HQ Team
February 2024: Scientists have developed a drug to treat malignant pleural mesothelioma, a fatal form of cancer that affects the lining of organs.
The drug ADI-PEG20, along with chemotherapy, increased the median survival of participants by 1.6 months, and quadrupled the survival at 36 months, compared to placebo-chemotherapy.
It is the culmination of 20 years of research at Queen Mary’s Barts Cancer Institute that began with Professor Peter Szlosarek’s discovery that malignant mesothelioma cells lack a protein called ASS1, which enables cells to manufacture their arginine — a non-essential amino acid.
Amino acids are the main compositions of protein, which provide key intermediate substrates for the activation of signalling pathways.
Cells can synthesise arginine through argininosuccinate synthase 1 (ASS1). This makes arginine depletion a therapeutic strategy for ASS1-silencing tumours and is also called arginine deprivation therapy.
‘Starvation of cancer cells’
“It’s truly wonderful to see the research into the arginine starvation of cancer cells come to fruition,” said Prof Szlosarek.
“This discovery is something I have been driving from its earliest stages in the lab, with a new treatment, ADI-PEG20, now improving patient lives affected by mesothelioma.”
There are ongoing studies assessing ADI-PEG20 in patients who have sarcoma or glioblastoma multiforme, a type of brain tumour and other cancers dependent on arginine.
The success of this chemotherapy in malignant pleural mesothelioma also suggests that the drug may be of benefit in the treatment of multiple other types of cancer, according to a statement from the institute.
The phase 3 clinical trial, which targeted the cancer’s metabolism, was sponsored by Polaris Pharmaceuticals. Mesothelioma has one of the lowest five-year survival rates of any solid cancer — between five and 10%.
Lining of lungs
The trial was conducted at 43 centres across five countries between 2017 and 2021.
Mesothelioma is a type of cancer that develops in the lining that covers the outer surface of some of the body’s organs. It’s usually linked to asbestos exposure.
The cancer mainly affects the lining of the lungs (pleural mesothelioma), although it can also affect the lining of the tummy (peritoneal mesothelioma), heart or testicles.
More than 2,700 people are diagnosed with mesothelioma each year in the UK. Most cases are diagnosed in people aged 75 and over, and men are affected more commonly than women.
