Severe Immune-related Adverse Events Research Articles

Stevens-Johnson syndrome and toxic epidermal necrolysis-like eruptions in patients treated with immune checkpoint inhibitors: a systematic review.

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment by targeting immune checkpoints such as PD-1, PDL-1, and CTLA-4, but concerns about severe immune-related adverse events persist. The scarcity of literature on dermatologic implications, especially severe reactions such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), highlights the urgent need for investigation. Our systematic review aims to address the gap in relevant literature by extensively examining the epidemiologic risk factors and management of SJS/TEN-like illnesses in ICI-treated patients to provide insights for risk assessment and clinical care. We identified 158 case reports that detailed the incidence of SJS/TEN in patients being treated with ICIs, examining demographic patterns, type of malignancy, clinical characteristics, and treatments linked to onset. We assessed mortality rates, risk elements, and the effectiveness of interventions to help guide clinical care. Analysis of 158 case reports revealed that SJS/TEN in ICI users is typically seen on average at the age of 63 and is more common in males. PD1 inhibitors such as nivolumab and pembrolizumab are often associated with various mucocutaneous patterns and significant risks with ICI use, especially TEN, which is linked to high morbidity and mortality rates. Our study notes limitations due to the inclusion of case reports or case series, such as potential publication and reporting biases, leading to skewed findings. Additionally, because of the heterogeneous reporting standards, the retrospective nature limits phenotypic precision, control for confounding variables, and data completeness. Our study provides valuable insights into the epidemiology, clinical features, management strategies, and outcomes of ICI-induced SJS/TEN, underscoring the importance of vigilant monitoring and personalized risk assessment in oncology practice. Continued research efforts are essential to optimize patient outcomes and enhance the safety profile of ICIs in cancer therapy.

PD-1 blockade combined with chemotherapy and bevacizumab in DNA mismatch repair-proficient/microsatellite stable colorectal liver metastases.

Single-agent immunotherapy is less effective in patients with DNA mismatch repair-proficient/microsatellite stable (pMMR/MSS) metastatic colorectal cancer (mCRC). Whether pMMR/MSS mCRC patients benefit from combination immunotherapy remains unclear. This study aimed to evaluate the efficacy and safety of anti-programmed cell death protein 1 (PD-1) therapy combined with chemotherapy and bevacizumab in pMMR/MSS colorectal liver metastases (CRLM) patients. A total of 12 patients with pMMR/MSS CRLM treated at The Sixth Affiliated Hospital of Sun Yat-sen University were enrolled. All patients were treated with at least 4 doses of PD-1 monoclonal antibody combined with chemotherapy and bevacizumab as neoadjuvant/adjuvant therapy. A total of 10 of the 12 patients received the combined therapies before primary tumor resection; the disease control rate (DCR) was 100% (10/10), and the objective response rate (ORR) was 70% (7/10). The ORR of liver metastases was 75% (9/12). Pathological complete response (pCR) was achieved in 1 primary tumor patient and 2 patients with hepatic lesions. A total of 5 patients underwent simultaneous resection of the primary tumor and liver metastases; 9 patients underwent microwave ablation for liver metastases. A total of 7 patients were assessed as having no evidence of disease (NED) with a median progression-free survival (PFS) interval of 9.2 (1.5-15.8) months after multimodality treatments for both primary and metastatic lesions. No severe immune-related adverse events (irAEs) and operational complications were observed. PD-1 blockade combined with chemotherapy and bevacizumab might be safe and effective for patients with pMMR/MSS CRLM. This treatment strategy might lead to better tumor regression and a higher chance of achieving NED.

Nivolumab maintenance improves overall survival of patients with advanced melanoma who experience severe immune-related adverse events on nivolumab plus ipilimumab

BackgroundThe combination of ipilimumab and nivolumab is a highly effective treatment for metastatic cutaneous melanoma. However, immune-related adverse events (irAEs) are common, often necessitating treatment interruption and the use of...

Tyrosine-protein kinase SYK-related gene signature in baseline immune cells associated with adjuvant immunotherapy-induced immune-related adverse events in melanoma.

