Neurological Immune Related Adverse Events Associated with Nivolumab, Ipilimumab, and Pembrolizumab Therapy-Review of the Literature and Future Outlook

Neuro-ophthalmic Complications of Immune-Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have revolutionized the field of oncology by modulating the immune cell-cancer cell interaction and thereby promoting immune system disinhibition in order to target several types of malignancies. There are three classes of immune checkpoint inhibitors (ICIs): anti-cytotoxic T-lymphocyte associated antigen 4 (CTLA-4), anti-programmed cell death protein-1 (PD-1), and anti-programmed cell death ligand-1 (PD-L1).It is not uncommon for physicians across all specialties to encounter a patient with a history of malignancy and ICI exposure, necessitating familiarity with their potential complications. In this review article, we discuss the most common immune-related adverse events (irAEs) pertaining to the central and peripheral nervous systems and their potential afferent and efferent neuro-ophthalmic manifestations. Early recognition and treatment of these irAEs, and discontinuation of the offending ICI are all critical steps to prevent morbidity and mortality.

Only three cycles of nivolumab showed remarkable durable response and reversible myeloradiculoneuropathy in a patient with metastatic papillary renal cell carcinoma type 2

Introduction

The efficacy of nivolumab for non-clear cell renal cell carcinoma is still unclear. We present a rare case of metastatic papillary renal cell carcinoma remarkably responded to nivolumab but developed myeloradiculoneuropathy as immune-related adverse event.

Case presentation

The patient had previously undergone radical nephrectomy for right renal mass and was diagnosed as papillary renal cell carcinoma type 2, pT3bN0M0. Three years after the first surgery, he received 3 mg/kg of nivolumab as a second-line drug for mediastinum lymph nodes and lung metastases. With three cycles of nivolumab, the patient felt progressive weakness of the legs and received two cycles of steroid-pulse therapy based on the diagnosis of myeloradiculoneuropathy. Although nivolumab therapy has been discontinued, the metastases show radiographic complete response at 2 years after the last nivolumab administration without any additional therapy.

Conclusion

Nivolumab may be a promising treatment option for non-clear cell renal cell carcinoma such as papillary renal cell carcinoma.

An update on the safety of nivolumab for the treatment of advanced melanoma

Introduction: Due to its unique mechanism of action as an immune checkpoint inhibitor, nivolumab has high antitumor activity, but at the same time this mechanism is responsible for immune-related adverse events that may limit patients' safety and therapy continuation.Areas covered: Long-term safety of nivolumab including 5-year follow-up, safety of nivolumab treatment after ipilimumab therapy, safety of nivolumab in challenging subgroups (elderly, patients with brain metastases, patients with autoimmune disorders), safety of nivolumab in with rare melanoma subtypes (including mucosal melanoma), as well as specificity of AEs reported for nivolumab treatment in melanoma patients in comparison to other cancer types and other immunotherapy molecules, and impact of AEs on response rates and PFS on nivolumab treatment are discussed.Expert opinion: Search for biomarkers that would help us to identify patient populations that may suffer from severe nivolumab toxicity could help in selecting patients that should not be treated with this type of therapy. Novel combinations and immunotherapy drugs including use of NKTR-214 (IL-2 pathway), lymphocyte-activation gene 3 (LAG-3), local injections of talimogene laherparepvec (T-VEC), or systemic use of T-cell receptors agonists such as OX40, CD137, ICOS-1, could provide regimens with limited toxicity and higher activity.

The Upregulation of Molecules Related to Tumor Immune Escape in Human Pituitary Adenomas

Human pituitary adenomas are one of the most common intracranial neoplasms. Although most of these tumors are benign and can be treated medically or by transsphenoidal surgery, a subset of these tumors are fast-growing, aggressive, recur, and remain a therapeutic dilemma. Because antibodies against immune checkpoint receptors PD-1 and CLTA-4 are now routinely used for cancer treatment, we quantified the expression of mRNA coding for PD-1, CLTA-4, and their ligands, PD-L1, PD-L2, CD80, and CD86 in human pituitary adenomas and normal pituitary glands, with the ultimate goal of exploiting immune checkpoint therapy in aggressive pituitary adenomas. Aggressive pituitary adenomas demonstrated an increased expression of PD-L2, CD80, and CD86 in compared to that of normal human pituitary glands. Furthermore, aggressive pituitary tumors demonstrated significantly higher levels of CD80 and CD86 compared to non-aggressive tumors. Our results establish a rationale for studying a potential role for immune checkpoint inhibition therapy in the treatment of pituitary adenomas.

