Fatal enteric plexus neuropathy after one dose of ipilimumab plus nivolumab: a case report

Immune-related intestinal pseudo-obstruction caused by immune checkpoint inhibitors: case report

Intestinal obstruction, a rare manifestation of immunotherapy-related gastrointestinal adverse events, can be severe and even life-threatening with intestinal perforation. We present a 64-year-old man with HCC and currently under the therapy with Pembrolizumab, who was admitted in our hospital with abdominal distension. Radiologic findings were consistent with small bowel ileus. After conservative treatment, the patient underwent colonoscopy where no cause of ileus was discovered. The patient received high-dose prednisone due to the side effects of immune checkpoint inhibitor therapy. This resulted in a gradual improvement of symptoms.

The Effect of Immune Checkpoint Inhibitor Therapy on Pre-Existing Gastroparesis and New Onset of Symptoms of Delayed Gastric Emptying

Immune checkpoint inhibitors (ICIs) can cause myenteric plexopathy, which could result in delayed gastric emptying (GE) and possibly gastroparesis. We assessed the clinical outcomes of patients who had pre-existing gastroparesis or who developed symptoms of delayed GE following ICI therapy. We retrospectively identified adults with ICD-9 and ICD-10 codes for gastroparesis who received ICI therapy between 1 January 2020 and 31 December 2022 at a tertiary cancer center. Of 76 eligible patients, 37 had pre-existing gastroparesis; 39 (0.2% of the more than 18,000 screened) developed symptoms of delayed GE after ICI therapy, of which 27 (69%) patients had an alternative etiology for delayed GE. Four patients (11%) with pre-existing gastroparesis had a flare-up after ICI, and the median time to flare-up was 10.2 months (IQR, 0.7-28.6 months); for patients with new onset of suspected delayed GE after ICI, the median time to symptom onset was 12.8 months (IQR, 4.4-35.5 months). The clinical symptom duration of patients without an alternative etiology (74.5 days (IQR, 21.5-690 days)) and those with an alternative etiology (290 days (IQR, 147-387 days)) did not differ significantly (p = 1.00). Delayed GE after ICI therapy is a rare presentation but has a late onset and a prolonged symptom duration.

Small-cell Lung Carcinoma with Gastrointestinal Pseudo-obstruction as a Paraneoplastic Neurological Syndrome Elicited by an Immune Checkpoint Inhibitor

Gastrointestinal pseudo-obstruction (GIPO) is a phenotype of the paraneoplastic neurological syndrome (PNS). We herein report a case of small-cell lung carcinoma (SCLC) with GIPO elicited by an immune checkpoint inhibitor (ICI). A 75-year-old man with SCLC developed intractable intestinal obstruction after receiving one course of anticancer drugs (durvalumab, etoposide, and carboplatin). The serum anti-Hu antibody (Hu-Ab) was positive, and the patient was diagnosed with GIPO. Corticosteroid treatment did not improve the GIPO, and the patient died. There are few reports of GIPO after ICI treatment in patients with lung cancer, so a further investigation will be required to elucidate the mechanism by which ICIs elicit PNS. Checking for neuronal antibodies may help identify patients with SCLC who are at risk of developing PNS due to ICI treatment.

Chronic immune-related adverse events arising from immune checkpoint inhibitors: an update

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment, improving outcomes for many patients. However, toxicities termed immune-related adverse events (irAEs) are limitations of these revolutionary treatments. These irAEs may resolve with treatment or ICI cessation (acute) or persist many months beyond therapy cessation (chronic). Acute irAEs were the first to be recognized and are thus more well studied. However, chronic irAEs have been highlighted in recent years and are becoming a topic of more intensive investigation. These chronic irAEs have been noted to affect many different organ systems, including endocrine, rheumatologic, gastrointestinal, dermatologic, neurologic, and cardiovascular systems. In this review, we discuss current knowledge surrounding the frequency, time course, and risk factors associated with chronic irAEs affecting various organ systems, treatment approaches, and future directions.

Review article: Contemporary management of gastrointestinal, pancreatic and hepatic toxicities of immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are effective oncologic agents which frequently cause immune-related adverse events (irAEs) which can impact multiple organ systems. Onco-Gastroenterology is a novel and emerging subspecialty within gastroenterology focused on cancer treatment-related complications. Gastroenterologists must be prepared to identify and manage diverse immune-mediated toxicities including enterocolitis, hepatitis, pancreatitis and other ICI-induced toxicities.

