4131 Background: Infiltrative hepatocellular carcinoma (HCC) is defined as a tumor with ill-defined border, no evidence of convex margination, and no typical enhancement pattern by imaging. This subtype of HCC is usually associated with poor prognosis and is frequently diagnosed at advanced stage. Blank-microsphere transcatheter arterial embolization (bTAE) and hepatic arterial infusion chemotherapy (HAIC) of oxaliplatin, 5-fluorouracil and leucovorin are effective and safe for HCC. This prospective study is to evaluate the safety and efficacy of bTAE-HAIC combined with Lenvatinib and Sintilimab for intermediate-advanced infiltrative HCC. Methods: This prospective phase II trial is a single-center, single-arm study designed to assess the efficacy and safety of TAE and HAIC, combined with sequential Lenvatinib and Sintilimab on infiltrative HCC. Patients with primary infiltrative HCC treated at our center between October 2023 and December 2024. The primary endpoint was objective response rate (ORR) according to mRECIST criteria. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and treatment-related adverse events (AEs). Results: A total of 30 patients who met the criteria were enrolled in this study and received at least 2 courses of TAE-HAIC combined with Lenvatinib and Sintilimab treatment. The median follow-up time was 7.1 months, and 10 patients died during the period. 5 patients (16.7%) achieved complete response (CR) after sequent ablation or radiotherapy, 20 patients (66.7) were evaluated as PR. The overall ORR was 83.3%. The median OS was 16.0 months (95%CI: 5.6-26.5 months). The 3-month, 6-month and 12-month rates of OS were 93.3%, 83.0% and 60.2%. The median PFS was 9.5 months (95%CI: 4.9-14.1 months), and the PFS rates at 3-month, 6-months and 12-month were 95.7%, 68.1% and 20.4%, respectively. The median liver-specific PFS was 11.7 months (95%CI: 7.7-15.7 months). The overall incidence of treatment related AEs was 76.7% according to the CTCAE 5.0 criteria. The incidence of Grade 1-2 AEs was 73.3%, and only one patient experienced Grade 3 AE. 10 patients (33.3%) received dose reduction, 9 patients (30.0%) discontinued drug therapy. Conclusions: The preliminary results of current study indicates that the combination regimen is safe and effective, and the AEs and complications are controllable and tolerable. This study provides a reference for further phase III clinical research, and a novel treatment option for the infiltrative HCC. Clinical trial information: NCT06070636 . Baseline characteristics. Variable All Patients (N = 30) Male 26 (86.7%) BCLC Stage C 28 (93.3%) Extrahepatic Metastasis 13 (43.3%) Tumor Number- Multiple（≥3） 16 (53.3%) Largest Diameter (cm) >10 cm 24 (80.0%) Largest Diameter (cm) >15 cm 8 (26.7%) Macrovascular Invasion 25 (83.3%) Portal Hypertension 12 (40.0%)
Zhou et al. (2026) studied this question.