Neurological adverse events of immune checkpoint inhibitors: An update of clinical presentations, diagnosis, and management

Unravelling the Acute, Chronic and Steroid-Refractory Management of High-Grade Neurological Immune-Related Adverse Events: A Call to Action

Rare side effects of immune-checkpoint inhibitors (ICIs) are known as neurological immune-related adverse events (n-irAEs). Typically, n-irAEs affect the peripheral nervous system, primarily presenting as myositis, polyradiculoneuropathy, or cranial neuropathy. Less commonly, they impact the central nervous system, resulting in encephalitis, meningitis, or myelitis. High-grade n-irAEs managing and recognizing remains challenging, considering the risk of mortality and long-term disability. To date, strong scientific data are lacking to support the management of high-grade clinical forms. We performed a systematic literature search, selecting all articles describing high-grade steroid-resistance n-irAEs. and we reported them in a practical review. Specifically, current recommendations advise stopping ICI use and beginning corticosteroid treatment. Our findings highlighted that in steroid-resistant n-irAEs, it should be recommended to quickly escalate to plasma exchange (PLEX) and/or intravenously immunoglobulins (IVIg), usually in association with other immunosuppressants. Furthermore, newer evidence supports the use of drugs that may specifically block inflammation without reducing the anti-tumour effect of ICIs. In this practical review, we provide new evidence regarding the therapeutic approach of high-grade n-irAEs, particularly in steroid-resistant cases. We would also stress the importance of informing the scientific community of the discrepancy between current guidelines and clinical evidence in these rare forms of pathology.

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.

Ultramicronized N-palmitoylethanolamine associated with analgesics: Effects against persistent pain

Current epidemiological data estimate that one in five people suffers from chronic pain with considerable impairment of health-related quality of life. The pharmacological treatment is based on first- and second-line analgesic drugs, including COX-2 selective and nonselective nonsteroidal anti-inflammatory drugs, paracetamol, antidepressants, anti-seizure drugs and opioids, that are characterized by important side effects. N-palmitoylethanolamine (PEA) is a body's own fatty-acid ethanolamide belonging to the family of autacoid local injury antagonist amides. The anti-inflammatory and pain-relieving properties of PEA have been recognized for decades and prompted to depict its role in the endogenous mechanisms of pain control. Together with its relative abundance in food sources, this opened the way to the use of PEA as a pain-relieving nutritional intervention. Naïve PEA is a large particle size lipid molecule with low solubility and bioavailability. Reducing particle size is a useful method to increase surface area, thereby improving dissolution rate and bioavailability accordingly. Micron-size formulations of PEA (e.g., ultramicronized and co-(ultra)micronized) have shown higher oral efficacy compared to naïve PEA. In particular, ultramicronized PEA has been shown to efficiently cross the intestinal wall and, more importantly, the blood-brain and blood-spinal cord barrier. Several preclinical and clinical studies have shown the efficacy, safety and tolerability of ultramicronized PEA. This narrative review summarizes the available pharmacokinetic/pharmacodynamic data on ultramicronized PEA and focuses to its contribution to pain control, in particular as 'add-on' nutritional intervention. Data showing the ability of ultramicronized PEA to limit opioid side effects, including the development of tolerance, have also been reviewed.

Neurological Adverse Events Related to Immune Checkpoint Inhibitors: A Practical Review

The increasing use of immune checkpoint inhibitors (ICI) in cancer therapy has brought attention to their associated neurotoxicities, termed neurological immune-related adverse events (n-irAEs). Despite their relatively rare incidence, n-irAEs pose a significant risk, potentially leading to severe, long-lasting disabilities or even fatal outcomes. This narrative review aims to provide a comprehensive overview of n-irAEs, focusing on their recognition and management. The review addresses a spectrum of n-irAEs, encompassing myositis, myasthenia gravis, various neuropathies, and central nervous system complications, such as encephalitis, meningitis, and demyelinating diseases. The key features of n-irAEs are emphasized in this review, including their early onset after initiation of ICIs, potential association with non-neurological irAEs and/or concurrent oncological response, the significance of ruling out other etiologies, and the expected improvement upon discontinuation of ICIs and/or immunosuppression. Furthermore, this review delves into considerations for ICI re-challenge and the intricate nature of n-irAEs within the context of pre-existing autoimmune and paraneoplastic syndromes. It underscores the importance of a multidisciplinary approach to diagnosis and treatment, highlighting the pivotal role of severity grading in guiding treatment decisions.