AIM

To provide a narrative review of the epidemiology, diagnostic evaluation and management of checkpoint inhibitor-induced gastrointestinal and hepatic toxicities.

METHODS

We searched Cochrane and PubMed databases for articles published through August 2023.

RESULTS

Gastrointestinal and hepatic irAEs include most commonly enterocolitis and hepatitis, but also pancreatitis, oesophagitis, gastritis, motility disorders (gastroparesis) and other rarer toxicities. Guidelines from the National Comprehensive Cancer Network, American Society of Clinical Oncology and European Society for Medical Oncology, in combination with emerging cohort and clinical trial data, offer strategies for management of ICI toxicities. Evaluation of irAEs severity by formal classification and clinical stability, and a thorough workup for alternative etiologies which may clinically mimic irAEs underlie initial management. Treatments include corticosteroids, biologics and other immunosuppressive agents plus supportive care; decisions on dosing, timing and choice of steroid adjuncts and potential for subsequent checkpoint inhibitor dosing are nuanced and toxicity-specific.

CONCLUSIONS

Expanding clinical trial and cohort data have clarified the epidemiology and clinical characteristics of gastrointestinal, pancreatic and hepatic toxicities of ICIs. Guidelines, though valuable, remain based principally on retrospective cohort data. Quality prospective, controlled studies may refine algorithms for treatment and potential immunotherapy rechallenge.

Contractility of isolated colonic smooth muscle strips from rats treated with cancer chemotherapy: differential effects of cisplatin and vincristine

Background

Certain antineoplastic drugs cause gastrointestinal disorders even after the end of treatment. Enteric neuropathy has been associated with some of these alterations. Our goal was to assess the impact of repeated treatment with cisplatin and vincristine on the contractility of circular and longitudinal muscle strips isolated from the rat colon.

Methods

Two cohorts of male rats were used: in cohort 1, rats received one intraperitoneal (ip) injection of saline or cisplatin (2 mg kg-1 week-1) on the first day of weeks 1-5; in cohort 2, rats received two cycles of five daily ip injections (Monday to Friday, weeks 1-2) of saline or vincristine (0.1 mg kg-1 day-1). Body weight and food and water intake were monitored throughout the study. One week after treatment, responses of colonic smooth muscle strips to acetylcholine (10-9-10-5 M) and electrical field stimulation (EFS, 0.1-20 Hz), before and after atropine (10-6 M), were evaluated in an organ bath.

Results

Both drugs decreased body weight gain. Compared to saline, cisplatin significantly decreased responses of both longitudinal and circular smooth muscle strips to EFS, whereas vincristine tended to increase them, although in a non-significant manner. No differences were observed in the muscle response to acetylcholine. Atropine abolished the contractile responses induced by acetylcholine, although those induced by EFS were only partially reduced in the presence of atropine.

Conclusion

The findings suggest that although both drugs cause the development of enteric neuropathy, this seems to have a functional impact only in cisplatin-treated animals. Understanding the effects of chemotherapy on gastrointestinal motor function is vital for enhancing the quality of life of cancer patients.

