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

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.

Early-Stage Triple-Negative Breast Cancer Journey: Beginning, End, and Everything in Between

Triple-negative breast cancer (TNBC) is a very heterogeneous and aggressive breast cancer subtype with a high risk of mortality, even if diagnosed early. The mainstay of early-stage breast cancer includes systemic chemotherapy and surgery, with or without radiation therapy. More recently, immunotherapy is approved to treat TNBC, but managing immune-rated adverse events while balancing efficacy is a challenge. The purpose of this review is to highlight the current treatment recommendations for early-stage TNBC and the management of immunotherapy toxicities.

Multidisciplinary treatment of a patient with severe immune checkpoint inhibitor-induced colitis: A case report

BACKGROUND

Immune checkpoint inhibitors (ICIs) are a new class of antitumor drugs that have been approved to treat a variety of malignant tumors. However, the occurrence of immune related adverse events (irAEs) has become an important reason for terminating treatment. ICIs sometimes lead to diarrhea and colitis, with severe enterocolitis potentially causing the hemorrhage of the lower gastrointestinal tract and colonic perforation. ICI-associated colitis is primarily treated with glucorticosteroids and/or agents targeting tumor necrosis factor-α. Here, we describe a case of severe ICI-associated colitis due to anti-programmed cell death ligand 1 (PD-L1) (durvalumab) treatment for small cell lung cancer with liver metastasis. The patient exhibited a poor response to rescuable therapy, and eventually received a laparoscopic subtotal colectomy and ileostomy. The data presented here will contribute to optimizing current treatment strategies for patients with severe ICI-associated colitis.

CASE SUMMARY

A 71-year-old man was admitted for a second course of anti-PD-L1 + IP (durvalumab + irinotecan + cisplatin) treatment to manage lung cancer with liver metastasis, diagnosed 1 mo previously. Four days after the second dose, the patient developed abdominal pain and bloody diarrhea. Due to the anti-PD-L1 medication history and colonoscopy findings of the patient, he was diagnosed with a colitis associated with ICI treatment. After treatment with sufficient glucocorticoids and two courses of infliximab, the patient developed severe lower gastrointestinal bleeding. After adequate assessment, the patient was treated by laparoscopic surgery, and was discharged in stable condition.

CONCLUSION

The early screening and hierarchical management of irAEs need the joint participation of a multidisciplinary team. For ICI-related colitis with ineffective medical treatment, timely surgical intervention could prevent the death of patients.

Utility of periodic medical questionnaires and examinations for immune-related adverse event screening: A prospective observational study

Background

Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) specific to the immunity-boosting activity of the drugs and may necessitate discontinuation of treatment depending on their severity. IrAEs may be difficult to diagnose in their early stages as they can occur in any organ. The present, prospective, observational study is the first to attempt to assess the utility of periodic medical questionnaires and laboratory, radiological, and physiological examinations in diagnosing irAEs.

Methods

We analyzed 51 patients who received immunotherapy for metastatic renal or urothelial carcinoma at Tokyo Metropolitan Tama Medical Center between 2016 and 2020. A medical questionnaire consisting of 41 questions and laboratory tests were administered to the patients on the day of each ICI administration and 1 week afterwards. A significant complaint was defined as a complaint not addressed in the questionnaire immediately prior to the first ICI administration.

Results

Fifty-one patients with metastatic renal or urothelial carcinoma were enrolled. The mean age was 72.1 years (range: 54–88 years). The male: female ratio was 32: 19. Of the total cohort, 26 (51%) patients had renal carcinoma, and 25 (49%) had urothelial carcinoma. The median follow-up time was 2.6 (range: 0.4–40.7) months. Thirty-three patients (65%) experienced irAEs.

Conclusions

In our cohort, periodic medical questionnaires and examinations were effective for early diagnosis and prompt treatment of irAEs. Although periodic examinations led to a high irAE diagnosis rate, the attendant medical cost was high. Further study is needed to find ways of addressing this issue.

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.

