Antitumor response to microscopic melanoma in the gastric mucosa mimicking ipilimumab-induced gastritis

Immune checkpoint inhibitor-associated gastritis: Patterns and management

Immune checkpoint inhibitors (ICIs) are widely used due to their effectiveness in treating various tumors. Immune-related adverse events (irAEs) are defined as adverse effects resulting from ICI treatment. Gastrointestinal irAEs are a common type of irAEs characterized by intestinal side effects, such as diarrhea and colitis, which may lead to the cessation of ICIs. Although irAE gastritis is rarely reported, it may lead to serious complications such as gastrorrhagia. Furthermore, irAE gastritis is often difficult to identify early due to its diverse symptoms. Although steroid hormones and immunosuppressants are commonly used to reverse irAEs, the best regimen and dosage for irAE gastritis remains uncertain. In addition, the risk of recurrence of irAE gastritis after the reuse of ICIs should be considered. In this editorial, strategies such as early identification, pathological diagnosis, management interventions, and immunotherapy rechallenge are discussed to enable clinicians to better manage irAE gastritis and improve the prognosis of these patients.

Clinical characteristics, diagnosis, treatment, and prognosis of nivolumab induced gastritis

Gastritis has recently been reported to be associated with nivolumab, and the clinical characteristics of nivolumab induced gastritis remain unclear. To explore the clinical characteristics of nivolumab induced gastritis, and to provide reference for the classification and treatment guidelines of immune checkpoint inhibitors -related gastritis. Case reports, case series, and clinical studies of nivolumab induced gastritis were retrospectively analyzed by searching the database from the establishment of the database until September 30, 2023. Forty-seven were included, with a median age of 57 years (range 16, 93). The median time of symptom onset was 6 months (range 0.5,36) and 6.5 cycles (range 2, 62). Nausea (29 cases, 61.7%), vomiting (29 cases, 61.7%), and epigastric pain (28 cases, 59.6%) were the most common complaints. Esophagogastroduodenoscopy mainly showed erythema (28 cases, 59.6%). Gastric mucosa biopsy showed epithelial inflammatory cell infiltration (22 cases, 46.8%) and apoptosis (15 cases, 31.9%). Most patients' symptoms and gastric mucosa improved or recovered after receiving systemic steroid and proton pump inhibitor therapy regardless of whether nivolumab was discontinued. Two patients died from gastritis related events. Gastritis should be considered as the cause of unexplained epigastric symptoms in the administration of nivolumab. Understanding the clinical features of nivolumab induced gastritis is very important for accurate diagnosis and timely management of these patients.

Immune Responses in Checkpoint Myocarditis Across Heart, Blood, and Tumor

Immune checkpoint inhibitors (ICIs) are widely used anti-cancer therapies that can cause morbid and potentially fatal immune-related adverse events (irAEs). ICI-related myocarditis (irMyocarditis) is uncommon but has the highest mortality of any irAE. The pathogenesis of irMyocarditis and its relationship to anti-tumor immunity remain poorly understood. We sought to define immune responses in heart, tumor, and blood during irMyocarditis and identify biomarkers of clinical severity by leveraging single-cell (sc)RNA-seq coupled with T cell receptor (TCR) sequencing, microscopy, and proteomics analysis of 28 irMyocarditis patients and 23 controls. Our analysis of 284,360 cells from heart and blood specimens identified cytotoxic T cells, inflammatory macrophages, conventional dendritic cells (cDCs), and fibroblasts enriched in irMyocarditis heart tissue. Additionally, potentially targetable, pro-inflammatory transcriptional programs were upregulated across multiple cell types. TCR clones enriched in heart and paired tumor tissue were largely non-overlapping, suggesting distinct T cell responses within these tissues. We also identify the presence of cardiac-expanded TCRs in a circulating, cycling CD8 T cell population as a novel peripheral biomarker of fatality. Collectively, these findings highlight critical biology driving irMyocarditis and putative biomarkers for therapeutic intervention.