Diagnosis and Differential Diagnosis of Neurological Adverse Events during Immune Checkpoint Inhibitor Therapy

Therapy with immune checkpoint inhibitors (ICIs) has improved overall survival and cancer-related morbidity of cancer treatment even in cancer entities with poor prognosis. Since the approval of the first ICI, ipilimumab, for treatment of advanced melanoma by the Food and Drug Administration (FDA) in 2011, the spectrum of indications and approved ICIs has grown, rapidly. Up to now, seven different ICIs for more than 20 indications are available. However, their mechanisms of action can lead to immune-related adverse events (irAEs). In particular, neurological irAEs are clinically relevant. Although they are rare, an early and accurate diagnosis is challenging and neurological disease course and sequelae are potentially fatal. Between 08/2017 and 03/2020, 31 patients received ICI treatment at Hannover Medical School and presented with neurological adverse events (N-irAEs). Treated malignancies were metastatic melanoma, bronchial carcinoma, and urothelial cell carcinoma. All patients received comprehensive neurological diagnostics including clinical examination and magnetic resonance imaging (MRI). Cerebrospinal fluid (CSF) analysis was obtained in 21 patients and electroneurography was performed in 22 patients. Although N-irAEs were suspected in all 31 patients, 11 patients had other conditions leading to neurological symptoms including tumor metastases in seven patients and hemorrhagic or ischemic stroke in four patients. In the following, these patients are referred to as the differential diagnosis (DD) group. Patients with N-irAEs suffered from immune mediated neuropathy (9/20), myositis and/or myasthenic syndrome (6/20), or encephalitis/cerebellitis (5/20). Except for cell count, CSF results did not differ between the N-irAEs and the DD group. Symptoms related to N-irAEs are rather unspecific potentially mimicking other tumor-related symptoms such as metastases. Patients with malignancy are predominantly not treated by neurologists. Because of the complexity of neurological symptoms, detailed neurological investigations in specialized institutions are necessary in patients with new neurological symptoms and need to be critically discussed with treating oncologists.

Immune manifestations with checkpoint inhibitors in a single Brazilian center: experience and literature review

Objectives

The presence of autoimmune events were recorded in patients receiving immune checkpoint inhibitors.

Materials & Methods

Retrospective study in patients receiving immune checkpoint inhibitors (ICIs) during the period of 2012-2019.

Results

A total of 554 patients received ICIs of which 123 developed an immune related adverse event. Twenty one (17%) with toxicity were identified as having a pre-existing autoimmune disease and 88 required treatment with corticosteroids or hormone replacement. Thirty two (26%) out of 123 had to temporarily discontinue ICIs due to autoimmune manifestations. Endocrine and skin manifestations were the most prevalent immune disorders in our cohort. In melanoma better efficacy was seen in patients with immune toxicity.

Conclusion

Autoimmune diseases appear in patients receiving ICIs in this real world experience. Our results differ from other series on the frequency of autoimmunity. Complete discontinuation of ICIs due to autoimmunity was rare.

Neuro-ophthalmic Complications of Immune Checkpoint Inhibitors: A Systematic Review

OBJECTIVE

Immune checkpoint inhibitors (ICIs) are novel cancer therapies that may be associated with immune-related adverse events (IRAEs) and come to the attention of neuro-ophthalmologists. This systematic review aims to synthesize the reported ICI-associated IRAEs relevant to neuro-ophthalmologists to help in the diagnosis and management of these conditions.

METHODS

A systematic review of the literature indexed by MEDLINE, Embase, CENTRAL, and Web of Science databases was searched from inception to May 2020. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Primary studies on ICIs and neuro-ophthalmic complications were included. Outcomes included number of cases and incidence of neuro-ophthalmic IRAEs.