Immune-related adverse events in various organs caused by immune checkpoint inhibitors

Current cancer immunotherapies target immune checkpoint molecules such as the inhibitory receptor programmed cell death-1 (PD-1), one of its ligands, programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen 4 (CTLA-4), a competitive ligand for CD28 binding to stimulatory receptors CD80 and CD86. Multiple biological drugs use monoclonal antibodies targeting PD-1, PD-L1 and CTLA-4 as cancer immunotherapies. These are termed immune checkpoint inhibitors (ICIs). However, activation of the immune system by ICIs can induce the development of immune-related adverse events (irAEs), which can affect multiple organ systems. The most frequent irAEs are cutaneous and mimic various types of spontaneous skin disorders. Most irAEs are classified as autoimmune conditions mediated by ICI-activated CD8⁺ cytotoxic T cells, some of which are also related to activated B cells and production of pathogenic antibodies. Interestingly, blockade of CTLA-4 mainly induces activation of T cells and inhibition of T_reg cells. On the other hand, the mechanisms underlying anti-PD-1/PD-L1 ICI-induced irAEs are more complicated. PD-1 is a receptor expressed on T and B cells, which binds not only PD-L1, but also PD-L2. The role of PD-L1 is dominant in Th1 and Th17 immunity, while PD-L2 works mainly in Th2 immunity. Better understanding of the mechanisms underlying irAEs will allow for better management of irAEs and improve outcomes and quality of life in cancer patients.

Risk of selected gastrointestinal toxicities in metastatic renal cell carcinoma patients treated with immuno-TKI combinations: a meta-analysis

OBJECTIVE

Recent years have registered the advent of novel treatment options for metastatic renal cell carcinoma (mRCC), including combination therapies with immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs). Immuno-TKI combinations have been suggested to improve clinical outcomes but may also result in increased toxicity, including gastrointestinal (GI) adverse events.

METHODS

Herein, we performed a meta-analysis aimed at comparing the risk of certain GI toxicities in mRCC patients treated with immuno-TKI combinations versus sunitinib monotherapy. Overall, four phase III trials (KEYNOTE-426, JAVELIN Renal 101, CheckMate 9ER, CLEAR) involving 3059 mRCC patients were available.

RESULTS

The meta-analysis suggested an increased risk of all-grade diarrhea, grade 3-4 diarrhea and grade 3-4 decreased appetite in patients treated with immuno-TKI combinations. Conversely, an apparently higher risk of all-grade nausea was observed in the sunitinib group.

CONCLUSION

The meta-analysis suggested that immuno-TKI combinations are associated with higher risk of GI toxicities compared with sunitinib. Beyond the efficacy of immuno-TKI combinations in mRCC patients, careful consideration should be given to treatment-related adverse events, including GI toxicities. Early recognition and treatment are critical to maximize recovery.

When steroids are not enough in immune-related hepatitis: current clinical challenges discussed on the basis of a case report

Unleashing adaptive immunity via immune checkpoint inhibitors (ICPIs) in many cancer types led to durable antitumor responses and prolonged survivals and also added some new immune-related adverse events (irAEs) to the ‘old-fashioned’ safety profile of chemotherapy. Among bowel and endocrine irAEs, immune-mediated hepatotoxicity/hepatitis is a less common and far less well-studied toxicity, which, however, could develop into a serious complication, especially when it becomes persistent or refractory to steroids. Its incidence, onset and severity vary widely, depending on the type of underlying treated cancer, the class, the dosage and the duration of immunotherapy as well as the way of its administration (as a single agent or in combination with other ICPI or chemotherapy). In this study, we present a patient with metastatic melanoma who developed severe steroid-resistant ir-hepatitis after treatment with ipilimumab and required triple concurrent immunosuppression with prednisolone, mycofenolate mofetil and tacrolimus in order for his liver toxicity to be resolved. Intrigued by this case, we focused further on melanoma, as the disease-paradigm of immunotherapy in cancer, reviewed the reported incidence of hepatotoxicity among phase III ICPIs-containing trials on melanoma and discussed the main clinical considerations regarding the diagnosis and the management of persistent/steroid-refractory ir-hepatitis. As more clinical experience is gradually gained on this challenging topic, better answers are provided to questions about the appropriate diagnostic workup, the necessity of liver biopsy, the available immunosuppressive options beyond corticosteroids (their combinations and/or their sequence) as well as the correct decision on withdrawing or resuming immunotherapy. Nonetheless, a thorough multidisciplinary discussion is still required to individualize the overall approach in each case after failure of steroids.

