Immune Checkpoint Inhibitors Treatment Research Articles

Hepatitis associated with immune checkpoint inhibitors-based combinations of other therapies: A real-world pharmacovigilance analysis based on the FDA adverse event reporting system (FAERS) database.

The combination regimen with immune checkpoint inhibitors (ICIs) and other therapies has been widely applied for patients with non-small-cell lung cancer (NSCLC). To date, no literature has systematically addressed the risk of hepatitis associated with the combination therapy. We conducted this pharmacovigilance analysis using the Food and Drug Administration Adverse Event Reporting System (FAERS). A total of 587,016 NSCLC reports were extracted from FAERS database spanning from the first quarter of 2013 to the second quarter of 2023. After filtering duplicate reports, logistic regression model was used to detect safety signals, and multivariable logistic regression model was used to confirm the interaction between ICI and other drugs. Of the 81,512 patients with NSCLC, 2785 cases developed hepatitis. Multivariable logistic regression analyses revealed that the adjusted ROR of ICI combined with targeted therapy (TT) was the highest 1.64 (95% CI, 1.32-2.02; P < 0.0001) among all therapies, while that of TT and ICI treatment were 1.07 (95% CI, 0.98-1.17; P = 0.1097) and 1.12 (95% CI, 1.03-1.22; P = 0.0111), respectively. The adjusted ROR for the interaction effect was 1.64 (95% CI, 1.32-2.02; P < 0.0001). Furthermore, the adjusted ROR of ICI combined with KRAS-targeted drugs was the highest 3.03 (95% CI, 1.49-5.93; P = 0.0016) among all targeted drugs, with an adjusted ROR of 3.03 (95% CI, 1.49-5.93; P = 0.0016), indicating a meaningful interaction of these two kinds of drugs. We confirmed that combination treatment of ICI and TT is associated with the amplified risk of hepatitis, which is partly due to the interaction between ICI and TT, and the KRAS-targeted drugs may harbor the highest potential for hepatitis induction among TT drugs when combined with ICI. Besides, the combination treatment of ICI- and KRAS-targeted drugs also increases the incidence of colitis, pulmonary embolism and dehydration.

Factors Inducing Cutaneous Adverse Reactions in Cancer Patients Treated with PD-1 and PD-L1 Inhibitors: A Machine-Learning Algorithm Approach

Immune checkpoint inhibitors (ICIs) show promise in cancer treatment but can lead to immune-related adverse events (irAEs), notably affecting the skin. Understanding the factors behind these skin reactions is crucial for effective management during treatment. Hence, the aim of this study was to uncover associations between patient characteristics and cutaneous adverse reactions among cancer patients undergoing ICI treatment. The study involved 209 cancer patients receiving ICIs. Statistical methods, including the chi-square test, Fisher's exact test, and multivariable logistic regression, were employed to analyze variables such as hypertension, antihistamine use, cancer metastasis, diabetes, and opioid usage. Additionally, machine learning techniques, including logistic regression, elastic net, random forest, and support vector machines (SVM), were utilized to develop predictive models anticipating skin-related adverse events. Results highlighted significant associations between specific patient attributes and the incidence of skin reactions post-ICI treatment. Notably, patients using antihistamines or with cancer metastasis exhibited higher rates of skin adverse reactions, while those with diabetes or using opioids displayed lower incidence rates. Robust performance in forecasting these adverse events was observed, particularly in the predictive models employing logistic regression and elastic net. This pioneering study contributes crucial insights into predictive modeling for ICI-induced skin reactions, emphasizing the importance of personalized treatment strategies. By identifying risk factors and utilizing tailored predictive models, healthcare providers can proactively manage adverse events, optimizing the benefits of ICIs while mitigating potential side effects.

Association among major adverse cardiovascular events with immune checkpoint inhibitors: A systematic review and meta-analysis.

This meta-analysis aimed to determine the incidence and overall risk of major adverse cardiovascular events (MACEs) related to immune checkpoint inhibitors (ICIs). We systematically searched all cohort studies, including the available MACE data in cancer patients receiving ICIs, in PubMed, Embase, and the Cochrane Library, from their inception to September 5, 2023. The primary outcome was the incidence of MACEs associated with ICI exposure, and the secondary outcome was the overall risk of MACEs associated with ICI exposure versus non-ICI exposure controls. Risk ratios with 95% confidence intervals were used in the random- or fixed-effects models. Overall, 26 cohort studies met the inclusion criteria, involving 109,883 cancer patients. In the median follow-up period ranging from 3.3 to 55.2 months, the incidence of MACEs associated with ICI exposure was 8.22%, ranging from 0.55% to 3.98%, among the nine MACEs, including myocarditis, tachyarrhythmia, pericarditis, pericardial effusions, cardiovascular death, myocardial infarction, heart failure, stroke, and conduction disorder. The incidence of MACE associated with non-ICI exposure was 3.84%, ranging from 0.81% to 4.72%. The risks of all-grade MACEs and pericardial effusions were significantly higher in the ICI group than in the non-ICI controls. ICI treatment, age, male sex, and prior radiation therapy were significantly associated with MACEs. The risk of MACEs during ICI treatment in patients with cancer is more common than is currently recognized. ICI use is closely associated with an increased risk of MACEs. Patients at risk were older, male, and had a history of radiation therapy.

