Neurological Adverse Events Induced by Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer: Current Perspectives and New Development

Clinical features, diagnosis, and treatment of pembrolizumab induced autoimmune encephalitis

Pembrolizumab has shown links to autoimmune encephalitis (AE), yet the exact clinical characteristics remain unclear. This study examines the clinical features of pembrolizumab-induced AE to enhance diagnostic accuracy and therapeutic strategies. Reports on pembrolizumab-induced AE were gathered via a searchable database, culminating on November 30, 2024. The median age at onset among the 34 patients was 68 years (range 47-82), with males constituting 67.6%. The average onset period for AE was 6 months (range 0.3-25) after the initial dose, with an average of 6 cycles (range 1-17). Commonly reported symptoms included confusion (38.2%), fever (35.3%), and decreased consciousness (32.4%). Cerebrospinal fluid analysis revealed elevated protein (55.9%), leukocytosis (70.6%), and normal blood glucose levels (38.2%). Antineuronal antibodies were found to be negative in 41.2% of cases and positive in 35.3%. Magnetic resonance imaging indicated T2/FLAIR hypersignal in 32.4% of cases, while the electroencephalogram revealed slow waves (11.8%) and diffuse slowing (11.8%). Following treatment with steroids, intravenous immunoglobulin, and plasmapheresis, 82.4% of patients experienced symptom improvement or recovery, though 5.9% succumbed to AE. Oncologists must consider the risk of AE when prescribing pembrolizumab. Early diagnosis and intervention for AE are crucial. Further research is needed to define the optimal treatment approach.

Determinants of immune checkpoint inhibitor use and factors linked to neurological adverse events in Korean lung cancer

Aim: Studies on immune checkpoint inhibitor (ICI)-related potential neurological adverse events (pNAEs) in Korean lung cancer (LC) patients are scarce. We aimed to examine ICI prescription trends from 2018 to 2022, patient characteristics and factors associated with ICI prescription or concurrent pNAEs in LC.Research design & methods: This observational, cross-sectional study of Korean LC patients investigated four ICIs (pembrolizumab, nivolumab, atezolizumab and durvalumab). The annual ICI prescription rate was calculated by dividing the number of LC patients prescribed ICIs with the total annual number of LC patients. Factors associated with ICI prescriptions or concurrent pNAEs were assessed.Results: The annual ICI prescription rate increased from 3.29% to 9.74% (average: 6.20%). Higher Charlson Comorbidity Index (CCI) scores were associated with more ICI prescriptions (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.07-1.08). Targeted therapy was associated with fewer prescriptions (OR: 0.45; 95% CI: 0.41-0.49). The anti-programmed cell death protein 1 (anti-PD-1) prescription rate was higher in patients with concurrent pNAEs than those without pNAEs (53.09% vs. 50.84%), and this was associated with higher pNAEs prevalence (OR: 1.10; 95% CI: 1.03-1.18).Conclusion: ICI prescription for LC has increased in Korea, CCI and anti-PD-1 increased pNAEs prevalence.

A Rare Case of Overlapping Durvalumab-induced Myositis, Takotsubo-like Morphological Changes Caused by Myocarditis, and Myasthenia Gravis

Immune checkpoint inhibitors can cause a range of immune-related adverse events, including myositis, Takotsubo cardiomyopathy, and myasthenia gravis. We herein report a rare case of a 78-year-old man with concurrent durvalumab-induced myositis, Takotsubo-like morphological changes caused by myocarditis, and myasthenia gravis. The patient initially required invasive ventilation and exhibited symptoms of myasthenia gravis after treatment with high-dose steroids. However, he subsequently achieved successful recovery after the administration of intravenous immunoglobulin, plasmapheresis, and high-dose steroids. We advocate vigilant neurological monitoring of patients with immune checkpoint inhibitor-induced myositis, including the assessment of ptosis and other relevant signs, so that prompt treatment can be initiated at the time of emergence or progression of immune checkpoint inhibitor-induced myasthenia gravis.