Gastrointestinal mucosal toxicities from immune checkpoint inhibitors: Current understanding and future directions

Immune checkpoint inhibitor (ICI) therapy has revolutionized the field of oncology over the past decade, leading to durable remissions in some patients but also producing a wide spectrum of treatment-limiting inflammatory toxicities that are referred to as immune-related adverse events (irAEs). Although irAEs can involve any organ system in the body, they most commonly affect the barrier tissues, including the gastrointestinal tract with colitis and enterocolitis affecting a significant fraction of patients on ICIs. We are beginning to understand the mechanisms that drive ICI colitis, with early experiments indicating a role for CD8+ resident memory T cells (TRMs) in the gut, which become activated and differentiate into cytotoxic cells in response to ICI therapy. The risk factors that define who will develop ICI colitis are not understood and substantial efforts are underway to identify potential biomarkers for risk of this and other toxicities. Optimal management of ICI colitis is also an area of active investigation. Current standard treatments are based largely on small, retrospective analyses, and while drugs like systemic glucocorticoids or the TNFα inhibitor infliximab do appear to be highly active in ICI colitis, the impact of these therapies on antitumor responses is poorly understood. As discussed in this review, future work will have to define the immune mechanisms driving ICI colitis in more detail and in comparison to antitumor responses in order to identify candidate pathways that can be targeted to improve ICI colitis without interfering in antitumor immunity. Studying these interventions will require randomized, controlled trials with both tumor and colitis endpoints, a goal that will necessitate collaboration across institutions and funding agencies. We are at a point where such collaborative trials are feasible, and have the potential to greatly improve the care of patients with ICI colitis as well as other irAEs.

Understanding and Overcoming the Inflammatory Toxicities of Immunotherapy

Checkpoint blockade immunotherapy has led to impressive therapeutic responses in a wide variety of tumors, but also leads to a spectrum of inflammatory toxicities that can involve any organ system in the body. Although most inflammatory toxicities resolve with systemic immune suppression, fatal toxicities can occur, and interruption and discontinuation of immunotherapy because of toxicity are common. In addition to their clinical impact, these inflammatory toxicities also provide a window into immune regulation in humans. By studying the cellular and molecular mechanisms that drive this inflammation, we have an opportunity to learn how the immune checkpoints, cytotoxic T lymphocyte antigen-4 and programmed death-1 and its ligand, maintain immune homeostasis throughout the body. Although we have an increasingly detailed understanding of the mechanisms that drive effective antitumor immunity, we have a rudimentary picture of the mechanisms of toxicity. Most toxicities involve barrier organs, suggesting an important role for interactions with the environment, including the microbiome. Early analyses have implicated cytotoxic T cells, although the antigens recognized by these cells, and the pathways activated by and around them are still unknown. By gaining a detailed understanding of the immune mechanisms of toxicity, we have the potential to develop novel interventions for them. These treatments should take advantage of differences between effective antitumor immunity and the principal drivers of organ inflammation. By targeting these mechanistic differences, we can develop therapies that can be used alongside immunotherapy, blocking inflammatory toxicity while preserving or even enhancing the response to cancer.

Multinational Association of Supportive Care in Cancer (MASCC) 2020 clinical practice recommendations for the management of severe gastrointestinal and hepatic toxicities from checkpoint inhibitors

Immune-related adverse events (IrAEs) affecting the gastrointestinal (GI) tract and liver are among the most frequent and most severe inflammatory toxicities from contemporary immunotherapy. Inflammation of the colon and or small intestines (entero)colitis is the single most common GI IrAE and is an important cause of delay of discontinuation of immunotherapy. The severity of these GI IrAEs can range from manageable with symptomatic treatment alone to life-threatening complications, including perforation and liver failure. The frequency and severity of GI IrAEs is dependent on the specific immunotherapy given, with cytotoxic T lymphocyte antigen (CTLA)-4 blockade more likely to induce severe GI IrAEs than blockade of either programmed cell death protein 1 (PD-1) or PD-1 ligand (PD-L1), and combination therapy showing the highest rate of GI IrAEs, particularly in the liver. To date, we have minimal prospective data on the appropriate diagnosis and management of GI IrAEs, and recommendations are based largely on retrospective data and expert opinion. Although clinical diagnoses of GI IrAEs are common, biopsy is the gold standard for diagnosis of both immunotherapy-induced enterocolitis and hepatitis and can play an important role in excluding competing, though less common, diagnoses and ensuring optimal management. GI IrAEs typically respond to high-dose corticosteroids, though a significant fraction of patients requires secondary immune suppression. For colitis, both TNF-α blockade with infliximab and integrin inhibition with vedolizumab have proved highly effective in corticosteroid-refractory cases. Detailed guidelines have been published for the management of low-grade GI IrAEs. In the setting of more severe toxicities, involvement of a GI specialist is generally recommended. The purpose of this review is to survey the available literature and provide management recommendations focused on the GI specialist.

