Immune checkpoint inhibitor-related myositis associated with atezolizumab therapy

Bilateral retrobulbar optic neuritis combined with optic perineuritis associated with atezolizumab treatment for small cell lung carcinoma

INTRODUCTION

Ocular immune-related adverse events (OirAEs) associated with novel cancer therapies of immune checkpoint inhibitors (ICIs) are emerging. Retrobulbar optic neuritis (ON) combined with optic perineuritis (OPN), associated with atezolizumab, has been rarely reported and has a unique clinical manifestation.

CASE DESCRIPTION

A 67-year-old woman was diagnosed with small-cell lung cancer. As maintenance therapy, atezolizumab was administered continuously for 10 cycles for approximately 14 months. One week after the administration of the tenth dose of atezolizumab, the patient experienced a bilateral, successive painless visual decline. The fundus and the retinal nerve fiber layer revealed no abnormalities, but the ganglion cell of the macula disappeared loss. The concentric shrinking of the peripheral visual field of the left eye was noticed. Orbital MRI revealed bilateral optic nerve thickening and peripheral optic nerve sheath enhancement ("tram-track" and "doughnut" signs). Serology, cerebrospinal fluid results, and image examination ruled out common causes of vision decline, and the condition was identified as bilateral retrobulbar ON combined with OPN as a probable atezolizumab-related immune adverse event. Thereafter, atezolizumab was discontinued, and intravenous methylprednisolone pulse (IVMP) (160 mg/day for 5 days) plus intravenous immunoglobulin (20 g/day for 3 days) was administered. The patient's visual function considerably improved after three weeks.

CONCLUSIONS

Retrobulbar ON and OPN associated with atezolizumab are rare side effects that are easily overlooked. Immune-related ON has unique features and requires early identification. The primary treatment for optic nerve irAEs is corticosteroids, but this is not standardized and should be used with caution.

Update on Neuro-ophthalmic Manifestations of Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

Immune checkpoint inhibitor (ICI) use has been on the rise for treatment of many different malignancies. Subsequently, more has been learned about immune-related adverse events (irAEs) that occur up to 12 months after treatment. This review summarizes the latest findings and management of neuro-ophthalmic associated irAEs.

RECENT FINDINGS

irAEs can affect the afferent and efferent neuro-ophthalmic pathways, thereby targeting central and peripheral nervous systems. As more cases are being reported, it is becoming apparent that neuro-ophthalmic irAEs often present with atypical features when compared to their spontaneous autoimmune counterparts. These neuro-ophthalmic presentations can also be signs of a more extensive inflammatory process that spans other organ systems, such as myopathies, endocrinopathies, and paraneoplastic syndromes. Awareness of neuro-ophthalmic irAEs and their atypical presentations can lead to early detection, termination of ICI treatment, and immunosuppressant therapy initiation.

Atezolizumab-induced myositis in a patient with small-cell lung cancer

OBJECTIVE

Myositis, an inflammatory disease affecting muscles, is a rare and potentially fatal immune-related adverse event associated with immune checkpoint inhibitors. There are limited data on its clinical features and management.

CASE PRESENTATION

Atezolizumab, in combination with etoposide and carboplatin, was initiated in the patient diagnosed with metastatic small-cell lung cancer. After four cycles, maintenance atezolizumab was initiated. At the third visit of the maintenance therapy, the patient reported weakness, edema, and tightness in the muscles that had progressed over the course of a week. Mild solid-food dysphagia was also observed. Neutrophilic leukocytosis with elevated creatine phosphokinase (9234 U/L), erythrocyte sedimentation rate (111 mm/h), and transaminase levels were observed. A diagnosis of myositis was considered based on clinical findings. Atezolizumab was omitted and an oral 0.5 mg/kg/day dose of methylprednisolone was administered. The myositis resolved within 10 days. During the treatment of myositis, the patient underwent prophylactic cranial irradiation. The steroid dose was tapered off within 35 days and then atezolizumab was restarted.

CONCLUSION

The literature contains only a few case reports about atezolizumab-induced myositis, highlighting the challenges in defining its clinical features and management. Prompt diagnosis and treatment are crucial to prevent severe complications, such as myocarditis or respiratory muscle paralysis.

