3629 - First line versus second line immunotherapy in recurrent/metastatic squamous cell carcinoma of the head and neck

Background

Programmed death-1 inhibitors (PD-1i) have been approved in the treatment of patients (pts) with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) who progressed on or after platinum-containing regimens. More recently, it has been shown that pembrolizumab was superior to the standard EXTREME regimen in first line setting in pts with R/M SCCHN with CPS > 20% and 1% in term of overall survival (OS). We aim in this study to compare the efficacy of immune checkpoint inhibitors (ICI) used as first versus second line in R/M SCCHN to define the best treatment strategy.

Methods

A retrospective study was conducted at 4 French university hospitals. Eligibility criteria were pts treated with ICI for R/M SCCHN as first or second line treatment only and for whom efficacy data were available between September 2014 and March 2019. Clinical and radiological data and outcome were collected from review of medical records.

Results

One hundred ninety two pts were included in this study: 57 pts (30%) received ICI as first line treatment (G1) and 135 pts (70%) as second line setting (G2). Median age at the beginning of ICI was 63 years (range 25-86). All pts were in clinical trials. In G1, ICI was given as monotherapy in 23% of pts and in 66% of pts in G2. The objective response rate (ORR) to ICI in G1 was 17.5% and 17.9% in G2 (p = 0.004). The median duration of response to ICI in G1 was 7.3 months compared to 15.2 months in G2 (p = 0.04). The median progression free survival in G1 was 3.3 months versus 2.7 months in G2 (p = 0.7). The mOS from the beginning of ICI was 12.2 months in G1 versus 11.6 months in G2 (p = 0.7). The mOS from the diagnosis of advanced disease was 15.9 months in G1 versus 22.1 months in G2 (p = 0.11) after a median follow-up of 28.5 months. In G1 38 pts (67%) and 73 pts (53%) in G2 received salvage chemotherapy (SCT) after progression on ICI. The ORR to SCT was 44% in G1 and 34% in G2.

Conclusions

ICI given as second line treatment were associated with similar OS but significant prolonged duration of response. We showed a trend to better OS in the cohort of pts who received ICI in second line setting (22 months).

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.