Systematic review: colitis associated with anti-CTLA-4 therapy

A Review of Cancer Immunotherapy Toxicity: Immune Checkpoint Inhibitors

Cancer immunotherapy, which leverages features of the immune system to target neoplastic cells, has revolutionized the treatment of cancer. The use of these therapies has rapidly expanded in the past two decades. Immune checkpoint inhibitors represent one drug class within immunotherapy with its first agent FDA-approved in 2011. Immune checkpoint inhibitors act by disrupting inhibitory signals from neoplastic cells to immune effector cells, allowing activated T-cells to target these neoplastic cells. Unique adverse effects associated with immune checkpoint inhibitors are termed immune-related adverse effects (irAEs) and are usually immunostimulatory in nature. Almost all organ systems may be affected by irAEs including the dermatologic, gastrointestinal, pulmonary, endocrine, and cardiovascular systems. These effects range from mild to life-threatening, and their onset can be delayed several weeks or months. For mild irAEs, symptomatic care is usually sufficient. For higher grade irAEs, discontinuation of therapy and initiation of immunosuppressive therapy may be necessary. The management of patients with irAEs involves multidisciplinary care coordination with respect to the long-term goals the individual patient. Clinicians must be aware of the unique and sometimes fatal toxicologic profiles associated with immunotherapies to ensure prompt diagnosis and appropriate management.

The Entire Intestinal Tract Surveillance Using Capsule Endoscopy after Immune Checkpoint Inhibitor Administration: A Prospective Observational Study

BACKGROUND

Despite the proven efficacy of immune checkpoint inhibitors (ICIs) against various types of malignancies, they have been found to induce immune-related adverse events, such as enterocolitis; however, the clinical features of ICI-induced enterocolitis remain to be sufficiently elucidated, which is significant, considering the importance of early detection in the appropriate management and treatment of ICI-induced enterocolitis. Therefore, the current study aimed to determine the utility of capsule endoscopy as a screening tool for ICI-induced enterocolitis.

METHODS

This single-center, prospective, observational study was conducted on patients with malignancy who received any ICI between April 2016 and July 2020 at Keio University Hospital. Next, second-generation capsule endoscopy (CCE-2) was performed on day 60 after ICI initiation to explore the entire gastrointestinal tract.

RESULTS

Among the 30 patients enrolled herein, 23 underwent CCE-2. Accordingly, a total of 23 findings were observed in 14 (60.8%) patients at any portion of the gastrointestinal tract (7 patients in the colon, 4 patients in the small intestine, 2 patients in both the colon and the small intestine, and 1 patient in the stomach). After capsule endoscopy, 2 patients (8.7%) developed ICI-induced enterocolitis: both had significantly higher Capsule Scoring of Ulcerative Colitis than those who had not developed ICI-induced enterocolitis (p = 0.0455). No adverse events related to CCE-2 were observed.

CONCLUSIONS

CCE-2 might be a safe and useful entire intestinal tract screening method for the early detection of ICI-induced enterocolitis in patients with malignancies.

Efficacy and safety of Infliximab for steroid-resistant immune-related adverse events: A retrospective study

The present study investigated outcomes of infliximab (IFX) treatment among 8 Japanese patients with various types of cancer (4 with malignant melanoma, 3 with lung cancer and 1 with renal cancer) who developed severe steroid-resistant immune-related adverse events (irAEs) in association with immune checkpoint inhibitors (ICIs) to determine its efficacy and safety. Information, including patient background, treatment progress, examination data and imaging data, was collected retrospectively from electronic medical records. Adverse reactions were evaluated using the Common Terminology Criteria for Adverse Events version 4.0. Specific ICIs used were anti-PD-1, anti-PD-L1 and anti-CTLA-4 antibody preparations in 7, 2 and 5 patients, respectively. Specific irAEs included grade 3 diarrhea/colitis in 7 patients and disseminated intravascular coagulation and myocarditis attributed to autoimmune activation in 1 patient. The median duration between systemic steroid and IFX treatments was 9 (range, 2-39) days. A total of 3 patients responded to IFX, 1 of whom responded after one dose and 2 responded after two doses. Respective diseases improved to grade 0 after a median of 18 (range, 9-32) days. No AEs were attributable to IFX. Additionally, anti-cytomegalovirus (CMV) and antibacterial agents were administered in parallel given the presence of CMV and Clostridium difficile (CD) infections in all patients, except in 1 exhibiting a marked IFX response after one dose. The combination of highly immunosuppressive IFX and high-dose systemic steroid administration over a long period presumably predisposed the patients to opportunistic enteric infections. Accordingly, early initiation of IFX treatment in conjunction with systemic steroid therapy should be considered for severe diarrhea/colitis and other irAEs. However, the possibility for CMV and CD infections should be recognized, and for these the treatment strategy may need to be modified at an early stage.

Immuno-oncology: a narrative review of gastrointestinal and hepatic toxicities

Vaccines, cytokines, and adoptive cellular therapies (ACT) represent immuno-therapeutic modalities with great development potential, and they are currently approved for the treatment of a limited number of advanced malignancies. The most up-to-date knowledge on the regulation of the anti-cancer immune response has recently led to the development and approval of inhibitors of immune checkpoints, which have produced unprecedented clinical activity in several hard to treat solid malignancies. However, severe adverse events (AEs) represent a limitation to the use of these drugs. Currently approved checkpoint inhibitors block cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death protein (PD-1) and its ligand (PD-L1), resulted in increased survival of patients with several solid and hematologic malignancies. The most common treatment AEs associated with these drugs are fatigue, rash, and auto-immune/inflammatory reactions. Many of the immune-related AEs are reversible and the strategies for their management include supportive care either with or without treatment withdrawal; nevertheless, in severe cases, hospitalization and treatment with immune suppressants, and/or immunomodulators may be required. Steroid therapy is a critical component of the treatment algorithm; nevertheless, the associated immunosuppression may compromise the antitumor response. This article provides a comprehensive and narrative review of luminal gastrointestinal and hepatic complications, including recommendations for their investigation and management.

Pembrolizumab-Induced Thyroiditis and Colitis-Presentation and Resolution on Serial FDG PET/CT

ABSTRACT

A 58-year-old man with previous melanoma of the left leg underwent whole-body 18F-FDG PET/CT to stage metastatic disease prior to commencing pembrolizumab. Follow-up FDG PET/CT after 3 months of treatment showed partial metabolic response of soft tissue and nodal metastases and diffuse increased thyroid and colonic uptake, suggestive of thyroiditis and colitis. Pembrolizumab was ceased, and a repeat FDG PET/CT scan showed regression of uptake in the thyroid gland and colon, in keeping with resolution of inflammatory change. Immune-related adverse events induced by Immune checkpoint inhibitors, such as pembrolizumab, should be recognized-cessation of treatment often leads to resolution.