The Evolving Treatment Landscape of Merkel Cell Carcinoma

OPINION STATEMENT

Merkel cell carcinoma (MCC) has a high risk of recurrence and requires unique treatment relative to other skin cancers. The patient population is generally older, with comorbidities. Multidisciplinary and personalized care is therefore paramount, based on patient preferences regarding risks and benefits. Positron emission tomography and computed tomography (PET-CT) is the most sensitive staging modality and reveals clinically occult disease in ~ 16% of patients. Discovery of occult disease spread markedly alters management. Newly diagnosed, localized disease is often managed with sentinel lymph node biopsy (SLNB), local excision, primary wound closure, and post-operative radiation therapy (PORT). In contrast, metastatic disease is usually treated systemically with an immune checkpoint inhibitor (ICI). However, one or more of these approaches may not be indicated. Criteria for such exceptions and alternative approaches will be discussed. Because MCC recurs in 40% of patients and early detection/treatment of advanced disease is advantageous, close surveillance is recommended. Given that over 90% of initial recurrences arise within 3 years, surveillance frequency can be rapidly decreased after this high-risk period. Patient-specific assessment of risk is important because recurrence risk varies widely (15 to > 80%: Merkelcell.org/recur) depending on baseline patient characteristics and time since treatment. Blood-based surveillance tests are now available (Merkel cell polyomavirus (MCPyV) antibodies and circulating tumor DNA (ctDNA)) with excellent sensitivity that can spare patients from contrast dye, radioactivity, and travel to a cancer imaging facility. If recurrent disease is locoregional, management with surgery and/or RT is typically indicated. ICIs are now the first line for systemic/advanced MCC, with objective response rates (ORRs) exceeding 50%. Cytotoxic chemotherapy is sometimes used for debulking disease or in patients who cannot tolerate ICI. ICI-refractory disease is the major problem faced by this field. Fortunately, numerous promising therapies are on the horizon to address this clinical need.

Dysautonomia associated with immune checkpoint inhibitors

OBJECTIVE

The purpose of this study is to report the clinical characteristics of dysautonomia associated with immune checkpoint inhibitors (ICIs).

METHODS

We reported two patients with autoimmune autonomic ganglionopathy (AAG) occurring as immune-related adverse events (irAEs). We also performed a review of previous case reports presenting dysautonomia during ICI therapy. Moreover, we conducted pharmacovigilance analyses using the US Food and Drug Administration Adverse Events Reporting System (FAERS) to investigate dysautonomia associated with ICI.

RESULTS

Two patients in our care developed both AAG and autoimmune encephalitis following ICI therapy for lung cancers. We comprehensively reviewed 13 published cases (M:F = 11:2, mean onset age of 53 years) with ICI-associated dysautonomia including AAG (n = 3) and autonomic neuropathy (n = 10). Of these, ICI monotherapy was performed in seven and combination ICI use in six. In 6 of 13 patients, dysautonomia appeared within one month after the start of ICIs. Orthostatic hypotension was observed in 7 and urinary incontinence or retention in five. All patients except three showed gastrointestinal symptoms. Anti-ganglionic acetylcholine receptor antibodies were undetectable. All but two patients received immune-modulating therapy. Immuno-modulating therapy was effective in three patients with AAG and two patients with autonomic neuropathy, but ineffective in the others. Five patients died, of either the neurological irAE (n = 3) or cancer (n = 2). The pharmacovigilance analyses using FAERS showed that ipilimumab monotherapy and the combination of nivolumab and ipilimumab constituted significant risks for developing dysautonomia, consistent with the review of literature.

CONCLUSION

ICIs can cause dysautonomia including AAG, and autonomic neuropathy is a neurological irAE.

Evaluation and management of acute high-grade immunotherapy-related neurotoxicity

Immune checkpoint inhibitor monoclonal antibodies allow the host's immune system to attack tumors, which has revolutionized cancer care over the last decade. As the use of immune checkpoint inhibitors has expanded, so have autoimmune-like complications known as immune-related adverse events. These include the infrequent but increasingly more common, potentially deadly neurological immune related adverse events. When feeling acutely ill, patients will often seek care not from their oncologist but from their family physician, clinics, emergency, and urgent care sites, or other available providers. Thus, while assessing acutely ill cancer patients who are experiencing neurological symptoms, non-oncologists should be prepared to recognize, diagnose, and treat neurological immune related adverse events in addition to more familiar conditions. This narrative review is designed to update acute care clinicians on current knowledge and to present a symptom-based framework for evaluating and treating neurological immune related adverse events based on the leading immunotoxicity organizations' latest recommendations.

Checkpoint Inhibitors and the Gut

Checkpoint inhibitors have revolutionized treatments in modern oncology, including many conditions previously relegated to palliative therapies only. However, emerging recognition of checkpoint inhibitor-related adverse events has complicated the status of checkpoint inhibitor-related therapies. This review article discusses gastrointestinal adverse events as a result of checkpoint inhibitor therapy, as well as limitations of current guidelines, thus providing recommendations for guideline revision and future study direction.