Immune-Related Peripheral Neuropathy Associated with Immune Checkpoint Inhibitors: Case Report and Review of Literature

Immune checkpoint inhibitors (ICIs) are a group of drugs that have improved outcomes for patients with various cancers. Generally considered safe and well tolerated, these drugs are occasionally linked to immune-mediated or immune-related adverse events. Among these, autoimmune neurological events are rare, displaying varying incidence rates across different studies. Peripheral neuropathy, although one of the more common neurological immune-related events, is at times underestimated. This case report highlights an adult patient diagnosed with metastatic intrahepatic cholangiocarcinoma. Initially, the patient underwent chemoimmunotherapy with gemcitabine, cisplatin, and durvalumab for eight cycles, achieving partial response without significant toxicity. Following this, the patient continued with maintenance monotherapy with durvalumab every 28 days. After completing six cycles of maintenance therapy, the patient suddenly experienced paresthesia and hypoesthesia in four limbs, accompanied by apraxia in the hands that was more pronounced on the right side. Additionally, the patient reported neuropathic pain in the right arm and encountered limitations in certain instrumental activities of daily living. Diagnostic studies, including laboratory and electrophysiological studies, combined with the clinical presentation, identified immune-related peripheral polyneuropathy. Durvalumab was suspended and prednisolone therapy was initiated, resulting in a rapid resolution of all neuropathic symptoms. In addition to the clinical case, this article reviews the literature on immunotherapy-associated peripheral neuropathy.

Facial palsy after administration of immune checkpoint inhibitors: case report, literature review and clinical care management

Neurological immune-related adverse events (irAEs) due to immune checkpoint inhibitors (ICI) are rare complications of immunotherapy, particularly dreadful for patients and clinical teams. Indeed, neurological irAEs are potentially severe and their diagnosis require prompt recognition and treatment. Additionally, the spectrum of neurological irAEs is broad, affecting either neuromuscular junction, peripheral or central nervous system. Here, we described the case of a 55-year man with metastatic melanoma, facing a brutal right peripheral cerebral palsy after his third ipilimumab/nivolumab infusion. After the case presentation, we reviewed the literature about this rare complication of immunotherapy, and described its diagnosis work-up and clinical management.

Fever of unknown origin associated with immune checkpoint inhibitors

Since the approval for the treatment of melanoma in 2014, immune checkpoint inhibitors (ICIs) have revolutionized the therapy pattern across various malignancies. Coinciding with their frequent usage, their adverse effects, including fever, cannot be neglected. In the context of cancer diseases and cancer treatments, fever of unknown origin (FUO), which has long posed a challenge for clinicians in terms of diagnosis and management, brings forth new connotation and significance. In this paper review, we present the concept of ICIs-associated FUO, consider activated immune system and elevated cytokines as common mechanisms by which ICIs induce fever and various immune-related adverse events (irAEs), summarize and compare the primary etiologies of ICI-associated FUO, and compare it with conventional types of FUO.

Drug-related sarcopenia as a secondary sarcopenia

Sarcopenia has a significant impact on falls, physical function, activities of daily living, and quality of life in older adults, and its prevention and treatment are becoming increasingly important as the global population ages. In addition to primary age-related sarcopenia, activity-related sarcopenia, disease-related sarcopenia, and nutrition-related sarcopenia have been proposed as secondary sarcopenia. Polypharmacy and potentially inappropriate medication based on multiple diseases cause health problems in older patients. In some cases, drugs used for therapeutic or preventive purposes act on skeletal muscle as adverse drug reactions and induce sarcopenia. Although sarcopenia caused by these adverse drug reactions may be more common in older patients, in particular those taking many medications, drug-related sarcopenia has not yet received much attention. This review summarizes drugs that may induce sarcopenia and emphasizes the importance of drug-related sarcopenia as a secondary sarcopenia. Geriatr Gerontol Int 2024; 24: 195-203.

Autonomic nervous system involvement in autoimmune encephalitis and paraneoplastic neurological syndromes

In autoimmune neurological diseases, the autonomic nervous system can be the primary target of autoimmunity (e.g. autoimmune autonomic ganglionopathy), or, more frequently, be damaged together with other areas of the nervous system (e.g. Guillain-Barré syndrome). Patients with autoimmune encephalitis and paraneoplastic neurological syndromes (PNS) often develop dysautonomia; however, the frequency and spectrum of autonomic signs and symptoms remain ill defined except for those scenarios in which dysautonomia is a core feature of the disease. Such is the case of Lambert-Eaton myasthenic syndrome, Morvan syndrome or anti-NMDAR encephalitis; in the latter, patients with dysautonomia have been reported to carry a more severe disease and to retain higher disability than those without autonomic dysfunction. Likewise, the presence of autonomic involvement indicates a higher risk of death due to neurological cause in patients with anti-Hu PNS. However, in anti-Hu and other PNS, as well as in the context of immune checkpoint inhibitors' toxicities, the characterization of autonomic involvement is frequently overshadowed by the severity of other neurological symptoms and signs. When evaluated with tests specific for autonomic function, patients with autoimmune encephalitis or PNS usually show a more widespread autonomic involvement than clinically suggested, which may reflect a potential gap of care when it comes to diagnosing dysautonomia. This review aims to revise the autonomic involvement in patients with autoimmune encephalitis and PNS, using for that purpose an antibody-based approach. We also discuss and provide general recommendations for the evaluation and management of dysautonomia in these patients.

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.