Immune-related adverse events of antibody-based biological medicines in cancer therapy.

Recombinant antibodies (Abs) are an integral modality for the treatment of multiple tumour malignancies. Since the Food and Drug Administration (FDA) approval of rituximab as the first monoclonal antibody (mAb) for cancer treatment, several mAbs and antibody (Ab)-based therapies have been approved for the treatment of solid tumour malignancies and other cancers. These Abs function by either blocking oncogenic pathways or angiogenesis, modulating immune response, or by delivering a conjugated drug. The use of Ab-based therapy in cancer patients who could benefit from the treatment, however, is still limited by associated toxicity profiles which may stem from biological features and processes related to target binding, alongside biochemical and/or biophysical characteristics of the therapeutic Ab. A significant immune-related adverse event (irAE) associated with Ab-based therapies is cytokine release syndrome (CRS), characterized by the development of fever, rash and even marked, life-threatening hypotension, and acute inflammation with secondary to systemic uncontrolled increase in a range of pro-inflammatory cytokines. Here, we review irAEs associated with specific classes of approved, Ab-based novel cancer immunotherapeutics, namely immune checkpoint (IC)-targeting Abs, bispecific Abs (BsAbs) and Ab-drug-conjugates (ADCs), highlighting the significance of harmonization in preclinical assay development for safety assessment of Ab-based biotherapeutics as an approach to support and refine clinical translation.

Multidisciplinary management of immunotherapy-related adverse events in solid tumors: An inter-institutional and telemedicine-based working team.

BACKGROUND: Although immune checkpoint inhibitors (ICIs) show a more favorable toxicity profile than classical cytotoxic drugs, their mechanism of action is responsible for peculiar new toxicities. There is an urgent need for a multidisciplinary approach to advice on how to manage organ-specific toxicities. METHODS: Our project aims to integrate the practices of two different hospitals into a single Italian regional collaborative model to treat immune-related adverse events (irAEs). The team structure is a multi-professional and multidisciplinary cooperative network that consists of different medical specialists. The team referrer is the medical oncologist and an existing telematic platform is used for specialists' cooperation. The leading oncologist first evaluates patients' clinical condition, therefore team intervention and teleconsultation are planned to activate proper management. After a first phase structured for general setting, outcomes analysis, data collection, and identification of critical issues, it is planned to define appropriate key performance indicators (KPIs) in quality, structure, process, and outcome settings. Therefore, a second phase would serve to implement KPIs. In the third phase, the proposal for the enlargement of the network with the extension to more centers in the context of the Regional Health Service will be performed. DISCUSSION: The multidisciplinary management of irAEs based on telemedicine fits into the debate on the renewal of healthcare systems and the push for change toward multidisciplinary with the rising use of telemedicine. To our knowledge, this is the first project reporting a multi-institutional experience for change of service in irAEs management.

Systemic capillary leak syndrome in a patient treated with nivolumab/ipilimumab immunotherapy for metastatic melanoma with concurrent COVID-19 vaccination.

Systemic capillary leak syndrome (SCLS) is a rare and life-threatening disorder characterised by leaking of intravascular fluid to extravascular tissues. An association with immunotherapy and COVID-19 vaccination has been reported as potential triggers. A case of a patient in her 70s developing SCLS after the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccination with a history of metastatic melanoma treated with nivolumab (PD-1 monoclonal antibody) and ipilimumab (anti-CTLA4 monoclonal antibody) is reported. The aetiology and management of SCLS are also reviewed in this case context.

Pituitary-adrenal axis dysfunction induced by tislelizumab immunotherapy for non-small cell lung cancer: a case series and literature review.

