Pembrolizumab-Associated Seronegative Myasthenia Gravis in a Patient With Metastatic Renal Cell Carcinoma

Pembrolizumab, a monoclonal antibody that inhibits programmed cell death protein-1 (PD-1), is an important treatment for various malignancies. Unfortunately, it has also been associated with a wide array of immune-related adverse events. We present a unique case of a patient who received a single dose of pembrolizumab and subsequently developed multiple immune-mediated complications, including dermatitis, hepatitis, myositis, myocarditis, and myasthenia gravis.

Section: Discussionmentioning

confidence: 99%

Multiple Autoimmune Complications After a Single Dose of Pembrolizumab

Ahdi¹,

AbdulMujeeb²,

Nabrinsky³

2023

“…Though MG can independently manifest as a paraneoplastic syndrome, the association with de novo diagnosis after starting pembrolizumab suggests a likely checkpoint-inhibitor-associated presentation of MG [ 3 ]. Our patient developed symptoms consistent with myasthenia gravis shortly after being treated with pembrolizumab, which included ptosis, dysarthria, cervical myalgia, generalized fatigue, and weakness.…”

Section: Discussionmentioning

confidence: 99%

A Case of Pembrolizumab-Induced Myasthenia Gravis

Kosick,

Patel,

Jasinski

et al. 2023

With the advent of new cancer treatments, immunotherapy has emerged as an increasingly promising strategy. Undoubtedly, it has pushed oncology into a new era and is providing patients with unprecedented results. As with many treatments, however, adverse effects lead to setbacks in progress. Pembrolizumab is an immunomodulating medication that functions by binding to programmed cell death protein 1 (PD-1) receptors of T cells thereby upregulating the immune system to more effectively detect and target cancer. Myasthenia gravis (MG) is a reported side effect of this medication. Our patient is an 87-year-old male with urothelial cell bladder cancer who developed MG following the administration of pembrolizumab and was treated with plasma exchange therapy. We aim to examine the existing literature concerning treatments for MG, with a particular focus on myasthenia gravis induced by pembrolizumab. We will discuss the occurrence rates and results of such instances, along with their implications for the future of these potential therapies.

“…Due to clinical concern for ICI neurotoxicity, methylprednisolone was initiated (1 g intravenously daily for five days) [ 2 , 7 ]. Ultimately the clinical picture was thought to be most consistent with seronegative MG [ 7 , 9 ]. Since the patient exhibited fluctuating weakness, other causes including inflammatory myopathy and acute inflammatory demyelinating polyradiculoneuropathy were considered less likely.…”

Section: Case Presentationmentioning

confidence: 99%

Case of Immune Checkpoint Inhibitor Induced Myasthenia Gravis

Gullapalli,

Arulprakash,

Safar

et al. 2024

An 85-year-old man was diagnosed with hepatocellular carcinoma (HCC) and was initially treated with transarterial chemoembolization (TACE) and sorafenib. He was then switched to nivolumab and ipilimumab in view of sorafenib intolerance and disease progression. Subsequently, he developed dysphagia and generalized dyspnea culminating in hypercapnic respiratory failure requiring intubation. After an extensive workup, the etiology of his fluctuating respiratory issues was narrowed down to a likely neuromuscular process. Although antibodies to acetylcholine receptors (anti-AChR Ab) were negative, he was treated with high-dose steroids due to clinical concern for Immune Checkpoint Inhibitor (ICI) neurotoxicity. His recovery post immune suppression and absence of recurrence after ICI cessation suggested the possibility of this being an ICI neurotoxicity manifesting with myasthenic symptoms. Incidentally, he also had evidence of aseptic meningitis on cerebrospinal fluid analysis further strengthening this diagnosis. This case illustrates the importance of early recognition of ICI toxicity which will in turn lead to initiating treatments sooner and also decreasing the length of illness.