Atezolizumab-associated myositis in a patient with unresectable hepatocellular carcinoma

INTRODUCTION

Combination treatment with atezolizumab and bevacizumab is the preferred first-line treatment for patients with unresectable or metastatic hepatocellular carcinoma with a Child-Pugh Class A liver function. Reactivation of the antitumor immune response with atezolizumab can result in the development of immune-related adverse events including colitis, skin rash, endocrinopathies, pneumonitis, and nephritis with renal dysfunction. However, the occurrence of myositis with immune checkpoint inhibitors is rare.

CASE REPORT

We report on a 67-year-old male patient with an initial diagnosis of hepatocellular carcinoma, stage IV, unresectable with underlying cirrhosis who experienced atezolizumab-associated myositis.

MANAGEMENT AND OUTCOME

Utilization of the American Society of Clinical Oncology guideline on managing immune checkpoint inhibitors adverse events helped guide the ordering of pertinent labs for monitoring and pharmacologic treatment. In our case, atezolizumab-induced myositis was resolved via a combination of corticosteroids, intravenous immunoglobulins, and plasmapheresis.

DISCUSSION

Recognition of the signs and symptoms of atezolizumab-associated myositis is recommended and utilization of the American Society of Clinical Oncology guideline to guide management and treatment of associated symptoms.

[A case of atezolizumab- and bevacizumab-induced myositis showing high intensity in the pterygoid muscles, soft palate, and tongue on STIR-MRI]

A 61-year-old woman was treated with atezolizumab plus bevacizumab for hepatocellular carcinoma with peritoneal dissemination. Blood tests revealed elevated creatine kinase (CK) that peaked at 2,657 U/l. After two cycles of atezolizumab plus bevacizumab combination therapy, she complained of progressive dysarthria and dysphagia. Needle electromyography showed myopathic changes. Initial MRI showed high signal intensity in the orbicularis oris muscle, soft palate, tongue, pterygoid muscles, and paravertebral muscles on STIR images. Myositis-specific autoantibodies were not detected. Based on these findings, the patient was diagnosed with immune checkpoint inhibitor-associated myositis. The clinical symptoms improved after administration of oral prednisone, and follow-up MRI showed reduced extent of areas of high signal intensity and almost complete resolution of signal abnormality in the paravertebral muscles. The CK level normalized after 1 months of oral steroid administration. MRI of the head and neck, including the tongue and soft palate, may be useful in diagnosis and for evaluating therapeutic efficiency in cases of bulbar symptoms that occur following the introduction of immune checkpoint inhibitors.

Ocular Toxicity of Targeted Anticancer Agents

The proliferation of targeted anticancer agents over the last two decades has revolutionized cancer treatment and improved survival in many previously refractory malignancies. However, many agents are associated with characteristic ophthalmic adverse effects. It is important that ophthalmologists recognize and maintain a high index of suspicion for these side effects in patients on targeted therapy. Most ophthalmic adverse effects can be treated with specific ocular therapy without discontinuation of cancer treatment, although it is important to be aware of the life-threatening and vision-threatening circumstances that would require therapy cessation in conjunction with the patient's oncologist. This review aims to summarize the ophthalmic adverse effects of targeted and hormonal anticancer agents and briefly describe their management.

Atezolizumab-induced myositis and myocarditis in a patient with metastatic urothelial carcinoma

Immune checkpoint inhibitors have revolutionised cancer therapy in the past decade. Although they have been indicated to treat a diverse range of malignant neoplasms, they are also associated with various immune-related adverse effects. We report the case of a 74-year-old man with a history of urothelial carcinoma who had atezolizumab-induced myocarditis and myositis resulting in acute hypercapnic respiratory failure, despite the discontinuation of atezolizumab and aggressive treatment with corticosteroids. This case highlights the importance of a multidisciplinary approach for early diagnosis and treatment of immune-related adverse events. Physicians must be aware of the risks associated with immune checkpoint inhibitors and have a basic knowledge regarding their management.

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.