In this video interview with Dr Monty Pal from the City of Hope Hospital in California, treatment of non-clear cell renal cell carcinoma (RCC) with a combination of cabozantinib plus atezolizumab is discussed. Most research is focussed on clear cell RCC; however, non-clear cell RCC accounts for about 25% of all RCC diagnoses and usually has worse outcomes than clear cell RCC. Non-clear cell RCC has different biology to clear cell RCC and, therefore, needs different treatments.
Both cabozantinib and immune checkpoint inhibitors have shown preliminary activity in non-clear cell RCC. Cabozantinib appears to enhance the response to immune checkpoint inhibitors and has shown encouraging results in combination with immune checkpoint inhibitors in various tumour types, such as clear cell RCC, urothelial carcinoma, metastatic prostate cancer, and hepatocellular carcinoma.
A group of patients (cohort 10) from the COSMIC-021 clinical trial was treated with a combination of cabozantinib and atezolizumab. Thirty (30) patients were enrolled with a follow-up of 13 months. Sixteen (16) patients (53%) remained on treatment. There were 15 papillary, 7 chromophobe and 8 other non-clear cell subtypes.
The response rate was 33% and there were 10 patients with partial responses. There were no complete responses and disease control rate was 93%. Median duration of response was 7.9 months and median progression-free survival was 9.5 months.
In conclusion, cabozantinib plus atezolizumab demonstrated encouraging clinical activity in patients with non-clear cell RCC with an acceptable safety profile. Further trials are ongoing with this combination of treatments in patients with papillary or unclassified non-clear cell RCC.