The results from one of the first clinical trials of a combination of a new drug, sitravatinib, with nivolumab for the second-line treatment of advanced kidney cancer were presented at the American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium in San Francisco last weekend.
Sitravatinib is a type of drug called a tyrosine kinase inhibitor (TKI), which works by limiting the growth of blood vessels to the tumour. Sitravatinib may also work by making the tissue around the tumour less attractive to cancer cells. Nivolumab is an immune checkpoint inhibitor that has been shown to work in kidney cancer. Nivolumab releases the ‘brakes’ on the immune system allowing the immune cells to kill the cancer cells more effectively.
The main purpose of this study was to see if patients could manage to take the two drugs together. There were 40 kidney cancer patients in this study. The side effects of the combination of sitravatinib and nivolumab appeared manageable. The most common side effect was diarrhoea, but it was not very bad. Four patients stopped treatment because of problems with side effects (only 10% of all patients). Researchers also wanted to find the best dose of sitravatinib for kidney cancer patients. A pill of 120 mg once a day gave the best results when combined with nivolumab. The researchers are planning a larger follow-up study with this dose of sitravatinib and nivolumab.
Although the results are still very early, the combination of these two drugs showed encouraging benefits for patients with advanced kidney cancer who had already been treated with a TKI (like sunitinib and pazopanib), without too many severe side effects.