Neurological Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors

The use of immune checkpoint inhibitors (ICIs) for the treatment of various advanced and aggressive types of malignancy has significantly increased both survival and long-term remission rates. ICIs block crucial inhibitory pathways of the immune system, in order to trigger an aggravated immune response against the tumor. However, this enhanced immune activation leads to the development of numerous immune-related adverse events (irAEs), which may affect any system. Although severe neurological irAEs are relatively rare, they carry a high disability burden, and they can be potentially life-threatening. Therefore, clinicians must be alert and act promptly when individuals receiving ICIs present with new-onset neurological symptoms. In this narrative review, we have collected all the currently available data regarding the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of post-ICI neurological irAEs. This review aims to raise physicians' awareness, enrich their knowledge regarding disease pathogenesis, and guide them through the diagnosis and management of post-ICI neurological irAEs.

Immune Checkpoint Inhibitor-Induced Guillain Barre Syndrome: A Single-Institution Case Report and Narrative Review

Guillain-Barré syndrome (GBS) resulting from the use of immune checkpoint inhibitors (ICIs) is relatively uncommon but has been reported. Herein, we discuss a case of a 67-year-old patient who received neoadjuvant ICI for treatment of non-small cell lung cancer and then presented with lower extremity weakness and areflexia, progressing to respiratory muscle and upper extremity weakness. Given the increasing use of ICI in cancer management, awareness of neurological autoimmune side effects is essential. ICI-mediated GBS can be severe and fatal if not diagnosed promptly. We discuss a case of ICI-induced GBS and review literature on current management approaches.

Assessment of Neurologic Safety Profile of Immune Checkpoint Inhibitors: Evaluation of Adverse Drug Reaction Reports

BACKGROUND

Immune checkpoint inhibitors (ICIs) used in immunotherapy have revolutionized cancer management. However, ICI therapy can come with serious neurologic risks.

OBJECTIVE

The objective of our study is to analyze the occurrence of neurologic events with ICIs.

METHODS

We referred to EudraVigilance (EV) and VigiAccess to evaluate the frequency of individual case safety reports (ICSRs), including neurologic events with ICIs. Data was gathered for a period from the date of ICI's marketing authorization till 30 January 2023. The computational assessment was conducted with the help of reporting odds ratio (ROR) and its 95% confidence interval (CI).

RESULTS

Overall, 8181 ICSRs in EV and 15905 ICSRs from VigiAccess were retrieved for neurologic events, with at least one ICI as the suspected drug. The majority of the ICSRs were reported for nivolumab, pembrolizumab, and ipilimumab, whereas frequently reported events were neuropathy peripheral, myasthenia gravis, seizure, Guillain-Barre syndrome, paraesthesia, syncope, encephalopathy, somnolence. Under EV, 92% of ICSRs were reported as serious, 10% included fatal outcomes, and nearly 61% cited patient recovery. Atezolizumab (ROR 1.64, 95% CI 1.75- 1.52), cemiplimab (ROR 1.61, 95% CI 1.98-1.3), and nivolumab (ROR 1.38, 95% CI 1.44-1.31) had a considerable increase in the frequency of ICSR reporting. Cerebrovascular accident, posterior reversible encephalopathy syndrome, tremor, and somnolence were identified as potential signals.

CONCLUSION

ICIs were significantly associated with neurologic risks, which cannot be generalized. A considerable increase in ICSR reporting frequency was observed with atezolizumab, cemiplimab, and nivolumab, while avelumab, pembrolizumab, durvalumab, and cemiplimab were linked with four potential signals. These findings suggest the consideration of a revision of the neurologic safety profile of ICIs. Furthermore, the necessity for additional ad-hoc research is emphasized.

Long-term complete remission after severe pembrolizumab-induced immune-related encephalitis in metastatic lung adeno-squamous carcinoma: A case report

Immune checkpoint inhibitors became the treatment of choice, in monotherapy or in association with platinum-based doublet chemotherapy, in first-line therapy for advanced-stage non-small-cell lung cancer without oncogenic driver. Nevertheless, it can be associated with diverse immune-related adverse events; several immune-related adverse events can also follow each other involving multiple organ systems, leading to immune checkpoint inhibitors discontinuation and immunosuppressive therapy that could compromise the prognosis of patients, with the exception of rare situations such as this clinical case. This case report illustrates a succession of immune-related adverse events including a rare and severe pembrolizumab-induced immune-related encephalitis in a patient with metastatic lung adeno-squamous carcinoma in whom we could observe a long-term and complete remission despite discontinuation of treatment and high-dose corticosteroids. In metastatic non-small-cell lung cancer, a disease with a poor initial prognosis, some patients can benefit from immune checkpoint inhibitors and can even now present a long-term and complete remission and this despite severe and rare immune-related adverse events, high-dose corticosteroids and an early discontinuation of treatment.

