The NSW government is pushing ahead with plans to trial cannabis-based medicines in children with epilepsy.
NSW parents whose children suffer dozens of epileptic seizures daily will be among the first in the world to access cannabis-based drugs if promised trials prove successful.
Premier Mike Baird on Tuesday announced a memorandum of understanding with UK-based GW Pharmaceuticals that allows NSW to host a world-first trial in children of a treatment containing the cannabinoid cannibidivarin.
"There are poor children that, almost every few seconds, are having a seizure, and traditional medicine is not having an impact," Mr Baird said.
The government is putting $3.5 million on the table for the Sydney Children's Hospitals Network (SCHN) to lead the trial, which is expected to start next year, subject to ethical approval.
The GW deal also allows a "compassionate access scheme" for Epidiolex, another treatment that contains cannabidiol, which is already being trialled on the US.
The scheme means a small number of children who are too sick to participate in a clinical trial could still access the drug from early next year.
NSW would also be cleared to host additional phase-three trials of Epidiolex, as well as a phase-four clinical trial, depending on those earlier results.
"The real impact is that because we have been part of these trials, we are then able to have our children - all our children in NSW - amongst the first in the world to be able to be prescribed these drugs when they're approved," Medical Research Minister Pru Goward told reporters.
Ms Goward said the negotiations almost stalled from the outset because a previous NSW government had courted GW Pharmaceuticals about a decade ago, and the company "wanted nothing to do with us".
So she personally flew to London to relay the state's "desperation" to find new treatment options for children with life-threatening, drug-resistant and often debilitating epilepsy.
"If we had had to start with a new drug, going through phase one, phase two; we would be waiting years and years and years for our children to be able to access this drug," she said.
SCHN's John Lawson hailed the government's move towards medical cannabis as "extremely brave".
"We as clinicians had pretty much given up on being able to access these medications," Dr Lawson said.
What the medical marijuana trials will look like
* Hundreds of children are likely to be involved in the phase-two clinical trial of cannabinoid cannibidivarin
* Participation will be open to children with the most severe forms of epilepsy
* NSW has been cleared to host phase-three clinical trials of Epidiolex, with a possible phase-four trial to follow
* The deal may pave the way for NSW to host a phase-three trial for children with Tuberous Sclerosis Complex, as well as a phase-two clinical trial for children with another form of treatment-resistant epilepsy