Gastrointestinal and Hepatic Complications of Immunotherapy: Current Management and Future Perspectives

PURPOSE OF REVIEW

Checkpoint inhibitor (CPI) immunotherapy has transformed the treatment of multiple cancers over the past decade, leading to durable remissions, but also to severe inflammatory toxicities. These toxicities, termed immune-related adverse events (irAEs), can affect any organ system in the body, but commonly induce inflammation in barrier organs. Gastrointestinal (GI) and hepatic irAEs are among the most frequent and most severe from contemporary immunotherapies, with inflammation in the colon and or small intestines (entero)colitis as the single most common GI irAE. The aim of this review is to describe the evidence supporting our current understanding of CPI enterocolitis and hepatitis, as well as the management of these entities.

RECENT FINDINGS

Although most patients who develop enterocolitis recover without long-term GI sequelae, enterocolitis is still an important reason for treatment discontinuation, which, in patients with metastatic cancer, can be a life-threatening outcome. At present, we have almost no prospective, randomized data regarding the management of CPI enterocolitis, and current management algorithms are based on expert opinion and small retrospective studies with a high likelihood of bias. Retrospective studies have defined colonic ulceration as a predictor of colitis responsiveness to corticosteroids, and have defined microscopic colitis as a subtype of CPI enterocolitis with a distinct treatment response. Corticosteroids appear to be effective for 60-70% of patients with CPI enterocolitis, with about a third of patients requiring escalation to a biologic agent such as infliximab or vedolizumab. Yet proper sequencing of these treatments to minimize risk and maximize treatment benefit has not been established, and we do not know how treatment of colitis influences cancer outcomes. CPI enterocolitis and hepatitis are important causes of treatment interruption and discontinue, and significant morbidity in patients undergoing immunotherapy. As guidelines for diagnosis and management rely heavily on expert opinion, we have an urgent need for randomized and prospective trials that use both colitis and cancer outcomes to determine optimal management strategies.

Budesonide treatment for microscopic colitis from immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (CPIs) are effective against a variety of malignancies but can be limited by inflammatory toxicities such as enterocolitis. Enterocolitis is typically treated with systemically active glucocorticoids. Endoscopy can stratify patients by the severity of mucosal inflammation, including identifying patients with colitis in the absence of visible mucosal changes: microscopic colitis. Whether patients with CPI microscopic colitis could be managed differently from colitis with more severe mucosal involvement is unclear. The objective of this study was to describe outcomes in CPI microscopic colitis focusing on the response to first line treatment with budesonide.

METHODS

We evaluated data from a retrospective cohort from a single-center large academic hospital. The participants were all adult patients evaluated by endoscopy for suspected CPI enterocolitis between 3/2017 and 3/2019. The exposures were: Mayo Endoscopic Score (range 0-3). The subset was: oral budesonide, maximum dose 12 mg daily, administered minimum of 5 weeks. The main outcomes and measures were: Primary: time from first CPI exposure to first glucocorticoid use; use of systemic glucocorticoids; time from symptom onset to resolution; continuation of CPI therapy; number of additional CPI infusions received. Secondary: admissions for symptom control; novel irAE development; need for second-line immunosuppression; oncologic outcomes.

RESULTS

We identified 38 patients with biopsy confirmed CPI enterocolitis, 13 in the microscopic colitis cohort, and 25 in the non-microscopic colitis cohort. Budesonide use was higher in the microscopic colitis cohort (12/13 vs 3/25, p < 0.001), and systemic glucocorticoid use was higher in non-microscopic colitis (22/25 vs. 3/13, p < 0.001). Time from symptom onset to resolution did not differ. Microscopic colitis patients more frequently remained on CPI after developing (entero)colitis (76.9% vs 16.0%, p < 0.001). Microscopic colitis patients tolerating further CPI received, on average, 4.2 CPI infusions more than non-microscopic colitis patients tolerating CPI (5.8 vs 1.6, p = 0.03). Microscopic colitis was associated with increased time-to-treatment-failure (HR 0.30, 95% CI 0.14-0.66) and progression-free survival (HR 0.22, 95% CI 0.07-0.70).

