Scientists have discovered a new treatment regime that could potentially extend the lives of people with the deadliest type of brain tumour.

A research breakthrough by a team at Imperial College London uses a drug to deplete the amino acid arginine, thereby making glioblastoma (GBM) tumours much more susceptible to radiotherapy.

Radiotherapy is used to shrink tumours, raising the hope the method could keep brain tumours at bay for much longer than at present.

GMB is the type of brain tumour that claimed the life of Dame Tessa Jowell, the former Labour MP and culture secretary who died in 2018.

Fewer than 1% of patients with GBM currently live for more than 10 years and, for many, the prognosis is as little as 12 months.

Arginine is a vital nutrient for tumour growth and our results show that reducing its supply makes tumours much more susceptible to radiotherapy

The new study, published in the Journal of Clinical Investigation, was funded by the charity Brain Tumour Research and experts hope it will lead to a clinical trial on patients.

Arginine is known to be used by a variety of cancer cells to fuel their growth and 70% of GBM tumours are able to make arginine.

In the lab study, researchers exposed these GMB tumours to a drug called ADI-PEG20.

The drug degrades arginine and the aim was to deprive tumours of access to it.

Through this deprivation, levels of nitric oxide are boosted, which helps activate immune cells around the tumour.

Experts found that the method had the greatest effect when the drug was used with ionising radiation.

Dr Nel Syed, who co-leads the team at the Brain Tumour Research Centre of Excellence at Imperial College London, said: “Arginine is a vital nutrient for tumour growth and our results show that reducing its supply makes tumours much more susceptible to radiotherapy.

“Removing arginine removes tumour immunosuppression and we found our approach meant immune cells around the tumour were more likely to attack and remove tumour cells.”

Dr Karen Noble, director of research, policy and innovation at Brain Tumour Research, said: “This is a significant and exciting finding.

“There is an urgent need for novel approaches to treat GBM which, in the majority of cases, is fatal.

“There have been no improvements to treatment options for this type of tumour in two decades.”

The team is now exploring how the drug may be used in the 30% of GMB tumours that are not able to make arginine.

Oscar Kirby-Hogarty, 29, from Wandsworth, south London, whose mother, Lesley, died of a GBM in 2019, said: “When my mum was diagnosed with a grade 4 GBM, I could not fathom that in this day and age, with all of the medical expertise we have, her prognosis was so bleak.

“Everyone always thinks cancer is something that happens to other people. I did too. For it to happen to us and for it to be a form of cancer that is so untreatable felt truly unfair.”

Oscar and his brother Tobi have raised money for research into brain tumours.

He added: “To hear that these developments are now being made makes me truly happy.

“To know that the work my brother Tobi and I have done to raise funds and support this cause means my mum’s legacy lives on, in spite of this cruel and indiscriminate illness.”