Results from a phase Ib study of a vaccinia virus called pexastimogene devacirepvec (Pexa-Vec) in combination with cemiplimab (a PD-1 checkpoint inhibitor) in patients with advanced renal cell carcinoma (RCC) show promising survival outcomes.
In the study, the recommended dose of Pexa-Vec was determined for kidney cancer patients. The recommended dose was then given in combination with cemiplimab to 16 patients with advanced RCC. There was a reduction in tumour burden in 75% of patients (12/16), three-quarters of whom had at least a 30% reduction in tumour burden. The best overall response was 37.5% (1 complete response and 5 partial responses). Six patients (37.5%) had stable disease and 4 patients (25%) had progressive disease as their best response. The disease control rate was 75%.
After 27 weeks of follow-up, 44% of patients had progression of their cancer. The combination had a good safety profile, with less than 6% of all adverse events graded as severe, most being transient in nature. Seven patients (41%) had at least one adverse event that was graded as severe.
Although there were limitations to this study, and the study is still ongoing, the combination of Pexa-Vec plus an immune checkpoint inhibitor appears to be a well tolerated and effective treatment for some people with advanced RCC.