CONCLUSIONS

Gastrointestinal mucosal inflammation without visible mucosal injury is a distinct, prevalent CPI enterocolitis subset that can be diagnosed by endoscopy. First-line budesonide appears effective in controlling "microscopic colitis" symptoms and prolonging immunotherapy duration. These findings present a compelling rationale for routine endoscopic evaluation of suspected CPI enterocolitis and suggest an alternative glucocorticoid-sparing treatment strategy for a subset of such patients.

Colitis after checkpoint blockade: A retrospective cohort study of melanoma patients requiring admission for symptom control

BACKGROUND

Immune checkpoint inhibitors (CPIs) have revolutionized oncologic therapy but can lead to immune-related adverse events (irAEs). Corticosteroids are first-line treatment with escalation to biologic immunosuppression in refractory cases. CPI-related gastroenterocolitis (GEC) affects 20%-50% of patients receiving CPIs and can carry significant morbidity and mortality. Severe CPI-related GEC is not well-described. We present the clinical characterization of all CPI-related GEC requiring admission at a single institution.

METHODS

Clinical, laboratory, radiographic, and endoscopic data were extracted from charts of all melanoma patients ≥18 years of age admitted to one institution for CPI-related GEC, from February 5, 2011 to December 13, 2016. Patients were followed until December 31, 2017 for further admissions. Survival, outcomes, and pharmaceutical-use analyses were performed.

RESULTS

Median time-to-admission from initial CPI exposure was 73.5 days. Median length of stay was 4.5 days. About 50.0% required second-line immunosuppression. Readmission for recrudescence occurred in 33.3%. Common Terminology Criteria for Adverse Events (CTCAE) grade was not significantly associated with outcomes. Hypoalbuminemia (P = 0.005), relative lymphopenia (P = 0.027), and decreased lactate dehydrogenase (P = 0.026) were associated with second-line immunosuppression. There was no difference in progression-free survival (PFS) or OS (P = 0.367, 0.400) for second-line immunosuppression. Subgroup analysis showed that early corticosteroid administration (P = 0.045) was associated with decreased PFS.

CONCLUSIONS

Severe CPI-related GEC typically manifests within 3 months of immunotherapy exposure. Rates of second-line immunosuppression and readmission for recrudescence were high. CTCAE grade did not capture the degree of severity in our cohort. Second-line immunosuppression was not associated with poorer oncologic outcomes; however, early corticosteroid exposure was associated with decreased PFS. Further investigation is warranted.

Concurrent therapy with immune checkpoint inhibitors and TNFα blockade in patients with gastrointestinal immune-related adverse events

BACKGROUND

Immune checkpoint inhibitors (ICI) have demonstrated remarkable efficacy as cancer therapeutics, however, their use remains limited due to the development of immune related adverse events (irAEs). Immune related enterocolitis (irEC) is among the most common severe irAEs leading to the discontinuation of ICIs. Inhibitors of tumor necrosis factor alpha (anti-TNFα) have been used to treat irEC. Recent animal studies have shown that concurrent treatment with anti-TNFα and ICIs improves tumor responses and decreases colitis severity. This approach has not yet been studied in prospective trials in humans. Here we describe, for the first time, the outcomes of patients who were treated concurrently with anti-TNFα and one or two ICIs.

CASE PRESENTATIONS

Five patients with different primary malignancies were treated with ipilimumab/nivolumab (2 patients), pembrolizumab (1 patient), ipilimumab (1 patient), or cemiplimab (1 patient). All patients developed irEC within 40 days of their first ICI dose. The patients presented with a combination of upper and lower gastrointestinal symptoms and subsequently underwent upper endoscopy and/or lower endoscopy. Endoscopy results demonstrated a spectrum of acute inflammatory changes across the gastrointestinal tract. Steroid therapy was used as first line treatment. To prevent prolonged steroid use and recurrence of gastrointestinal inflammation after resumption of cancer therapy, patients were treated concurrently with infliximab and ICI. Patients tolerated further ICI therapy with no recurrence of symptoms. Repeat endoscopies showed resolution of acute inflammation and restaging imaging showed no cancer progression.

CONCLUSIONS

Concurrent treatment with anti-TNFα and ICI appears to be safe, facilitates steroid tapering, and prevents irEC. Prospective clinical trials are needed to assess the outcomes of this treatment modality.