Immune checkpoint inhibition (ICI) shows benefits in adjuvant (AT) and neoadjuvant (NAT) melanoma treatments. However, ICI frequently induces severe immune-related adverse events (irAEs). Unlike metastatic disease, where irAEs are a clinical trade-off for treatment that improves survival, the toxicity burden from ICI in AT is a substantial clinical problem urging for irAE-predictive biomarkers. We assessed post-surgical, pre-ICI treatment peripheral CD4+ and CD8+ T cells from clinical trial patients (CheckMate-915) treated with AT nivolumab (NIVO, n=130) or ipilimumab/nivolumab (COMBO, n=82). Performing RNA-seq differential gene expression analysis we tested baseline differences associated with severe (grade 3-5) irAEs and constructed an irAE-predictive model using LASSO-regularized logistic regression. The analysis of predicted protein-protein interactions among differentially expressed genes (DEGs) in peripheral CD4+ cells revealed significant enrichment of the spleen tyrosine kinase (SYK) pathway, associated with severe irAEs in COMBO-treated patients. This gene-expression signature predicted severe-irAE COMBO patients (chi-square p-value=0.001) with 73% accuracy and was independent of disease recurrence (p=0.79). The irAE-predictive model incorporating this gene-expression signature demonstrated 82% accuracy (chi-square p-value=8.91E-06). We identified baseline gene-expression differences in key immune pathways of peripheral blood T cells from COMBO-treated patients with grade 3-5 irAEs, and defined a SYK-related gene signature correctly identifying ~60% of COMBO-treated patients with grade 3-5 irAE. This finding aligns with our previous work linking anti-CTLA-4 irAEs with a germline variant associated with high SYK expression. This gene signature may serve as a baseline biomarker of severe grade 3-5 irAE risk, which is especially important in AT.

Safety of immune checkpoint inhibitor rechallenge after severe immune-related adverse events: a retrospective analysis.

Immune checkpoint inhibitors (ICIs) present clinicians with the challenge of managing immune-related adverse events (irAEs), which can range from mild to severe due to immune system activation 1. While guidelines recommend discontinuing ICIs for grade 3 partial and all grade 4 irAEs, there is growing interest in rechallenging patients based on oncological outcomes, particularly for cardiovascular and neurological irAEs where data remains scarce 1,2. We retrospectively evaluated the safety of ICI rechallenge following grade 3-4 irAEs, specifically focusing on cardiovascular and neurological events, in patients discussed at our multidisciplinary immunotoxicity assessment board between 2019 and 2021. Fifteen patients were included, with a median time to severe irAE onset of 49 days. Among them, five patients experienced neurological adverse events (NAEs): aseptic meningitis (3), inflammatory polyradiculoneuropathy (1), and ophthalmoplegia (1), while one patient presented with myocarditis. Of the 15 patients retreated with ICIs after initial severe irAEs, 11 (73%) remained free of subsequent irAEs, two (13%) experienced recurrence of the initial irAE, and two (13%) developed new irAEs distinct from the initial event. The median time to event recurrence was 69 days, occurring no earlier than the initial severe irAE. In the subset analysis focusing on severe cardiovascular and neurological irAEs, rechallenge with ICIs was generally well tolerated. However, one patient treated with anti-PD1 experienced a relapse of grade 2 aseptic meningitis. Overall, our findings suggest that rechallenging with ICIs after severe irAEs, including those affecting the cardiovascular and neurological systems, may be safe, particularly after irAE regression and corticosteroid withdrawal.

The Current State of Systemic Therapy of Metastatic Uveal Melanoma.

Uveal melanoma (UM) is genetically a distinct tumor compared to cutaneous melanoma (CM), and due to its low mutational burden, it is far less perceptible to the immune system. Thus, treatments that have revolutionized the treatment of CM remain widely inefficient in metastatic UM or only demonstrate effectiveness in a small subpopulation of patients. To this end, the therapeutic benefit of immune checkpoint blockade is very limited and may come at the expense of severe immune-related adverse events that could potentially affect all organ systems. Notably, tebentafusp, an entirely novel class of anti-cancer drugs, has received official authorization for the treatment of metastatic UM. It is the first agent that demonstrated a survival advantage in a randomized controlled trial of metastatic UM patients. Despite the survival benefit and approval, the restriction of tebentafusp to HLA-A*02:01-positive patients and the low objective response rate indicate the persistent need for additional therapies. Thus, liver-directed therapies are commonly used for tumor control of hepatic metastases and represent a central pillar of the daily management of liver-dominant disease. Further, promising data from targeted therapies independent of MEK-inhibitors, such as the combination of darovasertib and crizotinib, raise hope for additional options in metastatic UM in the future. This narrative review provides a timely and comprehensive overview of the current treatment landscape for metastatic UM.

Risk factors for severe immune-related pneumonitis after nivolumab plus ipilimumab therapy for non-small cell lung cancer.

The efficacy of anti-CTLA-4 antibody (ipilimumab) plus anti-programmed cell death 1 antibody (nivolumab) in treating advanced non-small cell lung cancer (NSCLC) is impeded by an elevated risk of severe immune-related adverse events. However, our understanding of associations among pre-existing fibrosis, emphysematous changes, and objective indicators as predictive factors is limited for severe pneumonitis in NSCLC patients receiving this combination therapy. Thus, we retrospectively investigated these associations, including overall tumor burden, before treatment initiation in the Japanese population. We focused on patients (n = 76) with pre-existing interstitial lung disease (ILD) to identify predictors of severe pneumonitis. Variables included age, sex, smoking status, programmed cell death ligand 1 expression, overall tumor burden, chest computed tomography-confirmed fibrosis, serum markers, and respiratory function test results. Severe pneumonitis was more frequent in patients with squamous cell carcinoma, fibrosis, low diffusing capacity for carbon monoxide (%DLCO), and high surfactant protein D (SP-D) level. Notably, squamous cell carcinoma, baseline %DLCO, and SP-D level were significant risk factors. Our findings revealed the nonsignificance of tumor burden (≥85 mm) in predicting severe pneumonitis, emphasizing the importance of pre-existing ILD. Conversely, in cases without pre-existing fibrosis, severe pneumonitis was not associated with %DLCO or SP-D level (93.2% vs. 91.9%, and 63.3 vs. 40.9 ng/mL, respectively) and was more common in patients with a large overall tumor burden (97.5 vs. 70.0 mm). Vigilant monitoring and early intervention are crucial for patients with squamous cell carcinoma, high SP-D level, or low %DLCO undergoing ipilimumab plus nivolumab therapy.