Paraneoplastic Opsoclonus-myoclonus Syndrome with Anti-Hu and Anti-SOX-1 Antibodies after Immune-checkpoint Inhibitor Treatment Combined with Chemotherapy in a Patient with Small-cell Lung Cancer

A 69-year-old man with advanced small-cell lung cancer achieved partial remission after 3 courses of immunochemotherapy that included atezolizumab. Ten days after the last treatment, he developed paraneoplastic opsoclonus-myoclonus syndrome and required mechanical ventilation. Serology testing detected anti-Hu and anti-SOX-1 antibodies. Despite steroid pulse therapy, various anticonvulsants, continuous intravenous sedation, and a fourth course of chemotherapy without atezolizumab, his condition failed to improve. Paraneoplastic opsoclonus-myoclonus syndrome with autoantibodies after immune-checkpoint inhibitor treatment has not been reported previously. Although a causal relationship between immune-checkpoint inhibitors and paraneoplastic syndromes has been suggested, the mechanism remains unknown.

Esophageal Achalasia Induced by Ipilimumab and Nivolumab Combination: A Rare Neurological Manifestation of Immune-related Autonomic Neuropathy

Immunotherapy with immune checkpoint inhibitors (ICIs) has improved the prognosis of many cancers; a combination of nivolumab (anti-programmed cell death protein 1) and ipilimumab (anti-cytotoxic T-lymphocyte-associated protein 4) is approved as first-line therapy for advanced melanoma, with objective responses obtained in more than half of patients. However, this combination is associated with a high rate of immune-related adverse events, which are often severe and multiple. Neurological immune-related adverse events are rare but feared because they can be life-threatening, their diagnosis and management are challenging, and patients can have irreversible sequelae. We reported a case of a young patient treated by nivolumab and ipilimumab combination for metastatic melanoma. Severe dysphagia with regurgitations, major weight loss, uveitis, and vitiligo occurred after 3 infusions of nivolumab and ipilimumab. Magnetic resonance imaging and positron emission tomography scan showed complete remission of melanoma. The endoscopic examination did not find any digestive toxicity. Esophageal manometry revealed achalasia. This was associated with mydriasis, pathologic deep breath test, and alteration of the cutaneous sympathetic response on electromyogram, which was consistent with autonomic neuropathy. This rare etiology of atypical vomiting under ICI should be known by prescribers, as ICI prescription is widening in many new cancers.

Paraneoplastic Neuropathies: What's New Since the 2004 Recommended Diagnostic Criteria

The diagnostic criteria published by the PNS (Paraneoplastic Neurological Syndromes) Euronetwork in 2004 provided a useful classification of PNS, including paraneoplastic neuropathies. Subacute sensory neuronopathy (SSN) was the most frequently observed peripheral PNS, whereas other forms of neuropathy, as sensory polyneuropathy, sensorimotor polyneuropathy, demyelinating neuropathies, autonomic neuropathies, and focal nerve or plexus lesions, were less frequent. At the time of publication, the main focus was on onconeural antibodies, but knowledge regarding the mechanisms has since expanded. The antibodies associated with PNS are commonly classified as onconeural (intracellular) and neuronal surface antibodies (NSAbs). Since 2004, the number of antibodies and the associated tumors has increased. Knowledge has grown on the mechanisms underlying the neuropathies observed in lymphoma, paraproteinemia, and multiple myeloma. Moreover, other unrevealed mechanisms underpin sensorimotor neuropathies and late-stage neuropathies, where patients in advanced stages of cancer—often associated with weight loss—experience some mild sensorimotor neuropathy, without concomitant use of neurotoxic drugs. The spectrum of paraneoplastic neuropathies has increased to encompass motor neuropathies, small fiber neuropathies, and autonomic and nerve hyperexcitability syndromes. In addition, also focal neuropathies, as cranial nerves, plexopathies, and mononeuropathies, are considered in some cases to be of paraneoplastic origin. A key differential diagnosis for paraneoplastic neuropathy, during the course of cancer disease (the rare occurrence of a PNS), is chemotherapy-induced peripheral neuropathy (CIPN). Today, novel complications that also involve the peripheral nervous system are emerging from novel anti-cancer therapies, as targeted and immune checkpoint inhibitor (ICH) treatment. Therapeutic options are categorized into causal and symptomatic. Causal treatments anecdotally mention tumor removal. Immunomodulation is sometimes performed for immune-mediated conditions but is still far from constituting evidence. Symptomatic treatment must always be considered, consisting of both drug therapy (e.g., pain) and attempts to treat disability and neuropathic pain.