Development of preclinical and clinical models for immune-related adverse events following checkpoint immunotherapy: a perspective from SITC and AACR

Recent advances in cancer immunotherapy have completely revolutionized cancer treatment strategies. Nonetheless, the increasing incidence of immune-related adverse events (irAEs) is now limiting the overall benefits of these treatments. irAEs are well-recognized side effects of some of the most effective cancer immunotherapy agents, including antibody blockade of the cytotoxic T-lymphocyte-associated protein 4 and programmed death protein 1/programmed-death ligand 1 pathways. To develop an action plan on the key elements needed to unravel and understand the key mechanisms driving irAEs, the Society for Immunotherapy for Cancer and the American Association for Cancer Research partnered to bring together research and clinical experts in cancer immunotherapy, autoimmunity, immune regulation, genetics and informatics who are investigating irAEs using animal models, clinical data and patient specimens to discuss current strategies and identify the critical next steps needed to create breakthroughs in our understanding of these toxicities. The genetic and environmental risk factors, immune cell subsets and other key immunological mediators and the unique clinical presentations of irAEs across the different organ systems were the foundation for identifying key opportunities and future directions described in this report. These include the pressing need for significantly improved preclinical model systems, broader collection of biospecimens with standardized collection and clinical annotation made available for research and integration of electronic health record and multiomic data with harmonized and standardized methods, definitions and terminologies to further our understanding of irAE pathogenesis. Based on these needs, this report makes a set of recommendations to advance our understanding of irAE mechanisms, which will be crucial to prevent their occurrence and improve their treatment.

Fecal calprotectin as a predictor of gastrointestinal immune-related adverse events (CF-19): A prospective study

Background: Colitis is a frequent immune-related toxicity, without any biomarker that may predict its onset. It is endoscopically similar to intestinal inflammatory diseases, where fecal calprotectin (FC) is used as a biomarker to early-detect a relapse. We found contradictory evidence about FC and immunotherapy and no prospective study was already published.   Methods: We present an analytical, observational and prospective study of one year’s duration. We analyzed FC basal, and then prior to each cycle until the sixth, ending with quarterly follow-up. For evaluating the predictive value of FC we estimated the area under the ROC curve for basal absolute values and for each cycle, and calculated its relative percentage change with respect to basal. We also planned to estimate sensitivity, specificity and predictive values indexes for different cut-off points. Because of lack of recruitment we did a preliminary analysis at the end of the initially estimated period before suggesting its prolongation.   Results: 24 patients (19 male) were included in the study. This included n=15 diagnosed with lung cancer, head and neck, renal, bladder and colorectal cancer (n=2, each), and melanoma (n=1). They were treated with Anti PD-1/PDL-1 mono therapy (n=18), combo with chemo (n=2), or combo with anti-CTLA4 (n=2). Three patients had G1 colitis and two, >=G2, all treated with anti-PD1 and before 6th cycle, as described on literature. ROC curve presents AUC 0,559 (CI95%:0,32-0,798) and RR for colitis taking FC value is 1,001 for each 10 units (p=0,493).   Conclusion: Even though we must take into account the limitations of the study we cannot conclude that FC could be used as a predictor for detecting immune-mediated colitis.

Multi-detector computed tomography (MDCT)-based severity score as a prognostic tool in patients with suspected immune checkpoint inhibitor therapy associated colitis

OBJECTIVE

This study aimed to assess MDCT as a diagnostic and prognostic tool in patients with suspected immune checkpoint inhibitor (ICI)-related colitis.

MATERIALS AND METHODS

This retrospective cohort study included patients receiving ICIs at three hospitals between 2015 and 2019 who underwent both abdominopelvic MDCT and endoscopic biopsy to workup suspected ICI-related colitis. Two radiologists independently reviewed MDCT images for signs of colitis based on pre-defined features. Diagnostic performance of MDCT was calculated and categorical variables between treatment subgroups were compared. Logistic regression was used to develop proposed MDCT criteria for diagnosis and MDCT severity score based on a combination of MDCT features of colitis to predict the patient outcomes in ICI-related colitis.

