Background/Objectives: Patients with unresectable hepatocellular carcinoma (uHCC) refractory or intolerant to immune checkpoint inhibitor (ICI)-based regimens represent a growing yet therapeutically underserved population with limited treatment options. We investigated the efficacy, safety, and mechanistic underpinnings of lenvatinib combined with New FP hepatic arterial infusion chemotherapy (LEN–New FP) in this challenging clinical setting. Methods: We retrospectively analyzed 14 consecutive patients with uHCC treated with LEN–New FP between April 2022 and March 2025. Tumor response was assessed by the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Proper hepatic artery (PHA) diameter was serially measured on angiography as an exploratory assessment of vascular remodeling, and tumor vascularity was semi-quantitatively evaluated using a 4-point angiographic scoring system (Tumor Vascularity Score TVS). Results: The cohort comprised BCLC stage B/C (7/7), mALBI grade 1–2b, and 13 of 14 patients with prior ICI-containing therapy. The objective response rate and disease control rate were 85.7% and 100%, including two complete responses. Median overall survival was 22.8 months from LEN–New FP initiation (median follow-up: 15.1 months) and 36.2 months from first-line initiation; median intrahepatic progression-free survival was 10.4 months. A total of 11 of 14 patients (78.6%) transitioned to subsequent therapies, including four curative-intent conversions. PHA narrowing was observed in 10 of 13 evaluable patients (76.9%), with no clear association with hepatic function deterioration. TVS decreased in 10 of 12 evaluable patients (83.3%), with reduction observed in 90.0% of PR/CR cases. Conclusions: LEN–New FP achieved sustained intrahepatic tumor control and encouraging survival in aggressive uHCC, including ICI-refractory or -intolerant disease. The concordant reduction in PHA diameter and tumor vascularity score provides angiographic evidence of VEGFR inhibition-mediated vascular remodeling, offering mechanistic insight into the synergistic antitumor effects of this regimen and supporting LEN–New FP as a promising multimodal strategy within the evolving landscape of HCC treatment.
Maruta et al. (Wed,) studied this question.