Risk Factors of Immune-Mediated Hepatotoxicity Induced by Immune Checkpoint Inhibitors in Cancer Patients: A Systematic Review and Meta-Analysis

Immune checkpoint inhibitors (ICIs) significantly improve survival, while immune-mediated hepatotoxicity (IMH) has been reported. To evaluate the incidence and potential risk factors of IMH among cancer patients treated by ICIs, PubMed/Medline, Web of Science, Cochrane, and Embase were searched before 30 March 2024 for systematic review and meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated. Quality assessment was completed using the Newcastle–Ottawa scale. Of 1217 articles identified, 24 consisting of 9076 patients were included, with one study being prospective and the rest retrospective. The overall incidence of any grade IMH and grade ≥ 3 secondary to ICIs was 14% and 7%, respectively. The cholestatic pattern was more prevalent than the hepatocellular and mixed patterns. The meta-analysis revealed that ICI treatment was related to reduced risk of IMH in older patients (SMD: −0.18; 95% CI: −0.33 to −0.04), individuals with higher body mass index (WMD: −2.15; 95% CI: −3.92 to −0.38), males (OR: 0.44; 95% CI: 0.27 to 0.72), and patients with lung cancer (OR: 0.58, 95%CI 0.41 to 0.83). On the other hand, patients with liver metastasis (OR: 1.80; 95% CI: 1.47 to 2.20), history of ICI treatment (OR: 3.09; 95% CI: 1.21 to 7.89), diabetes (OR: 2.19; 95% CI: 1.36 to 3.51), chronic HBV (OR: 3.06; 95% CI: 1.11 to 8.46), and concomitant use of ICIs (OR: 8.73; 95% CI: 2.41 to 31.59) increased the risk of developing IMH. This study will provide clinicians with information on potentially high-risk groups for IMH, who need to be cautiously monitored for liver function when receiving immunotherapy.

Abstract PR017: A T-cell signature in circulating cell-free DNA at time of diagnosis predicts response to checkpoint inhibition

Abstract Immune checkpoint inhibitors (ICI) are increasingly used as first line of treatment in a range of cancer types, owing to their efficacy and advantageous toxicological profile. Currently, PD-L1 expression and tumor mutation burden (TMB) are the most common biomarkers to select patients for ICI treatment, yet response to ICI remains highly variable between patients, necessitating more accurate early predictors of treatment response. Circulating cell-free DNA (cfDNA) originates from dying cells throughout the body, each molecule carrying unique epigenetic features of its cell-type of origin. Most studies on cfDNA focus on tumor-derived fragments for diagnostics or minimal residual disease detection. However, variations in the contribution of immune cells and other stromal cell populations could provide important clues to classify a tumor with respect to treatment. To address this, we collected tumor and adjacent normal tissue as well as cfDNA from the blood of 33 patients enrolled in the LUD2015-005 trial in which ICI were administered to patients with non-resectable esophageal adenocarcinoma (EAC) for four weeks, before adding standard-of-care chemotherapy (ICI+CTX). For each patient, we took samples at diagnosis, before ICI+CTX, during and at the end of treatment. Tissue and cfDNA samples were sequenced using TET-Assisted Pyridine-borane Sequencing (TAPS), a method recently developed in Oxford which provides genome-wide high-depth, base- resolution DNA methylation and mutation information from low-input samples. We then selected a representative set of high-purity tumor tissue samples and combined them with whole- genome TAPS data from 9 healthy blood cell types and 5 gastrointestinal tissues to generate a GI-specific atlas of cell-type specific methylation. This atlas allows us to accurately quantify the contribution of tumor and 14 healthy cell types to the cfDNA collected from each patient at each timepoint. Strikingly, the presence of T-cell derived cfDNA at time of diagnosis (tDNA) is a strong positive predictive marker of overall survival (p=0.0024). In contrast, the fraction of tumor-resident T-cells, estimated by either bulk tissue TAPS or RNA sequencing, correlated only weakly with treatment response in this cohort, indicating that T-cell activity is more accurately captured by tDNA. Furthermore, we find that patients with a combination of high TMB and high tDNA have an 80% 2-year survival probability, as opposed to below 25% for others, suggesting that tDNA is derived from T-cells actively engaging tumor cells with high neoantigen load. In summary, we demonstrate that T-cell turnover, as reflected in differential methylation in a set of marker regions spanning only 24kb, is a promising biomarker of treatment response, especially when combined with neoantigen load: in the presented cohort, all but one long-term survivors (alive at last follow up &amp;gt; 3 years after diagnosis) were tDNA positive with high TMB. This demonstrates the power of cfDNA composition analysis for risk stratification in ICI treatment. Citation Format: Phil Xie, Zohar Etzioni, Chun-Xiao Song, Richard P Owen, Mark R Middleton, Xin Lu, Benjamin Schuster-Boeckler. A T-cell signature in circulating cell-free DNA at time of diagnosis predicts response to checkpoint inhibition [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr PR017.

