Cutaneous Toxicities in Lung Cancer Patients on Immune Checkpoint Inhibitor Therapy.

Background: Immune checkpoint inhibitors (ICPIs) have transformed the treatment of lung cancer in the recent years. However, disruption in immune homeostasis produces a unique spectrum of side effects termed as immune-related adverse events (irAEs). Cutaneous irAE are the most prevalent toxicity from the ICPIs. While there have been descriptions of the cutaneous irAEs from ICPIs in melanoma patients, observations are limited in non-small cell lung cancer (NSCLC). This is the largest single-institution cohort of NSCLC patients with cutaneous irAEs.

Methods: We conducted a retrospective chart review of our institution's electronic medical records from January 2017 to December 2018 with at least 1 year of follow up to characterize cutaneous adverse events induced by single agent anti PD-1/PD-L1 therapy in treatment of NSCLC.

Results: In total, 64 patients (40 men and 24 female) were identified with cutaneous irAE. The median time-to-onset was 3 months. Eczematous, morbilliform, and acneiform rashes were most prevalent. There were 28 patients who had previous dermatologic conditions and only 4 of them had related cutaneous manifestations. Most patients' (70%) rashes improved or resolved after treatment with oral antihistamines and topical steroids. Eight (13%) of them had a dose impact to their cancer treatment due to their rash, with 4 (6%) patients discontinuing their ICPIs.

Conclusions: Cutaneous adverse events appears to be one of the most prevalent irAEs with ICPIs and has been reported with all anti PD-1/PD-L1 therapies. While in most cases these dermatologic adverse events remain self-limiting, they may cause treatment interruption and impact life quality. Recognition and early intervention may improve patient symptoms and therapy compliance.