Correlation of patient HLA class I genotypes with severe immune-related adverse events: A retrospective study in Chinese population.

10586 Background: Immune checkpoint inhibitors (ICIs) are effective in multiple tumors. However, about 10% of immune-related adverse events (irAEs) are severe and can have serious or even life-threatening consequences for patients. We investigated whether Human leukocyte antigen (HLA) genes predispose to and thus hold a predictive role of developing of severe irAEs in Chinese population. Methods: In a case/control study, we collected data from patients with metastatic cancer treated with ICIs and developed severe irAEs (Grade ≥3 and required hospitalization). Patients treated with ICIs without any irAEs were used as controls. Data was collected from15th Nov, 2019 until 10th Oct, 2023. HLA typing was performed via next generation sequencing. Results: We enrolled 83 patients with severe irAEs and 286 patients treated with ICIs without any irAEs. We found HLA-B*15:27 (OR=9.1, X21,95 = 7.2, P = 0.008) and HLA-C*04:01 (OR=2.5, X21,95 = 7.0, P =0.008) were significantly associated with severe overall irAEs risk. When assessing irAE individually, a significant association between HLA-B*13:02 and serious myocarditis (OR = 3.4, X21,95 = 6.2, P =0.01) as well as striking enrichment for HLA-A*02:03 haplotypes in severe adrenal insufficiency (OR = 10.0, X21,95 = 19.1, P<0.0001) were observed. Conclusions: Specific HLA alleles were associated with severe irAEs. Consideration of pre-prescription HLA typing and vigilance for serious reactions to ICIs are warranted.

Treatment patterns and survival outcomes of patients admitted to the intensive care unit due to immune-related adverse events of immune checkpoint inhibitors.

Severe immune-related adverse events (irAEs) due to immune checkpoint inhibitors (ICIs) can lead to admission to the intensive care unit (ICU). In this retrospective study, we determined the incidence, treatment patterns and survival outcomes of this patient population at a comprehensive cancer center. All patients admitted to the ICU due to irAEs from ICI treatment between January 2015 and July 2022 were included. Descriptive statistics were reported on patient characteristics and treatment patterns during hospital admission. Overall survival (OS) from the time of ICU discharge to death was estimated using the Kaplan-Meier method. Over the study period, 5561 patients received at least one ICI administration, of which 32 patients (0.6%) were admitted to the ICU due to irAEs. Twenty patients were treated with anti-PD-1 plus anti-CTLA-4 treatment, whereas 12 patients were treated with ICI monotherapy. The type of irAEs were de novo diabetes-related ketoacidosis (n = 8), immune-related gastrointestinal toxicity (n = 8), myocarditis or myositis (n = 10), nephritis (n = 3), pneumonitis (n = 2), and myelitis (n = 1). The median duration of ICU admission was 3 days (interquartile range: 2-6 days). Three patients died during ICU admission. The median OS of the patients who were discharged from the ICU was 18 months (95% confidence interval, 5.0-NA). The incidence of irAEs leading to ICU admission in patients treated with ICI was low in this study. ICU mortality due to irAEs was low and a subset of this patient population even had long-term survival.

Phenotyping Hepatic Immune-Related Adverse Events in the Setting of Immune Checkpoint Inhibitor Therapy.

We present and validate a rule-based algorithm for the detection of moderate to severe liver-related immune-related adverse events (irAEs) in a real-world patient cohort. The algorithm can be applied to studies of irAEs in large data sets. We developed a set of criteria to define hepatic irAEs. The criteria include: the temporality of elevated laboratory measurements in the first 2-14 weeks of immune checkpoint inhibitor (ICI) treatment, steroid intervention within 2 weeks of the onset of elevated laboratory measurements, and intervention with a duration of at least 2 weeks. These criteria are based on the kinetics of patients who experienced moderate to severe hepatotoxicity (Common Terminology Criteria for Adverse Events grades 2-4). We applied these criteria to a retrospective cohort of 682 patients diagnosed with hepatocellular carcinoma and treated with ICI. All patients were required to have baseline laboratory measurements before and after the initiation of ICI. A set of 63 equally sampled patients were reviewed by two blinded, clinical adjudicators. Disagreements were reviewed and consensus was taken to be the ground truth. Of these, 25 patients with irAEs were identified, 16 were determined to be hepatic irAEs, 36 patients were nonadverse events, and two patients were of indeterminant status. Reviewers agreed in 44 of 63 patients, including 19 patients with irAEs (0.70 concordance, Fleiss' kappa: 0.43). By comparison, the algorithm achieved a sensitivity and specificity of identifying hepatic irAEs of 0.63 and 0.81, respectively, with a test efficiency (percent correctly classified) of 0.78 and outcome-weighted F1 score of 0.74. The algorithm achieves greater concordance with the ground truth than either individual clinical adjudicator for the detection of irAEs.

