This study is the first to validate the synergistic antitumor effect of combining cryoablation with PD-1 inhibitors and targeted therapy in patients with advanced intrahepatic cholangiocarcinoma, demonstrating a high objective response rate and durable survival benefit. Mechanistic analyses further reveal the treatment-induced systemic activation of antitumor immunity.
Literature Overview
This article, 'Cryoablation plus sintilimab and lenvatinib in advanced or metastatic intrahepatic cholangiocarcinoma: a phase 2 trial,' published in Nature Cancer, reviews and summarizes the findings of a single-arm, phase II clinical trial (CASTLE-01, NCT05010668). The study aimed to evaluate the efficacy and safety of sequential cryoablation followed by sintilimab (an anti-PD-1 antibody) combined with lenvatinib in patients with advanced or metastatic intrahepatic cholangiocarcinoma (ICC) who had progressed after chemotherapy. Results showed that this combination regimen exhibited significant clinical activity, with an objective response rate of 75%, a median progression-free survival of 16.8 months, and a median overall survival of 25.4 months, all with manageable safety. Moreover, dynamic multi-omics analyses revealed that cryoablation enhances tumor immunogenicity, promotes dendritic cell activation, and—synergistically with lenvatinib—improves T-cell infiltration. These findings provide a novel strategy and theoretical foundation for immunotherapy combinations in ICC.Background Knowledge
Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive malignancy of the biliary system, with a rising global incidence. For patients with advanced or metastatic disease, the first-line standard of care is gemcitabine plus cisplatin (GemCis). Although combining PD-1/PD-L1 inhibitors with chemotherapy has extended survival in recent years, second-line treatment options remain extremely limited. While the FOLFOX regimen is recommended, its efficacy is modest, with a median progression-free survival of only about 4 months. Targeted therapies are applicable only to a small subset of patients (approximately 13%–30%) harboring actionable alterations such as IDH1 mutations or FGFR2 fusions, leaving most patients without effective treatments. Immune checkpoint inhibitors show limited efficacy as monotherapy in the second-line setting, highlighting the need for novel combination strategies to enhance antitumor immune responses. Local ablative techniques such as cryoablation can release tumor antigens in situ, acting as an 'in vivo vaccine' to trigger systemic immunity—known as the abscopal effect. However, evidence for this effect in human solid tumors largely comes from preclinical models, with limited mechanistic investigation in clinical settings. Lenvatinib, a multi-target tyrosine kinase inhibitor, modulates the tumor microenvironment and promotes lymphocyte infiltration. Therefore, combining cryoablation as an immune primer with PD-1 inhibitors and lenvatinib may achieve synergistic antitumor effects. This study is based on that scientific hypothesis, exploring its clinical translational potential in ICC and filling a critical gap in mechanism-driven combination strategies for this disease.
Research Methods and Experiments
This study conducted a single-arm, phase II clinical trial (CASTLE-01, NCT05010668), enrolling 28 patients with advanced or metastatic intrahepatic cholangiocarcinoma who had progressed after chemotherapy. All patients underwent cryoablation on one liver lesion, followed two weeks later by sintilimab (200 mg every three weeks) combined with lenvatinib (8–12 mg/day). The primary endpoint was objective response rate (ORR) assessed by RECIST v1.1 criteria. Secondary endpoints included disease control rate (DCR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS), along with safety evaluation. Additionally, the study prospectively collected paired tumor biopsies and peripheral blood samples before treatment, two weeks after cryoablation, and after two cycles of combination therapy, performing bulk RNA-seq, single-cell RNA-seq (scRNA-seq), single-cell TCR sequencing (scTCR-seq), and imaging mass cytometry (IMC) to systematically analyze dynamic changes in the tumor immune microenvironment.Key Conclusions and Perspectives
Research Significance and Prospects
This study provides the first clinical evidence of the efficacy and safety of combining cryoablation with PD-1 inhibitors and lenvatinib in advanced intrahepatic cholangiocarcinoma, offering a highly promising new second-line therapeutic strategy for this difficult-to-treat cancer. The high response rate and durable survival benefits significantly surpass those of current standard therapies, with the potential to change clinical practice. More importantly, through in-depth multi-omics analyses, the study systematically elucidates the synergistic mechanisms of this combination: cryoablation acts as an 'immune primer,' enhancing antigen release and DC activation; lenvatinib serves as a 'microenvironment modulator,' promoting T-cell infiltration and penetration; and PD-1 inhibitors reverse T-cell exhaustion. Together, these components synergistically activate systemic antitumor immunity. This mechanistic model provides a theoretical framework for optimizing future combination immunotherapies.
Future studies could explore the potential of this regimen in first-line settings or validate its applicability in other 'cold' tumors. Additionally, the study identified baseline EP1 subpopulations as potentially prognostic, suggesting their utility as biomarkers, though validation in larger cohorts is needed. Although this study employed a single-arm design without a control group, its findings are highly informative and support the initiation of randomized phase III trials to confirm efficacy. Overall, this research not only delivers an effective treatment option but also deepens our understanding of how local ablation combined with systemic therapy can induce abscopal effects, advancing the field of precision cancer immunotherapy.
Conclusion
This study systematically evaluated the efficacy and mechanisms of sequential cryoablation followed by sintilimab combined with lenvatinib in patients with advanced or metastatic intrahepatic cholangiocarcinoma through a phase II clinical trial. The results demonstrated that this triple-combination regimen has significant antitumor activity, with an objective response rate of 75%, and median progression-free and overall survival reaching 16.8 and 25.4 months, respectively, with manageable safety. Multi-omics analyses revealed that cryoablation initiates systemic immune responses by enhancing tumor immunogenicity and dendritic cell activation, while lenvatinib remodels vasculature and stroma to promote sustained peripheral replenishment and deep intratumoral penetration of CD8+PD1hi effector T cells. This synergistic mechanism explains the regimen’s high clinical efficacy and confirms that cryoablation can cooperate with immunotherapy and targeted therapy to trigger systemic antitumor immunity. The study not only offers a new therapeutic option for patients with intrahepatic cholangiocarcinoma but also provides crucial theoretical support for optimizing combination immunotherapy strategies at the mechanistic level, demonstrating significant clinical translational value and scientific importance.
