Checkpoint Inhibitor-Induced Colitis-A Clinical Overview of Incidence, Prognostic Implications and Extension of Current Treatment Options

Anti-PD-L1 antibody retains antitumour effects while mitigating immunotherapy-related colitis in bladder cancer-bearing mice after CT-mediated intratumoral delivery

Drug local delivery system that directly supply anti-cancer drugs to the tumor microenvironment (TME) results in excellent tumor control and minimizes side effects associated with the anti-cancer drugs. Immune checkpoint inhibitors (ICIs) have been the mainstay of cancer immunotherapy. However, the systemic administration of ICIs is accompanied by considerable immunotherapy-related toxicity. To explore whether an anti-PD-L1 antibody administered locally via a sustained-release gel-forming carrier retains its effective anticancer function while causing fewer colitis-like side effects, CT, a previously reported depot system, was used to locally deliver an anti-PD-L1 antibody together with curcumin to the TME in bladder cancer-bearing ulcerative colitis model mice. We showed that CT-mediated intratumoral coinjection of an anti-PD-L1 antibody and curcumin enabled sustained release of both the loaded anti-PD-L1 antibody and curcumin, which contributed to substantial anticancer effects with negligible side effects on the colons of the UC model mice. However, although the anti-PD-L1 antibody administered systemically synergized with the CT-mediated intratumoral delivery of curcumin in inhibiting tumour growth, colitis was significantly worsened by intraperitoneal administration of anti-PD-L1 antibody. These findings suggested that CT is a promising agent for the local delivery of anticancer drugs, as it can allow effective anticancer functions to be retained while sharply reducing the adverse side effects associated with the systemic administration of these drugs.

Immunotherapy-induced colitis in metastatic colorectal cancer: a systematic review and meta-analysis

Colorectal cancer (CRC) presents significant mortality risks, underscoring the urgency of timely diagnosis and intervention. Advanced stages of CRC are managed through chemotherapy, targeted therapy, immunotherapy, radiotherapy, and surgery. Immunotherapy, while effective in bolstering the immune system against cancer cells, often carries toxic side effects, including colitis. This study aimed to evaluate the incidence of colitis in patients with metastatic CRC (mCRC) undergoing various immunotherapy treatments. Through a systematic search of Google Scholar and PubMed databases from inception until November 2023, nine relevant studies were identified. Subgroup analyses revealed a higher incidence of colitis, particularly in patients treated with anti-cytotoxic T-lymphocyte-associated molecule-4 (anti-CTLA-4) and combination therapies compared to monotherapy with programmed cell death receptor-1 (PD-1) or programmed cell death ligand receptor-1 (PDL-1) inhibitors. Notably, naive-treated metastatic CRC patients exhibited elevated colitis incidences compared to those previously treated. In conclusion, anti-CTLA-4 and combination therapies, such as nivolumab plus ipilimumab, were associated with increased colitis occurrences in metastatic CRC patients, highlighting the need for vigilant monitoring and management strategies, especially in immunotherapy-naive individuals.

New strategies in the diagnosis and treatment of immune-checkpoint inhibitor-mediated colitis

Immune-checkpoint inhibitor-mediated colitis (IMC) is an increasingly recognized adverse event in cancer immunotherapy, particularly associated with immune checkpoint inhibitors (ICIs) such as anti-cytotoxic T-lymphocyte antigen-4 and anti-programmed cell death protein-1 antibodies. As this revolutionary immunotherapy gains prominence in cancer treatment, understanding, diagnosing, and effectively managing IMC becomes paramount. IMC represents a unique challenge due to its immune-mediated nature and potential for severe complications. However, a precise picture of IMC pathophysiology is currently unavailable. Therefore, we aimed to summarize the existing data while acknowledging the need for further research. This comprehensive review explores the mechanisms underlying ICIs, gastrointestinal adverse effects, and, in particular, IMC's incidence, prevalence, and features. Our review also emphasizes the importance of recognizing IMC's distinct clinical and histopathological features to differentiate it from other forms of colitis. Furthermore, this paper highlights the urgent need for evolving diagnostic methods, therapeutic strategies, and a multidisciplinary approach to effectively manage IMC.

