Combination Immunotherapy Research Articles

Understanding the PULSAR effect in combined radiotherapy and immunotherapy using transformer-based attention mechanisms

PULSAR (personalized, ultra-fractionated stereotactic adaptive radiotherapy) is the adaptation of stereotactic ablative radiotherapy towards personalized cancer management. It has potential to harness the synergy between radiation therapy and immunotherapy, such as immune checkpoint inhibitors to amplify the anti-tumor immune response. For the first time, we applied a transformer-based attention mechanism to investigate the underlying interactions between combined PULSAR and PD-L1 blockade immunotherapy, based on the preliminary experimental results of a murine cancer model (Lewis Lung Carcinoma, LLC). The radiation and administration of α-PD-L1 were viewed as two external stimulation signals occurring in a temporal sequence. Our study demonstrates the utility of a transformer model in 1) predicting tumor changes in response to specific treatment schemes, and 2) generating self-attention and cross-attention maps. The cross-attention maps serve as a biological representation of the semantic similarity between source and target sentences in neural translation, offering insights into the causal relationships of the PULSAR effect. Our model offers a unique perspective with the potential to enhance the understanding of the temporal dependencies of the PULSAR effect on time, dose, and T cell dynamics. In a broader context, our proposed framework offers the potential to explore varying intervals and doses for subsequent treatments while monitoring the biological parameters impacted by these perturbations. This approach can lead to more personalized and rational radiation or drug interactions.

Hepatocellular carcinoma epi-immunotherapy with polyion complex micelles co-delivering HDAC8 inhibitor and PD-L1 siRNA

Hepatocellular carcinoma (HCC) lacking T cell infiltration is a malignancy with a poor prognosis and has an increasing incidence worldwide. Overexpression of histone deacetylase 8 (HDAC8) in HCC caused immune escape and promoted resistance to immune-checkpoint blockade therapy. Herein, we synthesized a polyion complex (PIC) to co-encapsulate the HDAC8 inhibitor PCI-34051 (PCI) and programmed death-ligand 1 small interfering RNA (siPDL1). The PIC micelles PCI-siPDL1@NPs efficiently delivered PCI and siPDL1 into Hepa1-6 cells and orthotopic Hepa1-6 tumors, inducing potent anti-tumor immune responses through a combination of epigenetic therapy and immunotherapy (epi-immunotherapy). PCI-siPDL1@NPs activated T cell-trafficking chemokine C-C motif ligand 4 (CCL4) production via HDAC8 inhibitor and decreased PD-L1 expression via siPDL1. The synergistic epi-immunotherapy significantly increased intratumoral CD8+ T cell infiltration, CD8+ T cell-mediated tumor cell killing, and the immunogenicity of HCC. Furthermore, PCI-siPDL1@NPs produced strong anti-tumor responses in the orthotopic Hepa1-6 HCC model and subcutaneous H22 model, which stimulated tumor regression and prolonged mice survival time. This study successfully constructed stable PIC micelles PCI-siPDL1, which synergistically activated antitumor immunity and reprogrammed the immunosuppressive tumor microenvironment for the treatment of HCC.

Manganese nanosheets loaded with selenium and gemcitabine activate the tumor microenvironment to enhance anti-tumor immunity

Breast cancer is among the most common malignant tumors globally. Despite advances in immunotherapy and targeted therapies, chemotherapy remains the primary clinical treatment. Gemcitabine, a cytosine nucleoside analog, is widely used for various solid tumors; however, its effectiveness is often limited by drug resistance and adverse side effects. In this study, we developed a novel drug delivery system, Mn/Se-Gem, designed to target tumor cells overexpressing CD44 and facilitate the controlled release of gemcitabine. This system exploits gemcitabine’s pH sensitivity and HA-mediated CD44 targeting to induce DNA damage. Simultaneously, it neutralizes the acidic tumor microenvironment and releases nano-selenium and manganese ions, which promote the excessive production of reactive oxygen species (ROS), leading to mitochondrial damage and enhanced apoptosis of cancer cells. Furthermore, Mn (II) activates the cGAS-STING pathway, increasing susceptibility to ROS-induced DNA double-strand breaks, promoting macrophage maturation, inhibiting M2 polarization, and enhancing the cytotoxic function of T lymphocytes against tumor cells. In summary, this combination of chemotherapy and immunotherapy presents a promising strategy for the treatment of breast cancer.