The survival benefits and the risk of severe renal injury of immune checkpoint inhibitors in patients with cancer: The real-world evidence from the National Clinical Cohort Collaborative (N3C).

e24142 Background: The survival benefits and the risks of severe immune-related adverse events (sirAEs) of Immune checkpoint inhibitors (ICI) vary dramatically among cancer patients. Among sirAEs, acute kidney injury (AKI) incidences are rising, often cause sustained renal damage, and are responsible for the deterioration of patients’ overall health and quality of life. There is an urgent need to support oncologists and nephrologists in choosing the right ICI drugs for the right patients. We aim to comprehensively scrutinize the tradeoff between the survival benefits and the severe AKI risk for ICI patients by leveraging the national electronic medical records (EMR) from the National Clinical Cohort Collaborative (N3C) registry. Our work provides real-world evidence for clinical decisions on ICI use. Methods: Cancer patients treated with ICI are followed up for at least 6 months using N3C data (01/01/2018 - 01/19/2024). Primary outcomes included severe AKI within 6 months of initiation or mortality up to the last follow-up. We fit multivariable Cox proportional hazards models to evaluate the effect of various ICI types, adjusting for age, gender, race, cancer types, smoking status, and comorbidities. Results: Our study cohort included 55,767 patients who received an ICI, with 25,197 deaths and 6,458 severe AKI events. The most common ICI used were PD-1 inhibitors (74.3%), PD-L1 inhibitors (16.6%), CTLA-4 inhibitors (0.3%), and combination treatments of PD-1 and CTLA-4 inhibitors (8.8%). Observed long-term severe AKI incidences exceeded prior reports, with 96%, 92%, 88%, and 71% at 1, 3, 6, and 36 months. Survival benefits of PD-1, CTLA-4 and their combinations versus PD-L1 inhibitors were comparable (HR: 0.94 [95%CI: 0.91–0.97]; HR: 0.81 [95%CI: 0.63–1.02]; HR: 1.09 [95%CI: 1.04–1.15]). Severe AKI risks were higher with CTLA-4 and combination therapy (HR: 1.48 [95%CI: 0.96–2.28]; HR: 1.96 [95%CI: 1.78–2.16]) compared to PD-L1 inhibitors, with PD-1 inhibitors also showing increased risk (HR: 1.15 [95%CI: 1.07–1.23]). We also scrutinize risk factors associated with significant AKI risk, including a history of AKI, congestive heart failure, dementia, complicated diabetes, hypertension, liver disease, other immunocompromised diseases, and cancers of the gynecologic type, prostate cancer, and gastrointestinal cancers, and being of Black race. Conclusions: Our work provides up-to-date and comprehensive real-world evidence of the survival benefits and severe renal injury risks for clinical decisions of ICI therapy. PD-L1 inhibitors are associated with a lower risk of severe AKI compared to PD-1, CTLA-4 inhibitors, and their combination. Future research should focus on identifying patient subgroups that may benefit from specific ICI therapies while minimizing adverse outcomes.

Stage IV renal cell carcinoma achieves pathologic complete response after two ipilimumab plus nivolumab courses despite severe immune-related adverse events: a case report

BackgroundIpilimumab (Ipi) plus nivolumab (Nivo) is the recommended first-line treatment for renal cell carcinoma (RCC). This report describes a case where pancreatic metastases disappeared after only two courses of Ipi + Nivo therapy. The primary tumor was cured by surgery, and a pathological Complete Response (pCR) was observed despite multiple serious immune-related Adverse Events (irAEs).Case presentationA 54-year-old woman with RCC and pancreatic metastasis at stage IV, diagnosed with intermediate risk according to the International Metastatic RCC Database Consortium classification, underwent initiation of Ipi + Nivo therapy. On day 26, she developed hyperthyroidism accompanied by tachycardia, leading to the commencement of metoprolol tartrate treatment. Following the resolution of tachycardia, a second course of Ipi + Nivo therapy was administered on day 50. By day 70, the patient exhibited Grade 3 hepatic dysfunction, followed by the onset of hypothyroidism on day 75, necessitating treatment with steroids and levothyroxine. After positive treatment, a Grade 3 skin disorder emerged on day 87 while tapering steroids, prompting treatment with methylprednisolone (mPSL) pulse therapy. The skin disorder responded to steroids, allowing for tapering. However, on day 113, a recurrence of Grade 3 skin disorder occurred, necessitating another mPSL pulse. The patient responded well to treatment, exhibiting improvement in her condition. On day 131, she presented at the hospital with complaints of respiratory distress, prompting a Computed Tomography (CT) scan that revealed interstitial pneumonia. By day 272, subsequent CT imaging showed the disappearance of pancreatic metastasis and shrinkage of the primary tumor. On day 294, she underwent a laparoscopic left nephrectomy. Pathological analysis confirmed a pCR in the primary tumor, indicating successful eradication of RCC through surgical intervention.ConclusionsThis case report presents a scenario where multiple severe irAEs appeared in a patient, yet metastases disappeared after only two courses of Ipi + Nivo therapy. The patient was ultimately cured by surgery and achieved a pCR. This case highlights that despite the occurrence of severe irAEs during RCC treatment with Ipi + Nivo therapy, they can be managed appropriately to maximize the therapeutic effects of checkpoint inhibitors.

