Patients with kidney cancer have been thrown a lifeline by an immune-boosting drug that dramatically reduces the risk of the disease returning – when it invariably turns fatal.

The injection, pembrolizumab, looks set to become the standard treatment given to patients after surgery after a trial saw survival rates soar.

Kidney cancer is curable with surgery alone in 60 per cent of cases – however, if it returns, the outlook is bleak. Just 15 per cent of patients survive for more than five years after a recurrence, with many dying within two years.

Part of the problem is that kidney cancer does not respond to standard chemotherapy – the treatment usually given to kill off cancer cells. It meant doctors could only wait until the disease returned before they were able to offer drugs, often to no avail.

Chesney Lewis (right) who was on the latest trial, pictured with his wife Marilyn (left)

But now the results of a major clinical trial suggest that being injected with pembrolizumab every three weeks for a year increases patients’ chances of survival by 38 per cent.

The drug works by helping the body’s immune system fighter cells to find and destroy tumours, and has already shown success in treating melanoma skin cancer, bladder and lung cancer, and lymphoma – a kind of blood cancer.

Pembrolizumab was first approved for use in the NHS for kidney cancer patients whose disease had come back in 2022 and, given alongside other targeted treatments called tyrosine kinase inhibitors which stop cancer cells growing and dividing, it boosted survival.

Prof Tom Powles, the director of Barts Cancer Centre in London, said: ‘Before we had pembrolizumab and the other targeted therapies, kidney cancer patients would often die with a year of a recurrence. This then improved to between two and five years.

Pembrolizumab looks set to become the standard treatment given to patients after surgery after a trial saw survival rates soar

‘Now we know if we give people pembrolizumab immediately after surgery, and patients take it for a year, we can reduce the risk of death and cure more patients.’

Prof Powles predicts that up to 80 per cent of kidney cancer patients could be offered pembrolizumab after surgery, as it has been proved to be so effective.

Previously, one in ten patients given pembrolizumab stopped taking it due to severe side effects, which can include diabetes, breathlessness and thyroid problems. However Prof Powles believes more patients might be willing to weather these problems now, as doctors are able to reassure them it is likely to help them live longer.

‘We’ve shown there is a higher risk of dying if you’re not given pembrolizumab before the cancer comes back,’ he says. ‘So patients will be much more inclined to have a treatment that increases the chance of them living longer.’

Retiree Chesney Lewis was one of the 1,000 people on the latest pembrolizumab trial and believes that he was in the half of patients who were given the drug over the placebo option. The 77-year-old, from Westcliffe-on-Sea in Essex, was diagnosed with kidney cancer in June 2018 during a routine screening for pancreatic cancer, which runs in his family.

A scan found that he had stage-four kidney cancer, and he was transferred to the Royal Free Hospital in London, where the following week he had his kidney removed.

He says: ‘It was just out of the blue. I felt like a very lucky man that they spotted the cancer. I was shocked, but relieved that it was dealt with right away.’

He was asked if he would join the study and had injections every three weeks for a year. Fortunately, he did not experience many side effects from his treatment.

He says: ‘Sometimes I felt tired and a bit lethargic but it was nothing too worrying. As far as I’m concerned, the whole experience was fantastic. Doctors saved my life by taking out the kidney that had the cancer, and whatever treatment I’ve had afterwards has protected me from it from coming back.

‘It means I can be with my family, enjoy my retirement and not worry about cancer.’