Abstract B047: Monitoring treatment response and toxicity in BRAF V600-mutant metastatic melanoma with circulating cell-free DNA

Abstract Background: The DREAMseq trial (EA6134, NCT02224781) was a national multi-center randomized phase III trial coordinated by ECOG-ACRIN that found that immune checkpoint inhibitor (IO) treatment achieves improved survival outcomes compared to targeted therapy (TT) in patients with BRAF V600-mutant metastatic melanoma. Still, approximately 40% of patients do not respond to IO, and existing biomarkers fail to distinguish this subset of patients who do not benefit from IO therapy. Additionally, as many as 80% of patients may experience immune- related adverse events (irAEs), which range from mild dermatological symptoms to life- threatening myocarditis. Here, we explore the use of the methylation status of cell-free DNA (cfDNA) in serially collected blood samples to measure response and toxicity in the context of IO- and TT-treated metastatic melanoma. Methods: Serial serum samples were collected from patients with BRAF V600-mutant metastatic melanoma treated with ipilimumab/nivolumab (IO) or dabrafenib/trametinib (TT). Circulating cfDNA was isolated from serially collected serum samples, enriched for regions of interest by hybridization capture and sequenced using enzymatic methyl-seq. Cell-type deconvolution was performed to determine the abundance of cell type- specific methylation patterns of cfDNA molecules in patient serum at different time points of treatment. The BRAF V600 mutation abundance in total cfDNA was also assessed. Results: We identified melanocyte lineage-specific DNA methylation regions and demonstrate that the methylation status of these regions remains conserved in malignant melanoma. We characterized the changes in abundance of the melanocyte-lineage cfDNA over the course of treatment and show that these changes distinguish responders from non-responders to either IO or TT. Furthermore, we track the abundance of cell type-specific DNA from normal tissues to identify markers indicative of adverse effects or disease progression. Conclusions: We established melanocyte-lineage methylation markers and evaluated the use of cell-type specific DNA methylation to monitor treatment effects of immune checkpoint or BRAF/MEK inhibitors in metastatic melanoma using serially collected blood samples. Citation Format: Sidharth S Jain, A. Patrick IV McDeed, Megan E McNamara, Amber R Alley, Dori S Rosenstrauch, Harry Sun, Natalie Thompson, John M Kirkwood, Geoffrey T Gibney, Michael B Atkins, Anton Wellstein. Monitoring treatment response and toxicity in BRAF V600-mutant metastatic melanoma with circulating cell-free DNA [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B047.

Real-world analysis of the incidence and risk factors of pneumonitis in non-small cell lung cancer patients treated with combined thoracic radiotherapy and immunotherapy

Abstract Objectives Combining radiotherapy with immune checkpoint inhibitor (ICI) treatment has emerged as an important therapeutic regimen. However, this combined treatment may increase the risk of pneumonitis. The aim of this study is to analyze the incidence and risk factors for pneumonitis in non-small cell lung cancer (NSCLC) patients receiving combined thoracic radiotherapy and ICI (RT + ICI) treatment in the real-world clinical setting, offering a reference and guidance for clinical physicians. Methods This study identified 447 patients with pathologically confirmed NSCLC at West China Hospital of Sichuan University from 2016 to 2021. Clinical characteristics, treatment regimens, immune-related adverse events (irAEs), and hematological data were collected and analyzed. Results Patients receiving combined RT + ICI treatment had a higher risk of developing pneumonitis than those receiving ICI treatment alone (26.9 vs. 6.7 %, p&lt;0.001). The multivariate logistic analysis identified the following independent risk factors for pneumonitis in patients undergoing combined RT + ICI treatment: history of lung disease (p=0.032), first-line ICI treatment (p=0.001), anti-PD-L1 instead of anti-PD-1 treatment (p=0.035), and the development of immunotherapy-related thyroid dysfunction (p=0.019). The independent risk factors were incorporated into a nomogram to predict the incidence of pneumonitis. The area under the receiver operating characteristic curve is 0.727, suggesting an acceptable predictive efficacy. Conclusions Compared to ICI monotherapy, NSCLC patients receiving the combination of thoracic radiotherapy and ICI treatment are at higher risk of developing pneumonitis. The nomogram holds promise for facilitating the risk assessment and early identification of pneumonitis in NSCLC patients receiving combined RT + ICI treatment.