BACKGROUND: Adverse events of secondary adrenal insufficiency caused by anti-PD-1 immune agents are relatively rare in clinical practice, so in this article, we retrospectively analyzed three patients who suffered secondary adrenal cortex dysfunction caused by tislelizumab immunotherapy for Non-Small Cell Lung Cancer (NSCLC)and reviewed the literature. This rare immune-related adverse event was investigated by summarizing the clinical features of the patients. CASE PRESENTATION: We reported three NSCLC patients who suffered secondary adrenal cortex dysfunction induced by tislelizumab immunotherapy at our hospital from July 2021 to October 2023. We analyzed and summarized the clinical characteristic, laboratory examination, pathological staging, etc. We also reviewed related literature of pituitary inflammation and adrenal cortex dysfunction caused by immunotherapy. RESULTS: The median age of the three patients was 56 years. All the patients had a history of smoking. After receiving tislelizumab treatment (median cycle: 7), laboratory examination showed a decrease in morning cortisol and adrenocorticotropic hormone (ACTH), both were diagnosed with secondary adrenal insufficiency. Only one patient had symptoms of fatigue, vomiting, and weight loss. One of these patients also had simultaneous subclinical hypothyroidism. All three patients discontinued immunotherapy and received replacement therapy with glucocorticoids. At the last follow-up, none of the three patients restarted immunotherapy, because cortisol did not return to normal. This is similar to that of previous reports. CONCLUSION: Based on previous reports and our three cases, when laboratory tests of NSCLC patients receiving immunotherapy showed a decrease in morning cortisol and ACTH levels, especially when clinical symptoms were obvious, the possibility of immunotherapy-related pituitary inflammation causing secondary adrenal cortex dysfunction should be considered. Prompt monitoring and hormone replacement therapy should be provided to prevent adrenal crises.

Case report: Potential role of immunotherapy in thymic malignancies: a unique case of a durable and complete response upon an immune checkpoint inhibitor.

Thymic epithelial tumors are rare malignancies with an incidence of 1.7 cases per million people per year. They pose significant management challenges due to their association with autoimmune disorders. In this case report, we present the 21-year history of a patient diagnosed with advanced B2/B3 thymoma and Good's syndrome. The patient achieved a complete and durable response after receiving only two cycles of the immune checkpoint inhibitor Nivolumab. However, this positive outcome was accompanied by the development of severe immune-related myocarditis complicated by reactivation of cytomegalovirus. Moreover, the patient developed a highly uncommon subdiaphragmatic pararectal dissemination of the thymic tumor, which is a condition rarely described in the literature. Despite the success in achieving complete and durable response with immune checkpoint inhibitors, the emergence of immune-related adverse events highlights the potential challenges associated with these treatments, emphasizing the need for careful monitoring and a comprehensive understanding of the intricate interplay between cancer, immune system dysregulations and immunotherapy.

Risk and safety profile in checkpoint inhibitors on non-small-cel lung cancer: A systematic review.

Treating non-small-cell lung cancer (NSCLC) has gained increased importance in recent years due to the high mortality rate and dismal five-year survival rate. Immune checkpoint inhibitors (ICI) are a promising approach with exceptional outcomes in NSCLC thanks to the antigenic nature of cells. Conversely, immune system over-stimulation with ICI is a double-edged sword that can lead to various negative effects ranging from mild to life-threatening. This review explores current breakthroughs in nanoparticle-based ICI and their limitations. The PubMed, Scopus and Web of Science were examined for relevant publications. Thirty-eight trials (N = 16,781) were included in the analyses. The mixed effects analyses on quantifying the treatment effect contributed significantly to the subgroups within studies for ICI treatment effect. Models confirmed ICI's higher impact on treatment effectivity and the decrease in respondents' mortality compared to conventional treatment regiments. ICI might be used as first-line therapy due to their proven effectiveness and safety profile.

Outcome of an Accelerated Treatment Algorithm for Patients Developing Diarrhea as a Complication of Ipilimumab-Based Cancer Immunotherapy in a Community Practice.

Immune-mediated diarrhea represents a serious complication of checkpoint inhibitor therapy, especially following ipilimumab-based treatment. Efficient diagnosis and control of diarrhea remains an ongoing challenge. We developed an accelerated management paradigm for patients with ipilimumab-induced diarrhea. Patients who developed significant diarrhea (>five loose stools/day) were presumed to be developing immune colitis. Therapy was interrupted and patients were treated with a methylprednisolone dose pack. If diarrhea was not completely resolved, high-dose steroids and infliximab were promptly added. Only non-responding patients underwent further evaluation for infection or other causes of diarrhea. A total of 242 patients were treated with ipilimumab-based regimens. Forty-six developed significant diarrhea (19%) and thirty-four (74.4%) had a rapid resolution of diarrhea following glucocorticosteroid and infliximab treatment. The median time to resolution of diarrhea was only 8.5 ± 16.4 days. Accelerated treatment for presumed immune-mediated diarrhea resulted in the rapid control of symptoms in the majority of patients. There were no intestinal complications or deaths. Immunosuppressive therapy for diarrhea did not appear to decrease the remission rate or survival. After the control of diarrhea, most patients were able to continue their planned immunotherapy. Further testing in 11/46 patients with unresponsive diarrhea revealed additional diagnoses, allowing their treatment to be adjusted.

