Adjuvant and neoadjuvant immunotherapies in hepatocellular carcinoma.

Liver cancer, specifically hepatocellular carcinoma (HCC), is the sixth most common cancer and the third leading cause of cancer mortality worldwide. The development of effective systemic therapies, particularly those involving immune-checkpoint inhibitors (ICIs), has substantially improved the outcomes of patients with advanced-stage HCC. Approximately 30% of patients are diagnosed with early stage disease and currently receive potentially curative therapies, such as resection, liver transplantation or local ablation, which result in median overall survival durations beyond 60 months. Nonetheless, up to 70% of these patients will have disease recurrence within 5 years of resection or local ablation. To date, the results of randomized clinical trials testing adjuvant therapy in patients with HCC have been negative. This major unmet need has been addressed with the IMbrave 050 trial, demonstrating a recurrence-free survival benefit in patients with a high risk of relapse after resection or local ablation who received adjuvant atezolizumab plus bevacizumab. In parallel, studies testing neoadjuvant ICIs alone or in combination in patients with early stage disease have also reported efficacy. In this Review, we provide a comprehensive overview of the current approaches to manage patients with early stage HCC. We also describe the tumour immune microenvironment and the mechanisms of action of ICIs and cancer vaccines in this setting. Finally, we summarize the available evidence from phase II/III trials of neoadjuvant and adjuvant approaches and discuss emerging clinical trials, identification of biomarkers and clinical trial design considerations for future studies.

Molecular portraits of patients with intrahepatic cholangiocarcinoma who diverge as rapid progressors or long survivors on chemotherapy.

OBJECTIVE: Cytotoxic agents are the cornerstone of treatment for patients with advanced intrahepatic cholangiocarcinoma (iCCA), despite heterogeneous benefit. We hypothesised that the pretreatment molecular profiles of diagnostic biopsies can predict patient benefit from chemotherapy and define molecular bases of innate chemoresistance. DESIGN: We identified a cohort of advanced iCCA patients with comparable baseline characteristics who diverged as extreme outliers on chemotherapy (survival <6 m in rapid progressors, RP; survival >23 m in long survivors, LS). Diagnostic biopsies were characterised by digital pathology, then subjected to whole-transcriptome profiling of bulk and geospatially macrodissected tissue regions. Spatial transcriptomics of tumour-infiltrating myeloid cells was performed using targeted digital spatial profiling (GeoMx). Transcriptome signatures were evaluated in multiple cohorts of resected cancers. Signatures were also characterised using in vitro cell lines, in vivo mouse models and single cell RNA-sequencing data. RESULTS: Pretreatment transcriptome profiles differentiated patients who would become RPs or LSs on chemotherapy. Biologically, this signature originated from altered tumour-myeloid dynamics, implicating tumour-induced immune tolerogenicity with poor response to chemotherapy. The central role of the liver microenviroment was confrmed by the association of the RPLS transcriptome signature with clinical outcome in iCCA but not extrahepatic CCA, and in liver metastasis from colorectal cancer, but not in the matched primary bowel tumours. CONCLUSIONS: The RPLS signature could be a novel metric of chemotherapy outcome in iCCA. Further development and validation of this transcriptomic signature is warranted to develop precision chemotherapy strategies in these settings.

Lenvatinib plus pembrolizumab versus lenvatinib plus placebo for advanced hepatocellular carcinoma (LEAP-002): a randomised, double-blind, phase 3 trial.

