A retrospective cohort study of PD-L1 expression in recurrent and/or metastatic squamous cell carcinoma of the head and neck (SUPREME-HN).

Abstract

6040 Background: Patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) have a poor prognosis. Targeting the PD-1/PD-L1 axis has resulted in clinically meaningful antitumor activity and improved overall survival (OS) in R/M HNSCC patients. Tumoral PD-L1 expression correlates with response to blocking PD-1/PD-L1 antibodies. We investigated the prognostic value of PD-L1 expression in R/M HNSCC patients. Methods: Archival tumor samples from R/M HNSCC patients diagnosed between March 2011 and June 2015 at 12 institutions in 6 countries were stained for PD-L1 and clinic-demographic data were abstracted from medical records. Tumoral PD-L1 protein expression was assessed with the validated Ventana SP263 assay and scored as high (≥25% of tumor cells [TC]) or low/negative ( < 25% of TC). Extracted data included demographic and tumor characteristics, treatment patterns, and clinical outcomes. Descriptive analyses were conducted and survival estimated by the Kaplan-Meier method. OS was defined from the diagnosis index date of R/M disease to time of death. Results: As ofSeptember 26, 2016 (interim analysis), data were available for 143 patients of whom 138 were eligible for analysis. Median age was 62.0 years (range, 28.0−88.0), 76.8% were male, and 84.0% were white. PD-L1 protein expression was high in 43 patients (31.2%), low/negative in 91 (65.9%), and unknown in 4 (2.9%). Median OS (8.2 vs. 8.8 months; P = 0.94) and progression-free survival (PFS) from the start of first-line (6.0 vs. 5.6 months; P = 0.29) or second-line therapy (7.1 vs. 1.8 months; P = 0.11) did not significantly differ between PD-L1 high and low/negative patients, respectively. There were no significant differences in OS based on PD-L1 status within subgroups defined by age, race, tobacco or alcohol use, primary tumor site, performance status, metastatic disease at diagnosis, or treatment with platinum-based chemotherapy. Conclusions: Interim analyses indicate that PD-L1 status is not associated with OS or PFS in R/M HNSCC patients.