Abstract 4136727: The role of immune mechanism in Immune Checkpoint Inhibitor-Associated Myocarditis: seeking key genes

Background: Immune checkpoint inhibitors (ICIs) are extensively employed in cancer treatment; however, the development of ICI-associated myocarditis (ICI-MC) introduces a severe and potentially fatal complication with elusive pathophysiological mechanisms. This study aimed to pinpoint pivotal immune-related genes in ICI-MC and unveil potential therapeutic targets using bioinformatics. Methods: Utilizing the GSE180045 dataset (comprising three groups: Group A - ICI patients without immune adverse events, Group B - ICI patients with non-myocarditis immune adverse events, Group C - ICI patients with myocarditis), we scrutinized differentially expressed genes (DEGs) between ICI-MC samples (Group C) and non-myocarditis controls (Group A&amp;B). These DEGs were cross-referenced with 1796 immune-related genes (IRGs) from the immPort database to derive IR-DEGs. We conducted functional enrichment analyses (GO, KEGG, GSEA), constructed a PPI network, and identified hub genes. Validation was performed using the GSE4172 dataset, and optimal feature genes (OFGs) were identified from the overlap of hub genes and validation DEGs. Predictions of target miRNAs were made, and a ceRNA network was constructed. Target drugs for hub genes were forecasted using the cMAP database. Results: We pinpointed 58 DEGs between ICI-MC and controls, leading to the identification of 32 IR-DEGs after intersecting with 1796 IRGs. Functional analyses revealed enrichment in cell lysis, CD8+ T cell receptor, natural killer cell-mediated cytotoxicity, and RAGE signaling. Up-regulated hub genes (IL7R, PRF1, GNLY, CD3G, NKG7, GZMH, GZMB, KLRB1, KLRK1, CD247) were highlighted. In the validation dataset, 407 DEGs were uncovered, resulting in the identification of 3 OFGs (KLRB1, NKG7, GZMH). Predicted target miRNAs, lincRNAs, and circRNAs formed a comprehensive ceRNA network. The top 10 drugs with elevated connectivity scores included acetohydroxamic-acid, suggesting caution in ICI treatment. Conclusion: NKG7, GZMH, and KLRB1 emerged as pivotal immune-related genes in ICI-MC. Biological enrichments encompassed cell lysis, CD8+ T cell receptor pathway, natural killer cell-mediated cytotoxicity, RAGE signaling, and proinflammatory pathways. The ceRNA network shed light on critical molecules, emphasizing the need to avoid drugs like acetohydroxamic-acid in ICI treatment.

Abstract 4136202: Incident Hypertension and Survival Outcomes After Immune Checkpoint Inhibitor Initiation

Introduction: Immune checkpoint inhibitors (ICIs) are commonly used as anticancer agents linked with dramatic antitumor response but are associated with cardiotoxicity. Recent isolated reports have suggested ICIs may link with hypertension (HTN) after years of treatment. Yet, the timing and long-term ramifications of this HTN are unknown. Methods: From a large cohort of well-phenotyped cancer patients treated with ICIs from 2011-2022, we assessed the incidence of new or worsened HTN [systolic blood pressure (SBP) ≥130 mmHg (or in a higher HTN stage) on two occasions within a three-month period or addition of an antihypertensive medication] after ICI initiation. Secondary endpoints included major cardiovascular events (MACE), defined as symptomatic arrhythmia, myocardial infarction, stroke, heart failure, or cardiac death. Observed incident HTN rates were compared to Framingham-predicted rates, using JNC 8 cutoffs of 140/90 mmHg. Landmark analysis, excluding patients who were observed to have new HTN but had SBPs ≥130 mmHg on two occasions within six-months prior to ICI initiation, identified patients with possible undiagnosed HTN. Multivariable regression and survival analysis were used to define factors associated with new worsened HTN and MACE and the relationship between SBP increase and MACE risk. Further, the effect of standard antihypertensive classes on the prevention of ICI-related HTN will be assessed. Results: Overall, from 312 patients treated with ICIs (mean age 63.5 years, 67.4% baseline HTN, 11.0% on dual ICI-therapy), 50.0% (156/312) developed new or worsened HTN over a mean of 27 months follow-up. Cumulative incidence of new HTN by 1-year was 50.0% wherein the mean peak increase in SBP was 12 mmHg. In landmark analysis, excluding those with undiagnosed HTN and applying the JNC 8 cutoff of ≥140/90 mmHg, the observed new HTN rate was 21.4% at 1 year, &gt;2-fold higher than the Framingham-predicted rate of 9.3% (RR 2.3, P &lt;0.0001). In those with preexisting HTN, 49% developed worsened HTN. In multivariate analysis, only time on ICI treatment, ECOG status, and autoimmune disease history were associated with new or worsened HTN after ICI-initiation ( P &lt;0.05 for all). Further, only prior autoimmune disease and ECOG status associated with MACE; while beyond traditional cancer factors, only new or worsening HTN associated with lower mortality. Conclusions: Collectively, these data suggest that HTN may be common with ICIs, and prognosticates survival.