RESULTS

Neuro-ophthalmic complications of ICIs occurred in 0.46% of patients undergoing ICI and may affect the afferent and efferent visual systems. Afferent complications include optic neuritis (12.8%), neuroretinitis (0.9%), and giant cell arteritis (3.7%). Efferent complications include myasthenia gravis (MG) (45.0%), thyroid-like eye disease (11.9%), orbital myositis (13.8%), general myositis with ptosis (7.3%), internuclear ophthalmoplegia (0.9%), opsoclonus-myoclonus-ataxia syndrome (0.9%), and oculomotor nerve palsy (0.9%). Pembrolizumab was the most common causative agent for neuro-ophthalmic complications (32.1%). Mortality was highest for MG (19.8%). Most patients (79.8%) experienced improvement or complete resolution of neuro-ophthalmic symptoms due to cessation of ICI and immunosuppression with systemic corticosteroids.

CONCLUSION

While incidence of neuro-ophthalmic IRAEs is low, clinicians involved in the care of cancer patients must be aware of their presentation to facilitate prompt recognition and management. Collaboration between oncology and neuro-ophthalmology teams is required to effectively manage patients and reduce morbidity and mortality.

International Consensus Guidance for Management of Myasthenia Gravis: 2020 Update

Objective

To update the 2016 formal consensus-based guidance for the management of myasthenia gravis (MG) based on the latest evidence in the literature.

Methods

In October 2013, the Myasthenia Gravis Foundation of America appointed a Task Force to develop treatment guidance for MG, and a panel of 15 international experts was convened. The RAND/UCLA appropriateness method was used to develop consensus recommendations pertaining to 7 treatment topics. In February 2019, the international panel was reconvened with the addition of one member to represent South America. All previous recommendations were reviewed for currency, and new consensus recommendations were developed on topics that required inclusion or updates based on the recent literature. Up to 3 rounds of anonymous e-mail votes were used to reach consensus, with modifications to recommendations between rounds based on the panel input. A simple majority vote (80% of panel members voting “yes”) was used to approve minor changes in grammar and syntax to improve clarity.

Results

The previous recommendations for thymectomy were updated. New recommendations were developed for the use of rituximab, eculizumab, and methotrexate as well as for the following topics: early immunosuppression in ocular MG and MG associated with immune checkpoint inhibitor treatment.

Conclusion

This updated formal consensus guidance of international MG experts, based on new evidence, provides recommendations to clinicians caring for patients with MG worldwide.

Immune Checkpoint Inhibitor-Induced Polymyositis and Myasthenia Gravis with Fatal Outcome

We here report on a 74-year-old man diagnosed with a pT3cN0 BRAF-mutated and mismatch repair-deficient adenocarcinoma in the colon ascendens and 3 liver metastases. After hemicolectomy, the patient received treatment with the PD-1 inhibitor pembrolizumab. Three weeks later (on day 22), laboratory tests showed leukocytosis and an increase in transaminases; immune checkpoint inhibitor (ICI)-induced hepatitis was suspected and prednisolone therapy was initiated. On day 29, the patient was acutely hospitalized due to dyspnea, somnolence and walking difficulties. Dysarthria, hoarseness, muscle pain and weakness had developed and the dose of prednisolone was increased. Serum levels of lactate dehydrogenase, creatine kinase and myoglobin were increased and ICI-induced myositis was suspected. Antibodies against acetylcholine receptor and titin were present, indicating myasthenia gravis. Eventually, bulbar myopathy developed, including dysarthria and dysphagia, and the patient could no longer attain saturation without oxygen. The patient was transferred to the intensive care unit, intubated and given methylprednisolone, intravenous immunoglobulins and infliximab. The patient developed carbon dioxide retention and died on day 39. Microscopical examination of the intercostal musculature, diaphragm, cervical musculature and tongue showed inflammatory infiltration and fibrosis consistent with a pronounced myositis. In the liver, microscopical examination did not show metastases from colorectal cancer but instead a hepatocellular cancer. The cause of death was determined as respiratory insufficiency due to polymyositis. In conclusion, ICIs may induce myositis combined with neurological immune-related adverse events. In patients developing muscle weakness and pain under ICI therapy, myositis should be suspected.

Inflammatory Myeloradiculitis Secondary to Pembrolizumab: A Case Report and Literature Review

Immune checkpoint inhibitors are the most important new medications in oncology and include inhibitors of programmed cell death protein-1 (PD-1) such as Pembrolizumab, Nivolumab, and Cemiplimab. These anticancer agents prevent tumour immune evasion and have been associated with a range of immune-related adverse events (irAEs) including those involving the nervous system. In this case report and literature review, we present the first case of inflammatory myeloradiculitis secondary to Pembrolizumab. We also summarise the characteristics, treatment, and outcomes of other cases reported in the literature which include a component of myelitis. Finally, we make general recommendations on management.

