A combination of two drugs could effectively help treat patients with an advanced form of kidney cancer, a study has found.
In a clinical trial, people who received the immunotherapy drug avelumab plus axitinib, a targeted agent, had a significant advantage in progression-free survival compared with those who received sunitinib (Sutent), a targeted drug that has been a standard treatment for advanced clear cell renal cell carcinoma -- the most common form of kidney cancer.
"Patients receiving the drug combination also had a higher response rate -- meaning their tumors shrank -- than the sunitinib-only group," said Toni K Choueiri, of Dana-Farber Cancer Institute in the US.
"This is certainly better than sunitinib -- hopefully this will lead to Food and Drug Administration approval soon," said Choueiri.
While progression-free survival was improved with the combination treatment, additional follow-up is needed to show whether the two-drug therapy extends overall survival compared to the standard regimen.
The study, published in the New England Journal of Medicine, to combine avelumab with a drug that targets the vascular endothelial growth factor receptor (VEGFR).
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VEGFR blockers like sunitinib and axitinib are designed to starve tumors by disrupting their blood supply. Immunotherapy drugs such as avelumab -- which blocks an immune checkpoint called PD-L1 -- work by activating "exhausted" immune T cells so they can more effectively attack cancer cells.
The clinical trial involved 886 patients with previously untreated, advanced renal cell carcinoma who were randomised to receive the drug combination or sunitinib alone.
The results from this study showed that the median progression-free survival (PFS) -- the length of time before the cancer began to worsen -- was 13.8 months in the combination group and 7.2 months in patients receiving only sunitinib.
These results specifically applied to patients whose cancer cells tested positive for the PD-L1 checkpoint that is blocked by avelumab. The PFS for the overall population (PD-L1 positive or negative) was similar -- 13.8 months versus 8.4 months.
The proportion of patients whose tumors shrank was 55.2 per cent with avelumab plus axitinib and 25.5 per cent with sunitinib in the patients who were positive for PD-L1.
"Interestingly, the analysis showed that all subgroups -- good, intermediate, and poor-risk patient -- benefited from the combination treatment," said Choueiri.
Nearly all patients in both treatment groups experienced some side effects. In the combination treatment group, 38.2 per cent of patients experienced immune-related adverse events, the most frequent being thyroid disorders, observed in 107 patients.