Abstract 4117414: Risk Factors Associated with Cardiac Hospital Admissions in Cancer Patients Treated with Immune Checkpoint Inhibitors

Background: Immune checkpoint inhibitors (ICIs) are highly effective anti-cancer treatments for several cancers. However, treatment with ICIs is associated with metabolic perturbations, accelerated atherosclerosis, and increased risks of adverse cardiovascular events. In this study, we aimed to determine risk factors associated with cardiac hospital admissions in patients treated with ICIs for their cancer. Methods: Retrospective data was collected for all patients treated with ICIs between 1 January 2010 and 1 January 2020 through the Hunter New England Local Health District (HNELHD), Australia. Patient medical history and demographics were collected through electronic medical records. Outcome data was obtained from the HNELHD Institutional Cardiac and Stroke Outcomes Unit database. Cardiac admission was defined as cardiac disease based on hospital administration ICD-10 codes. Binary logistic regression was used for multivariate analysis and performed through SPSS version 28. Results: A total of 1,080 patients were included in the final analysis. Mean age of patients was 66.9 ± 11.7 years, with the majority male sex ( n =685; 63.4%). Primary cancer diagnosis of patients treated with ICIs included melanoma ( n =417; 38.7%), and cancer of the lung ( n =327; 30.3%). Nivolumab monotherapy was the most used first-line ICI treatment ( n =475; 44.0%) followed by pembrolizumab monotherapy ( n =428; 39.6%). A total of 266 (24.6%) patients had at least one cardiac hospital admission. On univariate analysis, pre-existing cardiovascular disease (CVD) ( p &lt;0.001), diabetes mellitus ( p &lt;0.001), chronic kidney disease ( p &lt;0.001), and prior CVD medications ( p &lt;0.001) were associated with cardiac hospitalisation. On multivariate analysis, prior history of heart failure ( p &lt;0.001), hypertension ( p =0.003), ischaemia, and peripheral vascular disease ( p =0.049) were independently associated with an increased risk of cardiac hospital admission. Conclusions: In cancer patients treated with ICIs, pre-existing CVD risk factors increases the risk of cardiac-associated hospitalisations. Adequate CVD risk modification and monitoring during treatment with ICIs may be necessary to reduce cardiac hospitalisations.

IMMU-13. TRANS-SPECIES STUDY OF IDH-MUTANT REPLICATION-REPAIR DEFICIENT HIGH-GRADE GLIOMAS (RRD-HGG) AND RESPONSE TO COMBINED TARGETED AND IMMUNOTHERAPY: AN IRRDC STUDY

Abstract BACKGROUND AND AIMS IDH-mutant gliomas comprise &amp;lt;10% of HGG in children. RRD-HGG comprise 5-10% of childhood HGG, demonstrate high mutation burden (TMB) and respond to immune-checkpoint inhibition (ICI). The impact of RRD within childhood IDH-mutant gliomas, and effective therapeutic options for these patients are not well-established. METHODS Clinical and multi-omic analyses were performed on IDH mut -RRD-HGG registered to the IRRDC and the Toronto glioma taskforce. Tumor development and genomic data were studied from a novel IDH mut -RRD-HGG immunocompetent mouse model. Outcome following ICI and targeted therapy were evaluated. RESULTS RRD was detected in &amp;gt;60% of childhood IDH mut -HGG. IDH1-mutations were detected in 20% of RRD-HGG. All patients with IDH mut -RRD-HGG (n=49) harboured germline variants in MMR genes (CMMRD: 65%, Lynch: 35%). Contrary to sporadic IDH mut -gliomas, &amp;gt;91% were WHO-grades 3/4. Diffuse/multifocal disease involving the frontal lobe was frequent. TMB (median: 28 mutations/Mb) was lower than IDH-wildtype RRD-HGG (p&amp;lt;0.05). POLE/POLD1 mutations were absent. TP53 and ATRX were frequent somatic hits. Copy number changes, particularly CDKN2A/2B loss, were common. IDH-mutation contributed to an immune-suppressed microenvironment, with lower CD8-T-cell infiltration (immunohistochemistry) and tumor-inflammation scores (transcriptome; p&amp;lt;0.05). A novel mouse model (Olig2-Cre+/Msh2LoxP/LoxP/LSL-Idh1R132H/+) demonstrated similar TMB, diffuse cerebral involvement, slower growth, and lesser immune infiltrates as compared with IDH-wildtype RRD-HGG models, and provided opportunity for therapeutic testing. RRD contributed to poor survival in IDHmut-gliomas (p&amp;lt;0.001). Despite hypermutation, ICI monotherapy resulted in inferior survival in IDH mut -RRD-HGG vs IDH-wildtype RRD-HGG (p&amp;lt;0.05). Five patients developed metachronous IDH mut -RRD-HGG while on anti-PD1 treatment for IDH-wildtype RRD-HGG, suggesting intrinsic ICI-resistance. Ivosidenib (IDH-inhibitor) demonstrated objective response in 4/8 IDH mut -RRD-HGG. Furthermore, for IDH mut -RRD-HGG on ICI treatment, the addition of ivosidenib prolonged survival at 12-months in comparison to those without IDH-inhibition (p=0.01) CONCLUSIONS Hypermutant RRD-HGG with IDH1;p.R132H harbour unique immuno-biology and do not respond to anti-PD1 monotherapy. The addition of IDH-inhibition demonstrated favourable responses, supporting need for evaluation of the combination in clinical trials.