Self-delivered sonodynamic nanomedicine for enhanced tumor immunotherapy by simultaneously reversing the immunosuppression and immune resistance

Sonodynamic therapy (SDT) shows potential for noninvasive eradication of local solid tumors. However, its efficacy in suppressing metastatic tumors is limited by factors such as insufficient tumor accumulation, the immunosuppressive tumor microenvironment, and acquired immune tolerance. To address these challenges, we developed self-delivering sonodynamic nanomedicine incorporating Toll-like receptor (TLR) agonists R848 and programmed death-ligand 1 (PD-L1) inhibitors JQ1 for combined SDT and immunotherapy. These nanomedicines enhanced tumor accumulation of sonosensitizers, enabling potent SDT and induction of immunogenic cell death (ICD). Additionally, the co-encapsulated R848 and JQ1 alleviated tumor immunosuppression and immune tolerance, synergizing effectively with SDT to elicit a robust antitumor immune response. By integrating enhanced SDT with activated antitumor immunity, significant inhibition of primary, distant, and lung metastatic tumors was achieved. This study introduces a novel approach for combining SDT with immunotherapy using self-assembled active pharmaceutical ingredients.

Combinatorial immunotherapy of anti-MCAM chimeric antigen receptor modified expanded natural killer cells and NKTR-255 against neuroblastoma

Pediatric patients with recurrent metastatic neuroblastoma (NB) have a dismal 5-year survival. Novel therapeutic approaches are urgently needed. The melanoma cell adhesion molecule (MCAM/CD146/MUC18) is expressed in a variety of pediatric solid tumors, including NB, and constitutes anovel target for immunotherapy. Here, we developed a chimeric antigen receptor (CAR) expressing natural killer (NK) cell-targeting MCAM by non-viral electroporation of CAR mRNA into exvivo expanded NK cells. Expression of anti-MCAM CAR significantly enhanced NK cell cytotoxic activity compared to mock NK cells against MCAMhigh but not MCAMlow/knockout NB cells invitro. Anti-MCAM-CAR-NK cell treatment significantly decreased tumor growth and prolonged animal survival in an NB xenograft mouse model. NKTR-255, a polymer-conjugated recombinant human interleukin-15 agonist, significantly stimulated NK cell proliferation and expansion and further enhanced the in vitro cytotoxic activity and invivo anti-tumor efficacyofanti-MCAM-CAR-NK cells against NB. Our preclinical studies demonstrate that exvivo expanded andmodified anti-MCAM-CAR-NK cells alone and/or incombination with NKTR-255 are promising novel alternative therapeutic approaches to targeting MCAMhigh malignant NB.

Chidamide and venetoclax synergistically regulate the Wnt/β-catenin pathway by MYCN/DKK3 in B-ALL.

B-cell acute lymphocytic leukemia (B-ALL) is a malignant proliferative B-lymphocyte disease. Although the outcome of B-ALL has greatly improved with combined chemotherapy, immunotherapy, and hematopoietic stem cell transplantation, some patients still experience drug resistance, relapse and a low long-term survival rate, therefore, finding novel approaches to improve the outcome of adult B-ALL patients is critical. Our previous studies revealed that the selective histone deacetylase inhibitor (HDACi) chidamide can inhibit the Wnt/β-catenin signaling pathway by inhibiting MYCN and increasing the expression of DKK3 in B-ALL cells. Some studies have indicated that histone deacetylase inhibitors (HDACis) can dysregulate the B-cell lymphoma-2 (BCL2) protein family, we speculate that chidamide and BCL2 inhibitor venetoclax synergistically inhibit the Wnt/β-catenin signaling pathway by inhibiting MYCN expression and increasing DKK3 expression. In our study, the in vitro and in vivo experiments confirmed that chidamide and venetoclax synergistically inhibited the expression of MYCN and increased the expression of DKK3 by inhibiting the activity of HDAC and BCL2, inhibiting the Wnt/β-catenin signaling pathway and B-ALL cell proliferation. These findings indicate that the HDACi chidamide and the BCL2 inhibitor venetoclax can be used in combination to treat B-ALL, providing a new method and strategy for treating B-ALL.