Pembrolizumab-induced immune-mediated fatal colitis with concurrent giardia infection

Advancements in medicine have enabled the use of monoclonal antibodies in the field of oncology. However, the new adverse effects of immunotherapeutic agents are still being reported. We present the first case of pembrolizumab-induced fatal colitis with concurrent Giardia infection in a patient with metastatic ovarian cancer. A 47-year-old woman with metastatic ovarian cancer who was being treated with pembrolizumab admitted to our clinic complaining of persisting bloody diarrhoea. Her stool antigen test was positive for Giardia. The patient received metronidazole. A colonoscopy with mucosal biopsy was performed upon no clinical or laboratory improvement. Colonoscopy detected deep exudative ulcers in sigmoid colon and rectum. The cytopathological evaluation revealed immune-mediated ischemic colitis. The treatment was rearranged with methylprednisolone. Upon an increase in bloody diarrhoea frequency and C-reactive protein levels, infliximab was started. However, the patient became refractory to infliximab therapy after the second dose and was deceased due to septic shock.

Gastrointestinal adverse events of immunotherapy

Cancer immunotherapy with immune-checkpoint inhibitors (ICIs) has emerged as an effective treatment for different types of cancer. ICIs are monoclonal antibodies that inhibit the signaling pathway that suppress antitumor T-cell activity. Patients benefit from increased overall and progression-free survival, but the enhancement of normal immunity can result in autoimmune manifestations, called immune-related adverse events (IRAEs), which may lead to a discontinuation of cancer therapy and to severe also life-threating events. IRAEs may affect any organs or system in the human body, being the gastrointestinal (GI) tract one of the most involved districts. Imaging plays an important role in recognizing GI IRAEs and radiologist should be familiar with the main spectrum of radiological appearance. Indeed, early detection of GI IRAEs is crucial for proper patient management and reduces morbidity and mortality. The purpose of this review is to present the most relevant imaging manifestation of GI IRAEs.

Imaging spectrum of adverse events of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs), a form of immunotherapy, are increasingly used for a variety of malignancies and have been linked to numerous treatment-related side effects known as immune-related adverse events (irAEs). IrAEs can affect multiple organ systems and are important to recognise in order to avoid misinterpretation as progressive tumour and to ensure appropriate management. In this pictorial review, we will briefly discuss radiological response criteria of immunotherapy and describe the imaging appearances of the wide spectrum of these ICI-associated toxicities.

Effect of probiotics and gut microbiota on anti-cancer drugs: Mechanistic perspectives

Bacteria present in probiotics, particularly the common Lactobacillus and Bifidobacterium microbes, have been found to induce anti-cancer action by enhancing cancer cell apoptosis and protecting against oxidative stress. Probiotics supplements also decrease the cancer-producing microorganism Fusobacterium. Studies have demonstrated that gut microbiota modifies the effect of chemo/radiation therapy. Gut microbes not only enhance the action of chemotherapy drugs but also reduce the side effects of these medications. Additionally, gut microbes reduce immunotherapy toxicity, in particular, the presence of Bacteroidetes or Bifidobacterium decreases the development of colitis by ipilimumab therapy. Probiotics supplements containing Bifidobacterium also reduce chemotherapy-induced mucositis and radiation-induced diarrhea. This review focused on elucidating the mechanism behind the anti-cancer action of Bifidobacterium species. Available studies have revealed Bifidobacterium species decrease cancer cell proliferation via the inhibition of growth factor signaling as well as inducing mitochondrial-mediated apoptosis. Moreover, Bifidobacterium species reduce the adverse effects of chemo/immuno/radiation therapy by inhibiting proinflammatory cytokines. Further clinical studies are needed to identify the powerful and suitable Bifidobacterium strain for the development of adjuvant therapy to support chemo/immuno/radiation therapy.

Nanobodies targeting immune checkpoint molecules for tumor immunotherapy and immunoimaging (Review)

The immune checkpoint blockade is an effective strategy to enhance the anti-tumor T cell effector activity, thus becoming one of the most promising immunotherapeutic strategies in the history of cancer treatment. Several immune checkpoint inhibitor have been approved by the FDA, such as anti-CTLA-4, anti-PD-1, anti-PD-L1 monoclonal antibodies. Most tumor patients benefitted from these antibodies, but some of the patients did not respond to them. To increase the effectiveness of immunotherapy, including immune checkpoint blockade therapies, miniaturization of antibodies has been introduced. A single-domain antibody, also known as nanobody, is an attractive reagent for immunotherapy and immunoimaging thanks to its unique structural characteristic consisting of a variable region of a single heavy chain antibody. This structure confers to the nanobody a light molecular weight, making it smaller than conventional antibodies, although remaining able to bind to a specific antigen. Therefore, this review summarizes the production of nanobodies targeting immune checkpoint molecules and the application of nanobodies targeting immune checkpoint molecules in immunotherapy and immunoimaging.

Gut microbiome and checkpoint inhibitor colitis

Immune checkpoint inhibitor therapies such as ipilimumab, are increasingly being used as a treatment option for a variety of cancers, including metastatic melanoma and have demonstrated effectively a prolonged survival. These agents have an immunological mode of action that predisposes patients to a number of immune-related adverse events, colitis being one of the most commonly encountered complications. The pathogenesis for the development of colitis is unclear, and there is a growing consensus that the ecosystem of the gastrointestinal microbiota plays a significant role. Based on this suspected connection, studies are being carried out to explore the changes in the microbiota in patients on these medications who develop colitis. Conceivably, the modulation of the gut microbiota could offer a therapeutic benefit. Fecal microbiota transplantation is one therapeutic option that is currently being investigated, though there are still more data needed to evaluate its efficacy. In this review, we recapitulate the mechanisms of action of immune checkpoint inhibitors, their adverse events, with a focus on colitis and the role gut microbiota are suspected to play, and finally discuss the microbiota modulation therapies being investigated.

Gastrointestinal side effects of cancer treatments

Cancer survival rates have significantly improved over the last number of years due to advancements in cancer therapies. Unfortunately this has come at a cost. Therapeutic side effects are feared complications of therapy that may result in decreased quality of life and early cessation of the therapy, which can have knock-on effects on outcomes. This article outlines the main gastrointestinal side effects seen with radiation therapy, chemotherapy and immunotherapy, and discusses appropriate investigation and management.

Gastrointestinal and liver immune-related adverse effects induced by immune checkpoint inhibitors: A descriptive observational study

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are effective agents against several malignancies. However, they are associated with gastrointestinal and liver immune-related adverse events (GI-IrAEs and LI-IrAEs), which can lead to their temporary or permanent discontinuation.

AIM

The aim of this study was to evaluate the efficacy and gastrointestinal and liver toxicity of ICIs in oncological treatments in actual clinical practice.

MATERIAL AND METHODS

Patients with advanced cancer who received at least 1ICI dose between May 2015 and September 2018 were retrospectively assessed.