BACKGROUND: Systemic therapies have improved the management of hepatocellular carcinoma, but there is still a need to further enhance overall survival in first-line advanced stages. This study aimed to evaluate the addition of pembrolizumab to lenvatinib versus lenvatinib plus placebo in the first-line setting for unresectable hepatocellular carcinoma. METHODS: In this global, randomised, double-blind, phase 3 study (LEAP-002), patients aged 18 years or older with unresectable hepatocellular carcinoma, Child Pugh class A liver disease, an Eastern Cooperative Oncology Group performance status of 0 or 1, and no previous systemic treatment were enrolled at 172 global sites. Patients were randomly assigned (1:1) with a central interactive voice-response system (block size of 4) to receive lenvatinib (bodyweight <60 kg, 8 mg/day; bodyweight ≥60 kg, 12 mg/day) plus pembrolizumab (200 mg every 3 weeks) or lenvatinib plus placebo. Randomisation was stratified by geographical region, macrovascular portal vein invasion or extrahepatic spread or both, α-fetoprotein concentration, and Eastern Cooperative Oncology Group performance status. Dual primary endpoints were overall survival (superiority threshold at final overall survival analysis, one-sided p=0·019; final analysis to occur after 532 events) and progression-free survival (superiority threshold one-sided p=0·002; final analysis to occur after 571 events) in the intention-to-treat population. Results from the final analysis are reported. This study is registered with ClinicalTrials.gov, NCT03713593, and is active but not recruiting. FINDINGS: Between Jan 17, 2019, and April 28, 2020, of 1309 patients assessed, 794 were randomly assigned to lenvatinib plus pembrolizumab (n=395) or lenvatinib plus placebo (n=399). Median age was 66·0 years (IQR 57·0-72·0), 644 (81%) of 794 were male, 150 (19%) were female, 345 (43%) were Asian, 345 (43%) were White, 22 (3%) were multiple races, 21 (3%) were American Indian or Alaska Native, 21 (3%) were Native Hawaiian or other Pacific Islander, 13 (2%) were Black or African American, and 46 (6%) did not have available race data. Median follow up as of data cutoff for the final analysis (June 21, 2022) was 32·1 months (IQR 29·4-35·3). Median overall survival was 21·2 months (95% CI 19·0-23·6; 252 [64%] of 395 died) with lenvatinib plus pembrolizumab versus 19·0 months (17·2-21·7; 282 [71%] of 399 died) with lenvatinib plus placebo (hazard ratio [HR] 0·84; 95% CI 0·71-1·00; stratified log-rank p=0·023). As of data cutoff for the progression-free survival final analysis (April 5, 2021), median progression-free survival was 8·2 months (95% CI 6·4-8·4; 270 events occurred [42 deaths; 228 progressions]) with lenvatinib plus pembrolizumab versus 8·0 months (6·3-8·2; 301 events occurred [36 deaths; 265 progressions]) with lenvatinib plus placebo (HR 0·87; 95% CI 0·73-1·02; stratified log-rank p=0·047). The most common treatment-related grade 3-4 adverse events were hypertension (69 [17%] of 395 patients in the lenvatinib plus pembrolizumab group vs 68 [17%] of 395 patients) in the lenvatinib plus placebo group), increased aspartate aminotransferase (27 [7%] vs 17 [4%]), and diarrhoea (25 [6%] vs 15 [4%]). Treatment-related deaths occurred in four (1%) patients in the lenvatinib plus pembrolizumab group (due to gastrointestinal haemorrhage and hepatorenal syndrome [n=1 each] and hepatic encephalopathy [n=2]) and in three (1%) patients in the lenvatinib plus placebo group (due to gastrointestinal haemorrhage, hepatorenal syndrome, and cerebrovascular accident [n=1 each]). INTERPRETATION: In earlier studies, the addition of pembrolizumab to lenvatinib as first-line therapy for advanced hepatocellular carcinoma has shown promising clinical activity; however, lenvatinib plus pembrolizumab did not meet prespecified significance for improved overall survival and progression-free survival versus lenvatinib plus placebo. Our findings do not support a change in clinical practice. FUNDING: Eisai US, and Merck Sharp & Dohme, a subsidiary of Merck.

Global trends in hepatocellular carcinoma epidemiology: implications for screening, prevention and therapy.

Hepatocellular carcinoma (HCC) mortality rates are increasing globally, and particularly in the Western world. Cirrhosis remains the predominant risk factor for HCC. However, epidemiological shifts in the incidence of HCC from patients with virus-related liver disease to those with non-viral aetiologies, including alcohol-associated and metabolic dysfunction-associated steatotic liver disease, have important implications for prevention, surveillance and treatment. Hepatitis B vaccination and antiviral therapy for hepatitis B and C are effective for primary prevention of virus-related HCCs, but chemoprevention strategies for non-viral liver disease remain an unmet need. Emerging data suggest associations between aspirin, statins, metformin and coffee and reduced HCC incidence, although none has been proved to be causally related. Secondary prevention of HCC via semi-annual surveillance is associated with improvements in early detection and thus reduced mortality; however, current tools, including abdominal ultrasonography, have suboptimal sensitivity for the detection of early stage HCC, particularly in patients with obesity and/or non-viral liver disease. Promising blood-based or imaging-based surveillance strategies are emerging, although these approaches require further validation before adoption in clinical practice. In the interim, efforts should be focused on maximizing use of the existing surveillance tools given their prevalent underuse globally. Remarkable advances have been made in the treatment of HCC, including expanded eligibility for surgical therapies, improved patient selection for locoregional treatments and increased systemic treatment options, including immune-checkpoint inhibitors. In this Review, we discuss trends in the epidemiology of HCC and their implications for screening, prevention and therapy.