Integrated immunogenomic analyses of high-grade serous ovarian cancer reveal vulnerability to combination immunotherapy

Integrated immunogenomic analyses of high-grade serous ovarian cancer reveal vulnerability to combination immunotherapy

A case of delayed initial response to combination ipilimumab and nivolumab in malignant pleural mesothelioma

Malignant pleural mesothelioma has a poor prognosis with limited therapeutic options Although numerous trials have shown that combination immunotherapy with nivolumab and ipilimumab is one of the first line treatments for patients with unresectable MPM, there is limited data on delayed responses over a long follow up period. We report a case of a delayed response 7 months after the cessation of immunotherapy in a patient who initially had progressive malignant pleural mesothelioma with metastases.

Neoadjuvant Therapy in Robotic Lung Surgery: Elevating Surgical Complexity Without Compromising Outcomes

Background: Neoadjuvant therapy, particularly the combination of chemotherapy and immunotherapy, has become standard in treating locally advanced non-small cell lung cancer (NSCLC). While this approach improves pathologic responses, its effect on postoperative outcomes following robotic-assisted thoracic surgery (RATS) is not fully characterized. Objective: This study aimed to evaluate the impact of neoadjuvant therapy on postoperative outcomes in patients undergoing RATS for NSCLC, focusing on operative time, conversion rates to open surgery, and postoperative complications. Methods: A retrospective cohort analysis was performed on patients who underwent RATS for NSCLC between February 2019 and August 2024. Propensity score matching was utilized to balance preoperative characteristics between the groups. The primary outcomes compared were operative time, conversion rates to open surgery, and postoperative complications, with statistical significance defined as p < 0.05. Results: A total of 253 patients were included in the analysis, of whom 23 received neoadjuvant therapy (either chemotherapy or chemoimmunotherapy) and 230 did not. The neoadjuvant group had significantly longer operative times (250 min vs. 221 min, p = 0.001) but there were no significant differences in conversion rates to open surgery (8.7% vs. 3.9%, p = 0.5). However, the neoadjuvant group showed a higher incidence of prolonged air leaks (>5 days) (39.13% vs. 35.21%, p < 0.001). Other parameters, such as hospital stay and chest drainage duration, showed no statistically significant differences between the groups (p = 0.860 and p = 0.760, respectively). Conclusions: These findings support the feasibility of robotic-assisted thoracic surgery following neoadjuvant therapy in NSCLC, suggesting that this approach may be safely integrated into clinical practice for selected patients. Further studies are needed to define patient selection criteria and optimize postoperative management, potentially guiding personalized treatment strategies in complex cases.

Reversible Electroporation for Cancer Therapy.

Reversible electroporation refers to the use of high voltage electrical pulses on tissues to increase cell membrane permeability. It allows targeted delivery of high concentrations of chemotherapeutic agents including cisplatin and bleomycin, a process known as electrochemotherapy (ECT). It can also be used to deliver toxic concentrations of calcium and gene therapies that stimulate an anti-tumour immune response. ECT was validated for palliative treatment of cutaneous tumours. Evidence to date shows a mean objective response rate of ∼80% in these patients. Regression of non-treated lesions has also been demonstrated, theorised to be from an in-situ vaccination effect. Advances in electrode development have also allowed treatment of deep-seated metastatic lesions and primary tumours, with safety demonstrated in vivo. Calcium electroporation and combination immunotherapy or immunogene electrotransfer is also feasible, but research is limited. Adverse events of ECT are minimal; however, general anaesthesia is often necessary, and improvements in modelling capabilities and electrode design are required to enable sufficient electrical coverage. International collaboration between preclinical researchers, oncologists and interventionalists is required to identify the most effective combination therapies, to optimise procedural factors, and to expand use, indications and assessment of reversible electroporation. Registries with standardised data collection methods may facilitate this.