RESULTS

132 patients with non-small cell lung cancer (65.15%, n=86); melanoma (22.7%, n=30); renal carcinoma (9.09%, n=12); and other tumours (3%, n=4) were included. The treatments administered were nivolumab (n=82), pembrolizumab (n=28), atezolizumab (n=13), durvalumab (n=2), ipilimumab (n=1) and the antiCTLA-4/PD-1 combination (n=6). In total, 51 patients (38.6%) developed IrAEs, 17 (12.9%) of which experienced GI-IrAEs. Of these, 8 (47%) needed steroids and 1patient required surgery due to intestinal perforation. Grade I Li-IrAEs were observed in 4 patients (3.03%): 2 (50%) required corticosteroids and 1 patient had to discontinue treatment. Four patients (66.6%) who received combination therapy experienced GI-IrAEs. IrAE incidence were not associated with age, gender or drug response.

CONCLUSIONS

GI-IrAEs are one of the most common adverse events in patients receiving ICIs. A multidisciplinary approach and a greater understanding of these events could help to reduce morbidity and therapy discontinuation.

Lymphocytic Colitis With Increased Apoptosis: A Marker of Mutation in T-Cell-Mediated Immunity?

Lymphocytic colitis is a subtype of microscopic colitis that is mostly seen in adults. It presents mainly as chronic nonbloody diarrhea, with the hallmark of normal or near-normal endoscopy. In this case series, we are presenting 4 pediatric patients with lymphocytic colitis with prominent apoptosis of the colonic gland epithelium. Remarkably, all the patients have genetic mutations known to be associated with autoimmune enteropathy. Three patients have a CTLA4 mutation, and 1 patient has an STAT3 mutation. These mutations were previously reported in association with inflammatory bowel disease, but a specific connection with lymphocytic colitis has not been described. This report investigates the histopathology of such lesions in children and adolescents.

Oral mucositis: the hidden side of cancer therapy

Inflammation response of epithelial mucosa to chemo- radiotherapy cytotoxic effects leads to mucositis, a painful side effect of antineoplastic treatments. About 40% of the patients treated with chemotherapy develop mucositis; this percentage rises to about 90% for head and neck cancer patients (HNC) treated with both chemo- and radiotherapy. 19% of the latter will be hospitalized and will experience a delay in antineoplastic treatment for high-grade mucositis management, resulting in a reduction of the quality of life, a worse prognosis and an increase in patient management costs. Currently, several interventions and prevention guidelines are available, but their effectiveness is uncertain. This review comprehensively describes mucositis, debating the impact of standard chemo-radiotherapy and targeted therapy on mucositis development and pointing out the limits and the benefits of current mucositis treatment strategies and assessment guidelines. Moreover, the review critically examines the feasibility of the existing biomarkers to predict patient risk of developing oral mucositis and their role in early diagnosis. Despite the expression levels of some proteins involved in the inflammation response, such as TNF-α or IL-1β, partially correlate with mucositis process, their presence does not exclude others mucositis-independent inflammation events. This strongly suggests the need to discover biomarkers that specifically feature mucositis process development. Non-coding RNAs might hold this potential.

Imaging and clinical manifestations of immune checkpoint inhibitor-related colitis in cancer patients treated with monotherapy or combination therapy

PURPOSE

To determine the frequency, imaging, and clinical manifestations of immune checkpoint inhibitor (ICI)-related colitis in cancer patients on monotherapy or combination therapy.

METHODS

The electronic medical records of 1044 cancer patients who received ICIs were retrospectively reviewed to identify 48 patients who had a clinical diagnosis of immune-related colitis. Imaging studies were reviewed to identify patients with imaging manifestations of colitis. Demographic data, type of ICIs, symptoms, presence of other immune-related adverse events (irAEs), and management were recorded.

RESULTS

There was imaging evidence of immune-related colitis in 34 patients (24 men; median age: 63.5 years). The median time to onset of colitis was 75 days (IQR 25-75, 49.5-216 days) in patients receiving monotherapy (group 1) and 78 days (IQR 25-75, 44.3-99.5 days) in patients undergoing combination therapy (group 2) following start of ICI. Symptoms included diarrhea (91.1% [31 of 34]), nausea/vomiting (52.9% [18 of 34]), and abdominal pain (52.9% [18 of 34]). The most common imaging findings were bowel wall thickening (97% [33 of 34]) and fluid-filled colon (82.3% [28 of 34]). Colitis was diffuse in 21 of 34 (61.8%) patients. Imaging manifestations did not differ between the two groups (p > 0.05). Steroids and antibiotics were used to treat colitis in 29 of 34 (85.2%) and 13 of 34 (38.2%) patients, respectively. No patients in group 1 experienced concurrent irAEs, but 5 of 18 (27.8%) of patients in group 2 had other irAEs (p = 0.046).

CONCLUSION

Immune-related colitis occurred in 3.3% of patients receiving ICIs with bowel wall thickening, fluid-filled colon and pancolitis being the most common imaging manifestations. Imaging manifestations did not differ between patients receiving monotherapy or combination therapy. However, concurrent irAEs were significantly observed in patients undergoing combination therapy.

Safety evaluation of immune-based combinations in patients with advanced renal cell carcinoma: a systematic review and meta-analysis

INTRODUCTION

Immune-based combinations, including nivolumab plus ipilimumab, pembrolizumab plus axitinib, and (at a lesser extent) avelumab plus axitinib, should be regarded among the new standards of care for first line therapy of metastatic renal cell carcinoma. Toxicity profiles are different among all these above combinations, as well as between them and targeted agents monotherapies, including sunitinib (i.e. the control arm of all the above studies).

AREAS COVERED

We performed a systematic review and meta-analysis with the aim to compare adverse events from immune-based combinations versus sunitinib monotherapy across four recent randomized controlled trials (CheckMate-214, Keynote-426, IMmotion-151, and JAVELIN Renal 101) of front-line treatment for metastatic renal cell carcinoma, with particular attention to those from the ipilimumab plus nivolumab combination.

EXPERT OPINION

Beyond efficacy and activity, the ipilimumab plus nivolumab combination appears feasible, being endowed by an acceptable safety profile, in line with that of the other available options for the treatment of metastatic RCC. The different patterns of toxicities emerging from this systematic review and meta-analysis need to be kept in mind while choosing the appropriate treatment for each individual patient. Furthermore, prevention, prompt identification, and treatment of immune-related adverse events remains an area to be improved.

Abdominal CT manifestations of adverse events to immunotherapy: a primer for radiologists

Immunotherapy is a rapidly growing field within oncology and is being increasingly used in the management of several malignancies. Due to their unique mechanism of action on the immune system and neoplastic cells, the response pattern and adverse events of this novel therapy are distinct from conventional systemic therapies. Accordingly, the imaging appearances following immunotherapy including adverse events are unique and at times perplexing. Imaging is integral to management of patients on immunotherapeutic agents and a thorough understanding of its mechanism, response patterns and adverse events is crucial for precise interpretation of imaging studies. This review provides a description of the mechanism of action of current immunotherapeutic agents and the organ-wise description of their side effects.

Analysis of immune-related adverse events caused by immune checkpoint inhibitors using the Japanese Adverse Drug Event Report database

PURPOSE

The aim of our study was to characterize the clinical features of immune-related adverse events (irAEs) associated with immune checkpoint inhibitors (ICIs) in a real-world setting using the Japanese Adverse Drug Event Report (JADER) database.

