Retrospective cohort study of immunotherapy prescribing patterns and immune-related adverse events in patients with head and neck cancer

Immunotherapy is approved for first-line treatment of recurrent/metastatic head and neck cancer (HNC). A retrospective cohort study using MarketScan Commercial and multistate Medicaid databases investigated immunotherapy prescribing patterns and the incidence of and risk factors for immune-related adverse events (irAEs) in HNC patients aged younger than 65 years from 2016 to 2022. Among 47,365 HNC patients, 2254 (4.8%) received immunotherapy. The rate of immunotherapy prescription slightly increased over time. Pembrolizumab dominated the prescribing market (87% in 2022). The 90-day overall irAE-rate was 41.2% and the 90-day severe irAE rate was 2.7%. Comorbidity score was associated with severe irAEs at 90 days, as were baseline hypothyroidism and liver disease. The authors conclude that use of immunotherapy has minmally increased in patients younger than 65 years. irAEs were frequent and associated with individual comorbidities, whereas severe irAEs were rare and associated with overall comorbidity status.