Safe Stop IPI-NIVO trial: early discontinuation of nivolumab upon achieving a complete or partial response in patients with irresectable stage III or metastatic melanoma treated with first-line ipilimumab-nivolumab – study protocol

BackgroundPatients with irresectable stage III or metastatic melanoma presenting with poor prognostic factors are usually treated with a combination of immune checkpoint inhibitors (ICIs), consisting of ipilimumab and nivolumab. This combination therapy is associated with severe immune related adverse events (irAEs) in about 60% of patients. In current clinical practice, patients are usually treated with ICIs for up to two years or until disease progression or the occurrence of unacceptable AEs. The incidence of irAEs gradually increases with duration of treatment. While durable tumour responses have been observed after early discontinuation of treatment, no consensus has been reached on optimal treatment duration. The objective of the Safe Stop IPI-NIVO trial is to evaluate whether early discontinuation of ICIs is safe in patients with irresectable stage III or metastatic melanoma who are treated with combination therapy.MethodsThe Safe Stop IPI-NIVO trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 80 patients with irresectable stage III or metastatic melanoma who are treated with combination therapy of ipilimumab-nivolumab and have a complete or partial response (CR/PR) according to RECIST v1.1 will be included to early discontinue maintenance therapy with anti-PD-1. The primary endpoint is the rate of ongoing response at 12 months after start of ICI. Secondary endpoints include ongoing response at 24 months, disease control at different time points, melanoma specific and overall survival, the incidence of irAEs and health-related quality of life.DiscussionFrom a medical, healthcare and economic perspective, overtreatment should be prevented and shorter treatment duration of ICIs is preferred. If early discontinuation of ICIs is safe for patients who are treated with the combination of ipilimumab-nivolumab, the treatment duration of nivolumab could be shortened in patients with a favourable tumour response.Trial registrationClinicalTrials.gov ID NCT05652673, registration date: 08–12-2022.

Immune checkpoint inhibitor therapy in patients with cancer and pre-existing systemic sclerosis

ObjectiveImmune checkpoint inhibitor (ICI) therapies have dramatically improved outcomes in multiple cancers. ICI's mechanism of action involves immune system activation to augment anti-tumor immunity. Patients with pre-existing autoimmune diseases, such as systemic sclerosis (SSc), were excluded from initial ICI clinical trials due to concern that such immune system activation could precipitate an autoimmune disease flare or new, severe immune related adverse events (irAE). In the present study, we report our experience with ICIs in patients with pre-existing SSc. MethodsPatients with SSc who received ICI therapy for cancer were identified from the Johns Hopkins Scleroderma Center Research Registry. Through chart review and prespecified definitions, we identified whether patients experienced worsening SSc activity or new irAEs. SSc disease activity worsening was pre-defined as an increase in modified Rodnan skin score (mRSS), new scleroderma renal crisis, progression of interstitial lung disease (ILD) on CT scan, increased Raynaud's phenomenon frequency or severity, new pulmonary hypertension, or myositis flare. IrAEs also included active inflammatory arthritis and dermatitis. ResultsEight patients with SSc who received ICI therapy for cancer were included. Overall, SSc symptoms remained stable during and after ICI therapy. None of the patients with long-standing sine or limited cutaneous SSc (lcSSc) had progressive skin thickening after ICI therapy. One patient, who was early in his diffuse cutaneous SSc (dcSSc) disease course, experienced worsening skin thickening and renal crisis. Three patients (38 %) experienced a total of five irAEs (grade 2: diarrhea, mucositis and dermatitis; grade 3: pneumonitis, and grade 4: nephritis). The patient with grade 4 nephritis developed scleroderma renal crisis and immune checkpoint related nephritis simultaneously. There were no deaths due to irAEs. ConclusionIn this study, ICI therapy was well tolerated in patients with longstanding, sine or lcSSc. IrAE were common but generally manageable. Patients with early, active SSc may be at greater risk from ICI therapy, but more research is needed.

Noncovalently particle-anchored cytokines with prolonged tumor retention safely elicit potent antitumor immunity.