METHODS

The irAEs were defined using the preferred terms of the Medical Dictionary for Regulatory Activities. irAEs were categorized as follows: adrenal insufficiency, colitis, eye diseases, hematological disorder, hepatitis, hyperthyroidism, hypopituitarism, hypothyroidism, myasthenia gravis, myocarditis, nephritis/renal dysfunction, pneumonitis, rash, and type 1 diabetes mellitus. We used several indices such as reporting odds ratio (ROR) to assess disproportionality in pharmacovigilance data, time-to-onset analysis using Weibull shape parameters, and the association rule mining technique to evaluate possible risk factors between variables in the spontaneous reporting system database.

RESULTS

The JADER database contained 534 688 reports from April 2004 to June 2018. The RORs of pneumonitis including interstitial lung disease for nivolumab, pembrolizumab, and ipilimumab were 7.02 (95% confidence interval: 6.55-7.52), 9.08 (8.28-9.97), and 1.74 (1.27-2.38), respectively. The median onsets (quartiles, 25-75%) of myocarditis caused by nivolumab and pembrolizumab were 28.0 (15.5-60.5) and 18.0 (13.0-44.5) days, respectively. Co-therapy with nivolumab and ipilimumab may be associated with irAEs in several categories as per the association rule mining analysis.

CONCLUSION

Our results demonstrated a potential risk of irAEs associated with ICIs, based on RORs and time-to-onset analysis. Furthermore, our findings indicated that patients receiving nivolumab and ipilimumab as co-therapy should be carefully monitored.

Evolving insights into the mechanisms of toxicity associated with immune checkpoint inhibitor therapy

Immune checkpoint inhibitors have emerged as a revolutionary treatment option for patients with various types of malignancy. Although these agents afford a significant improvement in outcomes for melanoma and other previously untreatable malignancies, their novel mechanism of action may predispose patients to immune-related adverse effects (irAEs). In the tumour neoantigen environment, these irAEs are due to the activation of the immune system by the blockade of suppressive checkpoints, leading to increases in T-cell activation and proliferation. IrAEs have been reported in almost any organ and at any point in time, even months to years after discontinuation of therapy. Certain populations with distinct physiological changes, genetic risk factors, and specific antigen exposures may be more highly predisposed to develop irAEs. This review discusses the incidence and mechanisms of irAEs and the relationship between host factors and irAE occurrence.

Side effects and management in immunotherapy based on immune checkpoint inhibitors

Immune checkpoint inhibitors, which exert their antitumor effects by targeting suppressive immune molecules, are a class of monoclonal antibody drugs based on certain immune checkpoints. Cancer immunotherapies lead to unique toxicity profiles distinct from the toxicities of other cancer therapies, depending on their mechanism of action. Immune-related adverse events can involve any organ or system. These effects are frequently low grade and reversible, affecting the skin, gastrointestinal tract, liver, endocrine system, and lung most commonly. However, some adverse effects can be severe and life-threatening. Therefore, the effective management of immune-related adverse events and reducing the occurrence of grade 3-4 treatment-related adverse events are critical in optimizing treatment outcomes. In this review, we summarize the clinical guidelines and the latest studies, and focus on the common toxic effects and management of the adverse events related to anti-cytotoxic T lymphocyte-associated antigen-4 or programmed death-1/programmed death-ligand-1 monoclonal antibody drugs, in order to provide better management of immune-related adverse events.

A Multidisciplinary Toxicity Team for Cancer Immunotherapy-Related Adverse Events

BACKGROUND

Immune checkpoint inhibitors (ICIs) may cause immune-related adverse events (irAEs). Methods to obtain real-time multidisciplinary input for irAEs that require subspecialist care are unknown. This study aimed to determine whether a virtual multidisciplinary immune-related toxicity (IR-tox) team of oncology and medicine subspecialists would be feasible to implement, be used by oncology providers, and identify patients for whom multidisciplinary input is sought.

PATIENTS AND METHODS

Patients treated with ICIs and referred to the IR-tox team in August 2017 through March 2018 were identified. Feasibility was defined as receipt of electronic referrals and provision of recommendations within 24 hours of referral. Use was defined as the proportion of referring providers who used the team's recommendations, which was determined through a postpilot survey. Demographics and tumor, treatment, and referral data were collected. Patient features and irAE associations were analyzed.

RESULTS

The IR-tox team was found to be feasible and used: 117 referrals from 102 patients were received in 8 months, all providers received recommendations within 24 hours, 100% of surveyed providers used the recommendations, and 74% changed patient management based on IR-tox team recommendations. Referrals were for suspected irAEs (n=106; 91%) and suitability to treat with ICIs (n=11; 10%). In referred patients, median age was 64 years, 54% were men, 13% had prior autoimmunity, and 46% received ICI combinations versus monotherapy (54%). The most commonly referred toxicities were pneumonitis (23%), arthritis (16%), and dermatitis (15%); 15% of patients had multisystem toxicities. Multiple referrals were more common in those treated with combination ICIs (odds ratio [OR], 6.0; P=.035) or with multisystem toxicities (OR, 8.1; P=.005). The IR-tox team provided a new multidisciplinary forum to assist providers in diagnosing and managing complex irAEs. This model identifies educational and service needs, and patients with irAEs for whom multidisciplinary care is most sought.

CONCLUSIONS

A virtual multidisciplinary toxicity team for irAEs was a feasible and used service, and facilitated toxicity identification and management.

Severe cytomegalovirus gastritis after pembrolizumab in a patient with melanoma

Immunotherapy has emerged as a standard of cancer treatment, with an increasing number of indications. Recently, opportunistic infections have been reported in several cases in which immunotherapy has led to an increased susceptibility to infection. The present case is the first report of cytomegalovirus (cmv) gastritis occurring in a patient with melanoma during immunotherapy without immune-related adverse events (iraes) and without the use of immunosuppressant agents. A 43-year-old woman presented with stage iii malignant melanoma. She underwent wide excision of skin, with lymph node dissection, and she started immunotherapy with a 3-week cycle of pembrolizumab. The patient demonstrated stable disease response, and no iraes were observed during her initial treatment courses. However, after the 9th treatment cycle, she began to experience epigastric pain that worsened significantly, requiring a visit to the emergency centre. Imaging by computed tomography (ct) and integrated positron-emission tomography/ct revealed severe diffuse gastroduodenitis with acute pancreatitis. Esophagogastroduodenoscopy showed diffuse oozing, hemorrhagic, edematous, and exfoliative mucosa involving the entire gastric wall, defined as acute hemorrhagic gastritis. Biopsies of the gastric wall revealed cmv infection. Those findings were consistent with a diagnosis of cmv gastritis, and the patient received antiviral therapy with ganciclovir. After treatment, she recovered enough to resume immunotherapy. This case report presents a rare occurrence of cmv gastritis related to immunotherapy. As more patients are treated with immunotherapy, incidences of cmv infections are expected to increase; a high index of clinical suspicion is therefore needed in symptomatic patients.

