The TGA has rejected an application to down-schedule psilocybin and MDMA from Schedule 9 (prohibited substance) to Schedule 8 (controlled substance), affirming its interim decision.
The amendment to the Poisons Standard would have made both drugs available outside of clinical trials, for psychotherapeutic mental illness treatments under specialist supervision in a medically controlled setting.
Submissions in favour of the application noted that more addictive drugs, like methadone, ketamine and cannabis, are already in Schedule 8. But the interim decision to keep both drugs on Schedule 9 was supported by the Royal Australian and New Zealand College of Psychiatrists (RANZCP) and the AMA, which argued more and larger high-quality studies were needed to establish the safety and efficacy of using psilocybin and MDMA to treat mental illness.
The TGA agreed that more data was needed to justify rescheduling. While both drugs showed promise in “highly selected populations”, the benefit of these treatments was “very limited” with “only potential therapeutic value” shown in a clinical trial setting. In addition, it said the risk of the drugs getting out into the community by making them accessible in a clinical setting were too high and would potentially expose people to dangerous effects, not all of which are yet known.
“The potential for poor clinical practice is significant and could prove to be a hurdle affecting public health,” the report said.
The TGA said its decision did not affect trials currently underway, and more evidence could lead to reconsideration down the track.
UNSW researcher and addiction specialist Dr Jonathan Brett is currently involved in clinical trials using psilocybin to treat methamphetamine addiction. He told The Medical Republic there were pros and cons to the TGA’s decision.
On the one hand, there’s the argument that people who need these treatments shouldn’t be denied them outside clinical trials, he pointed out.
“But if there’s a feeling that there isn’t sufficient evidence, the concern would be that down-scheduling would potentially be a barrier to [further research],” he said.
“If you could access treatment through the clinics, why would you be part of a trial, particularly a randomised controlled trial where you’ve got 50% chance of getting a placebo? What I’ve heard is there are concerns in the scientific community about that happening.”
Dr Brett said the decision affects the cost-effectiveness of some trials that involve giving treatment on a regular basis because participants would not be able to take the drug home, but he said it wouldn’t slow down research in general.
“Hopefully, once there is sufficient evidence and if the evidence is positive, then it will be down-scheduled,” he said.