Preclinical studies have shown that immunostimulatory cytokines elicit antitumor immune responses but their clinical use is limited by severe immune-related adverse events upon systemic administration. Here, we report a facile and versatile strategy for noncovalently anchoring potent Fc-fused cytokine molecules to the surface of size-discrete particles decorated with Fc-binding peptide for local administration. Following intratumoral injection, particle-anchored Fc cytokines exhibit size-dependent intratumoral retention. The 1-micrometer particle prolongs intratumoral retention of Fc cytokine for over a week and has minimal systemic exposure, thereby eliciting antitumor immunity while eliminating systemic toxicity caused by circulating cytokines. In addition, the combination of these particle-anchored cytokines with immune checkpoint blockade antibodies safely promotes tumor regression in various syngeneic tumor models and genetically engineered murine tumor models and elicits systemic antitumor immunity against tumor rechallenge. Our formulation strategy renders a safe and tumor-agnostic approach that uncouples cytokines' immunostimulatory properties from their systemic toxicities for potential clinical application.

Abstract 6681: Altered microbial community stability and increases in circulating B cells are associated with the development of severe immune related adverse events during ICI-immunotherapy

Abstract Background: Immune related adverse events (irAEs) are a major hurdle to the success of immune checkpoint inhibitor (ICI) immunotherapy. There is increasing evidence that the gut microbiota influences irAE development, however the microbe-immune crosstalk underpinning this remains cryptic. Methods: Paired pre- & post-treatment (baseline/week 6) stool samples from 129 Australian and Dutch melanoma patients treated on trial with neo-adjuvant combination anti-PD1/anti-CTLA4 immunotherapy were analyzed with 16S rRNA gene sequencing. Matched PBMCs at both timepoints were analyzed using mass cytometry (n=71). Results: ICI immunotherapy resulted in changes in the relative abundance of specific bacterial groups in the faecal microbiota, however the microbial community as a whole remained relatively stable. In particular enhanced oralization of the gut microbiome was observed with treatment, including a significant increase in the relative abundance of oral Streptococcus species in the gut (P=0.0004). These changes were particularly evident in patients whose microbial communities were Bacteroidaceae (Ba)-dominated at baseline, and those who developed severe (grade 3+) irAEs. Indeed, Ba-dominated microbiomes were linked with comparatively higher rates of severe irAEs compared to patients with Ruminococcaceae (Ru)-dominated gut microbiomes (P= 0.0440). Furthermore, Ba patients developed severe irAEs earlier during treatment, prior to week 6 (P=0.0016). A significant reduction in transitional B cells (CD24+ CD38hi CD27-) (P<0.0001) and an increase in activated B cells subsets (CD27- CD38- CD24- populations) (P=0.0022) were observed between baseline and week 6 across all patients who developed or went on to develop severe irAEs. Most notably, Ba patients who developed early, severe irAEs specifically had significantly higher frequencies of overall circulating B cells (P=0.0018) and lower frequencies of ICOS+ Tregs at week 6 post treatment (P=0.0005), which was not observed in Ru-dominated irAE patients. Conclusions: Higher risk of early, severe irAEs were associated with Bacteroidaceae-dominated gut microbiomes, reduced microbial community stability, and increases in activated circulating B cells during treatment. We postulate that differing baseline microbial community assemblages are associated with altered pre-established intestinal homeostasis influencing the likelihood of irAE development. Together, the data highlights a potential relationship between B cells, the gut microbiota and irAE development which may point to early steps in the induction of irAEs during ICI immunotherapy. Citation Format: Rebecca C. Simpson, Erin R. Shanahan, Ines P. Silva, Irene L. Reijers, Judith M. Versluis, Alexander M. Menzies, Gonzalez Maria, Umaimainthan Palendira, James S. Wilmott, Christian Blank, Richard A. Scolyer, Georgina V. Long. Altered microbial community stability and increases in circulating B cells are associated with the development of severe immune related adverse events during ICI-immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6681.

Abstract 2712: Development of GB268, a tri-specific antibody targeting PD-1/CTLA-4/VEGF, with enhanced anti-tumor efficacy and reduced toxicity in pre-clinical studies