Immune checkpoint inhibitor-induced inflammatory arthritis: identification and management

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy.

AREAS COVERED

In this review, the authors focus on ICI-IIA. Relevant articles were identified through PubMed searches, spanning 2010 to the present. The authors detail the current understanding of its pathogenesis, diagnostic evaluation, and management strategies.

EXPERT OPINION

ICI-IIA is a complex irAE that we are just beginning to understand mechanistically and pathologically. It often presents later in the disease course than other irAEs and, due to various reasons, is under-recognized. In some patients, ICI-IIA may become a chronic disease, which distinguishes it from most irAEs that resolve after ICI discontinuation. Multiple important questions still demand further research including which patients may develop ICI-IIA? What are possible diagnostic and prognostic markers? Do anti-arthritis therapies interfere with the anti-tumor response? and when should steroid-sparing agents be initiated? Close collaboration and shared decision-making between oncologists, rheumatologists, and the patient are essential when managing this particular irAE.

A Case of Anti-CRMP5 Paraneoplastic Neurological Syndrome Induced by Atezolizumab for Small Cell Lung Cancer

We herein report a 76-year-old man who developed irritability and forgetfulness 5 months after the introduction of atezolizumab for the treatment of small cell lung cancer (SCLC). Brain magnetic resonance imaging showed lesions of the striatum, and an investigation of the serum revealed a high titer of anti-CRMP5 antibody. After stopping atezolizumab and starting steroid pulse therapy, these clinical features improved. Given these findings, it is considered that CRMP5-assciated striatal encephalitis was induced by atezolizumab in this case with SCLC.

The Terrible Triad of Checkpoint Inhibition: A Case Report of Myasthenia Gravis, Myocarditis, and Myositis Induced by Cemiplimab in a Patient with Metastatic Cutaneous Squamous Cell Carcinoma

Background

We report a case of a patient with squamous cell carcinoma (SCC) who developed myasthenia gravis (MG), myositis, and myocarditis after receiving cemiplimab, an anti-PD-1 immune checkpoint inhibitor (ICI). Case Presentation. An 86-year-old man with metastatic periocular SCC presented with decreased vision in the left eye, severe fatigue, and lower back and bilateral hip pain 3 weeks after receiving cemiplimab. Within hours, he developed dysphonia, pharyngeal secretions, and dysphagia, necessitating intubation. Endomyocardial biopsy revealed active lymphocyte-mediated necrosis consistent with ICI-induced myocarditis. Anti-striated muscle and anti-acetylcholine receptor antibodies were elevated, consistent with myositis and myasthenia gravis. Despite plasma exchange therapy, steroids, and intravenous immunoglobulin, he died from cardiac arrest.

Conclusions

The presence of myasthenia gravis, myocarditis, or myositis should prompt evaluation for all three toxicities as they may represent an overlap syndrome. The severity of these immunotoxicities highlights the need for clinicians to suspect multiple simultaneous adverse effects of ICIs.

Myasthenia Gravis: From the Viewpoint of Pathogenicity Focusing on Acetylcholine Receptor Clustering, Trans-Synaptic Homeostasis and Synaptic Stability