Critical Appraisal of Guideline Recommendations on Systemic Therapies for Advanced Hepatocellular Carcinoma: A Review.

Importance: The combination of immune checkpoint inhibitors with antiangiogenic agents has revolutionized the treatment landscape of advanced hepatocellular carcinoma (HCC). However, due to rapid publication of new studies that attained their predefined primary end points, a lack of robust cross-trial comparison of first-line therapies, and diverging clinical guidelines, no clear-cut treatment flowchart and sequence of therapies are available. This critical analysis of the recommendations for the management of advanced HCC from the main scientific societies in the US and Europe adopted an integrated approach to provide information on the clinical benefit (overall survival and progression-free survival) and safety profile of these therapies using the European Society for Medical Oncology (ESMO)-Magnitude of Clinical Benefit Scale (MCBS) score and an ad hoc network meta-analysis. Observations: There is a major consensus among guidelines that atezolizumab plus bevacizumab has a primacy as the recommended first-line treatment of choice in advanced HCC. On progression after immunotherapy-containing regimens and for patients with contraindications for immunotherapies, most guidelines maintain the established treatment hierarchy, recommending lenvatinib or sorafenib as the preferred options, followed by either regorafenib, cabozantinib, or ramucirumab. Thus far, the first-line immune-based regimen of tremelimumab plus durvulumab has been integrated only in the American Association for the Study of Liver Diseases guidance document and the latest National Comprehensive Cancer Network guidelines and is recommended for patients with a high risk of gastrointestinal bleeding. Overall, in the first-line setting, both atezolizumab plus bevacizumab and sintilimab plus IBI305 (a bevacizumab biosimilar) received the highest ESMO-MCBS score of 5, indicating a substantial magnitude of clinical benefit. In a network meta-analysis, no significant differences in overall survival were found among the various combination regimens. However, the newly reported combination of camrelizumab plus rivoceranib was associated with a significantly higher risk of treatment-related adverse events compared with atezolizumab plus bevacizumab (relative risk, 1.59; 95% CI, 1.25-2.03; P < .001). Conclusions and Relevance: This narrative review found that atezolizumab plus bevacizumab is regarded as the primary standard of care for advanced HCC in the first-line setting. These findings from integrating the recommendations from scientific societies' guidelines for managing advanced HCC along with new data from cross-trial comparisons may aid clinicians in decision-making and guide them through a rapidly evolving and complex treatment landscape.

WNTinib is a multi-kinase inhibitor with specificity against ß-catenin mutant hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. ß-Catenin (CTNNB1)-mutated HCC represents 30% of cases of the disease with no precision therapeutics available. Using chemical libraries derived from clinical multi-kinase inhibitor (KI) scaffolds, we screened HCC organoids to identify WNTinib, a KI with exquisite selectivity in CTNNB1-mutated human and murine models, including patient samples. Multiomic and target engagement analyses, combined with rescue experiments and in vitro and in vivo efficacy studies, revealed that WNTinib is superior to clinical KIs and inhibits KIT/mitogen-activated protein kinase (MAPK) signaling at multiple nodes. Moreover, we demonstrate that reduced engagement on BRAF and p38α kinases by WNTinib relative to several multi-KIs is necessary to avoid compensatory feedback signaling-providing a durable and selective transcriptional repression of mutant ß-catenin/Wnt targets through nuclear translocation of the EZH2 transcriptional repressor. Our studies uncover a previously unknown mechanism to harness the KIT/MAPK/EZH2 pathway to potently and selectively antagonize CTNNB1-mutant HCC with an unprecedented wide therapeutic index.

Sublethal necroptosis signaling promotes inflammation and liver cancer.