The efficacy and safety of neoadjuvant chemoradiotherapy combined with immunotherapy for locally advanced rectal cancer patients: a systematic review.

Background: Several studies have explored the effectiveness of PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy (nCRT) in the treatment of locally advanced rectal cancer(LARC), particularly in microsatellite stable(MSS) or mismatch repair proficient(pMMR) LARC patients. We undertook a single-arm systematic review to comprehensively evaluate the advantages and potential risks associated with the use of PD-1/PD-L1 inhibitors in conjunction with nCRT for patients diagnosed with locally advanced rectal cancer. Methods: The PubMed, Embase, Cochrane Library, ClinicalTrials.gov, ASCO and ESMO were searched for related studies. The main outcomes were pathologic complete response (pCR), major pathological response (MPR), anal preservation, and adverse effects (AEs). Results: Fourteen articles including 533 locally advanced rectal cancer (LARC) patients were analyzed. The pooled pCR, MPR, and anal preservation rates were 36%, 66% and 86%. Grade ≥3 adverse events occurred in 20%. Subgroup analysis showed that; dMMR/MSI-H had a pooled pCR (100%) and MPR (100%), pMMR/MSS had a pooled pCR (38%) and MPR (60%); the short-course radiotherapy and long-course radiotherapy had pooled pCR rates of 51% and 30%, respectively. The rates of pCR for the concurrent and sequential immuno-chemoradiotherapy subgroups at 30% and 40%, mirroring pCR rates for the PD-L1 and PD-1 inhibitor subgroups were 32% and 40%, respectively. Conclusion: In cases of locally advanced rectal cancer, PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy have shown promising response rates and acceptable toxicity profiles. PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy hence has a positive outcome even in MSS LARC patients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#myprospero, identifier CRD42023465380.

Monitoring immunE DysregulAtion foLLowing Immune checkpOint-inhibitioN (MEDALLION): protocol for an observational cancer immunotherapy cohort study.

BACKGROUND: Checkpoint inhibitors (CPIs) are widely used in cancer treatment, with transformative impacts on survival. They nonetheless carry a significant risk of toxicity in the form of immune-related adverse events (IrAEs), which may be sustained and life-altering. IrAEs may require high-dose and/or prolonged steroid use and represent a significant healthcare burden. They mimic immune-mediated inflammatory diseases (IMIDs) but understanding of their pathogenesis is limited. The MEDALLION project aims to determine targetable mechanisms of immune dysregulation in IrAE development, employing an immune monitoring approach to determine changes in circulating and tissue resident cells of CPI recipients who do/do not develop them and assessing the contribution of the microbiome in parallel. METHODS: MEDALLION is a non-randomised longitudinal cohort study aiming to recruit 66 cancer patient recipients of anti-PD1/PD-L1, anti-CTLA-4 or combination therapy. Eligible participants include those with malignant melanoma in the adjuvant or metastatic setting, mesothelioma and non-small cell lung carcinoma (NSCLC) treated in the metastatic setting. Comprehensive clinical evaluation is carried out alongside blood, skin swab and stool sampling at the time of CPI initiation (baseline) and during subsequent routine hospital visits on 6 occasions over a 10-month follow-up period. It is conservatively anticipated that one third of enrolled patients will experience a "significant IrAE" (SirAE), defined according to pre-determined criteria specific to the affected tissue/organ system. Those developing such toxicity may optionally undergo a biopsy of affected tissue where appropriate, otherwise being managed according to standard of care. Peripheral blood mononuclear cells will be analysed using multi-parameter flow cytometry to investigate immune subsets, their activation status and cytokine profiles. Stool samples and skin swabs will undergo DNA extraction for 16 S ribosomal RNA (rRNA) sequencing and internal transcribed spacer (ITS) gene sequencing to determine bacterial and fungal microbiome diversity, respectively, including species associated with toxicity. Stored tissue biopsies will be available for in situ and single-cell transcriptomic evaluation. Analysis will focus on the identification of biological predictors and precursors of SirAEs. DISCUSSION: The pathogenesis of IrAEs will be assessed through the MEDALLION cohort, with the potential to develop tools for their prediction and/or strategies for targeted prevention or treatment. TRIAL REGISTRATION: The study was registered on 18/09/2023 in the ISRCTN registry (43,419,676).