Myasthenia gravis (MG) is a disease of the postsynaptic neuromuscular junction (NMJ) where nicotinic acetylcholine (ACh) receptors (AChRs) are targeted by autoantibodies. Search for other pathogenic antigens has detected the antibodies against muscle-specific tyrosine kinase (MuSK) and low-density lipoprotein-related protein 4 (Lrp4), both causing pre- and post-synaptic impairments. Agrin is also suspected as a fourth pathogen. In a complex NMJ organization centering on MuSK: (1) the Wnt non-canonical pathway through the Wnt-Lrp4-MuSK cysteine-rich domain (CRD)-Dishevelled (Dvl, scaffold protein) signaling acts to form AChR prepatterning with axonal guidance; (2) the neural agrin-Lrp4-MuSK (Ig1/2 domains) signaling acts to form rapsyn-anchored AChR clusters at the innervated stage of muscle; (3) adaptor protein Dok-7 acts on MuSK activation for AChR clustering from “inside” and also on cytoskeleton to stabilize AChR clusters by the downstream effector Sorbs1/2; (4) the trans-synaptic retrograde signaling contributes to the presynaptic organization via: (i) Wnt-MuSK CRD-Dvl-β catenin-Slit 2 pathway; (ii) Lrp4; and (iii) laminins. The presynaptic Ca²⁺ homeostasis conditioning ACh release is modified by autoreceptors such as M1-type muscarinic AChR and A2A adenosine receptors. The post-synaptic structure is stabilized by: (i) laminin-network including the muscle-derived agrin; (ii) the extracellular matrix proteins (including collagen Q/perlecan and biglycan which link to MuSK Ig1 domain and CRD); and (iii) the dystrophin-associated glycoprotein complex. The study on MuSK ectodomains (Ig1/2 domains and CRD) recognized by antibodies suggested that the MuSK antibodies were pathologically heterogeneous due to their binding to multiple functional domains. Focussing one of the matrix proteins, biglycan which functions in the manner similar to collagen Q, our antibody assay showed the negative result in MG patients. However, the synaptic stability may be impaired by antibodies against MuSK ectodomains because of the linkage of biglycan with MuSK Ig1 domain and CRD. The pathogenic diversity of MG is discussed based on NMJ signaling molecules.

Prevalence and Characteristics of Neuroinfectious Disease Inquiries Within the Emerging Infections Network: A 22-Year Retrospective Study

Background

To monitor emerging infectious diseases, the Centers for Disease Control and Prevention and the Infectious Disease Society of America established the Emerging Infections Network (EIN), allowing infectious disease specialists to post inquiries about clinical cases. We describe the frequency and characteristics of neuroinfectious disease-related inquiries.

Methods

The EIN listserv was retrospectively reviewed from February 1997 to December 2019 using search terms associated with neurologic diseases. We recorded case summaries, disease type (ie, meningitis, encephalitis), inquiry type (diagnostic approach, result interpretation, management decisions), unique patient populations, exposures, pathogens, ultimate diagnosis, and change in clinical care based on responses.

Results

Of 2348 total inquiries, 285 (12.1%) related to neuroinfectious diseases. The majority involved meningitis (99, 34.7%) or encephalitis (56, 19.6%). One hundred fifteen inquiries (40%) related to management, 34 (12%) related to diagnostic workup, and 22 (8%) related to result interpretation. Eight (2.8%) specifically involved results of cerebrospinal fluid polymerase chain reaction testing. Sixty-three (22.1%) involved immunosuppressed patients (29 human immunodeficiency virus-positive cases [46%]). The most common pathogens were Treponema pallidum (19, 6.7%) and Cryptococcus neoformans (18, 6.3%). In 74 (25%) inquiries, patients had neurologic symptoms without a clear infection, 38 (51.3%) of which included noninfectious neurologic etiologies in the differential diagnosis.

Conclusions

This study demonstrates the significant challenges of diagnosis and management of neuroinfectious diseases within the field of infectious diseases. It also highlights the importance of curated forums to guide the approach of difficult cases, in particular instances that mimic infectious diseases. Finally, the EIN listserv may assist in identifying areas for research and training to address these complexities.

Autoimmune encephalitis associated with Ma2 antibodies and immune checkpoint inhibitor therapy

Immune checkpoint inhibitors have transformed the treatment of advanced malignancy, while increasing the risk of immune-related adverse events. A 56-year-old woman who had received nivolumab for stage 4 renal cell carcinoma subsequently developed altered behaviour, memory deficits and worsening of previously stable epilepsy. MR scan of the brain showed bilateral FLAIR (fluid-attenuated inversion recovery) hyperintensity of the mesial temporal lobes, and there were anti-Ma2 antibodies in both serum and cerebrospinal fluid. She was treated with corticosteroids but developed further clinical relapses requiring immunoglobulin and rituximab. The immune-related adverse events relating to immune checkpoint inhibitors are an emerging challenge for the neurologist. Some cases are refractory and require serial immunosuppression.

