Diabetes Australia.

The consultation was held after outcry from professional bodies and consumer organisations over the PBAC’s approach to the ‘a’ flagging of biosimilars that would allow pharmacists to substitute biosimilars for brand name original biologics.

Marabani said that while the meeting was constructive and their concerns were listened to, there was still work to do.

“We sought some clarity about the PBAC position that ‘a’ flagging was going to be the default option for biosimilars and were reassured that decisions would be evidence based and made on a case by case basis,” she said.

But the potential for a rheumatology patient to be swapped between drugs multiple times was a sticking point.

“It’s a very difficult concept to try and get across a single switch from one drug to another is a different proposition to going to the chemist every month and getting a potentially different drug every time you go,” she told the limbic.

The evidence for multiple switching was limited and large complex biologics and biosimilars like monoclonal antibodies were very different to smaller molecule biosimilars which are much less immunogenic, she explained.

“The immunogenicity is the thing that concerns us as it may mean people with stable disease could conceivably lose control of their disease, or people could develop new toxicities…There are good theoretical grounds for being concerned about this,” she said.

“It’s all very new and trying to assess these new and complicated drugs using old paradigms may not even work,” she added.

“We support the introduction of biosimilars and want the PBS to be affordable, we just want to do our part to ensure that biosimilars are introduced into the Australian market smoothly,” she said.

This week the PBAC will consider its first biosimilar of Janssen’s biologic infliximab (Remicade).