Charlotte Wyse was just fifteen months old when doctors found a large, malignant tumour on her brain.

Known as paediatric ependymoma, the rare and devastating cancer is the third most common brain tumour in children.

Charlotte endured 18 surgeries and multiple rounds of chemotherapy as well as radiation.

"There was so much uncertainty around Charlie's treatment and if it was working," her mother Rebecca said.

"She was physically exhausted and there were times when her little body just wasn't responding.

"We were also very aware that if the treatment didn't work, there were no other options and that was terrifying."

Charlotte is now 15 and cancer-free but many children aren't so lucky.

An Australian-developed drug that could offer hope for children diagnosed with ependymoma will be used in a world-first clinical trial.

Lead researcher David Ziegler at the Kids Cancer Centre said there were just two treatments currently available; surgery to remove the tumour and radiation.

"However for at least one in three children, the tumour will grow back again," Prof Ziegler said at the launch of the trial at Sydney Children's Hospital.

"Sadly, almost all children or adolescents with relapsed ependymoma will die from the disease."

The trial will test Deflexifol - a co-formulation of a chemotherapy called 5-FU and leucovorin - expected to be a less toxic and more effective compared with other versions of drugs commonly used to treat adult cancers.

The treatment has shown promising results in treating tumours in adults.

"Excitingly the old drug 5-FU has been discovered to be active against ependymoma, but until now it hasn't been possible to get high enough concentrations into the brain," Prof Ziegler said.

"With this new formulation, we are aiming to use higher doses, with less side effects that should also be much more effective."

Health Minister Ryan Park says the world-leading research will make a real difference to the lives of these children and their families.

"I am determined to build a NSW health system that not only embraces, but places ourselves at the centre of innovation and advancement," he said.

The Kids with Cancer Foundation has pledged more than $1.2 million over five years with support from the Cancer Institute NSW.

The trial will open at children's cancer centres nationally for children across Australia and if successful will be expanded internationally.

"Our ultimate goal is to make sure every child is cured and no child is left behind and that's exactly what we're doing here," Prof Ziegler said.