New drugs for rheumatological conditions may be missing out on PBS listings because the rheumatology speciality is not providing the right input to the Pharmaceutical Benefits Advisory Committee, the chair of the committee says.

PBAC chair Professor Andrew Wilson told the ARA 2018 conference in Melbourne that rheumatologists could learn a lot from oncologists when it comes to providing the kind of data needed to gain an approval for PBS listing.

Describing the PBAC decision-making process, Professor Wilson said the committee worked within tight legislative constraints that require it to show a drug will provide a minimal clinically important clinical difference at an acceptable cost.

But much of the input from rheumatology and other specialties failed to outline a drug’s likely place in therapy and duration of therapy or relevant data on benefits, he said.

“Most of the advice we get ignores the context of our decision making. It’s poorly directed to the key issues and uncertainties that we have to deal with in making decisions,” Professor Wilson told the conference.

“We work within a legislative framework, so it’s no good saying to us ‘why don’t you think about this?’ if that sits outside of our mandate as to what we can consider.”

Professor Wilson pointed to the model used by the Medical Oncologist Group of Australia (MOGA), which had adopted an objective valuation framework based on pre-agreed measures of key outcomes.

“They’ve moved from just providing us with their best guess to come up with advice that is built within a specific value framework. It gets them to think carefully about what the value propositions are and framing them in a way that is relevant to our decision making.”

“It has changed the nature of the input that that group is providing and I’d urge [rheumatologists] to think about whether as an Association if there’s something you could do in a similar way,” he said.

Professor Wilson said the PBAC’s decision-making task was becoming more difficult in the face of rising community expectations and the high prices of drugs being sought by industry. The PBAC also had to struggle with immature data from short term trials, from which it was asked to extrapolate benefits for what could be lifelong treatment.

“In your field we see that with the biological DMARDs where the patient starts on one, which loses its efficacy for that particular patient, and the patient rotates on to another. Most of the drugs have never been trialled in that situation.”

And he predicted that PBAC decision making would become even more challenging when the government’s accelerated approval scheme for promising new drugs starts in mid 2018. This will allow drugs with as-yet-unproven benefits for serious conditions to gain provisional approval for two years if they appear to be safe.

“This will of course add to our decision-making dilemmas. Then the fun will really begin,” he said.