Stuttering as a signal of encephalopathy associated with toripalimab in a pancreatic ductal adenocarcinoma patient: a case report

BACKGROUND

Immune checkpoint inhibitor (ICI) combined with chemotherapy has exhibited promising results in small sample studies of pancreatic cancer patients. The efficacy of toripalimab, a programmed cell death protein 1 (PD-1) monoclonal antibody has been explored in the previous studies and it was established that immune-related adverse events (irAEs) associated with administration of this drug deserve proper attention and adequate management.

CASE PRESENTATION

A 43-year-old female patient with advanced pancreatic ductal adenocarcinoma (PDAC) was treated with toripalimab in combination with gemcitabine and nab-paclitaxel (T-GA) as the first-line treatment. She developed immune-related encephalopathy with stuttering as the main clinical symptom and Magnetic resonance imaging (MRI) showed multiple cerebral white matter demyelination changes, concomitant with asymptomatic cardiac enzyme elevation and hypothyroidism. The symptoms resolved after the discontinuation of toripalimab and corticosteroid treatment.

CONCLUSIONS

Stuttering might be an early sign of neurotoxicity which can be easily neglected during the treatment. These findings provide guidance for the identification of these rare and occult neurological irAEs (n-irAEs) in the clinical practice.

Immunotherapy Resumption/Rechallenge in Melanoma Patients after Toxicity: Do We Have Another Chance?

Introduction: Immune checkpoint inhibitors (ICIs) have radically changed the prognosis of several neoplasias, among them metastatic melanoma. In the past decade, some of these new drugs have appeared together with a new toxicity spectrum previously unknown to clinicians, until now. A common situation in daily practice is that a patient experiences toxicity due to this type of drug and we need to resume or rechallenge treatment after resolving the adverse event. Methods: A PubMed literature review was carried out. Results: The published data regarding the resumption or rechallenge of ICI treatment in melanoma patients is scarce and heterogeneous. Depending on the study reviewed, the recurrence incidence of grade 3–4 immune-related adverse events (irAEs) ranged from 18% to 82%. Conclusion: It is possible to resume or rechallenge, but each patient should be evaluated by a multidisciplinary team for close monitoring and assessment of the risk/benefit ratio before initiating treatment.

Imaging assessment of toxicity related to immune checkpoint inhibitors

In recent years, a wide range of cancer immunotherapies have been developed and have become increasingly important in cancer treatment across multiple oncologic diseases. In particular, immune checkpoint inhibitors (ICIs) offer promising options to improve patient outcomes. However, a major limitation of these treatments consists in the development of immune-related adverse events (irAEs) occurring in potentially any organ system and affecting up to 76% of the patients. The most frequent toxicities involve the skin, gastrointestinal tract, and endocrine system. Although mostly manageable, potentially life-threatening events, particularly due to neuro-, cardiac, and pulmonary toxicity, occur in up to 30% and 55% of the patients treated with ICI-monotherapy or -combination therapy, respectively. Imaging, in particular computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT), plays an important role in the detection and characterization of these irAEs. In some patients, irAEs can even be detected on imaging before the onset of clinical symptoms. In this context, it is particularly important to distinguish irAEs from true disease progression and specific immunotherapy related response patterns, such as pseudoprogression. In addition, there are irAEs which might be easily confused with other pathologies such as infection or metastasis. However, many imaging findings, such as in immune-related pneumonitis, are nonspecific. Thus, accurate diagnosis may be delayed underling the importance for adequate imaging features characterization in the appropriate clinical setting in order to provide timely and efficient patient management. ¹⁸F-FDG-PET/CT and radiomics have demonstrated to reliably detect these toxicities and potentially have predictive value for identifying patients at risk of developing irAEs. The purpose of this article is to provide a review of the main immunotherapy-related toxicities and discuss their characteristics on imaging.