Results from the IMmotion151 phase III clinical trial were published in JAMA Oncology this week and showed that a combination of atezolizumab and bevacizumab did not improve overall survival time compared with sunitinib in patients with previously untreated, metastatic renal cell carcinoma (RCC).

The researchers said they “do not have a clear explanation” for these results with atezolizumab and bevacizumab. Prior results from IMmotion151 showed that the combination improved the time to when the medicine stopped working and the cancer started growing again (progression-free survival) compared to sunitinib.

The study involved 915 patients, of which 40% were positive for PD-L1 biomarkers. In the PD-L1 positive group of patients, the combination of atezolizumab plus bevacizumab had longer average progression-free survival of 11.2 months versus 7.7 months for sunitinib.

The atezolizumab plus bevacizumab combination also seemed more tolerable, with fewer severe or life-threatening side effects and treatment stoppages.

Patients were followed-up for a minimum of 40 months and overall survival time was similar between the two treatments. The average overall survival time was 36.1 months with the atezolizumab plus bevacizumab combination and 35.3 months with sunitinib.

The overall survival results were similar for patients who were positive for PD-L1 as well. The average overall survival time was 38.7 months with atezolizumab-bevacizumab and 31.6 months with sunitinib.

Read more in Renal & Urology News here