Superior survival benefits of triple combination immunotherapy compared to standard chemotherapy as second-line treatment for advanced biliary tract cancer: a retrospective analysis

BackgroundAdvanced biliary tract cancer (BTC) is associated with a poor prognosis and limited options for second-line treatment. The TOPAZ-1 and KEYNOTE-966 trials have demonstrated the benefits of combining immune checkpoint inhibitors (ICIs) with chemotherapy in treating BTC. However, the efficacy of FOLFOX as a second-line therapy is limited, highlighting the need for more effective treatment approaches.MethodsThis retrospective study compared a triple regimen—comprising ICIs, tyrosine kinase inhibitors, and chemotherapy—to standard chemotherapy in patients with metastatic BTC who had progressed on first-line gemcitabine-based therapy. The primary endpoint was progression-free survival (PFS), with secondary endpoints including overall survival (OS), overall response rate (ORR), disease control rate (DCR), and safety.ResultsOf the 121 patients, 86 received the triple regimen and 35 received standard chemotherapy. The triple regimen showed a significantly higher ORR (37.2% vs. 2.8%, p < 0.0001) and DCR (89.5% vs. 71.4%). The median PFS was 6 months for the triple regimen compared to 2.0 months for standard chemotherapy (HR 0.29, p < 0.0001). The median OS was 16.0 months for the triple regimen versus 6.0 months for standard chemotherapy (HR 0.35, p < 0.0001). Treatment-related adverse events were comparable between the groups.ConclusionThe triple combination of immunotherapy offers superior survival benefits compared to standard chemotherapy as a second-line treatment for advanced BTC, warranting further investigation for potential clinical adoption.

Immunotherapy-mediated myocarditis and concurrent vasospastic angina in a patient with established ischaemic heart disease: a case report

Abstract Background Immunotherapy has become a pillar of modern oncological management but is associated with significant immunotherapy-related adverse events (IRAEs). While myocarditis is a prominent IRAE which clinicians are increasingly aware of, immunotherapy-related coronary vasospasm is far less appreciated and can be especially difficult to elucidate in pre-existing coronary artery disease. This case demonstrates the approach to diagnosis and management of multiple cardiovascular and non-cardiovascular IRAEs Case Summary A 57-year old male with a history of metastatic melanoma on combined immunotherapy and ischaemic heart disease with multiple previous percutaneous coronary interventions presented with typical chest pain and troponin rise. Differential diagnoses for this presentation included a non-ST elevation myocardial infarction, myocarditis and coronary vasospasm. Coronary angiogram did not reveal any new significant obstructive coronary artery disease while cardiac MRI did not reveal any radiological features consistent with myocarditis. However, empirical treatment for IRAEs resulted in both clinical and biochemical improvement and ability to discharge the patient on steroids and coronary vasodilators, having been GTN-infusion dependent as an inpatient. Discussion Cardiovascular IRAEs are important to be aware of when managing patients on immunotherapy and more than one IRAE can occur concurrently. Given the caveats of non-invasive imaging and invasive nature of endomyocardial biopsy, the clinical history is key in establishing these crucial diagnoses which will significantly impact ongoing oncological management.

