“This is the longest survival seen in a phase 3 study of advanced liver cancer,” lead study author Dr. Richard S. Finn, of the UCLA Jonsson Comprehensive Cancer Center, said in a virtual presentation of the data.
Updated study results from the phase 3 IMbrave150 trial demonstrated that Tecentriq (atezolizumab) in combination with Avastin (bevacizumab) continues to show improved survival outcomes in patients with previously untreated advanced hepatocellular carcinoma, compared with Nexavar (sorafenib).
“The median survival for (Tecentriq/Avastin) is now over 19 months. This is the longest survival seen in a phase 3 study of advanced liver cancer,” lead study author Dr. Richard S. Finn, director of the Signal Transduction and Therapeutics Program at the UCLA Jonsson Comprehensive Cancer Center, said in a virtual presentation of the data during the 2021 American Society of Clinical Oncology Gastrointestinal Cancers Symposium.
The combination therapy, based on findings from the primary analysis of the IMbrave150 trial, was approved by the Food and Drug Administration (FDA) in May 2020 for the treatment of previously untreated patients with unresectable or metastatic hepatocellular carcinoma.
The global, multicenter, randomized, open-label study enrolled 501 treatment-naive patients with locally advanced or metastatic and/or unresectable hepatocellular carcinoma and randomized them 2:1 to receive 1,200 mg of intravenous (IV) Tecentriq every three weeks plus 15 mg/kg of IV Avastin every three weeks (336 patients) or 400 mg of Nexavar twice daily (165 patients) until unacceptable toxicity or loss of clinical benefit.
Updated patient disposition indicated that 18% of patients in the combination arm and 3% of patients in the Nexavar arm remain on treatment, respectively. Sixty percent of patients in the combination arm have discontinued the study versus 74% in the Nexavar arm, primarily because of death (53% and 60%, respectively).
At a median follow-up of 15.6 months, the median overall survival was 19.2 months with the combination versus 13.4 months with Nexavar. The median progression-free survival was 6.9 months with Tecentriq and Avastin versus 4.3 months with Nexavar, respectively.
“The baseline characteristics have not changed from the primary analysis. The majority of patients came from outside of Asia and had high-risk features, such as an elevated alpha-fetoprotein, macrovascular invasion, or extrahepatic spread,” said Finn.
With an additional 12 months of follow-up, the updated results also demonstrated an 18-month overall rate of 52% with the combination versus 40% with Nexavar. The 18-month progression-free survival rates were 24% and 12%, respectively.
“We see with longer follow-up that we have more responses with (Tecentriq/Avastin) than initially reported,” said Finn.
The confirmed objective response rate (the proportion of patients who had a complete or partial response to treatment) was 30% with the combination versus 11% with Nexavar, with complete response rates of 8% and less than 1%, respectively. The disease-control rate was 74% with the combination versus 55% with Nexavar.
The median duration of response was 18.1 months with the combination versus 14.9 months with Nexavar. Fifty-six percent of patients in the combination arm had an ongoing response at the clinical cutoff versus 28% of patients in the Nexavar arm.
In the Chinese cohort (194 patients), the median overall survival was 24 months in the combination arm versus 11.4 months in the Nexavar arm. The 18-month overall survival rates were 56% and 33%, respectively.
In terms of safety, all-grade treatment-related adverse effects occurred in 86% of patients in the combination arm versus 95% of patients in the Nexavar arm. The rates of grade 3 and 4 (more serious or severe) treatment-related adverse events were 43% and 46%, respectively.
Adverse events leading to withdrawal from any component of treatment occurred in 22% of patients in the combination arm versus 12% in the Nexavar arm. Adverse events leading to dose interruption of any study treatment occurred in 59% and 44% of patients, respectively.
“The safety and tolerability of the combination remains consistent with what we saw in the primary analysis,” concluded Finn.
A version of this story originally appeared on OncLive® as “Atezolizumab/Bevacizumab Combo Maintains Survival Advantage in Advanced HCC.”
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