The JAK-STAT Pathway as a Therapeutic Strategy in Cancer Patients with Immune Checkpoint Inhibitor-Induced Colitis: A Narrative Review

Immunotherapy has emerged as a pivotal component in the treatment of various malignancies, encompassing lung, skin, gastrointestinal, and head and neck cancers. The foundation of this therapeutic approach lies in immune checkpoint inhibitors (ICI). While ICIs have demonstrated remarkable efficacy in impeding the neoplastic progression of these tumours, their use may give rise to substantial toxicity, notably in the gastrointestinal domain, where ICI colitis constitutes a significant aspect. The optimal positioning of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors in the therapeutic management of ICI colitis remains unclear. Numerous reports have highlighted notable improvements in ICI colitis through the application of pan-JAK-STAT inhibitors, with tofacitinib, in particular, reporting evident clinical remission of colitis. The precise mechanism by which JAK-STAT inhibitors may impact the pathogenetic process of ICI colitis remains inadequately understood. However, there is speculation regarding their potential role in modulating memory resident CD8+ T lymphocytes. The elucidation of this mechanism requires further extensive and robust evidence, and ongoing JAK-STAT-based trials are anticipated to contribute valuable insights.

Thermally engineered MSC-derived extracellular vesicles ameliorate colitis in mice by restoring the imbalanced Th17/Treg cell ratio

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have garnered extensive interest for their immunomodulatory properties in immune-mediated inflammatory diseases. However, the development of EVs as clinical drugs often faces challenges such as low production yield and suboptimal therapeutic efficacy. In this study, we discovered that thermally engineering was able to enhance the yield of MSC-EVs. Moreover, the PD-L1 expression of EVs released from the thermal engineering MSCs was found to be upregulated significantly, and these EVs ameliorated the symptoms and pathological damages in murine dextran sulfate sodium (DSS)-induced colitis model. The therapeutic effect on DSS-induced colitis was mediated through the regulation of the Th17/Treg cell balance, demonstrating the immunomodulatory properties of the thermally engineering MSC-EVs. Overall, our findings suggest that thermal engineering can be utilized as a promising strategy for enhancing EV production and may provide a potential therapeutic approach for clinical treatment of colitis.

Refractory pembrolizumab immunotherapy-related colitis requiring biological therapy in an inactive HBcAb carrier

Immune checkpoint inhibitors are a class of cancer immunotherapy, with a constellation of side effects that require early recognition and management. We present a patient with metastatic adenocarcinoma started on pembrolizumab a month prior, who was admitted to the hospital for bloody diarrhoea. He underwent flexible sigmoidoscopy with biopsy proven grade 3 immune-mediated diarrhoea and colitis. He developed progressively worsening diarrhoea despite appropriate intravenous corticosteroids therapy, and initiation of corticosteroid-sparing therapy was complicated by discovery of hepatitis B core antibodies indicating a chronic hepatitis B carrier state. We discuss our work-up of new onset haemorrhagic diarrhoea in a patient on immunotherapy for metastatic non-small cell lung cancer, as well as a review of current guidelines for antiviral prophylaxis in these patients.

The Role of Microbiota-Derived Vitamins in Immune Homeostasis and Enhancing Cancer Immunotherapy

Not all cancer patients who receive immunotherapy respond positively and emerging evidence suggests that the gut microbiota may be linked to treatment efficacy. Though mechanisms of microbial contributions to the immune response have been postulated, one likely function is the supply of basic co-factors to the host including selected vitamins. Bacteria, fungi, and plants can produce their own vitamins, whereas humans primarily obtain vitamins from exogenous sources, yet despite the significance of microbial-derived vitamins as crucial immune system modulators, the microbiota is an overlooked source of these nutrients in humans. Microbial-derived vitamins are often shared by gut bacteria, stabilizing bioenergetic pathways amongst microbial communities. Compositional changes in gut microbiota can affect metabolic pathways that alter immune function. Similarly, the immune system plays a pivotal role in maintaining the gut microbiota, which parenthetically affects vitamin biosynthesis. Here we elucidate the immune-interactive mechanisms underlying the effects of these microbially derived vitamins and how they can potentially enhance the activity of immunotherapies in cancer.

Check this out: treatment paradigms in immune-checkpoint inhibitor colitis

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICI) have become a pillar of cancer therapy for many people around the world. However, up to two-thirds of all patients undergoing ICI therapy will have immune-related adverse events (irAEs), including immune-checkpoint inhibitor colitis (ICIC). This review summarizes the most valuable and currently available information about the mechanism, diagnosis, and management of ICIC.

RECENT FINDINGS

Recent findings include several developments on the leading theories for the mechanisms of ICIC such as the role of the gut microbiome. New emerging therapy strategies include tocilizumab, ustekinumab, mycophenolate mofetil, and calcineurin inhibitors.