Efficacy of sintilimab combined with neoadjuvant chemotherapy and trastuzumab in conversional treatment of locally advanced HER2-positive gastric cancer: case analysis and literature review

BackgroundRegional lymph nodes that are fixed and fused into clusters or those exhibiting metastases outside the regional lymph nodes are generally classified as stage IV (M1) or unresectable. Patients with such nodes almost always need pre-operative treatment so that they can undergo surgical resection. Combining immunotherapy with trastuzumab and chemotherapy significantly improved the prognosis of HER-2 positive gastric/gastroesophageal junction (G/GEJ) cancer. However, very few reports are available on the role of immunotherapy in converting patients with unresectable cancer to resectable cancer.MethodsIn this study, we report on four patients with GC who were preoperatively treated with a combination of sintilimab, trastuzumab, and chemotherapy at Hubei Cancer Hospital, China, from January 2022 to October 2023. Both preoperative and postoperative clinical and pathological characteristics of each patient were analyzed. The preoperative tumor stage was cT4N3M1.ResultsPostoperative pathological results showed that two patients achieved pathological complete remission (pCR), while the pathological stage in the other two patients decreased to ypT1N0M0 and ypT2N0M0. None of them had nerve or vascular invasion. None of the patients had recurrences or metastases until the last follow-up (October 2024) after primary surgery. The present case report suggests that a combination of immunotherapy comprising trastuzumab and chemotherapy can improve the efficiency of conversion therapy for patients with HER-2 positive locally advanced G/GEJ cancer. This study also demonstrates the safety of immune checkpoint inhibitors in a conversional treatment approach.ConclusionWe showed that a pathological complete response (pCR) can be obtained even with unresectable advanced GC through treatment with sintilimab combined with neoadjuvant chemotherapy and trastuzumab.

Abstract IA025: Targeting the gut microbiome for cancer immunotherapy

Abstract Growing evidence suggests that the gut microbiota modulates the efficacy and toxicity of cancer therapy, most notably immunotherapy and its immune-related adverse effects. The impaired response to immunotherapy in patients treated with antibiotics supports this role of the microbiota. Until recently, results pertaining to the identification of the microbial species responsible for these effects were incongruent, and relatively few studies analyzed the underlying mechanisms. Gut microbial communities (microbiotypes) with non-uniform geographic distribution were associated with favorable and unfavorable outcomes, contributing to discrepancies between cohorts Now, a better understanding of the taxonomy of the species involved and of their mechanisms of action has been achieved. Defined bacterial species have been shown to promote a response to immune checkpoint inhibitors through the production of different products or metabolites, although a suppressive effect of Gram(-) bacteria may be dominant in some unresponsive patients. Machine learning approaches trained on patients’ microbiota composition can predict the ability of patients to respond to immunotherapy with some accuracy. Thus, the interest in modulating the microbiota composition to improve patients’ responsiveness to therapy has been mounting. Our data of a fecal microbiota transfer clinical trial in anti-PD1 refractory melanoma patients has provided clinical proof of concept of the possibility to target the gut microbiota composition in cancer therapy. Also, both in clinical studies and in experimental animals, diets rich in fibers improve the response to immunotherapy by modifying the gut microbiome suggesting the possibility of dietary approaches to target the microbiota composition in cancer therapy. However, while many early clinical studies have analyzed the association of the microbiota composition with the response to anti-PD-1 in cancer patients, emerging evidence suggests that the association may be context dependent and different types of mono or combination immunotherapies may be differentially regulated by the microbiota, Thus, a more personalized approach depending original gut microbiota composition of the patients and the type of immunotherapy protocol selected may be necessary for optimal clinical results. Citation Format: Giorgio Trinchieri. Targeting the gut microbiome for cancer immunotherapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr IA025.

Advances in the diagnosis and treatment of MET-variant digestive tract tumors.

