Radiation myelitis after durvalumab administration following chemoradiotherapy for locally advanced non-small cell lung cancer: an illustrative case report and review of the literature

The benefit of intravenous immune globulin in the treatment of delayed radiation myelopathy

Delayed radiation myelopathy (DRM) is a rare yet severe complication of radiotherapy. This condition has a progressive pattern that is often irreversible. Several therapeutic strategies have been introduced to alleviate disease complications, including corticosteroids, hyperbaric oxygen, anticoagulants, and antivascular endothelial growth factor (VEGF) agents. However, despite their beneficial effect, they have not been the definitive treatments for DRM. Here we present the case of a 55-year-old woman with a history of multiple myeloma who developed neurological complications 11 months after radiation therapy. As her radiologic findings demonstrated transverse myelitis, based on the DRM diagnostic criteria, the diagnosis of delayed radiation myelitis was reached. Therefore, methylprednisolone pulse therapy was initiated, resulting in the complete resolution of her neurological symptoms. However, on her follow-up examination, although she did not have new neurological complications, magnetic resonance imaging (MRI) demonstrated a residual enhancement in the thoracic spinal cord area. Hence, due to the possibility of myelitis progression and spinal cord atrophy, intravenous immune globulin (IVIG) was administered, resulting in the resolution of lesion enhancement. Considering this outcome and the immunomodulatory properties of IVIG, it could be regarded as a potential therapeutic option in the case of DRM activity.

Case series: Immune checkpoint inhibitor-induced transverse myelitis

Introduction

Increasing implementation of the highly efficacious immune checkpoint inhibitors (ICIs) has raised awareness of their various complications in the form of immune-related adverse events (irAEs). Transverse myelitis following ICIs is thought to be a rare but serious neurologic irAE and knowledge is limited about this distinct clinical entity.

Cases

We describe four patients across three tertiary centers in Australia with ICI-induced transverse myelitis. Three patients had a diagnosis of stage III-IV melanoma treated with nivolumab and one patient had stage IV non-small cell lung cancer treated with pembrolizumab. All patients had longitudinally extensive transverse myelitis on magnetic resonance imaging (MRI) spine and clinical presentation was accompanied by inflammatory cerebrospinal fluid (CSF) findings. Half of our cohort had received spinal radiotherapy, with the areas of transverse myelitis extending beyond the level of previous radiation field. Inflammatory changes on neuroimaging did not extend to the brain parenchyma or caudal nerve roots, except for one case involving the conus medullaris. All patients received high dose glucocorticoids as first-line therapy, however the majority relapsed or had a refractory state (3/4) despite this, requiring escalation of their immunomodulation, with either induction intravenous immunoglobulin (IVIg) or plasmapheresis. Patients in our cohort who relapsed had a poorer outcome with more severe disability and reduced functional independence following resolution of their myelitis. Two patients had no progression of their malignancy and two patients had malignancy progression. Of the three patients who survived, two had resolution of their neurological symptoms and one remained symptomatic.

Conclusion

We propose that prompt intensive immunomodulation is favored for patients with ICI-transverse myelitis in an attempt to reduce associated significant morbidity and mortality. Furthermore, there is a significant risk of relapse following cessation of immunomodulatory therapy. We suggest one treatment approach of IVMP and induction IVIg for all patients presenting with ICI-induced transverse myelitis based on such findings. With the increasing use of ICIs across oncology, further studies are required to explore this neurological phenomenon in greater detail to help establish management consensus guidelines.

Drug-related immune-mediated myelopathies

Iatrogenic immune-mediated inflammatory disorders of the spinal cord are an uncommon but potentially severe complication of drug therapy for several human diseases. Particularly the introduction of novel biological agents in the treatment of systemic inflammatory disorders and cancer immunotherapy have led to a significant increase in immune-related adverse events of the central nervous system (CNS). The use of Tumor necrosis factor alpha (TNF-alpha) inhibitors in rheumatic and inflammatory bowel diseases has been associated with demyelinating and other inflammatory CNS conditions, including myelitis. The introduction of immune checkpoint inhibitors in the treatment of several human malignancies has led to an increase in drug-induced immune-related adverse events including in the CNS. Other drugs that have been associated with immune-mediated myelitis include tyrosine-kinase inhibitors and chimeric antigen receptor (CAR) T Cell therapy. A high degree of suspicion is necessary when diagnosing these conditions, as early diagnosis and treatment is crucial in preventing further neurological damage and disability. The treatment of drug-induced inflammatory myelitis typically involves administration of high-dose intravenous corticosteroids, however additional immunosuppressive agents may be required in severe or refractory cases. While most cases are monophasic and remit following discontinuation of the offending agent, chronic immunosuppressive therapy may be indicated in cases with a progressive or relapsing disease course or when a diagnosis of a specific underlying neuro-inflammatory disorder is made. Outcomes are generally favorable, however depend on the specific therapeutic agent used, the clinical presentation and patient factors. In this review we aim to describe the clinical characteristics, imaging findings and management for the most common forms of iatrogenic immune-mediated myelopathies.