Application of immune checkpoint inhibitors and microsatellite instability in gastric cancer.

In this editorial we comment on the article by Li published in the recent issue of the World Journal of Gastroenterology. We focus specifically on the application of immune checkpoint inhibitors (ICIs) and microsatellite instability (MSI) in gastric cancer (GC). The four pillars of GC management have long been considered, including surgery, chemotherapy, radiotherapy and targeted therapy. However, immunotherapy has recently emerged as a "fifth pillar", and its use is rapidly expanding. There are four principal strategies for tumor immunotherapy: ICIs, tumor vaccines, adoptive immunotherapy and nonspecific immunomodulators. Of them, ICIs are the most advanced and widespread type of cancer immunotherapy for GC. Recent breakthrough results for ICIs have paved the way to a new era of cancer immunotherapy. In particular, inhibition of the PD-1/PD-L1 axis with ICIs, including nivolumab and pembrolizumab, has emerged as a novel treatment strategy for advanced GC. Unfortunately, these therapies are sometimes associated with often subtle, potentially fatal immune-related adverse events (irAEs), including dermatitis, diarrhea, colitis, endocrinopathy, hepatotoxicity, neuropathy and pneumonitis. We must be aware of these irAEs and improve the detection of these processes to prevent inappropriate discharges, emergency department revisits, and downstream complications. Recent studies have revealed that MSI-high or mismatch- repair-deficient tumors, regardless of their primary site, have a promising response to ICIs. So, it is important to detect MSI before applying ICIs for treatment of GC.

Efficacy and safety of tocilizumab in patients with refractory generalized myasthenia gravis.

BACKGROUND: We aimed to compare the efficacy of tocilizumab with conventional immunotherapy in refractory patients with acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (gMG). METHODS: This single-center prospective cohort study was based on patients from an MG registry study in China and conducted from February 10, 2021 to March 31, 2022. Adult refractory patients with AChR-Ab+ gMG were assigned to tocilizumab or conventional immunotherapy groups. The primary efficacy outcome was the mean difference of MG activities of daily living (MG-ADL) change at weeks 4, 8, 12, 16, 20, 24 corresponding to that at the baseline between the two groups. A generalized estimating equation model was used for the primary outcome analysis. Safety was assessed based on adverse events. RESULTS: Of 34 eligible patients, 20 (mean [standard deviation] age, 53.8 [21.9] years; 12 [60.0%] female) received tocilizumab and 14 received conventional immunotherapy (45.8 [18.0] years; 8 [57.1%] female). The tocilizumab group had greater reduction in MG-ADL score at week 4 (adjusted mean difference, -3.4; 95% CI, -4.7 to -2.0; p < 0.001) than the conventional immunotherapy group, with significant differences sustained through week 24 (adjusted mean difference, -4.5; 95% CI, -6.4 to -2.6; p < 0.001). At week 24, the proportion of patients achieving higher levels of MG-ADL (up to 7-point reduction) and QMG (up to 11-point reduction) scores improvement was significantly greater with tocilizumab. Tocilizumab had acceptable safety profiles without severe or unexpected safety issues. CONCLUSION: Tocilizumab is safe and effective in improving the MG-ADL score and reducing prednisone dose in refractory AChR-Ab+ gMG, suggesting tocilizumab has the potential to be a valuable therapeutic option for such patients.

Anti-PD-1 cancer immunotherapy induces central nervous system immune-related adverse events by microglia activation.

Cancer treatment with anti-PD-1 immunotherapy can cause central nervous system immune-related adverse events (CNS-irAEs). The role of microglia in anti-PD-1 immunotherapy-induced CNS-irAEs is unclear. We found that anti-PD-1 treatment of mice caused morphological signs of activation and major histocompatibility complex (MHC) class II up-regulation on microglia. Functionally, anti-PD-1 treatment induced neurocognitive deficits in mice, independent of T cells, B cells, and natural killer cells. Instead, we found that microglia mediated these CNS-irAEs. Single-cell RNA sequencing revealed major transcriptional changes in microglia upon anti-PD-1 treatment. The anti-PD-1 effects were mediated by anti-PD-1 antibodies interacting directly with microglia and were not secondary to peripheral T cell activation. Using a proteomics approach, we identified spleen tyrosine kinase (Syk) as a potential target in activated microglia upon anti-PD-1 treatment. Syk inhibition reduced microglia activation and improved neurocognitive function without impairing anti-melanoma effects. Moreover, we analyzed CNS tissue from a patient cohort that had received anti-PD-1 treatment. Imaging mass cytometry revealed that anti-PD-1 treatment of patients was associated with increased surface marker expression indicative of microglia activation. In summary, we identified a disease-promoting role for microglia in CNS-irAEs driven by Syk and provide an inhibitor-based approach to interfere with this complication after anti-PD-1 immunotherapy.