The receptor tyrosine kinase encoded by the MET gene plays an important role in various cellular processes such as growth, survival, migration and angiogenesis, and its abnormal activation is closely related to the occurrence and development of various tumors. This article reviews the recent advances in diagnosis and treatment of MET-variant digestive tract tumors. In terms of diagnosis, the application of next-generation sequencing technology and liquid biopsy technology makes the detection of MET variants more accurate and efficient, providing a reliable basis for individualized treatment. In terms of treatment, MET inhibitors such as crizotinib and cabotinib have shown good efficacy in clinical trials. In addition, the combination of immunotherapy and MET inhibitors also demonstrated potential synergies, further improving the therapeutic effect. However, the complexity and heterogeneity of drug resistance mechanisms are still one of the difficulties in current research. In the future, it is necessary to further deepen the understanding of the mechanism of MET variation and explore new combination treatment strategies to improve the overall survival rate and quality of life of patients. The diagnosis and treatment of MET-variant digestive tract tumors are moving towards precision and individualization, and have broad application prospects.

Adverse events after nivolumab and ipilimumab combined immunotherapy in advanced renal cell carcinoma: a multicentre experience in Poland

BackgroundImmune checkpoint inhibitors (ICIs) have been employed in the adjuvant and metastatic setting of renal cell carcinoma (RCC) treatment. Among ICIs, combined immunotherapy has the highest risk for immune-related adverse events (irAEs). We aimed to document the incidence of irAEs in RCC patients treated with nivolumab and ipilimumab as data from the European population remain limited.Materials and methodsWe analysed data from 88 RCC patients treated with nivolumab + ipilimumab between May 2022 and June 2024 across six high-volume oncology units in Poland. We reviewed irAEs and estimated their impact on survival parameters via univariate and multivariate Cox proportional hazards regression models, along with log-rank tests.ResultsWith a median follow-up of 11.3 months, the median overall survival (OS) was not reached, whereas the median progression-free survival (PFS) was 12.8 months (6.3–19.3). A total of 74 irAEs were recorded in 50 patients. The most frequent events were endocrine (n = 20, 27%), hepatic (n = 15, 17%), general (n = 12, 13.6%), and cutaneous (n = 11, 12.5%). The occurrence of irAEs was associated with a 60% lower risk of disease progression (hazard ratio 0.44, 95% confidence interval 0.2–0.87, p = 0.018) without impacting OS and higher disease control rate (n = 45, 90% vs. n = 24, 63.2%, p = 0.004). In contrast, patients with hepatotoxicity had poorer outcomes, with a 2.6-fold greater risk of death (p = 0.05).ConclusionsIrAEs may serve as a predictive factor for the efficacy of the nivolumab + ipilimumab regimen in RCC patients. Special attention is needed for hepatotoxicity, as it can significantly impact survival outcomes.

Immunotherapy + Neoadjuvant Chemoradiation may Improve Outcomes in Esophageal Cancer

In patients diagnosed with unresectable, locally advanced esophageal cancer, the triple combination of radiation, chemotherapy, and immunotherapy made tumors more amenable to surgery, which was associated with significantly improved outcomes, including a better survival rate rather compared to non-surgical treatment alone.

FeS2@COF based nanocarrier for photothermal-enhanced chemodynamic/thermodynamic tumor therapy and immunotherapy via reprograming tumor-associated macrophages

Developing high-performance nanomedicines to enhance antitumor efficacy remains a hot point in the field of biomedicine. In this study, we designed a versatile nanocomposite (FeS₂@COF-HA/AIPH) integrating covalent organic frameworks (COF) functionalized with pyrite (FeS₂) for synergistic photothermal (PTT), chemodynamic (CDT), thermodynamic (TDT) therapies, and immunotherapy. The superior photothermal effects and catalytic capabilities of FeS₂@COF enabled a minimally invasive PTT/CDT combination. The nanoplatform, with its mesoporous structure, also served as a drug delivery system, encapsulating the thermos-decomposable initiator AIPH. The hyaluronic acid (HA) coating not only improved tumor-targeting efficiency but also prevented nonspecific AIPH release. Under near-infrared (NIR) irradiation, the localized hyperthermia triggered AIPH decomposition, generating toxic alkyl radicals (•R) for TDT, further enhancing CDT efficiency. The combination of PTT, CDT, TDT, and immunotherapy led to potent antitumor effects with minimal systemic toxicity, both in vitro and in vivo. Notably, the nanoplatform effectively reprogrammed tumor-associated macrophages (TAMs) from an M2 to M1 phenotype, boosting antitumor immunity. This multifunctional platform thus offers a promising strategy for integrated PTT, CDT, TDT, and immune activation in tumor therapy.

