Both progression-free survival and overall survival were significantly improved in patients with unresectable hepatocellular carcinoma (HCC) who received combination treatment with atezolizumab plus bevacizumab compared with sorafenib, according to the results of the phase 3 IMbrave150 study.
The trial included 336 patients with treatment-naive disease who were randomly assigned in a 2:1 ratio to receive the immunotherapy plus anti-vascular endothelial growth factor (VEGF) combination or sorafenib.
At the primary analysis, atezolizumab plus bevacizumab reduced the risk for death by 42% (hazard ratio [HR], 0.58; 95% CI, 0.42-0.79; P <.001) compared with sorafenib. The 12-month overall survival was 67.2% for combination therapy compared with 54.6% for sorafenib.
Similarly, progression-free survival was also improved with combination treatment. Median progression-free survival was 6.8 months compared with 4.3 months with sorafenib (HR, 0.59; 95% CI, 0.47-0.76; P <.001). At 6 months, progression-free survival was 54.5% in the atezolizumab plus bevacizumab group compared with 37.2% for sorafenib.
“This benefit was generally consistent across clinical subgroups and confirms previous phase 1b findings that showed the clinical benefit of targeting both angiogenesis and PD-L1 signaling in unresectable liver cancer,” the researchers wrote.
Confirmed objective responses occurred in 27.3% of patients assigned the combination compared with 11.9% assigned sorafenib (P <.001). About 87% of patients assigned atezolizumab plus bevacizumab who responded had a duration of response 6 months or longer compared with 59.1% of responders assigned to receive sorafenib.
“The spectrum, incidence, and severity of adverse events observed with the combination of atezolizumab and bevacizumab were consistent with the known safety profile of each agent and the underlying disease,” the researchers noted.
High-grade adverse events were infrequent with combination therapy, with the exception of hypertension, which occurred in 15.2% of patients.
Finn RS, Qin S, Ikeda M, et al. Atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma. N Engl J Med. 2020;382(20):1894-1905.