Novel Targeted Therapies for Metastatic Thyroid Cancer-A Comprehensive Review

The knowledge on thyroid cancer biology has grown over the past decade. Thus, diagnostic and therapeutic strategies to manage thyroid cancer are rapidly evolving. With new insights into tumor biology and cancer genetics, several novel therapies have been approved for the treatment of thyroid cancer. Tyrosine kinase inhibitors (TKIs), such as lenvatinib and sorafenib, have been successfully utilized for the treatment of radioactive iodine (RAI)-refractory metastatic differentiated thyroid cancer (DTC). In addition, pretreatment with mitogen-activated protein kinase (MAPK) inhibitors (trametinib and selumetinib) has been shown to restore RAI avidity in previously RAI-refractory DTCs. Local therapies, such as external beam radiation and radiofrequency/ethanol ablation, have also been employed for treatment of DTC. Vandetanib and cabozantinib are the two TKIs currently approved by the Food and Drug Administration (FDA) for the treatment of medullary thyroid cancer (MTC). Other novel therapies, such as peptide receptor radionuclide therapy and carcinoembryonic antigen (CEA) vaccine, have also been utilized in treating MTC. Ongoing trials on selective rearranged-during-transfection (RET) protooncogene inhibitors, such as LOXO-292 and BLU-667, have demonstrated promising results in the treatment of metastatic MTC resistant to non-selective TKIs. The FDA-approved BRAF/MEK inhibitor combination of dabrafenib and trametinib has revolutionized treatment of BRAFV600E mutation positive anaplastic thyroid cancer. Several other emerging classes of medications, such as gene fusion inhibitors and immune checkpoint inhibitors, are being actively investigated in several clinical trials. In this review, we describe the molecular landscape of thyroid cancer and novel targeted therapies and treatment combinations available for the treatment of metastatic thyroid cancer.

CTLA-4 and HLA-DQ are key molecules in the regulation of mDC-mediated cellular immunity by Tregs in severe aplastic anemia

Background

Regulatory T cells (Tregs) inhibit the activation of cluster of differentiation (CD) 4⁺, CD8⁺T cells and the antigen‐presenting process of antigen‐presenting cells, and may play an important role in acquired severe aplastic anemia (SAA).

Methods

Flow cytometry was used to measure CD4⁺CD25⁺CD127^dim Tregs, cytotoxic T lymphocyte antigen 4 (CTLA‐4) expression on Tregs, and human leukocyte antigen (HLA)‐DQ expression on myeloid dendritic cells (mDCs). The correlations of CTLA‐4 and HLA‐DQ with immune status and clinical indicators and the changes in these indicators after immunosuppressive therapy (IST) were analyzed.

Results

In SAA patients, the number of Tregs and their CTLA‐4 expression were low but recovered after IST; the HLA‐DQ expression on mDCs was high but decreased after IST. The CTLA‐4 expression on Tregs and the HLA‐DQ expression on mDCs showed a negative correlation. The CTLA‐4 on Tregs was positively but HLA‐DQ on mDCs negatively correlated with the number of Tregs, natural killer (NK) cell number, and CD4⁺T/CD8⁺T ratio. CTLA‐4 was positively but HLA‐DQ negatively correlated with the percentage of granulocytoid and erythroid cells in bone marrow, white blood cell count in PB, absolute neutrophil count in PB, and the percentage of reticulocytes in PB.

Conclusions

CTLA‐4/HLA‐DQ may be key in the regulation of Tregs on mDCs in SAA patients. Our findings should be helpful for further investigation of the mechanism of immune pathogenesis in SAA patients. Studies on the regulators of Treg and CTLA‐4 activity will be valuable for SAA therapeutic target research and disease monitoring.

The Contribution of Epigenetics to Cancer Immunotherapy

Effective anticancer immunotherapy treatments constitute a qualitative leap in cancer management. Nonetheless, not all patients benefit from such therapies because they fail to achieve complete responses, suffer frequent relapses, or develop potentially life-threatening toxicities. Epigenomic signatures in immune and cancer cells appear to be accurate and promising predictors of patient outcomes with immunotherapy. In addition, combined treatments with epigenetic drugs can exploit the dynamic nature of epigenetic changes to potentially modulate responses to immunotherapy. Candidate epigenetic biomarkers may provide a rationale for patient stratification and precision medicine, thus maximizing the chances of treatment success while minimizing unwanted effects. We present a comprehensive up-to-date view of potential epigenetic biomarkers in immunotherapy and discuss their advantages over other indicators.

British Society of Gastroenterology endorsed guidance for the management of immune checkpoint inhibitor-induced enterocolitis

Immune checkpoint inhibitors are a novel class of cancer treatment that have improved outcomes for a subset of cancer patients. They work by antagonising inhibitory immune pathways, thereby augmenting immune-mediated antitumour responses. However, immune activation is not cancer-specific and often results in the activation of immune cells in non-cancer tissues, resulting in off-target immune-mediated injury and organ dysfunction. Diarrhoea and gastrointestinal tract inflammation are common and sometimes serious side-effects of this type of therapy. Prompt recognition of gastrointestinal toxicity and, in many cases, rapid institution of anti-inflammatory or biologic therapy (or both) is required to reverse these complications. Management of organ-specific complications benefits from multidisciplinary input, including engagement with gastroenterologists for optimal management of immune checkpoint inhibitor-induced enterocolitis. In this British Society of Gastroenterology endorsed guidance document, we have developed a consensus framework for the investigation and management of immune checkpoint inhibitor-induced enterocolitis.

Gastrointestinal Tract Adverse Events

Immune checkpoint inhibitors (ICIs) have shown significant benefit in cancer patients. Their success, however, is associated with immune-related adverse events (irAEs), which commonly affect the gastrointestinal tract, resulting in diarrhea and colitis. IrAEs range from mild self-limiting to severe life-threatening diseases and potentially limit the use of these medications. Diagnosis of ICI-induced enterocolitis is based on clinical symptoms, physical examination, stool tests, endoscopic and histologic evaluation, and/or imaging. Current management strategy is mainly anti-diarrheal agents for mild symptoms and immunosuppressants (e.g., corticosteroids, and infliximab or vedolizumab) for more severe diseases.

Side effect management during immune checkpoint blockade using CTLA-4 and PD-1 antibodies for metastatic melanoma - an update

CTLA-4 and PD-1 play a key role in tumor-induced downregulation of lymphocytic immune responses. Immune checkpoint inhibitors have been shown to alter the immune response to various cancer types. Anti-CTLA-4 and anti-PD-1 antibodies affect the interaction between tumor, antigen-presenting cells and T lymphocytes. Clinical studies of the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab have provided evidence of their positive effects on overall survival in melanoma patients. Combined treatment using ipilimumab and nivolumab has been shown to achieve five-year survival rates of 52 %. Such enhancement of the immune response is inevitably associated with adverse events. Knowledge of the spectrum of side effects is essential, both in terms of prevention and management. Adverse events include colitis, dermatitis, hypophysitis, thyroiditis, hepatitis and other, less common autoimmune phenomena. In recent years, considerable progress has been made in the detection and treatment of the aforementioned immune-related adverse events. However, early diagnosis of rare neurological or cardiac side effects, which may be associated with increased mortality, frequently pose a challenge. The present update highlights our current understanding as well as new insights into the spectrum of side effects associated with checkpoint inhibitors and their management.