IMMU-40. INVESTIGATING THE ROLE OF MUTATIONAL BURDEN IN TUMOR IMMUNOGENICITY USING A PRE-CLINICALMLH1-DEFICIENT GLIOBLASTOMA MODEL

Abstract BACKGROUND Although there is an established correlation between tumor mutational burden (TMB) and response to immune checkpoint inhibition (ICI) in many cancers, such an association has not been definitively shown in high-grade gliomas. Most studies of ICI therapy in gliomas, including glioblastoma (GBM), have failed to demonstrate efficacy, with the exception of hypermutated cases resulting from rare inherited defects in mismatch repair (MMR) genes. We sought to investigate the association of TMB to immune response using a syngeneic murine model with a spectrum of mutational burdens. METHODS We used CRISPR-Cas9 to knockout the MMR gene Mlh1 in the murine glioma model SB28, an ICI-resistant cell line with a very low mutational burden (108 non-synonymous mutations). RESULTS Single-cell sorted Mlh1 knockout SB28 clones revealed a two- to six-fold increase in TMB. Importantly, loss of Mlh1 also brought about global changes in immune- and inflammatory-related gene expression in vitro, without correlation to increasing TMB. While all clones had the same rate of in vitro proliferation, flank injection of a high TMB vs a low TMB SB28 Mlh1 knockout clone resulted in similar survival benefits compared to Mlh1 wildtype SB28. CONCLUSIONS These preliminary results suggest that, although disruption of the MMR system may result in heightened tumor immunogenicity, elevated TMB may not be the sole significant determinant. We are currently investigating tumor proliferation after flank injection in immunocompromised mice to confirm that slowed growth is immune-related, as well as clone-specific response to ICI treatment. We are also exploring the role of specific cytokines/chemokines in conferring this survival advantage and potential immune response. By generating a GBM model of varied mutational burdens and immune profiles and comparing to the baseline SB28 cell line, we can interrogate the relative significance of TMB in tumor immunogenicity and ICI response.

Unveiling the influence of tumor and immune signatures on immune checkpoint therapy in advanced lung cancer.

This study investigates the variability among patients with non-small cell lung cancer (NSCLC) in their responses to immune checkpoint inhibitors (ICIs). Recognizing that patients with advanced-stage NSCLC rarely qualify for surgical interventions, it becomes crucial to identify biomarkers that influence responses to ICI therapy. We conducted an analysis of single-cell transcriptomes from 33 lung cancer biopsy samples, with a particular focus on 14 core samples taken before the initiation of palliative ICI treatment. Our objective was to link tumor and immune cell profiles with patient responses to ICI. We discovered that ICI non-responders exhibited a higher presence of CD4+ regulatory T cells, resident memory T cells, and TH17 cells. This contrasts with the diverse activated CD8+ T cells found in responders. Furthermore, tumor cells in non-responders frequently showed heightened transcriptional activity in the NF-kB and STAT3 pathways, suggesting a potential inherent resistance to ICI therapy. Through the integration of immune cell profiles and tumor molecular signatures, we achieved an discriminative power (area under the curve [AUC]) exceeding 95% in identifying patient responses to ICI treatment. These results underscore the crucial importance of the interplay between tumor and immune microenvironment, including within metastatic sites, in affecting the effectiveness of ICIs in NSCLC.

Peritumoral Venous Vessels: Autobahn and Portal for T cells to Melanoma Brain Metastasis.

Melanoma brain metastasis is associated with high morbidity and mortality and remains a major clinical challenge. Despite recent successes with combination immune checkpoint inhibitors (ICI) in the treatment of affected patients, the mechanistic underpinnings of T cell entry and response to these drugs in brain metastasis are poorly understood. Using real-time intravital microscopy, Messmer and colleagues identified peritumoral venous vessels (PVVs) as critical sites for T cell entry into brain metastases, a process accelerated by ICI treatment. The expression of intercellular adhesion molecule 1 (ICAM-1) on PVVs was found to be important for T cell recruitment in pre-clinical models and associated with increased T cell infiltration in human brain metastatic lesions. This study highlights PVVs as key vascular entry points for T cells into brain metastases, laying the foundation for enhancing the efficacy of cancer immunotherapies.

