Efficacy and safety of immune checkpoint inhibitors in elderly patients (≥70 years) with squamous cell carcinoma of the head and neck.

Background: Recent meta-analysis showed that immune checkpoint inhibitors (ICIs) have comparable activity between younger and older patients. However, little is known about efficacy and safety of ICI in elderly patients with relapsed/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). The aim of this study is to compare the efficacy of ICI for patients aged ≥70 y to that for younger patients, while taking into account potential confounding factors.

Methods: A retrospective study was conducted at four hospitals in France. Patients treated with ICI for R/M SCCHN between September 2014 and December 2018 were eligible. Patients' charts were reviewed for clinical and radiological data as well as oncologic outcomes.

Results: We included 226 patients, of whom 67 were aged ≥70 years. Objective response rate (ORR), median overall survival (OS) and median progression-free survival (PFS) were 23%, 9.7 months and 2.7 months, respectively, for elderly patients, compared to 13%, 8.7 months and 1.9 months for younger patients (respective p-values: 0.071, 0.87 and 0.21). After adjustment for performance status, site of progression, number of ICI drugs, time between initial diagnosis and ICI start and number of previous lines, age ≥70 years was significantly associated with a better PFS (hazard ratio [HR], 0.66; p = 0.021) but not OS (HR, 0.91; p = 0.59). Grade 3-5 adverse events (AEs) occurred in 15% of patients aged ≥70 years and in 8% of younger patients (p = 0.13).

Conclusion: Patients aged ≥70 years with R/M SCCHN may respond to ICI similarly as younger patients in terms of ORR, OS and PFS, while maintaining comparable rate of AEs.