Longitudinal extensive transverse myelitis after chemoradiation therapy with durvalumab, a rare complication: case report

Background

Longitudinal extensive transverse myelitis is a rare and potentially life-threatening complication of chemoradiation. Certain chemotherapy agents have been proposed to increased neurotoxicity with chemoradiation therapy. One such agent is durvalumab, a human IgG1 monoclonal antibody that blocks programmed death ligand 1, allowing T-cells to recognize and kill tumor cells. Durvalumab and other immune checkpoint inhibitors may also cause transverse myelitis without concomitant treatment with radiation. Durvalumab is a standard therapy for non-small cell lung carcinoma. Here we present a case of a 68-year-old male who presented after chemoradiation and durvalumab therapy with transverse myelitis extending outside the irradiation site.

Case presentation

A 68-year-old male presented to the emergency department with pain and weakness in his feet and hesitancy of urination. Medical history is significant for non-small cell lung cancer treated with chemoradiotherapy and consolidation therapy with durvalumab for one year. His last radiation treatment was 15 months prior, and his last infusion of durvalumab was 3 months prior. Exam revealed severe weakness of bilateral legs with absent vibration sensation. MRI showed central longitudinal extensive transverse myelitis extending from C4-T11. CSF studies showed 8 WBC with 63% lymphocyte predominance and a protein of 48. Oligoclonal bands and angiotensin-converting enzyme were negative. Serum Neuromyelitis Optica antibody (AQP4-IgG) and Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) were negative. Infectious workup came back negative. The patient was treated with steroids and plasma exchange with mild improvement. Etiology remained unknown, but longitudinal extensive transverse myelitis following durvalumab chemoradiotherapy was thought to be the likely cause. He was discharged on a high-dose prednisone taper with outpatient follow-up. His condition worsened near the end of the steroid taper. High-dose prednisone and cyclophosphamide infusions were started with mild improvement and stabilization of the patient’s condition. He transitioned to methotrexate after completion of six cyclophosphamide infusions. The patient expired due to complications from his cancer.

Conclusion

Longitudinal extensive transverse myelitis is a rare and potentially life-threatening complication of durvalumab therapy. As durvalumab has become a standard treatment for non-small cell lung cancer, it is important to be able to identify and treat side effects.

Central Nervous System Demyelination Associated With Immune Checkpoint Inhibitors: Review of the Literature

Immune checkpoint inhibitors (ICI) are a novel class of antineoplastic treatment that enhances immunity against tumors. They are associated with immune adverse events, and several neurological syndromes have been described, including multiple sclerosis and atypical demyelination. We performed a systematic literature review of case reports with neurological immune adverse events that presented with central nervous system demyelination, up to December 2019. We found 23 cases: seven with myelitis, four isolated optic neuritis, one neuromyelitis optica spectrum disorder, five multiple sclerosis, and six with atypical demyelination. Ipilimumab was the most frequently used ICI (11/23). The median time to develop symptoms from the onset of ICI was 6.5 weeks [range 1.0–43.0], and from last ICI dose was 14 days [range 0–161]. Anatomopathological examination was performed in four cases, with the finding of a T-cell mediated immune response. Outcomes were generally favorable after immunosuppression: 18 patients had improvement or a full recovery, three patients did not respond to treatment, three patients died, and in one, treatment was not reported. We describe the patients' clinical presentation, treatment administered, and outcomes. We further speculate on possible pathophysiological mechanisms and discuss potential treatments that may be worth investigating.

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.

Radiation myelitis after pembrolizumab administration, with favorable clinical evolution and safe rechallenge: a case report and review of the literature

Background

Neurologic complications as myelitis are very rare but extremely deleterious adverse effects of both immunotherapy and radiotherapy. Many recent studies have focused on the possible synergy of these two treatment modalities due to their potential to enhance each other’s immunomodulatory actions, with promising results and a safe tolerance profile.

Case presentation

We report here the case of a 68-year-old man with metastatic non-small-cell lung cancer (NSCLC) who developed myelitis after T12-L2 vertebral radiotherapy, with motor deficit and sphincter dysfunction, while on treatment with pembrolizumab (an immune checkpoint inhibitor). The spinal abnormalities detected by magnetic resonance imaging (MRI), suggestive of myelitis, faithfully matched the area previously irradiated with 30 Gy in 10 fractions, six and a half months earlier. After immunotherapy discontinuation and steroid treatment, the patient rapidly and completely recovered. On progression, pembrolizumab was rechallenged and, after 8 cycles, the patient is on response and there are no signs of myelitis relapse.

Conclusion

The confinement within the radiation field and the latency of appearance are suggestive of delayed radiation myelopathy. Nevertheless, the relatively low dose of radiation received and the full recovery after pembrolizumab discontinuation and steroid therapy plead for the contribution of both radiotherapy and immunotherapy in the causality of this complication, as an enhanced inflammatory reaction on a focal post-radiation chronic inflammatory state. In the three previously described cases of myelopathy occurring after radiotherapy and immunotherapy, a complete recovery had not been obtained and the immunotherapy was not rechallenged. The occurrence of a radiation recall phenomenon, in this case, can not be excluded, and radiation recall myelitis has already been described with chemotherapy and targeted therapy. Safe rechallenges with the incriminated drug, even immunotherapy, have been reported after radiation recall, but we describe it for the first time after myelitis.