University of Leicester researchers find drug to delay progression of a cancer
About 2,700 people are diagnosed with mesothelioma each year
Last updated 30th Apr 2025
There's new hope for patients with aggressive asbestos-linked cancer as University of Leicester researchers trial treatment for improved survival.
Researchers have said the discovery that a drug can control the growth of mesothelioma could provide "enormous hope" for patients.
Mesothelioma is an aggressive cancer that forms in the lining of the lungs or abdomen and is linked to breathing in or ingesting dangerous asbestos fibres.
A clinical trial run by the University of Leicester and the Cancer Research UK Southampton Clinical Trials Unit tested a class of drug known as PARP inhibitors.
The drugs work by blocking the repair of damaged DNA in cancer cells, causing the cancer cells to die and have previously been shown to improve the survival rate of patients with some types of breathing and ovarian cancers.
But now the results of the Nero clinical trial, which have been presented at the American Association of Cancer Research conference, have been shown to delay the worsening of mesothelioma for patients whose other treatment had stopped working.
About 2,700 people are diagnosed with the disease each year.
Professor Dean Fennell, Chair of Thoracic Medical Oncology at the University of Leicester and co-lead of the NERO trial says:
“In patients where initial treatment is unsuccessful and the cancer comes back, there are very few further options. Most patients will therefore only receive treatment to control their symptoms, rather than cure the disease.”
Only about 5% survive for five years or more.
A total of 88 patients at 11 hospitals around the UK took part in the trial, funded by the charity Asthma + Lung UK.
The researchers found that those given a PARP inhibitor called niraparib were found to have a 27% reduction in the risk of the cancer progressing or death, delaying the worsening of the disease by an average of 1.5 months, with some seeing a much longer period of time where the cancer is being controlled.
Retired architect James Fox, who was diagnosed with mesothelioma in 2018, is one of the trial patients who has shown a positive response to the treatment.
The 83-year-old grandfather-of-five from west Dorset, who previously had surgery, chemotherapy and immunotherapy, was invited to join the trial after his treatment had stopped working.
"I was told that it was a bit of a lottery to get on to it.
"But I thought, let's try it. I mean, what else, I'd gone well past the prognosis by then, so I'd try anything that was offered.
"Obviously, it seems to have worked for me so far. I feel very tired at times, but if I manage it properly, I'm fine."
Professor Gareth Griffiths, director of the Southampton Clinical Trials Unit and co-lead of the trial, said: "Although this increase may seem small, for this group of patients who have very few treatment options and a generally poor prognosis, this is a significant step forward.
"We have shown for the first time that this kind of drug can improve progression-free survival for mesothelioma patients compared with their usual treatment in the NHS.
"This gives enormous hope to those patients and their families and means we can now carry out further research to find out more about how these treatments could be tailored and enhanced to stimulate an even better response in more people."
'a meaningful difference to people with mesothelioma'
Dr Samantha Walker, director of research and innovation at Asthma + Lung UK, said: "This trial has made a meaningful difference to people with mesothelioma who were out of treatment options."
The team are now continuing their research to look for genetic biomarkers in a bid to identify those who are more likely to respond to the treatment as well as use artificial intelligence to help spot when the treatment is working.
Liz Darlison, CEO of Mesothelioma UK, said:
“Mesothelioma UK were delighted to support this study and would like to congratulation the NERO team and thank them on behalf of patients for generating evidence to support a new treatment option. Mesothelioma is a devastating disease, like many rare cancers we are desperate for new treatment options and these findings are a significant step forward, this offers real hope for patients.”
Looking to the future
The NERO team are now looking at the next steps for enhancing treatment for these patients.
“We are already doing some translational analysis on the samples taken from patients on the NERO trial which will tell us whether certain people, with certain genetic biomarkers, may respond even better to the treatment than others,” says Professor Fennell.
“We are also looking at an innovative sub-study which will use artificial intelligence to analyse patient scans to look at changes in the amount of cancer present allowing us to spot quickly whether the current treatment is working for the patient, which is a first in this cancer setting.”
Professor Griffiths continues: “We are also looking ahead to our next trial, SELECTmeso, which is a large platform trial testing several different drugs against mesothelioma. This trial will see patients tested for certain biomarkers, or genetic signals, in their tumours and then given the drug that is most likely to work for them.
"We really hope this step into more personalised medicine could further help these patients who desperately need better treatment options.”
The NERO trial was supported by mesothelioma patient, campaigner and “Meso Warrior” Mavis Nye, who was a long-term collaborator of Professors Fennell and Griffiths and who acted as a patient representative on the trial team as NERO was being set up. Mavis sadly passed away in November 2023 while the trial was taking place.