SUMMARY

The occurrence of irAEs remains a limiting factor for the use of immunotherapy in cancer treatment. Prompt diagnosis of ICIC with endoscopy and histologic confirmation can lead to early utilization of known effective treatments such as corticosteroids, infliximab, vedolizumab, and other emerging therapy strategies. We summarize the key points of this review article in our abstract video, Supplemental Digital Content 1, http://links.lww.com/COG/A44.

Immunotherapy-induced Colitis: A Comprehensive Review of Epidemiology, Clinical Presentation, Diagnostic Workup, and Management Plan

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of a variety of malignancies including advanced melanoma, non-small cell lung cancer, renal cell carcinoma, head and neck cancers among others. Since their introduction, there has been significant improvement in survival and prognosis in patients with advanced malignancies. Unfortunately, improved outcomes have come at a price of significant immune-related adverse events, with those of the gastrointestinal tract being the most common. Gastrointestinal immune-related adverse events frequently present as diarrhea and colitis, the severity of which can range from mild diarrhea to fulminant colitis with intestinal perforation. Currently, management of ICI-induced colitis is primarily guided by retrospective studies and expert opinion. A significant number of ICI-induced colitis responds to high-dose corticosteroids; however, some patients require further therapy with biologics. There is limited information on the factors which may predispose patients to ICI-induced colitis. Future research elucidating these risk factors along with development of a scoring system could allow for risk-stratification of patients before initiation of ICI therapy. Such a system may help clinicians and patients keep a high index of suspicion regarding ICI-induced colitis and could hopefully reduce the incidence of severe cases. Similarly, future studies should investigate protective factors against ICI-induced colitis, which could potentially allow more patients to safely benefit from ICI therapy.

Pharmacological Treatments Available for Immune-Checkpoint-Inhibitor-Induced Colitis

Immune checkpoint inhibitor treatment has shown revolutionary therapeutic effects in various carcinomas. However, immune-related adverse events (irAE) following this treatment can sometimes lead to treatment discontinuation. One such frequently encountered adverse event is immune-related colitis (irAE colitis). Corticosteroids (CS) are the first-line treatment for irAE colitis, but we often encounter CS-refractory or -resistant cases. The application of multiple biologics has been proposed as a therapy to be administered after CS treatment; however, the efficacy and safety of biologics for patients with irAE colitis who do not respond to CS have not been established. This review summarizes the treatment regimens available for irAE colitis, focusing on the mechanism of action of corticosteroids, infliximab, vedolizumab, and other drugs.

Bridging the Gap: Connecting the Mechanisms of Immune-Related Adverse Events and Autoimmunity Through PD-1

The emergence of anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4), anti-programmed cell death 1 ligand (anti-PD-1), and anti-PD-L1 antibodies as immune checkpoint inhibitors (ICIs) revolutionized the treatment of numerous types of tumors. These antibodies, both alone and in combination, provide great clinical efficacy as evidenced by tumor regression and increased overall patients' survival. However, with this success comes multiple challenges. First, while patients who respond to ICIs have outstanding outcomes, there remains a large proportion of patients who do not respond at all. This all-or-none response has led to looking downstream of programmed cell death 1 (PD-1) for additional therapeutic targets and for new combination therapies. Second, a majority of patients who receive ICIs go on to develop immune-related adverse events (irAEs) characterized by end-organ inflammation with T-cell infiltrates. The hallmarks of these clinically observed irAEs share many similarities with primary autoimmune diseases. The contribution of PD-1 to peripheral tolerance is a major mechanism for protection against expansion of self-reactive T-cell clones and autoimmune disease. In this review, we aim to bridge the gaps between our cellular and molecular knowledge of PD-1 signaling in T cells, ICI-induced irAEs, and autoimmune diseases. We will highlight shared mechanisms and the potential for new therapeutic strategies.

Immune Checkpoint Inhibitor-Associated Colitis: From Mechanism to Management

Immune checkpoint inhibitors (ICIs), as one of the innovative types of immunotherapies, including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors, have obtained unprecedented benefit in multiple malignancies. However, the immune response activation in the body organs could arise immune-related adverse events (irAEs). Checkpoint inhibitor colitis (CIC) is the most widely reported irAEs. However, some obscure problems, such as the mechanism concerning gut microbiota, the confusing differential diagnosis with inflammatory bowel disease (IBD), the optimal steroid schedule, the reintroduction of ICIs, and the controversial prognosis features, influence the deep understanding and precise diagnosis and management of CIC. Herein, we based on these problems and comprehensively summarized the relevant studies of CIC in patients with NSCLC, further discussing the future research direction of this specific pattern of irAEs.