It is currently not well known how necroptosis and necroptosis responses manifest in vivo. Here, we uncovered a molecular switch facilitating reprogramming between two alternative modes of necroptosis signaling in hepatocytes, fundamentally affecting immune responses and hepatocarcinogenesis. Concomitant necrosome and NF-κB activation in hepatocytes, which physiologically express low concentrations of receptor-interacting kinase 3 (RIPK3), did not lead to immediate cell death but forced them into a prolonged "sublethal" state with leaky membranes, functioning as secretory cells that released specific chemokines including CCL20 and MCP-1. This triggered hepatic cell proliferation as well as activation of procarcinogenic monocyte-derived macrophage cell clusters, contributing to hepatocarcinogenesis. In contrast, necrosome activation in hepatocytes with inactive NF-κB-signaling caused an accelerated execution of necroptosis, limiting alarmin release, and thereby preventing inflammation and hepatocarcinogenesis. Consistently, intratumoral NF-κB-necroptosis signatures were associated with poor prognosis in human hepatocarcinogenesis. Therefore, pharmacological reprogramming between these distinct forms of necroptosis may represent a promising strategy against hepatocellular carcinoma.

Epigenetic inactivation of the 5-methylcytosine RNA methyltransferase NSUN7 is associated with clinical outcome and therapeutic vulnerability in liver cancer.

BACKGROUND: RNA modifications are important regulators of transcript activity and an increasingly emerging body of data suggests that the epitranscriptome and its associated enzymes are altered in human tumors. METHODS: Combining data mining and conventional experimental procedures, NSUN7 methylation and expression status was assessed in liver cancer cell lines and primary tumors. Loss-of-function and transfection-mediated recovery experiments coupled with RNA bisulfite sequencing and proteomics determined the activity of NSUN7 in downstream targets and drug sensitivity. RESULTS: In this study, the initial screening for genetic and epigenetic defects of 5-methylcytosine RNA methyltransferases in transformed cell lines, identified that the NOL1/NOP2/Sun domain family member 7 (NSUN7) undergoes promoter CpG island hypermethylation-associated with transcriptional silencing in a cancer-specific manner. NSUN7 epigenetic inactivation was common in liver malignant cells and we coupled bisulfite conversion of cellular RNA with next-generation sequencing (bsRNA-seq) to find the RNA targets of this poorly characterized putative RNA methyltransferase. Using knock-out and restoration-of-function models, we observed that the mRNA of the coiled-coil domain containing 9B (CCDC9B) gene required NSUN7-mediated methylation for transcript stability. Most importantly, proteomic analyses determined that CCDC9B loss impaired protein levels of its partner, the MYC-regulator Influenza Virus NS1A Binding Protein (IVNS1ABP), creating sensitivity to bromodomain inhibitors in liver cancer cells exhibiting NSUN7 epigenetic silencing. The DNA methylation-associated loss of NSUN7 was also observed in primary liver tumors where it was associated with poor overall survival. Interestingly, NSUN7 unmethylated status was enriched in the immune active subclass of liver tumors. CONCLUSION: The 5-methylcytosine RNA methyltransferase NSUN7 undergoes epigenetic inactivation in liver cancer that prevents correct mRNA methylation. Furthermore, NSUN7 DNA methylation-associated silencing is associated with clinical outcome and distinct therapeutic vulnerability.

Nonalcoholic steatohepatitis-related hepatocellular carcinoma: pathogenesis and treatment.

Nonalcoholic fatty liver disease (NAFLD), including its more severe manifestation, nonalcoholic steatohepatitis (NASH), has a global prevalence of 20-25% and is a major public health problem. Its incidence is increasing in parallel to the rise in obesity, diabetes and metabolic syndrome. Progression from NASH to NASH-related hepatocellular carcinoma (HCC) (~2% of cases per year) is influenced by many factors, including the tissue and immune microenvironment, germline mutations in PNPLA3, and the microbiome. NASH-HCC has unique molecular and immune traits compared with other aetiologies of HCC and is equally prevalent in men and women. Comorbidities associated with NASH, such as obesity and diabetes mellitus, can prevent the implementation of potentially curative therapies in certain patients; nonetheless, outcomes are similar in patients who receive treatment. NASH-HCC at the early to intermediate stages is managed with surgery and locoregional therapies, whereas advanced HCC is treated with systemic therapies, including anti-angiogenic therapies and immune-checkpoint inhibitors. In this Review, we present the latest knowledge of the pathogenic mechanisms and clinical management of NASH-HCC. We discuss data highlighting the controversy over varying responses to immune-checkpoint inhibitors according to underlying aetiology and suggest that the future of NASH-HCC management lies in improved surveillance, targeted combination therapies to overcome immune evasion, and identifying biomarkers to recognize treatment responders.