Unveiling the influence of tumor and immune signatures on immune checkpoint therapy in advanced lung cancer

This study investigates the variability among patients with non-small cell lung cancer (NSCLC) in their responses to immune checkpoint inhibitors (ICIs). Recognizing that patients with advanced-stage NSCLC rarely qualify for surgical interventions, it becomes crucial to identify biomarkers that influence responses to ICI therapy. We conducted an analysis of single-cell transcriptomes from 33 lung cancer biopsy samples, with a particular focus on 14 core samples taken before the initiation of palliative ICI treatment. Our objective was to link tumor and immune cell profiles with patient responses to ICI. We discovered that ICI non-responders exhibited a higher presence of CD4+ regulatory T cells, resident memory T cells, and TH17 cells. This contrasts with the diverse activated CD8+ T cells found in responders. Furthermore, tumor cells in non-responders frequently showed heightened transcriptional activity in the NF-kB and STAT3 pathways, suggesting a potential inherent resistance to ICI therapy. Through the integration of immune cell profiles and tumor molecular signatures, we achieved an discriminative power (area under the curve [AUC]) exceeding 95% in identifying patient responses to ICI treatment. These results underscore the crucial importance of the interplay between tumor and immune microenvironment, including within metastatic sites, in affecting the effectiveness of ICIs in NSCLC.

Effects of sex and obesity on immune checkpoint inhibition-related cardiac systolic dysfunction in aged mice.

Despite accumulating data on underlying mechanisms, the influence of sex and prevalent cardio-metabolic co-morbidities on the manifestation and severity of immune checkpoint inhibitor (ICI)-induced cardiotoxicity has not been well defined. To elucidate whether sex and prevalent cardio-metabolic co-morbidities affect ICI-induced cardiotoxicity, we randomized 17-month-old male and female mice to receive control diet (CON) or high-fat diet (HFD) + L-NAME-a well-established mouse model of cardio-metabolic co-morbidities-for 17weeks (n = 5-7), and evaluated markers of T-cell function in the spleen. As expected, HFD + L-NAME significantly increased body- and heart weight, and serum cholesterol levels, and caused no systolic dysfunction, however, led to diastolic dysfunction, cardiomyocyte hypertrophy, and increased fibrosis only in males compared to corresponding CON. Western blot analyses of splenic immune checkpoint protein levels showed differential expression depending on sex and prevalent cardio-metabolic co-morbidities, suggesting T-cell exhaustion in both sexes on HFD + L-NAME, but more pronounced in males. In a sub-study with a similar setup, we tested cardiotoxic manifestations of ICI by treating mice with anti-PD-1 monoclonal antibody (ICI) for the last 2weeks of diet administration (n = 5-7). After 2weeks of ICI treatment, cardiac systolic functions significantly decreased in CON, but not in HFD + L-NAME groups of both sexes compared to baseline (before ICI administration). In conclusion, in this exploratory study using aged mice, we describe for the first time that ICI-related systolic dysfunction is diminished in both sexes when obesity and hypercholesterolemia are present, possibly due to obesity-related T-cell exhaustion.

Effect of body mass index on immune checkpoint inhibitor efficacy in patients with advanced cancer.

The need for predictive factors regarding the response to immune checkpoint inhibitors (ICIs) is increasing. Recent research indicates that an enhanced response to ICIs is associated with a higher body mass index (BMI). This study aims to evaluate the relationship between response to ICIs and BMI in solid tumors. We retrospectively analyzed patients with advanced cancer treated with ICIs at one academic center. We compared the treatment responses of patients classified as underweight/normal weight (BMI <25) and overweight/obese (BMI ⩾ 25) according to their BMI at the initiation of ICI treatment. After excluding underweight patients, we also compared the progression-free survival (PFS) and overall survival (OS) of normal-weight, overweight, and obese patients. Overall, 113 patients were evaluated. Forty-seven (41.6%) patients had BMI <25 and 66 (58.4%) patients had a BMI ⩾ 25. In underweight/normal patients, median PFS was 7.7 months (95% CI: 4.7-10.6) while it was 8.0 months (95% CI: 4.1-11.9) in overweight/obese patients (HR 1.16, 95% CI: (0.76-1.75), p=0.477). In underweight/normal patients, the median OS was 21.7 months (95% CI: 11.6-31.7) compared to 18.7 months (95% CI: 12.7-24.6) in overweight/obese patients (HR 1.06, 95% CI: (0.69-1.64), p=0.774). The objective response rate (ORR) was 38.3% in underweight/normal patients and 34.8% in overweight/obese patients (p = 0.707). After excluding underweight patients, there were also no significant differences in PFS (p = 0.914), OS (p = 0.642), and ORR (p = 0.909) between patients of normal weight, overweight, and obesity. Our research found no correlation between BMI and response to ICIs. Additional prospective studies are necessary to assess the effect of BMI on the response to ICIs.