RESULTS

A total of 118 MDCT scans from 108 patients were evaluated for suspected colitis, with 72 confirmed ICI-related colitis cases. Sensitivity, specificity, PPV, and NPV of MDCT for diagnosis of ICI-related colitis was 81% (58/72), 52 % (24/46), 73% (58/80), and 63% (24/38), respectively. Small bowel involvement was visualized in 25% of cases with ICI-related colitis (18/72). In melanoma patients presenting with diarrhea grade ≥ 2 (n = 40), MDCT had the best diagnostic performance for ICI-related colitis (specificity = 80% [8/10], PPV = 92% [23/25]). MDCT severity scores predicted intravenous steroid use (OR 10.3, p = 0.004), length of stay > 7 days (OR 9.0, p < 0.001), and endoscopic mucosal ulceration (OR 4.7, p = 0.02).

CONCLUSION

MDCT is a useful diagnostic and prognostic tool for evaluating patients with immune checkpoint inhibitor-related colitis. An MDCT-based severity score enables assessment of disease severity and predicts outcome.

KEY POINTS

• MDCT is useful for the diagnosis of colitis in patients receiving immune checkpoint inhibitor (ICI) therapy, and an MDCT-based severity score allows for prognostication of patient outcomes. • MDCT yielded moderate sensitivity (81%) for diagnosis of ICI-related colitis but limited specificity (52%). However, in symptomatic melanoma patients (grade 2-4 diarrhea) with a high pretest probability, MDCT proved useful for diagnosis with a high PPV (92%). • For ICI-related colitis, our proposed MDCT severity score has prognostic value in predicting intravenous steroid use, prolonged length of stay during inpatient admission (> 7 days), and endoscopic mucosal ulceration.

Histopathology of Gastrointestinal Immune-related Adverse Events: A Practical Review for the Practicing Pathologist

Immune checkpoint inhibitors target checkpoint proteins with the goal of reinvigorating the host immune system and thus restoring antitumor response. With the dramatic increase in the use of checkpoint inhibitors for cancer treatment, surgical pathologists have assumed a major role in predicting the therapeutic efficacy (score based on programmed cell death ligand 1 immunohistochemistry and mismatch repair protein loss) as well as diagnosing the complications associated with these medications. Immune-related adverse events (irAEs) manifest as histologic changes seen in both the upper and lower gastrointestinal tract, and when viewed in isolation, may be morphologically indistinguishable from a wide range of diseases including infections, celiac disease, and inflammatory bowel disease, among others. Evaluation of biopsies from both the upper and lower gastrointestinal tract can aid in the distinction of gastrointestinal irAEs from their mimics. In the liver, the histologic changes of hepatic irAEs overlap with de novo diseases associated with hepatitic and cholangitic patterns of injury. The diagnosis of irAEs requires communication and collaboration from the pathologist, oncologist, and gastroenterologist. This review provides a background framework and illustrates the histologic features and differential diagnosis of gastrointestinal and hepatic irAEs.

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.

Diagnostic utility of CT for suspected immune checkpoint inhibitor enterocolitis

BACKGROUND AND AIMS

Immune checkpoint inhibitor (ICI) enterocolitis is a common immune-related adverse event and can be fatal, especially when not diagnosed and treated promptly. The current gold standard for diagnosis is endoscopy with biopsy, but CT scan is a possible alternative. The primary objective of this study is to identify the diagnostic performance of CT in the evaluation of ICI enterocolitis.

METHODS

With institutional review board approval, we conducted a retrospective cohort study of patients who received ICI therapy between 2015 and 2019 across a healthcare system. Patients were included if they underwent both abdominal CT and endoscopy with biopsy within 3 days. The radiological and pathological diagnoses, as well as clinical characteristics, were extracted from the electronic medical record. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CT for diagnosing ICI enterocolitis when compared with tissue diagnosis.

RESULTS

Of the 4474 patients screened, 138 met inclusion criteria. Most common tumor types were melanoma (37%) and lung cancer (19%). Seventy-four per cent were treated with antiprogrammed cell death (PD-1)/PD-L1 therapy. Thirty-nine per cent had signs of enterocolitis on CT scan and 58% had biopsy-proven ICI enterocolitis. Sensitivity and specificity of CT were 50% and 74%, respectively. PPV was 73% and NPV was 52%. Of those with confirmed ICI enterocolitis, 70% had grade 3 or higher symptoms, 91% received steroids and 40% received infliximab.

CONCLUSION

The performance of CT scan for diagnosis of ICI enterocolitis is moderate to poor and does not replace endoscopy with biopsy.

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.