Identification of IGF2 as Genomic Driver and Actionable Therapeutic Target in Hepatoblastoma.

Management of hepatoblastoma (HB), the most frequent pediatric liver cancer, is based on surgical resection and perioperative chemotherapy regimens. In this study, we aimed to identify actionable targets in HB and assess the efficacy of molecular therapies in preclinical models of HB. Paired tumor and adjacent tissues from 31 HBs and a validation set of 50 HBs were analyzed using RNA-seq, SNP, and methylation arrays. IGF2 overexpression was identified as the top targetable HB driver, present in 71% of HBs (22/31). IGF2high tumors displayed progenitor cell features and shorter recurrence-free survival. IGF2 overexpression was associated in 91% of cases with fetal promoter hypomethylation, ICR1 deregulation, 11p15.5 loss of heterozygosity or miR483-5p overexpression. The antitumor effect of xentuzumab (a monoclonal antibody targeting IGF1/2) alone or in combination with the conventional therapeutic agent cisplatin was assessed in HB cell lines, in PDX-derived HB organoids and in a xenograft HB murine model. The combination of xentuzumab with cisplatin showed strong synergistic antitumor effects in organoids and in IGF2high cell lines. In mice (n = 55), the combination induced a significant decrease in tumor volume and improved survival compared with cisplatin alone. These results suggest that IGF2 is an HB actionable driver and that, in preclinical models of HB, the combination of IGF1/2 inhibition with cisplatin induces superior antitumor effects than cisplatin monotherapy. Overall, our study provides a rationale for testing IGF2 inhibitors in combination with cisplatin in HB patients with IGF2 overexpression.

International Liver Cancer Association (ILCA) white paper on hepatocellular carcinoma risk stratification and surveillance.

Major research efforts in liver cancer have been devoted to increasing the efficacy and effectiveness of surveillance for hepatocellular carcinoma (HCC). As with other cancers, surveillance programmes aim to detect tumours at an early stage, facilitate curative-intent treatment, and reduce cancer-related mortality. HCC surveillance is supported by a large randomised-controlled trial in patients with chronic HBV infection and several cohort studies in cirrhosis; however, effectiveness in clinical practice is limited by several barriers, including inadequate risk stratification, underuse of surveillance, and suboptimal accuracy of screening tests. There are several proposed strategies to address these limitations, including risk stratification algorithms and biomarkers to better identity at-risk individuals, interventions to increase surveillance, and emerging imaging- and blood-based surveillance tests with improved sensitivity and specificity for early HCC detection. Beyond clinical validation, data are needed to establish clinical utility, i.e. increased early tumour detection and reduced HCC-related mortality. If successful, these data could facilitate a precision screening paradigm in which surveillance strategies are tailored to individual HCC risk to maximise overall surveillance value. However, practical and logistical considerations must be considered when designing and implementing these validation efforts. To address these issues, ILCA (the International Liver Cancer Association) adjourned a single topic workshop on HCC risk stratification and surveillance in June 2022. Herein, we present a white paper on these topics, including the status of the field, ongoing research efforts, and barriers to the translation of emerging strategies.

Molecular Markers of Response to Anti-PD1 Therapy in Advanced Hepatocellular Carcinoma.

BACKGROUND & AIMS: Single-agent anti-PD1 checkpoint inhibitors convey outstanding clinical benefits in a small fraction (∼20%) of patients with advanced hepatocellular carcinoma (aHCC) but the molecular mechanisms determining response are unknown. To fill this gap, we herein analyze the molecular and immune traits of aHCC in patients treated with anti-PD1. METHODS: Overall, 111 tumor samples from patients with aHCC were obtained from 13 centers before systemic therapies. We performed molecular analysis and immune deconvolution using whole-genome expression data (n = 83), mutational analysis (n = 72), and histologic evaluation with an endpoint of objective response. RESULTS: Among 83 patients with transcriptomic data, 28 were treated in frontline, whereas 55 patients were treated after tyrosine kinase inhibitors (TKI) either in second or third line. Responders treated in frontline showed upregulated interferon-γ signaling and major histocompatibility complex II-related antigen presentation. We generated an 11-gene signature (IFNAP), capturing these molecular features, which predicts response and survival in patients treated with anti-PD1 in frontline. The signature was validated in a separate cohort of aHCC and >240 patients with other solid cancer types where it also predicted response and survival. Of note, the same signature was unable to predict response in archival tissue of patients treated with frontline TKIs, highlighting the need for fresh biopsies before immunotherapy. CONCLUSION: Interferon signaling and major histocompatibility complex-related genes are key molecular features of HCCs responding to anti-PD1. A novel 11-gene signature predicts response in frontline aHCC, but not in patients pretreated with TKIs. These results must be confirmed in prospective studies and highlights the need for biopsies before immunotherapy to identify biomarkers of response.

