The treatment outcomes of patients who failed to be randomly assigned after atezo/bev induction therapy in the Chinese TALENTop study.

e16183 Background: Hepatocellular carcinoma (HCC) patients with macrovascular invasion (MVI) are considered to be at an advanced stage of disease with limited treatment options. The combination therapy of atezolizumab (atezo) plus bevacizumab (bev) has become a global standard of care for those patients and made conversion resection possible. The Chinese TALENTop study (NCT04649489) is aiming to clarify whether hepatic resection may provide additional benefit in HCC patients with MVI responding to atezo/bev. For patients without opportunity to receive hepatic resection, subsequent treatment outcomes will be reported. Methods: Potentially resectable HCC patients with MVI and without extrahepatic metastasis are eligible for this study. Eligible patients receive 3 cycles of atezo/bev and 1 cycle of atezo as primary systemic therapy (induction phase). Patients assessed as partial response (PR) or stable disease (SD) per RECIST v1.1 and considered suitable for R0 hepatic resection are randomized in a 1:1 ratio to either Arm A, hepatic resection followed by atezo/bev for 1 year, or Arm B, continuing atezo/bev therapy. The primary endpoint is the time to treatment failure. Patients failed to be randomized will enter the survival follow-up phase. After 296 patients entered induction phase, the patient profile, subsequent treatments per local standard of care and survival of patients who failed to be randomized were analyzed. Results: From Apr 2021 to Jun 2023, 296 patients were enrolled and entered induction phase and 175 patients failed to be randomized and were followed up until Sept 2023. The main reasons for failure to be randomized were disease progression (64.6%), investigator assessment of unsuitability for R0 hepatic resection (14.3%), and others. The 175 patients were characterized with a median age of 52 (26-76), and 166 (95%) had HBV infection. Among them, 165 (94%) had combined PVTT, 24 (14%) had combined HVTT and 5 (3%) had combined IVCTT. At a median follow-up time of 10.9 months (9.7-13.1), the median overall survival (mOS) is 13.8 months (8.9-15.8), 6- and 12-month survival rate were 71% and 53%, respectively. As the result of best response during induction phase, 3 patients (1.7%) achieved PR, 92 patients (52.6%) achieved SD and 65 patients (37.1%) were PD. 123 patients (70%) received subsequent therapy. The mOS of patients received different subsequent therapies was showed below. Conclusions: This study provides data on HCC patients with MVI after receiving atezo/bev. The result shows favorable survival even in patients failed to randomization to receive conversion resection, and subsequent treatment strategy may differ survival outcomes. Clinical trial information: NCT04649489 . Table: see text