Abstract 5097: Effectiveness and safety of atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma: A multicenter, retrospective real-world study in China

Abstract Background: Atezolizumab plus bevacizumab (Atezo+Bev) has shown better benefits than sorafenib as the first-line treatment for unresectable hepatocellular carcinoma (uHCC) in IMbrave 150. However, the real-world evidence of Atezo+Bev in uHCC is limited, especially in China. We aimed to investigate the real-world effectiveness and safety of Atezo+Bev in Chinese patients with uHCC. Methods: Patients with uHCC treated with Atezo+Bev were included at 5 centers in China from Jan. 2021 to Jan. 2023. Overall response (ORR), organ-specific response rate (OSRR), disease control rates (DCR), time to disease progression (TPP), progression-free survival (PFS), metastasis-specific PFS and overall survival (OS) were calculated. Results: Among 48 patients, the median age was 58. 4 years with 85. 4% being male. A total of 35 and 13 patients received Atezo+Bev as 1st and 2nd line treatment, respectively. The median number of treatment cycles were 8, and 27 (56. 3%) patients received locoregional therapies. Detailed treatment response is in the Table. The overall ORR and DCR assessed by mRECIST were 60. 4% and 75. 0%, while the intra- and extrahepatic OSRR were 59. 4% and 62. 5%, respectively. With a median follow-up of 14. 5 months, the median PFS was 8. 5 months (95%CI: 4. 4, 11. 2) in 1st line setting and 5. 1 months (95%CI: 2. 1, 7. 9) in 2nd line setting. Median intra- and extrahepatic metastasis-specific PFS were 7. 9 and 7. 6 months, respectively. Median overall TTP was 7. 6 months. The median OS was not reached. A total of 36 patients (75%) experienced any grade adverse events, most commonly being thrombocytopenia (27. 1%, n=13), lymphopenia (25%, n=12) and abnormal liver function (14. 6%, n=7). Conclusion: This study confirmed effectiveness and safety of Atezo+Bev in the 1st line treatment of uHCC, and observed its potential in 2nd line in a real-world setting. Further studies are warranted to confirm these observations and refine treatment strategies. Table. Treatment response N (%) Response Evaluation Criteria in Solid Tumors (RECIST) 1. 1 (N=48) Modified RECIST (N=48) Complete response (CR) 7 (14. 6) 9 (18. 8) Partial response (PR) 12 (25. 0) 20 (41. 7) Stable disease (SD) 15 (31. 2) 7 (14. 6) Progressive disease 11 (22. 9) 12 (25. 0) Not evaluated 3 (6. 2) 0 ORR (CR+PR) 19 (39. 6) 29 (60. 4) DCR (CR+PR+SD) 34 (70. 8) 36 (75. 0) Citation Format: Hui Zhang, Minghua Shao, Binbin Tan, Yin Fu, Yuan, Hailei Chen. Effectiveness and safety of atezolizumab plus bevacizumab in unresectable hepatocellular carcinoma: A multicenter, retrospective real-world study in China abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 5097.