People with kidney cancer have been shown to have changes (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.

There were 746 patients enrolled in this phase 3 clinical trial, called LITESPARK-005. 374 patients were treated with belzutifan, and 372 with everolimus.

After an average of 18 months follow-up, the time to when the treatment stopped working and the cancer started growing again (progression-free survival) was significantly longer for belzutifan compared to everolimus, with nearly a quarter of the patients in the belzutifan group and just over 8 in 100 patients in the everolimus group alive and free from progression. More than 20 in 100 patients responded to treatment with belzutifan, compared to less than 4 in 100 patients responded to everolimus.

After and average of over 2 years follow-up, the overall survival time did not differ significantly between the groups. 

The tolerability of belzutifan and everolimus was similar, although less patients stopped treatment because of side effects in the belzutifan group.

Belzutifan showed a significant benefit over everolimus with respect to progression-free survival and response to treatment in previously treated patients with advanced kidney cancer.

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 The New England Journal of Medicine here