Abstract Background: Immunotherapy using immune checkpoint modulators such as anti-PD1/PD-L1 have been widely used in cancer therapy. Combination of checkpoint inhibition using anti-PD1 and anti-CTLA4 has improved therapeutic efficacy but is also accompanied by severe immune related adverse events (irAEs) which limited their clinical use. Bi-specific antibody targeting PD-1/CTLA-4 such as cadonilimab has shown improved clinical benefits with reduced irAEs in cervical cancer. Vascular endothelial growth factor (VEGF) is overexpressed in various solid tumors and anti-VEGF agents inhibit neovascularization and shrink tumor with time. Combined application of bevacizumab and PD-1/PD-L1 blockade displays durable and improved anti-tumor effects. We have recently developed a novel tri-specific antibody GB268, specifically targeting PD-1, CTLA-4 and VEGF with fine-tuned activity & potency for each arm to simultaneously block PD-1/CTLA-4 mediated immune-suppression and VEGF mediated tumor angiogenesis. Methods: GB268 is a hexavalent antibody with symmetrical structure, composed of anti-PD-1 VHH antibody, anti-CTLA-4 VHH antibody, and anti-VEGF conventional antibody. The Fc part is silenced by introducing L234A/L235A mutations. Comprehensive in vitro and in vivo characterization of GB268 have been carried out. Along with in vivo efficacy studies, toxicity has also been evaluated with a murine arthritis model in hPD1/hCTLA4 double-KI mice to assess immune related AEs. Results: GB268 specifically bound to PD-1, VEGF, and CTLA-4 with high affinity and completely blocked PD-1 and VEGF pathways in reporter systems. To reduce the CTLA4 inhibition-induced AEs, the CTLA-4 arm was intentionally designed to only partially block the interaction of CTLA4 to its ligands CD80/CD86, and furthermore, the blockade of CTLA-4 was highly dependent on PD-1 expression. GB268 displayed robust anti-tumor efficacy with attenuated toxicity in murine models. In multiple PBMC-humanized models including A375 melanoma model, HT29 colorectal cancer model, and NCI-H460 NSCLC model, etc., GB268 exhibited significantly better anti-tumor efficacy, compared to PD-1/CTLA-4 bsAb and PD-1/VEGF bsAb, or in the combination of monoclonal antibodies to PD-1, CTLA-4 or VEGF. In arthritis induction model using hPD1/hCTLA4 double KI mice, GB268 had improved tolerance than cadonilimab and at least 20-fold better safety profile than ipilimumab combined with nivolumab. Conclusions: GB268 is a first-in-class anti-PD-1/CTLA-4/VEGF tri-specific antibody with innovative design. Preclinical data demonstrated GB268 is very effective in provoking anti-tumor responses. At the meantime, immune-related AEs is alleviated. Thus, GB268 may emerge as a promising novel therapeutics for cancer treatment. Citation Format: Qinglin Du, Yaxua Lv, Juehua Xu, Fei Peng, Huanhuan Cao, Xueyan Yang, Zhen Qian, Xueqin Li, Yiqi Cao, Qian Ding, Yongcong Tan, Shuhua Han. Development of GB268, a tri-specific antibody targeting PD-1/CTLA-4/VEGF, with enhanced anti-tumor efficacy and reduced toxicity in pre-clinical studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2712.

Abstract 3993: A tunable safety switch for solid tumor CAR T-cell therapy

Abstract On-target off-tumor toxicity, cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS) are severe immune-related adverse events (irAEs) that are frequently associated with Chimeric Antigen Receptor (CAR) T-cell therapy. Current efforts to manage such therapy-related toxicities involve incorporation of an inducible suicide agent within CAR constructs, such as iCaspase-9 or herpes simplex virus type 1 thymidine kinase that can be selectively activated to produce toxic effects within CAR T cells and attenuate their activity. However, while activation of these agents helps to mitigate or overcome such unwarranted toxicities, the therapeutic benefit of CAR T cells anti-tumor activity is also compromised. Therefore, to continue maintenance of CAR T cells’ therapeutic function while minimizing irAEs, an ideal safety switch should 1) rapidly inhibit the activation and proliferation of CAR T cells exposed to the target antigen, 2) reversibly inhibit activity without inducing CAR T cell elimination and 3) be clinically translatable for safe application in patients. Our laboratory investigated one such safety switch to inhibit CAR T-cell activity while maintaining their therapeutic function. We showed that incorporating a mutant variant of c-KIT D816V (KITv) in the intracellular domain of mesothelin-targeting second-generation CAR T cells (M28z-KITv) improved efficacy in solid tumors with low antigen, or an immunosuppressive environment. Herein, we evaluate the use of Dasatinib, a clinically available multitarget (BCR, SRC, c-KIT) tyrosine kinase inhibitor (TKI), as a tunable safety switch to reversibly inhibit M28z-KITv CAR T-cell functional activity. In cohorts of mice established with lung adenocarcinoma, daily administration of Dasatinib starting on day 1 or day 3 after CAR T-cell administration stabilized tumor growth, which otherwise continued to regress in untreated mice, indicating inhibition of CAR T-cell functional activity. Upon discontinuation of Dasatinib, tumors regressed, indicating reversal of CAR T-cell functional activity. In an experiment conducted to investigate functional persistence of CAR T cells upon long-term exposure to Dasatinib (1 month), we noted uninhibited activity of CAR T cells to rechallenged tumors. Dasatinib, thus may act as a tunable safety switch to regulate M28z-KITv CAR T-cell activity without compromising its therapeutic function. Citation Format: Kyohei Misawa, Meriem Taleb, Srijita Banerjee, William-Ray Vista, Navin K. Chintala, Prasad S. Adusumilli. A tunable safety switch for solid tumor CAR T-cell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3993.