Investigational Biomarkers for Checkpoint Inhibitor Immune-Related Adverse Event Prediction and Diagnosis

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of multiple cancers. However, these promising therapies may also cause immune-related adverse events (irAEs) in a substantial proportion of patients. These autoimmune phenomena may affect almost any organ system and may occur at almost any point in therapy. In some instances, these toxicities are life-threatening and potentially permanent. Diverse clinical presentation and unpredictable timing further complicate their anticipation and diagnosis.

CONTENT

To improve patient safety and selection for ICI use, biomarkers for irAE diagnosis and prediction are under development. Clinicians may use traditional laboratory markers such as routine chemistries, creatinine clearance, thyroid function tests, and serum cortisol/adrenocorticotrophic hormone to monitor for specific irAEs, but noted aberrations may not necessarily represent an immune-mediated etiology. Novel biomarkers have the potential to be more specific to assist in the diagnosis of irAEs. The prediction of irAEs is more challenging. Apart from a history of autoimmune disease, no other clinical parameters are routinely used to project risk. Biomarker candidates under investigation for irAE diagnosis and prediction include blood cell analysis, chemokines/cytokines, autoantibodies, and genetic predisposition, such as human leukocyte antigen haplotype. Among other emerging candidates are immune-cell subsets, T-cell repertoire, fecal microbiome, tumor genomics, and radiomic characterization.

SUMMARY

Several conventional laboratory indexes of end-organ dysfunction are currently in routine clinical use for irAE monitoring and diagnosis. Novel biomarkers for the prediction and diagnosis of these irAEs, which primarily characterize patient immune function, represent an area of active investigation.

Colitis following the use of immune checkpoint inhibitors: A real-world analysis of spontaneous reports submitted to the FDA adverse event reporting system

BACKGROUND

Although colitis has been reported in patients treated with immune checkpoint inhibitors (ICIs), associations between colitis and ICIs had not been thoroughly assessed in real-world studies. Here, we identified and characterized significant colitis-associated with ICIs.

METHODS

Based on the Food and Drug Administration Adverse Event Reporting System (FAERS) from January 2004 to December 2019, the disproportionality analysis and Bayesian analysis, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN) and the multi-item gamma Poisson shrinker (MGPS) algorithms were adopted to data mining of the suspected adverse events of colitis after ICIs administrating. Clinical characteristics of patients with ICIs-associated colitis and the time to onset of colitis following different ICI regimens were collected.

RESULTS

A total of 3786 reports of colitis adverse events were identified with ICIs. Seven ICI monotherapies were associated with the reporting of colitis. Statistically significant ROR, PRR, information component (IC), and empirical Bayesian geometric mean (EBGM) emerged for all ICI monotherapies and combination therapies. ICIs-associated colitis affected mostly male (53.51%), with a wide mean age range (60.65 to 72 years). Colitis adverse events were commonly reported in patients with melanoma and lung cancer. Adverse outcomes of colitis concerning ICI were mainly outcomes of hospitalization-initiated or prolonged and other serious. Among colitis cases, 17.43% cases of colitis concerning ICI lead to death. The adverse event ofcolitis occurred earliest in ipilimumab monotherapy with a median time to onset of 64.21 days (IQR: 27-69 days) among all monotherapies.

CONCLUSIONS

ICI may lead to severe and disabling ICIs-associated colitis during therapy. Analysis of FAERS data identified signals for adverse events of colitis with ICI regimens. Practitioners should consider the factors that may increase the likelihood of colitis. The findings support a continued surveillance and risk factor identification studies.

Metabolic consequences of immune checkpoint inhibitors: A new challenge in clinical practice

Treatment of oncologic patients has progressed greatly the last few years with the development of immune checkpoint inhibitors (ICPIs). These drugs are associated with the immune system and, thus, may cause side effects of immune origin, the so called immune related adverse events (irAEs). Immune related AEs may actually affect all organs and systems and frequently resemble clinical entities commonly encountered in clinical practice. As ICPIs have improved both quality of life and life expectancy, clinicians of various specialties may need to deal with irAEs in their everyday practice. Therefore, they should be able to recognize them timely and treat them accordingly. Herein, we review the pathophysiology, clinical manifestations and treatment of irAEs.

Management of Patients With Immune Checkpoint Inhibitor-Induced Enterocolitis: A Systematic Review

Immune checkpoint inhibitors (ICIs) have improved the treatment of several cancers. These drugs increase T-cell activity and the antitumor immune response but also have immune-related adverse effects that can affect the gastrointestinal (GI) tract. These adverse effects have been observed in 7% to 30% of patients treated with ICIs. As the number of diseases treated with ICIs increases, gastroenterologists will see more patients with ICI-induced GI adverse events. We performed a systematic review of the incidence, risk factors, clinical manifestations, and management of the adverse effects of ICIs on the GI tract. Treatment with anti-cytotoxic T-lymphocyte-associated antigen-4 often causes severe enterocolitis, whereas treatment with inhibitors of programmed cell death 1 have less frequent and more diverse adverse effects. Management of patients with GI adverse effects of ICIs should involve first ruling out other disorders, followed by assessment of severity, treatment with corticosteroids, and rapid introduction of infliximab therapy for nonresponders.

Management Considerations for Immune Checkpoint Inhibitor-Induced Enterocolitis Based on Management of Inflammatory Bowel Disease

BACKGROUND

Immune checkpoint inhibitor therapy has significantly improved the outcomes of various advanced malignancies that were deemed unruly prior to its invention. Immune-mediated diarrhea and enterocolitis are among the most frequently encountered adverse events of immune checkpoint inhibitor therapy. Given the increasing use of these therapies in the treatment of an ever-growing number of malignancies, providing appropriate treatment for such adverse effects has become crucial.

METHODS

In this review, we summarize the current body of evidence concerning the management of immune-mediated diarrhea and enterocolitis. Additionally, management of immune-mediated diarrhea and enterocolitis is likened to that of inflammatory bowel disease, given the resemblance between both entities in pathogenesis and clinical features. Reviewing the literature raised several points regarding this devastating toxicity that still need further investigation by future efforts.

RESULTS

Endoscopic and histologic evaluation is pivotal in the assessment of immune-mediated diarrhea and enterocolitis and provides vital information regarding the severity of the disease to guide treatment. Corticosteroids are the main therapy for immune-mediated diarrhea and enterocolitis, with infliximab and vedolizumab as second-line agents. Recently, fecal microbiota transplantation has emerged as a treatment option for immune-mediated diarrhea and enterocolitis that is refractory to corticosteroids. Restarting immune checkpoint inhibitor therapy after resolution of immune-mediated diarrhea and enterocolitis carries a risk of recurrence that is mostly controllable with current immune-suppressive treatment.

CONCLUSIONS

Lastly, we propose a management algorithm for immune-mediated diarrhea and enterocolitis. Prospective research, preferably as collaborative efforts from oncology and gastroenterology specialists, is needed to refine the management of immune-mediated diarrhea and enterocolitis.