Acute motor axonal neuropathy after ipilimumab and nivolumab treatment in melanoma brain metastases: A case report and review of the literature

The use of immune checkpoint inhibitors including ipilimumab and nivolumab has expanded for several tumors including melanoma brain metastasis. These have resulted in a growing spectrum of neurologic immune-related adverse events, including ones that are rare and difficult to diagnose and treat. Here, we present a patient with melanoma brain metastasis who was treated with immune checkpoint inhibitors and developed an Acute Motor Axonal Neuropathy. To our knowledge, this is the first case of Acute Motor Axonal Neuropathy as an immune-related adverse event associated with combination treatment of ipilimumab and nivolumab, who was successfully treated. A 28-year-old woman with metastatic BRAF V600E melanoma developed melanoma brain metastasis and was enrolled on Checkmate 204, a Phase 2 clinical trial using ipilimumab (3 mg/kg intravenous) and nivolumab (1 mg/kg intravenous) every 3 weeks for four cycles, followed by monotherapy with nivolumab (240 mg intravenous) every 2 weeks. A few days after Cycle 2 of ipilimumab and nivolumab, she developed a pure motor axonal neuropathy consistent with Acute Motor Axonal Neuropathy. She was treated with several immunosuppressive treatments including high dose methylprednisolone, immune globulin, and infliximab, and her motor neuropathy eventually improved several months after onset of symptoms. Unfortunately, she had progression of her systemic disease and died several months later. This is the first case reported of Acute Motor Axonal Neuropathy associated with ipilimumab and nivolumab, successfully treated with immune-suppressive therapy. As the field of immunotherapy expands with the increasing use of the immune checkpoint inhibitors, it is critical to increase our knowledge and understanding of the neurologic immune-related adverse events associated with immune checkpoint inhibitors. This includes the spectrum of rare neurologic immune-related adverse events, which can be quite difficult to recognize and treat. Early consultations with neurology may expedite a diagnosis and treatment plan in patients with unexplained weakness receiving immune checkpoint inhibitor therapy.

Enteric plexus neuropathy associated with PD-L1 blockade in a patient with small-cell lung cancer

Immune checkpoint inhibitors have revolutionized the management of patients with cancer. The increasing use of these agents has brought up a new set of adverse events which are widely heterogenous and potentially life-threatening. Rare immune-related adverse events associated with nervous system have not been described thoroughly, but their early recognition and management may be crucial. Immune-related autonomic neuropathy may be presented with a constellation of symptoms ranging from gastrointestinal and urinary complaints, to sweating and hypotension. Intestinal pseudo-obstruction as consequence of immune-related myenteric autonomic neuropathy is an under-recognized, not-well described and potentially fatal adverse event. We herein, present a unique case of enteric plexus neuropathy induced by PD-L1 blockade in a patient with small-cell lung cancer.

Gastroparesis Following Immune Checkpoint Inhibitor Therapy: A Case Series

BACKGROUND

Immune checkpoint inhibitors (ICI) have improved outcomes in patients with various malignancies; however, they can cause immune-related hepatitis and enterocolitis. Patients on ICI may also develop upper gastrointestinal symptoms and undergo measurement of gastric emptying.

AIMS

Our aim was to review records of patients with gastroparesis following ICI therapy at two medical centers.

METHODS

We performed a retrospective review of all patients at Mayo Clinic and Brigham and Women's/Dana-Farber Cancer Center (BWH/DFCC) who underwent gastric scintigraphy for the assessment of symptoms of gastroparesis following ICI treatment up to January 2020. Clinical presentation, medical history, laboratory evaluation, imaging, treatment, and outcomes were retrieved from the records. Gastroparesis was diagnosed as delayed gastric emptying (GE) measured by gastric scintigraphy.

