Comparing the efficacy and safety of HepaSphere drug-eluting bead transarterial chemoembolization combined with hepatic arterial infusion chemotherapy versus hepatic arterial infusion chemotherapy alone in unresectable colorectal liver metastases.

3565 Background: Drug-eluting bead transarterial chemoembolization (DEB-TACE) and hepatic arterial infusion chemotherapy (HAIC) are widely employed treatments for unresectable colorectal liver metastases (CRLM). Limited evaluation exists regarding TACE plus HAIC versus HAIC alone. This study aimed to evaluate the efficacy of combining HepaSphere DEB-TACE with HAIC compared to HAIC alone in patients with unresectable CRLM. Methods: A total of 259 CRLM patients aged over 18 years, treated at Peking University Cancer Hospital between March 2015 and November 2022, were included in this retrospective study. Among them, 157 patients received HepaSphere DEB-TACE combined with HAIC (DEB-TACE-HAIC), while 102 patients received HAIC alone. Propensity score matching (PSM) was performed to avoid selection bias and enable comparative analysis of efficacy and safety between the two cohorts. The primary endpoint was progression-free survival (PFS), while secondary endpoints comprised hepatic progression-free survival (hPFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety. Results: PSM resulted in 83 pairs, achieving comparable baseline between DEB-TACE-HAIC and HAIC cohorts. Of these pairs, 116 were male and 50 were female. Notably, 51.2% of patients harbored mutations in either KRAS, NRAS, or BRAF genes. Prior to enrollment, 94.6% of patients had received systemic treatments. Median hPFS, PFS and OS were all higher in the matched DEB-TACE-HAIC cohort (median hPFS: 7.6 vs. 4.1 months, P=0.023; median PFS: 5.1 vs. 3.5 months, P=0.092; median OS: 15.5 vs. 14.7 months, P=0.513). ORR was 37.3% in the DEB-TACE-HAIC group and 27.7% in the HAIC group, with DCR of 75.9% and 69.9%, respectively. There were no treatment related deaths. Serious adverse events were comparable between the two groups, except for nausea, which occurred more frequently in the HAIC group (39.8% vs. 22.9%, P=0.019). Conclusions: DEB-TACE-HAIC demonstrated superior survival compared to HAIC alone in unresectable CRLM, even in patients refractory to systemic therapy. The combination of HepaSphere DEB-TACE and HAIC appears promising as a regional treatment option with improved outcomes and a comparable safety profile.