Diagnosis, monitoring, and management of adverse events from immune checkpoint inhibitor therapy

Immune checkpoint inhibitor therapy (icit) is now a standard of care for a variety of cancers in both the metastatic and adjuvant settings. As a result, an understanding of the timing, epidemiology, monitoring, diagnosis, and management of immune-related adverse events (iraes) associated with icit is imperative. This article reviews specific iraes by organ system, consolidating recommendations from multiple guidelines and incorporating data from case reports to highlight additional evolving therapeutic options for patients. Managing iraes requires early recognition, early intervention, and education of the patients and the multidisciplinary health care team alike. Given the durable responses observed with icit, and the irreversible nature of some of the iraes, further research into management of the sequelae of icit is required.

A review of cancer immunotherapy toxicity

Cancer immunotherapies, including checkpoint inhibitors and adoptive cell therapy, manipulate the immune system to recognize and attack cancer cells. These therapies have the potential to induce durable responses in multiple solid and hematologic malignancies and thus have transformed treatment algorithms for numerous tumor types. Cancer immunotherapies lead to unique toxicity profiles distinct from the toxicities of other cancer therapies, depending on their mechanism of action. These toxicities often require specific management, which can include steroids and immune-modulating therapy and for which consensus guidelines have been published. This review will focus on the toxicities of checkpoint inhibitors and chimeric antigen receptor T cells, including pathophysiology, diagnosis, and management.

Clinical diagnosis and treatment of immune checkpoint inhibitor-associated adverse events in the digestive system

Immunotherapy for malignant tumors is a hot spot in current research and the treatment of cancer. The activation of programmed cell death receptor-1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA)-4 relevant signaling pathway can inhibit the activation of T lymphocytes. Tumor cells can achieve immune escape by activating this signaling pathway. By inhibiting this signaling pathway, immune-checkpoint inhibitors (ICIs) activate T lymphocytes to clear the tumor cells. Therefore, the adverse effects of ICIs are mainly immune-related adverse events (irAEs). The digestive system, including the gastrointestinal tract and liver which are vital organs of digestion and absorption, metabolism and detoxification, as well as important immune-related organs, is the most commonly affected system of irAEs. This review explains the incidence, clinical features, diagnosis and treatment of liver and gastrointestinal adverse events in ICIs.

Recognition and management of the gastrointestinal and hepatic immune-related adverse events

Immunotherapy is revolutionizing the treatment paradigm for a broad spectrum of malignancies. However, the immune checkpoint inhibitors also cause a unique set of toxicities. In the digestive system, this has consisted for the most part as colitis and hepatotoxicity, but also include less-common manifestations. Baseline screening, early identification, timely diagnosis, rapid and adequate treatment can significantly minimize the toxicity of immunotherapy and improve prognosis. This article provides a comprehensive review of gastrointestinal and hepatic immune-related toxicities, including incidence, mechanism, clinical manifestation, diagnosis, treatment, and guidelines for resumption of immune checkpoint inhibitor therapy.

Clinical Characteristics and Treatment of Immune-Related Adverse Events of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have been changing the paradigm of cancer treatment. However, immune-related adverse effects (irAEs) have also increased with the exponential increase in the use of ICIs. ICIs can break up the immunologic homeostasis and reduce T-cell tolerance. Therefore, inhibition of immune checkpoint can lead to the activation of autoreactive T-cells, resulting in various irAEs similar to autoimmune diseases. Gastrointestinal toxicity, endocrine toxicity, and dermatologic toxicity are common side effects. Neurotoxicity, cardiotoxicity, and pulmonary toxicity are relatively rare but can be fatal. ICI-related gastrointestinal toxicity, dermatologic toxicity, and hypophysitis are more common with anti- CTLA-4 agents. ICI-related pulmonary toxicity, thyroid dysfunction, and myasthenia gravis are more common with PD-1/PD-L1 inhibitors. Treatment with systemic steroids is the principal strategy against irAEs. The use of immune-modulatory agents should be considered in case of no response to the steroid therapy. Treatment under the supervision of multidisciplinary specialists is also essential, because the symptoms and treatments of irAEs could involve many organs. Thus, this review focuses on the mechanism, clinical presentation, incidence, and treatment of various irAEs.

Checkpoint Inhibitor-Induced Colitis

Immune checkpoint inhibitors have revolutionized treatment and overall survival for several different types of cancer. Antibodies to cytotoxic T-lymphocyte-associated protein 4 and to programmed cell death protein 1 and its ligand enhance cytotoxic T-cell survival, thus augmenting antitumor action and consequently inducing immune-related adverse events, of which the most relevant is diarrhea and colitis. This review compiles recent data on pathophysiology, clinical manifestations, and treatment of immune-mediated colitis (IMC). The pathogenesis of IMC is not completely understood, but recent studies have focused on the role of regulatory T cells and interactions with the gut microbiome. While sharing similarities with inflammatory bowel disease, IMC is considered a distinct form of colitis with acute onset and rapid progression leading to potential complications including bowel perforation and death. Prompt recognition and management of IMC is imperative for optimal outcomes. Although prospective clinical trials are lacking to guide therapy, recent guidelines recommend early endoscopic evaluation to establish the diagnosis and prompt initiation of corticosteroids. Response to first-line therapy should be assessed early to determine the need of escalation to biologic agents. With treatment, most patients will experience full resolution of symptoms, and subsequent rechallenge with anti-programmed cell death protein 1 or anti-programmed death-ligand 1 inhibitors can be considered.

Organ-Specific Immune-Related Adverse Events Associated With Immune Checkpoint Inhibitor Monotherapy Versus Combination Therapy in Cancer: A Meta-Analysis of Randomized Controlled Trials

Background

Although combination therapy with immune checkpoint inhibitors (ICIs) provides a promising efficacy in multiple cancers, their use is facing challenges for a high incidence of adverse effects. This meta-analysis was conducted to compare the risks of organ-specific immune-related adverse events (IRAEs) associated with ICI monotherapy versus combination therapy among cancer patients.

Methods

Electronic databases were systematically searched to include eligible randomized controlled trials (RCTs). Any-grade and 3-5 grade IRAEs (colitis, pneumonitis, hepatitis, hypothyroidism, hyperthyroidism, and hypophysitis) were extracted for meta-analysis. Two reviewers independently assessed the methodological quality. The RevMan 5.3.5 software was used for meta-analysis.

