Medics at Swansea Bay University Health Board have discovered that by using genetic testing to identify a specific protein in patients’ blood, they can determine when to reintroduce the drug Panitumumab at a different stage in treatment, significantly extending life expectancy.
The breakthrough involves using a medical testing protocol called “re-challenge”, where the medication is administered, withdrawn and then given again at a different point in the patient’s care pathway.
Consultant oncologist Dr Craig Barrington said the approach is believed to be unique globally.
“We are not aware of any other country having this option for re-challenge, guided by genetic testing,” Dr Barrington said. “It is another exciting option for Welsh patients.
“We predict there’s going to be about 30 to 50 patients in Wales a year that may well get additional benefit from the use of this drug.”
Panitumumab is used to treat patients with metastatic and incurable left-sided colon cancer. The drug is not suitable for all patients, working only on those who have intact proteins rather than mutated ones.
Swansea Bay has been offering the drug for the past couple of years through the One Wales Medicines process, which provides access to treatments outside current marketing authorisation or licensing and prior to approval by the National Institute for Health and Care Excellence (NICE). Panitumumab received One Wales approval last June.
The consultants reassessed the drug’s use following a trial involving a test that looks for a specific DNA tumour protein in the blood. This test identified patients who could potentially benefit from re-challenge with Panitumumab, with a subsequent study confirming the effectiveness of the approach.
Dr Barrington explained that the drug works on approximately 50 per cent of patients from the beginning of cancer treatment. However, about 30 per cent of those exposed to it develop mutations, meaning reintroducing the drug would not provide any benefit for them.
“This drug works on patients if they have intact proteins. If proteins are mutated it won’t work,” he said.
One patient who benefited from the pioneering approach was Wyn Thomas from Gower, a former medical physicist who was 74 when he was diagnosed with stage four colon cancer in September 2021.
Although Mr Thomas has since died, the drug gave him months of precious extra time with his family before he passed away in March 2025 at the age of 76.
His wife Liz said the family had not expected him to have much time when he received his diagnosis.
“He was asked if he wanted to consider whether he wanted quality or longevity of life left, he said he wanted to live as long as he could,” Mrs Thomas said. “But he ended up with a good quality of life. He never gave up and was very determined.”
She described how her husband maintained an active life throughout much of his treatment.
“Throughout the summer of 2024 he was really good; he was out and about, cutting the grass, and at Christmas he was stuffing the turkey and carrying logs,” she said.
“We knew it would not last forever, and last January he complained of a pain in the knee, and he died in March. He only had about four or six weeks when he was desperately ill.”
Dr Barrington said he was convinced Panitumumab had extended Mr Thomas’s life significantly.
“When he first started cancer treatment, with what was available we think he would have had about two to two-and-a-half years, but he survived for three-and-a-half, so he outlived our prediction,” he said.
“There is no doubt in my mind that is because of the medication. Without it, it would have been half the time.
“Not only did we see that in the length of time since he commenced taking Panitumumab, but we also saw it on scans and the blood tests and how well he was responding to it.”
(Image: Swansea Bay University Health Board)
Mr Thomas was the brother of Bafta-winning Twin Town composer Mark Thomas, who also created music for Wallace and Gromit animations. Mark died following his own cancer battle in 2023.
Even during his treatment, Wyn continued to run his brother’s record label, collecting royalties and distributing them to musicians.
Mrs Thomas praised the care her husband received at Singleton Hospital.
“We tried everything for him, and he was alright for three-and-a-half years,” she said. “Everyone who supported him at Singleton was absolutely brilliant.”
As with other drugs accessed through the One Wales Medicines process, patients are given full explanations about how Panitumumab has been accessed and are talked through current data and evidence before beginning treatment.