Efficacy and safety of anti-PD-1/PD-L1-based dual immunotherapies versus PD-1/PD-L1 inhibitor alone in patients with advanced solid tumor: a systematic review and meta-analysis.

INTRODUCTION: Numerous randomized controlled trials (RCTs) have investigated PD-1/PD-L1 inhibitor-based combination therapies. The debate surrounding the potential additive clinical benefits of combination of two immune-oncology (IO) therapies for cancer patients persists. METHODS: Both published and grey sources of randomized clinical trials that compared anti-PD-1/PD-L1-based immunotherapy combinations with monotherapy in patients with advanced or metastatic solid tumors were encompassed. The primary outcome was progression-free survival (PFS), and secondary outcomes included objective response rate (ORR), overall survival (OS) and treatment-related adverse events (TRAEs). RESULTS: Our analysis encompassed 31 studies comprising 10,341 patients, which covered 12 distinct immune-oncology combination regimens. Across all patients, the immunotherapy combinations exhibited the capability to enhance the ORR (OR = 1.23 [95% CI 1.13-1.34]) and extend PFS (HR = 0.91 [95% CI 0.87-0.95]). However, the observed enhancement in OS (HR = 0.96 [95% CI 0.91-1.01]) was of no significance. Greater benefits in terms of PFS (HR = 0.82 [95% CI 0.72 to 0.93]) and OS (HR = 0.85 [95% CI 0.73 to 0.99]) may be particularly pronounced in cases where PD-L1 expression is negative. Notably, despite a heightened risk of any-grade TRAEs (OR = 1.72 [95% CI 1.40-2.11]) and grade greater than or equal to 3 TRAEs (OR = 2.01 [95% CI 1.67-2.43]), toxicity was generally manageable. CONCLUSIONS: This study suggests that incorporating an additional immunotherapy agent with PD-1/PD-L1 inhibitors can elevate the response rate and reduce the risk of disease progression, all while maintaining manageable toxicity. However, there remains a challenge in translating these primary clinical benefits into extended overall survival.

Clinical outcomes of immune checkpoint inhibitor combined with other targeted or immunological therapy regimens for the treatment of advanced bile tract cancer: a systematic review and meta-analysis.

Background and aims: A single immune checkpoint inhibitor (ICI) regimen has limited value in treating advanced bile tract cancer (BTC); therefore, ICI combination therapy is often applied. This meta-analysis aimed to evaluate the effectiveness and safety of ICI combination therapy for advanced BTC. Methods: The study protocol was registered on PROSPERO (CRD42023452422). Data on the median progression-free survival (PFS), median overall survival (OS), objective response rate (ORR), disease control rate (DCR), and grade ≥3 adverse events (AEs) reported in relevant studies were pooled and analyzed to determine the efficacy and safety of ICI combination therapy. Results: In total, 15 studies with 665 patients were included in this meta-analysis. The overall ORR and DCR were 34.6% and 77.6%, respectively. The overall median PFS and OS were 6.06 months [95% confidence interval (CI): 4.91-7.21] and 12.11 months (95% CI: 10.66-13.55), respectively. Patients receiving ICI combination therapy in addition to other therapies had a considerably prolonged median PFS and OS (z=9.69, p<0.001 and z=16.17, p<0.001). Patients treated as first-line treatment had a substantially longer median PFS and OS compared to patients treated as non-first-line treatment (z=11.19, p<0.001 and z=49.17, p<0.001). The overall pooled grade ≥3 AEs rate was 38.2% (95% CI: 0.268-0.497) and was not influenced by whether ICI therapy was combined with other treatments or not or the treatment line. Conclusion: Advanced BTC patients may benefit from ICI combination treatment without additional AEs. However, concurrent chemotherapy or radiotherapy is still needed to achieve better outcomes. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023452422.

