PD-1 Inhibitors-Related Neurological Toxicities in Patients with Non-Small-Cell Lung Cancer: A Literature Review

Abstract

The advent of immune checkpoint inhibitors gave rise to a new era in oncology and general medicine. The increasing use of programmed death-1 (PD-1) inhibitors in non-small cell lung cancer and in other malignancies means clinicians have to face up to new challenges in managing immune-related adverse events (irAEs), which often resemble autoimmune diseases. Neurological irAEs represent an emerging toxicity related to immunotherapy, and it is mandatory to know how to monitor, recognize, and manage them, since they can rapidly lead to patient death if untreated. Guidelines for the diagnosis and treatment of these irAEs have been recently published but sharing some of the most unusual clinical cases is crucial, in our opinion, to improve awareness and to optimize the approach for these patients. A literature review on the diagnosis and treatment of immune-related neurotoxicity's has been conducted starting from the report of four cases of neurological irAEs regarding cases of polyneuropathy, myasthenia gravis, Bell's palsy, and encephalopathy, all of which occurred in oncological patients receiving PD-1 inhibitors (pembrolizumab and nivolumab) for the treatment of non-oncogene addicted advanced non-small cell lung cancer. The exclusion of other differential diagnoses and the correlation between the suspension of immunotherapy and improvement of symptoms suggest that immunotherapy could be the cause of the neurological disorders reported.

Keywords: Bell’s palsy; encephalopathy; immunotherapy; myasthenia gravis; neurotoxicity; nivolumab; pembrolizumab; polyneuropathy.

Figure 1

Neurological immune-related adverse events (irAEs) management guidelines.