Injectable Polydopamine Nanoparticle-Incorporated Hydrogels for Antiangiogenesis and Stimulating Tumoricidal Immunity to Inhibit Metastasis and Recurrence Postresection.

Surgical resection is still the main means for clinical treatments of breast cancer, but the postoperative immunosuppressive microenvironment and neoangiogenesis of the residual tumors easily lead to tumor metastasis and recurrence, which will further endanger patients' lives. The combination of antiangiogenic therapy and immunotherapy may promote the mutually reinforced cycle of immune reprogramming and vascular normalization to avoid tumor metastasis and recurrence. Herein, we prepared polydopamine nanoparticles for improving tissue adhesion and enriching tumor-associated antigens. This nanoregulator together with regorafenib (REG) was further incorporated into a hydrogel developed from grafting adipic acid dihydrazide onto 2,2,6,6-tetramethylpiperidine-1-oxyl radical oxidized chitin and oxidized hyaluronic acid, which was injectable at the cavity after subcutaneous tumor surgery with good mechanical properties and degradability. The system showed long-term release of REG. After combining with anti-PD-L1, the hydrogel applied to the surgical wound exhibited a reduction in tumor metastasis and recurrence. This effect was achieved by suppressing angiogenesis and enhancing antitumor immunity, characterized by increased levels of effector T lymphocytes and activation of dendritic cells within tumors, spleens, and draining lymph nodes. The injectable hydrogel offers a promising strategy for postoperative management aimed at preventing tumor metastasis and recurrence.

Gadoxetic Acid-Enhanced Magnetic Resonance Imaging Features Can Predict Immune-Excluded Phenotype of Hepatocellular Carcinoma

Introduction: Immunotherapy is the first-line treatment for intermediate-advanced stage hepatocellular carcinoma (HCC), although its outcomes vary. This study aimed to identify imaging biomarkers of immunotherapy susceptibility linked to gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) and immune phenotypes, particularly immune-excluded phenotypes, with a tumor immune barrier. Methods: We performed immunohistochemical staining with a CD8+ antibody, and samples were classified into immune-inflamed, -intermediate, -excluded, and -ignored phenotypes. We assessed EOB-MRI findings obtained from 104 patients who underwent hepatectomy for HCC and evaluated the relationship between MRI findings and immune phenotype. Spatial transcriptome analysis of tumor tissues in each immune phenotype was performed to characterize the MRI findings. For validation, we analyzed the treatment effect on 60 nodules in another cohort of 27 patients who received combined immunotherapy using anti-programmed death-ligand 1 and anti-vascular endothelial growth factor (VEGF) antibodies. Results: HCCs with rim arterial phase hyperenhancement (APHE) (odds ratio [OR] 17.3 P=0.009), peritumoral enhancement on the arterial phase (OR 8.6, P<0.004), and intermediate intensity on the hepatobiliary phase (HBP) measured with a visual 3-point scale (OR 28.2, P=0.002) were associated with immune-excluded phenotype, where tumors tended to be larger and of the single nodular type with extranodular growth and confluent multinodular rather than the simple nodular type. Spatial transcriptome analysis revealed a spatial relationship among cytotoxic T lymphocytes, VEGF signals, and cancer-associated fibroblasts at the tumor-invasive margins in this phenotype. From the validation study, nodules with any one of these three imaging findings had a significantly prolonged time to-nodular progression (P=0.007, median not reached vs. 226 days). Conclusion: HCCs with rim APHE, peritumoral enhancement on arterial phase, and intermediate intensity on HBP with visual 3-point scale could be non-invasive biomarkers to predict the immune-excluded phenotype with tumor immune barrier. These HCCs were most likely to respond to the combined immunotherapy.