RESULTS

At Mayo Clinic, 2 patients (median age 59 years, 1 male [M], 1 female [F]) had delayed GE, while 4 patients (median age 53 years, 3M, 1F) had normal GE following ICI use. Of those with delayed GE (diagnosed after 38 and 2 months of ICI initiation), 1 patient was treated for non-Hodgkin's lymphoma and melanoma with ipilimumab; a second patient with breast cancer was treated with pembrolizumab. At BWH/DFCC, 2 patients (median age 56 years, 1M, 1F) had normal GE after ICI treatment, while a 62-year-old female with non-small cell lung cancer developed gastroparesis 3 months following initiation of nivolumab.

CONCLUSION

This report documents gastroparesis as a potential adverse effect of ICI. Further studies should explore the potential for ICI therapy to damage anti-inflammatory macrophages that preserve the enteric neurons.

Neurological complications of immune checkpoint inhibitor cancer immunotherapy

Neurological autoimmunity is increasingly recognized as a complication of immune checkpoint inhibitor (ICI) cancer immunotherapy. ICIs act by enhancing endogenous anti-tumor immune responses and can also lead to autoimmunity affecting all organs. ICI-related neurological autoimmunity is rare, most often manifests with neuromuscular involvement and more rarely affects the central nervous system. Neurological complications often often present in the first three months of ICI treatment but can also appear after ICI discontinuation. These can occur in patients with tumors not traditionally associated with paraneoplastic neurological autoimmunity, such as melanoma and renal-cell carcinoma and should be suspected when a new neurological symptoms present while on ICI and cannot be explained by disease progression or as a consequence of metabolic dysfunction. Treatment consists of ICI discontinuation or withdrawal depending on the severity with or without immunosuppression. Generally, improvement is observed depending on the patient's baseline characteristics and neurological presentation.

Neurologic Complications of Immune Checkpoint Inhibitors in Thoracic Malignancies

Immune checkpoint inhibitors (ICIs) have transformed the prognosis of cancers previously considered lethal. The spectrum of therapeutic indications is rapidly expanding, including the vast majority of thoracic malignancies. By enhancing the immune responses against cancer, the ICI treatments lead to the development of immune-related adverse events (irAEs) that may affect any organ. Severity varies from mild to fatal clinical manifestations. Neurologic involvement is relatively rare and highly heterogeneous, including central and peripheral nervous system diseases associated with neural-specific autoantibodies or not, central nervous system vasculitis, and granulomatous and demyelinating disorders. Symptoms often manifest within the first four cycles of treatment and can develop regardless of the class of ICI used. An unfavorable outcome is found in up to one-third of patients and is generally associated with the patients' clinical characteristics (e.g., age, coexistence of systemic adverse events), cancer type (e.g., lung cancer versus other), and specific clinical setting (e.g., ICI treatment in patients with preexisting paraneoplastic neurologic autoimmunity, ICI rechallenge after a first neurologic irAE). Diagnosis should be suspected in patients with new-onset neurologic symptoms while on ICI treatment which are not explained by metastatic disease or other metabolic/infectious disorders. Recommended treatment is based on clinical severity and consists of ICI discontinuation with or without immunosuppressive/immunomodulatory therapy, although alternative approaches are reasonable depending on cancer status (e.g., aggressive immunosuppression without discontinuing ICI in patients with initial cancer response). Early recognition and appropriate treatment of these neurologic irAEs are crucial for improved patient outcomes and therapeutic planning.

Management of Immunotherapy Adverse Events in Oncological Patients: Anti-CTLA-4, Anti-PD-1/PD-L1

BACKGROUND

The widespread use of immunotherapy drugs in the oncological field has led to the spread of new toxicities compared to the more common chemotherapy treatments. This is because immunotherapy with anti-CTLA-4 (Cytotoxic T Lymphocytes-Associated Antigen 4), anti- PD-1 and anti-PD-L1 monoclonal antibodies has become the standard-of-care in a growing number of indications. Any organ or tissue can be involved, but more commonly, side effects are reported regarding skin, colon, endocrine glands, liver, lung and kidney. Other less frequent, but more serious, adverse events are neurological and myocarditis.

METHODS

We performed an electronic search on PUBMED of the literature concerning immunotherapy- related toxicities and their management in oncological patients from 2007 to 2020, with particular attention to the most recent publications.

AIM

To summarize the different types of immunotherapy-related toxicities, together with their incidence and diagnosis, and to simplify their management, especially in the emergency setting.