Surgical resection following chemoradiotherapy for thoracic SMARCA4-deficient undifferentiated tumor: a report of two cases

BackgroundThoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a high-grade malignant neoplasm with a poor prognosis. Most cases of SMARCA4-UT have extensive chest wall and mediastinum involvement. The efficacy of surgical resection has not been clearly established. Here, we report two surgical cases of SMARCA4-UT with chest wall invasion after chemoradiotherapy.Case presentationThe first patient was a 40-year-old man with back pain. Computed tomography revealed a 6.8 cm mass in contact with the thoracic vertebrae near the intervertebral foramen, which was suspected to involve the third to fifth ribs. The patient was diagnosed with SMARCA4-UT with clinical T3N0M0 stage IIB. The tumor shrank after chemoradiotherapy, and conversion surgery combined with partial vertebrectomy was performed. Histopathological findings revealed 30% residual tumor in the tumor bed. Thirty-six days after surgery, the patient developed multiple liver metastases and peritoneal dissemination. Chemotherapy combined with immune checkpoint inhibitor treatment was performed, resulting in tumor shrinkage. However, peritoneal dissemination recurred within a short interval. The patient died 5 months postoperatively. The second patient was a 74-year-old man with chest pain. Computed tomography revealed a 7.4-cm mass in the left upper lobe with invasion of the third and fourth ribs. The patient was initially diagnosed with non-small cell lung cancer with clinical T4N1M0 stage IIIA. The tumor shrank after induction chemoradiotherapy, and a left upper lobectomy combined with the chest wall resection was performed. Based on histopathological findings, the patient was diagnosed with SMARCA4-UT. The residual tumor percentage was 3%. The patient was followed up for 12 months postoperatively without recurrence.ConclusionsWe performed the complete resection of SMARCA4-UT following chemoradiotherapy. The two surgical cases had different postoperative courses. Radical surgery after chemoradiotherapy is effective for local control. However, its long-term prognostic efficacy remains unclear. Multidisciplinary approaches and further investigations of novel therapeutic options are required.

Long-term Responders to Nanoparticle Albumin-bound Paclitaxel Following Immune Checkpoint Inhibitor in Non-small Cell Lung Cancer.

The efficacy of cytotoxic chemo-therapy has been reported to improve after immune checkpoint inhibitor (ICI) administration. We previously conducted a multicenter prospective clinical study to evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) after ICI treatment. In that study, some patients showed a long-term response to nab-PTX, which is not usually observed with single-agent chemotherapy. The present study aimed to evaluate the clinical characteristics of these patients. We retrospectively analyzed updated data from 29 patients enrolled in our clinical study who received nab-PTX monotherapy after ICI treatment. We defined a "long-term responder" as a patient who achieved a 1-year progression-free survival (PFS). Among the 29 patients, 10 (34.5%) were long-term responders, two of whom achieved a 5-year PFS. A key difference between long-term and non-long-term responders was that the long-term responders had a significantly higher number of patients with Eastern Cooperative Oncology Group-performance status of 0 (70.0% versus 10.5%; p=0.002). Furthermore, median cycles of previous ICIs and median treatment cycles were significantly higher in long-term responders than in non-long-term responders (8 cycles versus 3 cycles; p=0.03) (5.9 months versus 2.0 months; p=0.02). In the 10 long-term responders, six patients required at least a one-stage dose reduction owing to adverse events, and four patients required a two-stage dose reduction. Nab-PTX administration after ICI treatment may elicit a long-term response. A long-term response can be achieved even with a dose reduction due to adverse events.

High RRM2 Correlates with Mitochondrial and Immune Responses in the Eosinophilic Subtype of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC), the predominant subtype of RCC, is distinguished by unique biological characteristics and heterogeneity, including eosinophilic and clear subtypes. Notwithstanding progress in therapy, immune checkpoint inhibitors (ICIs), and tyrosine kinase inhibitors (TKIs), the prognosis for individuals with metastatic ccRCC remains poor, presumably owing to metabolic alterations leading to mitochondrial dysfunction, which affects treatment response variability. We analyzed histological and immunohistochemical data from a cohort at Dalian Medical University's First Affiliated Hospital alongside RNA-sequencing transcriptome data from the TCGA database. Histologically, eosinophilic and clear ccRCC subtypes were evaluated using Kaplan-Meier and Cox proportional hazards models for survival analysis and prognosis. Differential gene expression (DEG) analysis and Gene Set Enrichment Analysis were performed to explore transcriptomic differences and relevant pathways. The study discovered substantial histological and molecular differences between the eosinophilic and clear cell subtypes of ccRCC. The eosinophilic subtype linked with frequent high-grade tumors (69.05% eosinophil vs 35.35% clear) and a poorer prognosis (HR=2.659, 95% CI:1.437-4.919, P=0.002). DEG analysis revealed distinct expression patterns among subtypes and identified a risk score signature that remained significant even after adjusting for clinical variables (HR=3.967, 95% CI: 1.665-9.449, P=0.002), showing less favorable survival in the high-risk group (P < 0.0001). RRM2 emerged as the most prognostic gene from this risk score, particularly in the eosinophilic subtype, alongside other clinical variables. By IHC, RRM2 shows high IHC score in eosinophilic compared to clear subtype (P=0.019). In addition, highly expressed RRM2 correlates with poor outcomes and is linked to mitochondrial genes, immunological pathways, and ICIs treatment. These findings show significant differences in prognosis between subtypes. RRM2 was the most prognostic gene from the discovered novel risk score signature associated with subtypes. Future research is essential to validate these insights and their therapeutic implications for ccRCC management.