Studies looking at the genes of people with kidney cancer have shown mutations in a gene called the von Hippel-Lindau gene (VHL). This results in high levels of a protein called hypoxia-inducible factor, or HIF-2α in the blood of these patients. This causes changes in the cancer cells that make the tumour grow. A new medicine called belzutifan is a tablet that blocks the action of HIF-2α and, therefore, blocks cancer cell growth.

In a small phase 1 clinical trial, the safety and effectiveness of belzutifan was assessed in 55 patients with advanced kidney cancer who had already been on several treatments. Patients were followed for an average of almost 3 and a half years.

After 3.5 years follow-up, a quarter of the patients were still responding to treatment and their cancer was either stable or had shrunk in size.

Nearly all patients reported a side effect to treatment (96%). Four in 10 side effects were serious. The most common side effects were anaemia (24%) and low blood oxygen levels (hypoxia, 13%). There were no life-threatening side effects or deaths related to treatment with belzutifan.

Belzutifan is well tolerated and effective in patients with advanced clear cell kidney cancer after a follow-up of nearly 3 and a half years. A phase 3 clinical trial is ongoing in patients with advanced kidney cancer that haas already been treated, comparing belzutifan to everolimus.

Belzutifan has been approved in some countries (including Scotland) for the treatment of people with VHL disease who develop tumours in the kidney, brain and spinal cord, or pancreas.

Read more in UroToday here