Inflamed and non-inflamed classes of HCC: a revised immunogenomic classification.

OBJECTIVE: We previously reported a characterisation of the hepatocellular carcinoma (HCC) immune contexture and described an immune-specific class. We now aim to further delineate the immunogenomic classification of HCC to incorporate features that explain responses/resistance to immunotherapy. DESIGN: We performed RNA and whole-exome sequencing, T-cell receptor (TCR)-sequencing, multiplex immunofluorescence and immunohistochemistry in a novel cohort of 240 HCC patients and validated our results in other cohorts comprising 660 patients. RESULTS: Our integrative analysis led to define: (1) the inflamed class of HCC (37%), which includes the previously reported immune subclass (22%) and a new immune-like subclass (15%) with high interferon signalling, cytolytic activity, expression of immune-effector cytokines and a more diverse T-cell repertoire. A 20-gene signature was able to capture ~90% of these tumours and is associated with response to immunotherapy. Proteins identified in liquid biopsies recapitulated the inflamed class with an area under the ROC curve (AUC) of 0.91; (2) The intermediate class, enriched in TP53 mutations (49% vs 29%, p=0.035), and chromosomal losses involving immune-related genes and; (3) the excluded class, enriched in CTNNB1 mutations (93% vs 27%, p<0.001) and PTK2 overexpression due to gene amplification and promoter hypomethylation. CTNNB1 mutations outside the excluded class led to weak activation of the Wnt-ßcatenin pathway or occurred in HCCs dominated by high interferon signalling and type I antigen presenting genes. CONCLUSION: We have characterised the immunogenomic contexture of HCC and defined inflamed and non-inflamed tumours. Two distinct CTNNB1 patterns associated with a differential role in immune evasion are described. These features may help predict immune response in HCC.

Novel microenvironment-based classification of intrahepatic cholangiocarcinoma with therapeutic implications.

OBJECTIVE: The diversity of the tumour microenvironment (TME) of intrahepatic cholangiocarcinoma (iCCA) has not been comprehensively assessed. We aimed to generate a novel molecular iCCA classifier that incorporates elements of the stroma, tumour and immune microenvironment ('STIM' classification). DESIGN: We applied virtual deconvolution to transcriptomic data from ~900 iCCAs, enabling us to devise a novel classification by selecting for the most relevant TME components. Murine models were generated through hydrodynamic tail vein injection and compared with the human disease. RESULTS: iCCA is composed of five robust STIM classes encompassing both inflamed (35%) and non-inflamed profiles (65%). The inflamed classes, named immune classical (~10%) and inflammatory stroma (~25%), differ in oncogenic pathways and extent of desmoplasia, with the inflammatory stroma showing T cell exhaustion, abundant stroma and KRAS mutations (p<0.001). Analysis of cell-cell interactions highlights cancer-associated fibroblast subtypes as potential mediators of immune evasion. Among the non-inflamed classes, the desert-like class (~20%) harbours the lowest immune infiltration with abundant regulatory T cells (p<0.001), whereas the hepatic stem-like class (~35%) is enriched in 'M2-like' macrophages, mutations in IDH1/2 and BAP1, and FGFR2 fusions. The remaining class (tumour classical: ~10%) is defined by cell cycle pathways and poor prognosis. Comparative analysis unveils high similarity between a KRAS/p19 murine model and the inflammatory stroma class (p=0.02). The KRAS-SOS inhibitor, BI3406, sensitises a KRAS-mutant iCCA murine model to anti-PD1 therapy. CONCLUSIONS: We describe a comprehensive TME-based stratification of iCCA. Cross-species analysis establishes murine models that align closely to human iCCA for the preclinical testing of combination strategies.