Using an existing drug for late-stage kidney cancer at an earlier stage of the disease could reduce the risk of cancer recurring by a third, according to new research.

The findings from the Phase III trial are presented at the European Association of Urology congress (EAU21).

There is a high risk of kidney cancer returning, following surgery to remove tumours, but there is currently no treatment to help prevent this.

The KEYNOTE study involved just under 1000 patients with kidney cancer who had undergone surgery. Half of them were given the immunotherapy drug pembrolizumab, or pembro, and the other half a placebo.

Pembro is used to treat a number of cancers, including late-stage kidney cancer, where the disease has spread to other organs.

The international trial across 20 countries was the first time the drug had been used with patients at an early stage of the disease.

The team found that over two years, patients on pembro were a third less likely to see their disease return than those on the placebo.

Follow-up with patients is continuing, to determine the impact of the treatment on survival rates over a five-year period.

The study also showed that the side effects from the drug were similar to those normally expected with a cancer treatment.

Co-investigator on the study, Professor Thomas Powles of Barts Cancer Institute at Queen Mary University of London, said: "This early data from the trial is very promising, with a clear reduction in the disease recurring in patients on pembro. There are signs as well that the drug may improve survival rates, but we can't be sure of that for another few years. We're hopeful that this trial, when complete, will provide a strong case for this drug to be approved for use by the medicines regulator."

Combination immunotherapy promising for advanced bladder cancer

Professor Powles is presenting further findings at EAU21 from another trial, which also involves a new use for an existing cancer immunotherapy drug.

The DANUBE study looked at durvalumab in patients with late-stage bladder cancer, where the disease had already spread to other parts of the body. Durvalumab is used widely as a lung cancer treatment, particularly in the USA.

Over 1000 patients were recruited to the trial, with a third of them receiving durvalumab, a third receiving durvalumab combined with a new immunotherapy drug, tremelimumab, and a third receiving standard chemotherapy.

They found that overall, the immunotherapy drugs did not increase survival more than standard chemotherapy.

However, in exploratory analysis, in a subset of patients (those who had a raised level of a specific biomarker (PD-L1) and who weren't eligible for the chemotherapy drug cisplatin) the activity of durvalumab was increased by the addition of tremilimumab.

Professor Powles said: "While we weren't comparing durvalumab against other licensed immune therapies in this clinical situation, we could see the new combination of immunotherapies did show some additional promise that warranted a more detailed look."

Two large randomised controlled trials are now underway, testing durvalumab and tremelimumab against the existing immunotherapy treatments, both in late-stage and early-stage bladder cancer, in patients with high levels of the LD-P1 biomarker who can't be given cisplatin. The results from the first trial should be reported later this year, while the other is still recruiting.

Source: European Association of Urology