TACE/HAIC combined with bevacizumab and tislelizumab as third-line therapy for colorectal cancer with unresectable liver metastases: A prospective, observational real-world study (TABTiC).

Abstract

e15617 Background: Microsatellite stable (MSS) colorectal cancer (CRC) with unresectable liver metastases has limited effective third-line options. This study evaluated the efficacy and safety of transarterial chemoembolization/ hepatic arterial infusion chemotherapy (TACE/HAIC) combined with bevacizumab and tislelizumab in this setting. Methods: This single-center, prospective, observational study enrolled 21 patients with MSS CRC and unresectable liver metastases who failed at least two prior systemic therapies. One patient was excluded per protocol, leaving 20 evaluable patients. All received at least one cycle of TACE/HAIC combined with bevacizumab and tislelizumab. Primary endpoints was overall response rate(ORR) after 1 month of receiving the first combination therapy. Secondary endpoints included progression-free survival (PFS) , overall survival (OS), disease control rate (DCR), safety, and exploration of predictive biomarkers. Results: After the first efficacy assessment, the DCR was 70% (14/20 patients with stable disease, SD). No complete or partial responses were observed. The 6-month and 12-month PFS rates were 68.0% and 42.0%, respectively. Median PFS was 7.0 months and OS were 12.0 months (OS data immature, follow-up ongoing). Patients with < 2 extrahepatic metastatic sites had significantly longer PFS (6.5 vs. 3.2 months, P = 0.03). Grade ≥3 adverse events occurred in 29.4% of patients, primarily neutropenia (11.8%), hypertension (8.8%), and liver dysfunction (5.9%), with no treatment-related deaths. Exploratory biomarker analysis suggested that lower baseline BMI (< 24 kg/m²) was associated with better outcomes (P < 0.05), and a greater decrease in absolute lymphocyte count (ALC) after treatment correlated with progressive disease (PD). Conclusions: The combination of TACE/HAIC, bevacizumab, and tislelizumab demonstrated promising disease control and survival benefit with a manageable safety profile as a third-line therapy for MSS CRC with unresectable liver metastases. Baseline BMI and extrahepatic metastatic burden may help identify patients more likely to benefit. Further studies are warranted to optimize the regimen and validate predictive biomarkers. Clinical trial information: ChiCTR2500101315.