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

Abstract

6035 Background: Recent meta-analysis showed that immune checkpoint inhibitors (ICI) have comparable activity in younger vs older patients (pts) (≥65 years (y)). However little is known about efficacy and safety of ICI in elderly pts with relapsed/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). The aim of this study is to compare efficacy and grade ≥3 immune-related adverse events (irAEs) of ICI in pts ≥70 y with R/M SCCHN to younger pts. Methods: A retrospective study was conducted at 4 French hospitals. Eligibility criteria were pts treated with ICI for R/M SCCHN between September 2014 and December 2018. Clinical and radiological data and outcome were collected from review of medical records. Results: Two hundred twenty six pts were enrolled including 67 pts ≥ 70 y. Median age of elderly pts was 75y (range 70-87). Elderly pts received ICI as first-line treatment in 21% of pts vs 17% in younger pts. In elderly pts, 9% had ECOG of 0, 72% had ECOG of 1 and 15% had ECOG of 2 at ICI initiation vs 34%, 62% and 4% respectively in younger pts (p = 0.0006). In elderly pts, 22% had only loco-regional relapse at ICI initiation, 30% only distant recurrence and 49% had both vs 42%, 32% and 26% respectively (p = 0.0014). Elderly pts received ICI as monotherapy in 73% of pts vs 52% (p = 0.0027). The ORR in elderly pts was 23% vs 13% in younger pts (p = 0.071). After a median follow-up of 16.8 months (m) (range 10.7-23.7), median OS was 9.7m in elderly pts vs 8.7m in younger pts (p = 0.87). Median PFS was 2.7 m in elderly pts vs 1.9 m (p = 0.2). After adjustment for ECOG, type of evolution, 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 (HR = 0.66 (95%CI = 0.47;0.93), p = 0.02) but was not significantly associated with OS (HR = 0.91 (95%CI = 0.61;1.34), p = 0.62). Grade ≥3 irAEs occurred in 15% of elderly pts vs 8% of younger pts (p = 0.13). Patients with grade ≥3 irAEs had a significantly higher ORR than pts without Grade ≥3 irAEs (36% vs 14%, p = 0.007). Conclusions: Elderly pts treated with ICI had significantly higher PFS but not OS after adjustment. Grade ≥3 irAEs were associated with significantly higher ORR to ICI in the whole population.