CONCLUSION

Usually, for grade I toxicities, it is not recommended to stop immunotherapy; for most of grade II toxicities, immunotherapy should be postponed to when toxicity will have regressed to grade I, considering the possibility of corticosteroid treatment for most toxicities. The majority of grade III and IV require administration of high-dose corticosteroid intravenous therapy and suspension of immunotherapy. Mortality related to immune checkpoint inhibitors' toxicity, occurring at a rate of 0.3-1.3%, is well below fatality rates due to other oncologic interventions and should not discourage the promising results so far reached by immunotherapy.

Immune checkpoint inhibitors-induced neuromuscular toxicity: From pathogenesis to treatment

Immune checkpoint inhibitors (ICIs) are increasingly used and are becoming the standard of care in the treatment of various tumor types. Despite the favorable results in terms of oncological outcomes, these treatments have been associated with a variety of immune-related adverse events (irAEs). Neurological irAEs are rare but potentially severe. Neuromuscular disorders represent the most common neurological irAEs following anti-PD-1, anti-PD-L1, and anti-CTLA-4 treatment, and include myositis, myasthenia gravis, and demyelinating polyradiculoneuropathy. Instrumental findings may differ from typical neuromuscular disorders occurring outside ICIs treatment. Despite initial severity, neurological irAEs often respond to immune-modulating therapies. Prompt irAEs diagnosis, ICIs discontinuation, and early treatment with corticosteroids, together with patient education and a multi-disciplinary approach, are important for optimizing clinical outcomes. Intravenous immunoglobulin, plasma exchange, and other immune-modulating treatments should be considered in more severe cases. Consideration of re-challenging with the same immunotherapy drug may be given in some cases, based on clinical picture and initial severity of irAEs.

Incidence and characteristics of neurotoxicity in immune checkpoint inhibitors with focus on neuromuscular events: Experience beyond the clinical trials

Immune checkpoint inhibitors (ICIs) are associated with various neurological adverse events (NAEs). We herein explored the incidence and clinical phenotype of immune-related NAEs in cancer patients. Medical records of ICI-treated cancer patients were reviewed between the years 2010 and 2018, with an aim to characterize immuno-related NAEs. A total of 1185 ICIs-treated patients were identified, 63.7% of which were males and 36.3% were females, with a mean age of 63.4 ± 7.3 years. Twenty-four from the overall ICIs-treated patients (2%) developed NAEs. No differences were identified in terms of age, sex, tumor type and class of ICIs between the patients who developed NAEs and those who did not. The median number of cycles of ICI treatment before NAEs onset were 4.5 (1-10), and the median time was 102 days. Peripheral nervous system (PNS) involvement was present in 14 patients (58.4%) and central nervous system (CNS) involvement in 10 (33.3%), including 2 patients with aseptic meningitis and polyradicular involvement. Amongst PNS complications, there were five (20.8%) with axonal sensory neuropathies, four (16.7%) with Guillain-Barre-like syndromes, and four (16.7%) with myositis and/or myasthenic syndromes. The majority of patients with PNS-related NAEs (n = 11; 78.6%) improved after ICIs discontinuation and treatment with immune-modulating therapies. The time to neuromuscular toxicities onset was significantly shorter, compared to CNS NAEs (median 70 vs 119 days, P = .037). Immune-related NAEs mostly present with neuromuscular complications. Discontinuation of ICIs and appropriate treatment should be commenced early throughout the process, in order to maximize a favorable outcome.

An autoimmune-based, paraneoplastic neurologic syndrome following checkpoint inhibition and concurrent radiotherapy for merkel cell carcinoma: case report

PURPOSE

Merkel cell carcinoma is highly sensitive to both radiation and immunotherapy. Moreover, concurrent radioimmunotherapy may capitalize on anti-tumor immune activity and improve Merkel cell treatment response, although an enhanced immune system may cross-react with native tissues and lead to significant sequelae.

METHODS

Here we present a case study of a patient with metastatic Merkel cell carcinoma treated with radiotherapy concurrent with pembrolizumab.

RESULTS

After radioimmunotherapy, the patient developed sensory neuropathy, visual hallucinations, and mixed motor neuron findings. Neurologic dysfunction progressed to profound gastrointestinal dysmotility necessitating parenteral nutrition and intubation with eventual expiration.