[Drug-related exanthema under immunotherapy and targeted oncological therapy]. / Arzneimittelexantheme unter Immun- und zielgerichteter onkologischer Therapie.

BACKGROUND: Oncological therapies can cause a variety of mucocutaneous adverse events. Exanthematous adverse events can be challenging in the context of the urgent need for cancer treatment due to their spread, sometimes rapid progression, and mucous membrane or organ involvement. MATERIALS AND METHODS: This article provides an overview of the most important exanthematic dermatoses as side effects of modern drug-based tumor therapies with diagnostic and therapeutic information for clinicians, taking into account the current literature and guidelines. RESULTS: Exanthematous adverse events of immune checkpoint inhibitors, EGFR antagonists, kinase inhibitors, bispecific T­cell engagers, and the CCR4 inhibitor mogamulizumab are reviewed in detail. CONCLUSIONS: Cutaneous side effects are common across all drug classes and cover a broad spectrum. While some adverse events are specific to one drug class, many exanthemas can occur with both oncological immunotherapies and various targeted therapies. A reliable diagnosis, dose adjustment or discontinuation of the offending agent in consultation with the treating oncologists and appropriate symptomatic therapy are important for correct management. In the case of severe, life-threatening drug reactions, however, permanent discontinuation of the drug is essential.

Drug-induced Lung Disease in the Oncology Patient: From Cytotoxic Agents to Immunotherapy.

Drug-induced lung disease is commonly encountered, especially in the oncology setting. Diagnosis is challenging because clinical and radiologic findings are nonspecific, often overlapping with other lung pathologies in these patients due to underlying neoplasia, infection, or other treatment effects such as radiotherapy. Furthermore, oncology patients often receive multiple antineoplastic agents concurrently, and virtually every agent has an association with lung injury. In this article, we will review a variety of antineoplastic agents that are associated with drug-induced injury and discuss incidence, their typical timing of onset, and imaging features.

Toxicity in Older Patients with Cancer Receiving Immunotherapy: An Observational Study.

BACKGROUND: Checkpoint inhibition has emerged as an effective treatment strategy for a variety of cancers, including in older adults. However, older patients with cancer represent a heterogenous group as they can vary widely in frailty, cognition, and physical status. OBJECTIVE: This study aims to investigate the association between clinical frailty and immune-related treatment toxicity, hospitalization, and treatment discontinuation due to immune-related treatment toxicity in older patients treated with checkpoint inhibitors. METHODS: Patients aged 70 years and older treated with checkpoint inhibitors were selected from the TENT study, IMAGINE study, and "Tolerability and safety of immunotherapy study". Clinical frailty was assessed by the Geriatric-8 test score and World Health Organization (WHO) status. Outcomes were grades 3-5 toxicity, hospitalization, and treatment discontinuation due to toxicity during treatment. RESULTS: Of 99 patients included, 22% had comorbidities. While 33% of the patients were considered frail based on an abnormal Geriatric-8 test score of < 15, physical impairments were considered absent in 51% (WHO score of 0) and mild in 40% (WHO score of 1). Despite the limited sample size of the cohort, consistent trends were observed with patients with an abnormal Geriatric-8 test score of < 15 or a higher WHO score of 1 for having higher odds of toxicity [odds ratio (OR) 2.32 (95% CI 0.41-13.02); OR 1.33 (95% CI 0.45-4.17)], treatment discontinuation due to immune-related treatment toxicity [OR 2.25 (95% CI 0.61-8.31); OR 2.18 (95% CI 0.7-6.73)], and hospitalization due to immune-related treatment toxicity [OR 3.72 (95% CI 0.39-35.4); OR 1.31 (95% CI 0.35-4.9)]. Moreover, in a sub-analysis, we observed that the treatment discontinuation due to immune-related treatment toxicity occurred often in patients with grade 1-2 toxicity as well. CONCLUSIONS: Although not statistically significant, in older patients treated with immunotherapy in a real-life population with cancer, we observed consistent trends towards increased toxicity, hospitalization, and treatment discontinuation with increasing frailty. Larger studies are needed to confirm these exploratory results. Moreover, older patients with a lower toxicity grade 1-2 experienced early treatment discontinuation frequently, suggesting a lower tolerance of toxicity.