169P - Conversion response and prognostic factors in HCC patients with macrovascular invasion treated with atezolizumab plus bevacizumab

Background

The TALENTop study (NCT04649489) is aiming to clarify whether hepatic resection may provide additional benefit in HCC patients with macrovascular invasion (MVI) who responded to conversion therapy with atezolizumab plus bevacizumab (atezo/bev). This study is onging and the primary analysis is expected at a later time; instead, this analyse is to demonstrate the conversion results of atezo/bev. To describe the response and safety outcomes of the conversion therapy and prognostic factors associated with being suitable for R0 hepatic resection.

Methods

HCC patients with MVI and without extrahepatic metastasis are eligible for this study. After received 3 cycles of atezo/bev and 1 cycle of atezo (induction phase), patients assessed as PR or SD (RECIST v1.1) and considered suitable for R0 hepatic resection are 1:1 randomized to 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 (tumor recurrence or progression or death). Treatment efficacy in the induction phase were analysed.

Results

From Apr 2021 to Dec 2022, 201 patients were enrolled and entered induction phase and completed induction phase therapy of atezo/bev at cut-off date (Apr 2023). The patients were characterized with a median age of 55 (26-78) and 187 (93%) had HBV infection. Mean tumor diameter evaluated by IRF is 100 mm (26-231 mm). All patients had MVI at baseline and 191 (95%) had PVTT. According to RECIST v1.1 criteria, 38 patients (18.9%) achieved PR and 106 patients (52.7%) achieved SD with 3 cycles of atezo/bev and 1 cycle of atezo. ORR and DCR were 18.9% and 71.6%, respectively. Grades ≥3 TRAEs occurred in 26 patients (12.9%). Most common TRAE was fever (13.4%) and proteinuria (10.9%). Of 201 patients, 73 patients (36.3%) were evaluated as suitable for R0 resection and randomized. In univariate logistic regression, PVTT with vp1-2, AFP＜400ng/mL, NLR (neutrophil-lymphocyte ratio)＜2.63, tumor diameter＜100mm were associated with randomization.

Conclusions

Atezo/bev showed high response rate and conversion rate in the HCC patients with MVI, suggesting a promising conversion strategy in this population.

Clinical trial identification

NCT04649489.

Editorial acknowledgement

Legal entity responsible for the study

Zhongshan Hospital, Fudan University.

Funding

Shanghai Roche Pharmaceuticals Ltd., China.

Disclosure

All authors have declared no conflicts of interest.