Results

A total of 10 studies involving 8 RCTs with 2716 patients were included in this study. The most common any-grade adverse event was colitis (14.5%), followed by hypothyroidism (13.8%), hepatitis (10.4%), hypophysitis (10.0%), hyperthyroidism (9.3%), and pneumonitis (4.6%). Meta-analysis showed that ICI combination therapy significantly increased the risks of any-grade IRAEs in colitis [relative risk (RR), 3.56; 95% confidence interval (CI), 1.56–8.12; p < 0.05], pneumonitis (RR, 2.31; 95% CI, 1.54–3.45; p < 0.05), hepatitis (RR, 2.54; 95% CI, 1.65–3.91; p < 0.05), hypothyroidism (RR, 2.17; 95% CI, 1.71–2.76; p < 0.05), hyperthyroidism (RR, 3.13; 95% CI, 2.08–4.70; p < 0.05), and hypophysitis (RR, 3.54; 95% CI, 2.07–6.07; p < 0.05) compared with ICI monotherapy, as well as 3-5 grade IRAEs in colitis (RR, 2.50; 95% CI, 1.62–3.86; p < 0.05), pneumonitis (RR, 1.99; 95% CI, 1.00–3.93; p = 0.05), and hepatitis (RR, 2.70; 95% CI, 1.29–5.63; p < 0.05).

Conclusions

This meta-analysis demonstrated that, compared with ICI monotherapy, patients receiving ICI combination therapy significantly increased organ-specific IRAEs in colitis, hypothyroidism, hepatitis, hypophysitis, hyperthyroidism, and pneumonitis. The incidence and severity of organ-specific IRAEs were drug and dose independent.

CTLA-4: From mechanism to autoimmune therapy

CD28 and CTLA-4 are both important stimulatory receptors for the regulation of T cell activation. Because receptors share common ligands, B7.1 and B7.2, the expression and biological function of CTLA-4 is important for the negative regulation of T cell responses. Therefore, elimination of CTLA-4 can result in the breakdown of immune tolerance and the development of several diseases such as autoimmunity. Inhibitory signals of CTLA-4 suppress T cell responses and protect against autoimmune diseases in many ways. In this review, we summarize the structure, expression and signaling pathway of CTLA-4. We also highlight how CTLA-4 defends against potentially self-reactive T cells. Finally, we discuss how the CTLA-4 regulates a number of autoimmune diseases that indicate manipulation of this inhibitory molecule is a promise as a strategy for the immunotherapy of autoimmune diseases.

SEOM clinical guideline for the management of immune-related adverse events in patients treated with immune checkpoint inhibitors (2019)

The use of immune checkpoint inhibitors has emerged as an effective treatment option for patients with several tumor types. By increasing the activity of the immune system, they can induce inflammatory side effects, which are often termed immune-related adverse events. These are pathophysiologically unique toxicities, compared with those from other anticancer therapies. In addition, the spectrum of the target organs is very broad. Immune-inflammatory adverse events can be life threatening. Prompt diagnosis and pharmacological intervention are instrumental to avoid progression to severe manifestations. Consequently, clinicians require new skills to successfully diagnose and manage these events. These SEOM guidelines have been developed with the consensus of ten medical oncologists. Relevant studies published in peer-review journals were used for the guideline elaboration. The Infectious Diseases Society of America grading system was used to assign levels of evidence and grades of recommendation.

Imaging of tumour response to immunotherapy

A wide range of cancer immunotherapy approaches has been developed including non-specific immune-stimulants such as cytokines, cancer vaccines, immune checkpoint inhibitors (ICIs), and adoptive T cell therapy. Among them, ICIs are the most commonly used and intensively studied. Since 2011, these drugs have received marketing authorisation for melanoma, lung, bladder, renal, and head and neck cancers, with remarkable and long-lasting treatment response in some patients. The novel mechanism of action of ICIs, with immune and T cell activation, leads to unusual patterns of response on imaging, with the advent of so-called pseudoprogression being more pronounced and frequently observed when compared to other anticancer therapies. Pseudoprogression, described in about 2–10% of patients treated with ICIs, corresponds to an increase of tumour burden and/or the appearance of new lesions due to infiltration by activated T cells before the disease responds to therapy. To overcome the limitation of response evaluation criteria in solid tumors (RECIST) to assess these specific changes, new imaging criteria—so-called immune-related response criteria and then immune-related RECIST (irRECIST)—were proposed. The major modification involved the inclusion of the measurements of new target lesions into disease assessments and the need for a 4-week re-assessment to confirm or not confirm progression. The RECIST working group introduced the new concept of “unconfirmed progression”, into the irRECIST. This paper reviews current immunotherapeutic approaches and summarises radiologic criteria to evaluate new patterns of response to immunotherapy. Furthermore, imaging features of immunotherapy-related adverse events and available predictive biomarkers of response are presented.

Remission of ulcerative colitis flare-up induced by nivolumab

BACKGROUND

Immune checkpoint inhibitors (ICIs) have been used to treat many cancers, but ICIs are rarely administered for malignant tumours coexisting with inflammatory bowel disease.

METHODS AND RESULTS

We report a 77-year-old man experiencing an ulcerative colitis (UC) flare-up after receiving nivolumab as third-line therapy for multiple metastases of renal cell carcinoma. Mild UC (proctitis form) had been diagnosed at age 59 years and remission was maintained for 17 years with only a low dose of 5-ASA. After nivolumab treatment, the patient developed diarrhoea, bloody stools and was hospitalised. Computed tomography revealed inflammation involving the entire colon and endoscopy revealed severe UC exacerbation. Histological analysis showed UC findings and also increased crypt apoptosis which is unusual for inflammatory bowel diseases, while being typical of ICI-induced colitis. As with ICI-induced colitis, this exacerbation was strongly suggested to have been caused by nivolumab, although remission was achieved by increasing the 5-ASA dose to 4000 mg without prednisolone.

CONCLUSION

The administration of ICI for UC is not as yet sufficiently safe and further research is required.

Mechanistic classification of immune checkpoint inhibitor toxicity as a pointer to minimal treatment strategies to further improve survival

Improved anti-tumour responses under immune checkpoint inhibition (ICI) are associated with concomitant autoimmune disease development termed immune related adverse events (irAEs), of which approximately 5% are rheumatic in nature. Generally, oncologists and other specialists vigorously treat irAEs in spite of the generally accepted beneficial effect of irAEs on tumour survival. Herein, we highlight mechanistic insights on how tumour responses and certain types of autoimmunity appear to be inextricably linked around CD8+ T-cell mediated responses and that strategies that interfere with such shared immunopathgenesis could impact of survival. We discuss the possible circumstances in which intensive immunosuppressive therapy for irAEs that occur with ICIs might blunt anti-tumour immunity. We also discuss potential therapeutic strategies for emergent ICI related autoimmunity and propose some treatment considerations and research questions to minimize the impact of overzealous immunosuppression strategies on tumour responses. Thus, refraining from using powerful therapeutic armamentarium to treat irAEs, especially when these are not considered as life-threating might improve the prognosis of ICI therapy.

Toxicities associated with checkpoint inhibitors-an overview

Immunotherapy has an increasing role in the management of cancer, both in metastatic disease and as an adjuvant therapy. However, sensitization of the immune system with checkpoint inhibitors comes with a unique side effect profile. Full appreciation of this can take some time to emerge as some adverse events are rare, or can be subtle and potentially overlooked. Clinician awareness of these side effects can be particularly important in patients with pre-existing autoimmune conditions. Here we describe common symptoms and diagnostic strategies for organ-specific side effects of anti-CTLA-4 and anti-PD-1/PD-L1 immunotherapy agents.