Achievement of cancer- and treatment-free status by atezolizumab plus bevacizumab combined with or without curative conversion in patients with transarterial chemoembolization-unsuitable, intermediate-stage hepatocellular carcinoma: A multicenter cohort study.

Abstract

535 Background: Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. Tumor shrinkage is achieved, and cancer- and treatment-free status is possible in many cases using curative conversion with resection, ablation, or selective transarterial chemoembolization (TACE). This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter study was conducted to clarify the value of curative conversion in intermediate-stage HCC meeting TACE-unsuitable criteria. Methods: This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. Cancer-free rate, treatment-free rate, time to cancer-free status, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, recurrence-free survival (RFS), and overall survival (OS) were assessed in patients who achieved cancer-free status using resection, ablation, selective TACE, or atezolizumab plus bevacizumab alone. Results: Cancer-free status was achieved in 38 patients (35%) (median observation period: 17. 7 months). The modalities of curative conversion were as follows: resection, 7; ablation (including patients who underwent ablation after TACE), 13; and selective TACE (including lenvatinib-TACE sequential therapy), 15. Three patients achieved cancer-free status with only atezolizumab plus bevacizumab therapy. Among the 38 cancer-free patients, 24 achieved treatment-free status. RF5 was 31.8 months (95% confidence interval, 30.5-33.0), and two patients experienced recurrence after reaching cancer-free status. Regarding OS, there were no deaths in any of the groups, and excellent outcomes were obtained. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved cancer-free status, five achieved treatment-free status. Conclusions: The curative conversion rate (cancer-free rate) in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 22% of patients achieved treatment-free status. Thus, achieving cancer-free and/or treatment-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread. Clinical trial information: NCT03434379 .