Abstract 7527: Investigating biomarkers for immune-related adverse events following immune checkpoint inhibitor therapy in recurrent lung cancer patients

Abstract Background: The application of immune checkpoint inhibitors (ICIs) as adjuvant therapy post-lung cancer surgery is expected to confer significant benefits. However, the risk factors for severe immune-related adverse events (irAEs) remain incompletely understood, and managing irAEs may require long-term steroid use. The identification of biomarkers for irAEs in patients with surgically resected lung cancer is an urgent need. Methods: We analyzed 43 lung cancer patients who received ICI treatment for recurrence postoperatively. Macrodissection of lung cancer lesions was performed on FFPE specimens from resected lungs, from which total RNA was extracted. We conducted gene expression analysis of 770 immune-related genes using the PanCancer Immune Profiling Panel (NanoString Technologies, Inc., Seattle, WA, USA). The relationship between gene expression changes and irAEs or the efficacy of ICI treatment was examined. For validation, immunostaining of proteins strongly associated with irAEs was performed to determine their expression status in tissue specimens. Results: Among the 43 patients (30 males, 13 females, median age 68), 28 had adenocarcinoma, and 15 had squamous cell carcinoma. PD-L1 positivity was observed in 36 patients. The treatment regimens included pembrolizumab monotherapy for 18 patients and combination immunotherapy for 25 patients, with 25 patients responding to treatment and 7 developing irAEs. There was a marked difference in gene expression between adenocarcinoma and squamous cell carcinoma, with a notably higher number of tumor-infiltrating lymphocytes (TILs) in adenocarcinoma. An increase in TILs was observed in cases with irAEs across both cancer types. Additionally, an increased CD8/Treg ratio and CD8/exhausted T cell ratio were noted in adenocarcinomas with irAEs. A strong correlation between IRF5 gene expression and the occurrence of irAEs in adenocarcinoma was also confirmed by immunohistochemistry. Conclusion: We have identified tumor immune microenvironments correlated with the onset of irAEs following ICI treatment in patients with postoperative recurrence of lung cancer. This discovery could contribute to perioperative treatment strategies and improve our understanding of tumor immune mechanisms. Citation Format: Yujin Kudo, Jun Matsubayashi, Satoshi Takahashi, Masaru Hagiwara, Masatoshi Kakihana, Toshitaka Nagao, Tatsuo Ohira, Norihiko Ikeda. Investigating biomarkers for immune-related adverse events following immune checkpoint inhibitor therapy in recurrent lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7527.

Abstract 3208: A nano sized system for the treatment of gastrointestinal cancers

Abstract Despite the recent progress in cancer immunotherapies, most patients do not benefit from the currently available immune checkpoint blockers, and many develop severe immune-related adverse events. Therefore, it is urgent to develop alternative, effective immunotherapeutic approaches. An example of non-responsive cancers are gastrointestinal (GI) cancers, which account for 26% of the global cancer incidence and 35% of all cancer-related deaths. In many GI cancers, the failure of immunotherapies to yield clinical response is partially attributed to the inefficient antigen presentation by DC, which results in insufficient T cell stimulation despite their expression of tumor-associated antigens (TAA). To overcome these hurdles, we designed novel polymeric-based nanoparticles (NP) to deliver a combination of GI cancers antigens of CEACAM5 protein and toll-like receptor ligands to DC. We chose to encapsulate CEACAM5 antigens because it is overexpressed in GI cancers, such as gastric cancer, colorectal cancer, and pancreatic cancer. With this approach, we aim to modulate the tumor milieu-immune cell interactions to an anti-cancer phenotype in order to control tumor growth and improve overall survival. Our NP present an average diameter below 200 nm, narrow polydispersity index, slightly negative surface charge, spherical morphology, and high antigens and immune potentiators loading. Cy5-labeled NPs were found to be extensively internalized by DC, which triggered their activation in vivo, shown by the increasing expression of DC-related co-stimulatory molecules such as CD80, CD86, and CD40. Furthermore, we assessed the immunotherapeutic effect of our NP on mouse models and on a human 3D multi-cellular spheroid ex-vivo model, composing the patient’s tumor cells and peripheral blood mononuclear cells (PBMC). We found that the NP successfully induced a potent immune-mediated anti-tumor response against CEACAM5-positive GI tumors, sensitizing the tumor microenvironment to other therapies and decreasing tumor volume, ultimately leading to prolonged survival. Taken together, the developed NP induced a strong antigen-specific immune response and overall sensitized CEACAM5-expressing GI cancers to the clinically relevant treatments in vivo, that so far have shown limited clinical outcomes in addition to a specific T cell anti-tumor activity that was shown on our patient-derived ex vivo model. Citation Format: Daniella Vaskovich, Rita Acúrcio, Ron Kleiner, Barbara Carreira, Ana Matos, Helena Florindo, Ronit Satchi-Fainaro. A nano sized system for the treatment of gastrointestinal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3208.