A real-world experience of hepatic arterial infusion chemotherapy combined with tislelizumab and lenvatinib for unresectable hepatocellular carcinoma with type IV portal vein tumor thrombus.

e16154 Background: Clinical improvement of interventional therapy with PD-(L)1 inhibitors plus molecular targeted therapies in have been confirmed by several studies, such as EMERALD-1, CHANCE001 etc. Limited data of this treatment in unresectable hepatocellular carcinoma (uHCC) patients (pts) with type IV portal vein tumor thrombus (PVTT) is available. This study aims to describe the efficacy and safety in uHCC pts with type IV PVTT (Vp4) who received HAIC combined with tislelizumab and lenvatinib (HAIC+Tisle+Len) in the real-world setting. Methods: This was a single-center, retrospective analysis of Vp4 uHCC pts treated with HAIC+Tisle+Len as first line systemic therapy between Apr 2020 and Dec 2022. Patient characteristics, treatment information, adverse events and survival data were collected. Pts received HAIC of modified FOLFOX (oxaliplatin, 85 mg/m 2 ; leucovorin, 400 mg/m 2 ; 5-fluorouracil bolus, 400 mg/m 2 on day 1; 5-fluorouracil infusion, 2400 mg/m 2 for 46 h), lenvatinib (8 or 12 mg once daily for body weight, 60 or ≥60 kg), and tislelizumab (200 mg q3w). HAIC was allowed to repeat on demands. Outcomes evaluated included overall survival (OS), progression free survival (PFS), overall response rate (ORR), overall disease control rate (DCR), and treatment-related adverse events (TRAEs). Results: A cohort of 54 pts was identified with a median age of 55 years (range 49-59). Pts characteristics were as follows: male (90.7%), hepatitis B (79.6%), BCLC C stage (100%), Child-Pugh A (88.9%), tumor number = 1 (50%), = 2 (7.4%), ≥3 (42.6%), tumor diameter ≥10 cm (42.6%), extrahepatic metastasis (7.4%), beyond up to steven status (90.7%). As of Dec 20, 2023, the median follow-up duration was 21.3 mo (95% CI, 16.1-26.0), and the median number of HAIC was 3 (range 2-4). The median PFS was 8.1 months (95% CI, 6.8-12.3), while the median OS reached 16.8 months (95% CI:13.1-NR). ORR was 53.7% (3 CR, 26 PR) per RECIST 1.1; ORR was 66.7% (12 CR, 24 PR) per mRECIST. DCR was 96.3% per either RECIST 1.1 or mRECIST. Two pts received surgical treatment after conversion, one of whom underwent liver transplantation and remains tumor-free. The post-PD therapies after first-line treatment were as follows: Tisle+Len (24.1%), TACE+Tisle+Len (18.5%), Tisle+Len+Radiotherapy (7.4%), HAIC+Tisle+Regorafenib (5.6%), others (18.5%). The most common grade 3-4 TRAEs were hypertension (14.8%), decrease in albumin (11.1%), anorexia (9.3%), leukopenia (9.3%), abdominal pain (7.4%) and AST/ALT elevation (7.4%). Conclusions: The combination of HAIC with tislelizumab and lenvatinib represents a promising efficacy and manageable safety for uHCC pts with Vp4, which supplements the trial data for Vp4-HCC with real world outcomes.