The KEYNOTE-426 study of the immune checkpoint inhibitor, pembrolizumab plus the VEGF inhibitor, axitinib for advanced renal cell carcinoma continues to show survival benefits compared with sunitinib as a first treatment after surgery.
In this oral presentation from the American Society for Clinical Oncology (ASCO) Annual Meeting, further follow-up data from KEYNOTE-426 over more than 42 months were presented to see how the pembrolizumab/axitinib combination helps patients survive.
Overall, 861 patients were randomly put into two groups to be given the pembrolizumab plus axitinib combination (432) or sunitinib (429). Patients were followed for an average of 42 months, during which time 418 patients had unfortunately died: 44.7% of the patients in the combination group and 52.4% in the sunitinib group. Pembrolizumab/axitinib continues to improve overall survival time (45.7 versus 40.1 months) and time to when the drug stopped working and the cancer started growing again (15.7 versus 11.1 months). Over the 42-month follow-up period overall survival rate was 57.5% with the combination compared to 48.5% with sunitinib, and progression-free survival rate was 25.1% compared to 10.6% with sunitinib. The cancer got smaller in 60.4% of patients on pembrolizumab/axitinib compared to 39.6% of patients on sunitinib. 10% of patients had a complete response with pembrolizumab/axitinib compared to 3.5% with sunitinib. Nearly half (47.2%) of the combination group received further anti-cancer medication, while nearly two thirds of the sunitinib group were given further treatment.
In summary, this is the longest follow-up of an immune checkpoint inhibitor combined with a VEGF inhibitor for the first treatment after surgery for renal cell carcinoma. These results show that pembrolizumab/axitinib continues to show improved survival and with no new side effects.
The extra follow-up information from KEYNOTE-426 also showed that pembrolizumab/axitinib benefited all risk groups of renal cell carcinoma patients, regardless of whether they had the PD-L1 gene, as well as patients with sarcomatoid renal cell carcinoma. Nearly 70% of patients had intermediate or poor risk disease, and the combination showed improved survival over 12 months (87.3% versus 71.3%), improved time to when the drug stopped working and the cancer started growing again (12.6 versus 8.2 months), and shrinkage of the cancer (55.8% versus 29.5%) compared to sunitinib in these patients. Nearly 5% of patients on the combination treatment had a complete response to treatment, while only 0.7% of patients had a complete response to sunitinib.
There were 105 patients with sarcomatoid renal cell carcinoma in the study. Pembrolizumab/axitinib improved the 12-month overall survival rate (83.4% versus 79.5%), time to when the drug stopped working and the cancer started growing again and cancer shrinkage rate (58.8% versus 31.5%) compared to sunitinib in patients with sarcomatoid renal cell carcinoma. There were complete responses to treatment in 11.8% of patients with no complete responses in the sunitinib group.