Neurologic complications of immune checkpoint inhibitors

Introduction: Immune checkpoint inhibitors (ICI) are associated with a wide spectrum of neurologic immune-related adverse events (irAEs) including meningo-encephalitis, myasthenia gravis and various neuropathies. Although relatively rare, they often present significant diagnostic complexity and may be under-recognized. Permanent neurologic deficits and/or fatality have been described but improvement is noted in most cases with ICI discontinuation and immunosuppressive therapy.Areas covered: This review highlights the most frequently reported ICI-associated neurologic toxicities with a particular focus on those that may be more severe and/or fatal. Data from case series and pharmacovigilance studies is leveraged to provide an overview of associated clinical features, expected outcomes and appropriate management. Various immunobiologic triggers have been proposed to explain why certain patients might develop neurologic irAEs and are also briefly discussed.Expert opinion: All providers who care for patients with cancer should be made aware of common neurologic irAEs and able to recognize when prompt evaluation and consultation with appropriate specialists are indicated. Symptoms suggestive of encephalitis, myasthenia-gravis or an acute polyradiculopathy such as Guillain-Barre Syndrome (GBS) in patients exposed to these agents warrant immediate attention with a low threshold for hospitalization to expedite work-up and monitor for severe and/or life-threatening manifestations.

Encephalitis related to immunotherapy for lung cancer: Analysis of a multicenter cohort

INTRODUCTION

Using immune-checkpoint inhibitors (ICIs) to manage cancer is associated with various immune-related adverse events. Central and/or peripheral neurological disorders are rare and potentially serious. We analyzed the characteristics of non-small-cell lung cancer (NSCLC) patients who developed immune-related encephalitis under anti-programmed-death protein-1 or its ligand (PD-1/PD-L1).

METHODS

Clinical, biological and radiological characteristics of ICI-treated NSCLC patients with immune-related encephalitis, from 6 centers, were evaluated retrospectively.

RESULTS

The 6 centers included 9 patients: all men, all smokers, median (range) age 67 (48-77) years, 78% adenocarcinomas, first- or second-line ICI for 5 and 4 patients, respectively. Two patients had non-active cerebral metastases at ICI onset. A median of 5 (1-22) ICI infusions preceded neurological symptoms, the most frequent being confusion (78%), fever (45%) and cerebellar ataxia (33%). CSF analyses revealed a median white blood cell count of 22/mm³ (1-210/mm³), with hyperlymphocytosis in 8 patients and high protein levels in all. All bacteriological and virological analyses were negative. Cerebral MRI was considered normal for 5 patients; 4 patients had FLAIR hypersignals consistent with brain parenchyma inflammation. Three patients required intensive care. All patients received corticosteroids (different doses), a median of 8.5 (6-18) days post-onset. Corticosteroids achieved rapid symptom regression without sequelae in 8 patients. The last patient, with the longest time until corticosteroid introduction, died. ICIs were never restarted in any patient.

CONCLUSION

Immune encephalitis, a rare but serious complication of anti-PD-1/PD-L1 therapy, carries a good prognosis when managed with early corticosteroids.

Myositis-myasthenia gravis overlap syndrome complicated with myasthenia crisis and myocarditis associated with anti-programmed cell death-1 (sintilimab) therapy for lung adenocarcinoma

Immune checkpoint inhibitors (ICIs) have improved clinical outcomes with a number of advanced malignancies. However, diverse immune-related adverse events (iRAEs) occurred with the widespread use of ICIs, some of which are rarely and life-threatening. Here we report a 66-year-old patient with lung adenocarcinoma who received two doses of sintilimab, a human monoclonal antibody against programmed cell death-1 (PD-1), experienced a fatal storm of iRAEs. He was admitted to the intensive care unit (ICU) by immune induced-myositis/myocarditis and rhabdomyolysis. Despite immediate immunosuppressive therapy with methylprednisolone (MP) and immunoglobulin intravenously, he developed into myositis-myasthenia gravis (MG) overlap syndrome complicated with myasthenia crisis. We commenced plasma exchange (PLEX), mechanical ventilation, immunosuppressive therapy, as well as other supportive therapies. Three months later, the patient's serum creatine phosphate kinase (CPK) and anti-acetylcholine receptor antibody (anti-AChR-Ab) returned to normal despite tumor progression. Herein we discuss the incidence, operating mechanism and management strategies of the fatal iRAEs. Early admission to the ICU and multidisciplinary collaborative treatment for unstable patients with iRAEs could help to achieve a favorable outcome.