CONCLUSION

This case represents a unique autoimmune paraneoplastic neurologic syndrome, likely specific to neuroendocrine tumors and motivated by concurrent radioimmunotherapy. Recognition of the potential role of radioimmunotherapy may provide an advantage in anticipating these severe sequelae.

Diagnosis and Management of Rare Immune-Related Adverse Events

Oncologic treatment is being revolutionized by a burgeoning number of immune checkpoint inhibitors (ICPis). To date, seven ICPis have received Food and Drug Administration approval, targeting cytotoxic T-lymphocyte antigen, programmed cell death, or programmed cell death ligand. Adverse events associated with checkpoint inhibition have been described in the literature. Guidelines exist for the most common of these, but as the use of ICPis becomes more common, the number of patients presenting with rare events will increase. This article reviews the diagnosis and management of rare ocular, hematological, luminal gastrointestinal, and rheumatological toxicities arising from ICPi treatment. KEY POINTS: As the use of immune checkpoint inhibitors (ICPis) becomes more common, the number of rare immune-related adverse events (irAEs) will increase. A high level of suspicion is required to identify and treat these toxicities. Although it can be difficult to definitively attribute rare irAEs to ICPis, a temporal and mechanistic relationship and the absence of other etiologies should make the treating physician suspicious for a rare irAE. Certain rare irAEs, such as celiac disease, do not require treatment with glucocorticoids. Thus, differentiating this irAE from other gastrointestinal irAEs has important implications for treatment.

Fatal myositis and spontaneous haematoma induced by combined immune checkpoint inhibitor treatment in a patient with pancreatic adenocarcinoma

BACKGROUND

Immune checkpoint inhibitors (ICIs) have achieved unprecedented success in cancer treatment over the past decade. The application of ICIs hasled to the discovery of various types of immune-related adverse events (irAEs). Here, we report a case of fatal myositis and spontaneous haematoma following concurrent treatment of nivolumab and ipilimumab for pancreatic adenocarcinoma.

CASE PRESENTATION

A 71-year-old gentleman with pancreatic adenocarcinoma underwent the Whipple procedure in September 2014. The patient received 8 cycles of adjuvant chemotherapy with gemcitabineand achieved a complete responsein April 2015. Treatment with the PD-1 inhibitor nivolumab was started due to suspected tumour recurrence in November 2015. In August 2016, the CTLA-4 inhibitor ipilimumab was added to nivolumab for 2 cycles. Eight weeks after the last dose, the patient developed severe myositis complicated with spontaneous haematomain skeletalmuscle. Pathology of the skeletal muscle autopsy revealed lymphocytic infiltration. Intense immunosuppressive therapy, including high-dose corticosteroids and methotrexate, resulted in clinical success in the treatment of myositis. However, the patient died of cancer recurrence.

CONCLUSION

Myositis due to immunotherapy can be a fatal adverse event of ICIs, which requires close monitoring and cautious management.

CTLA4 antagonists in phase I and phase II clinical trials, current status and future perspectives for cancer therapy

INTRODUCTION

In cancer, the immune response to tumor antigens is often suppressed by inhibitors and ligands. Checkpoint blockade, considered one of the most promising frontiers for anti-cancer therapy, aims to stimulate the immune anti-cancer response. Agents such as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) inhibitors offer prolonged survival with manageable side effects.

AREAS COVERED

We summarize the recent clinical successes of CTLA-4 inhibitors and place a strong emphasis on those in early phase clinical trials, often in combination with other immune check-point inhibitors, i.e., programmed cell death protein 1 (PD-1) and BRAF/mitogen-activated protein kinase inhibitors.

EXPERT OPINION

Recent phase I and phase II clinical trials confirm the efficacy of anti-CTLA-4 therapy for treatment of cancers such as renal cell carcinoma. These studies also indicated increased efficacy with combined immune checkpoint blockade with PD-1 or Ras/Raf/mitogen-activated protein kinase/ERK kinase (MEK)/extracellular-signal-regulated kinase (ERK) inhibitors. Researchers must search for new immune targets that may enable more effective and safe immune checkpoint blockade and cancer therapy. This goal may be achieved by next-generation combination therapies to overcome immune checkpoint therapy resistance.