1328P - PD-L1 expression and survival among advanced non-small cell lung cancer (NSCLC) patients treated with chemotherapy

Date 27 September 2014
Event ESMO 2014
Session Poster Display session
Topics Non-Small-Cell Lung Cancer, Metastatic
Cancer Immunology and Immunotherapy
Pathology/Molecular Biology
Translational Research
Presenter Steffen Sorensen
Citation Annals of Oncology (2014) 25 (suppl_4): iv426-iv470. 10.1093/annonc/mdu349
Authors S.F. Sorensen1, W. Zhou2, M. Dolled-Filhart3, J.B. Georgsen4, Z. Wang5, K. Emancipator6, D. Wu3, M. Busch-Sorensen7, P. Meldgaard8, H. Hager9
  • 1Oncology, Aarhus University Hospital, 8000 - Aarhus/DK
  • 2Epidemiology, Merck Research Laboratories, North Wales/US
  • 3Molecular Biomarkers And Diagnostics, Merck & Co., Inc., Rahway/US
  • 4Institute Of Pathology, Aarhus University Hospital, Aarhus/DK
  • 5Bards, Merck Sharp & Dohme, Beijing/CN
  • 6Molecular Biomarkers And Diagnostics, Merck Research Laboratories, Rahway/US
  • 7Epidemiology, Merck & Co., Inc., Ballerup/DK
  • 8Department Of Oncology, Aarhus University Hospital, 8000 - Aarhus/DK
  • 9Department Of Pathology, Aarhus University Hospital, 8000 - Aarhus/DK

Abstract

Aim

Recent clinical trial results suggest programmed cell death ligand-1 (PD-L1) expression measured by immunohistochemistry (IHC) may predict response to anti-PD-1 therapy. There are inconsistent results on whether PD-L1 expression is associated with survival among patients with advanced NSCLC treated with chemotherapy.

Methods

We evaluated the relationship between PD-L1 expression and overall survival (OS) among 204 advanced NSCLC patients treated at Aarhus University Hospital from 2007 to 2012. PD-L1 expression was measured using a prototype IHC assay with the 22C3 antibody. PD-L1-strong and -weak positivity were defined to be traceable to the clinical trial version of the assay. Kaplan-Meier methods, log-rank test, and Cox proportional hazards models were used for survival analysis, adjusting for age, gender, histology, smoking history, and performance status.

Results

Median (range) age was 65 years (33-86), 55% were female, 22% had squamous cell carcinoma, and 88% were stage IV. All patients received chemotherapy as initial therapy, including 83% treated with carboplatin/vinorelbine, 15% with carboplatin/vinorelbine/bevacizumab, and 2% with others; 32% of patients also received radiotherapy with initial therapy. Twenty-five percent of patients were PD-L1-strong–positive, and 50% were PD-L1-weak–positive. There was no statistically significant association between PD-L1 expression and survival, with an adjusted hazard ratio (AHR) of 1.34 (95% CI, 0.88-2.03; median OS, 9.0 mo) for the PD-L1-strong–positive group and 1.07 (95% CI, 0.74-1.55; median OS, 9.8 mo) for the PD-L1-weak–positive group when compared with the PD-L1-negative group (median OS, 7.5 mo). There was no association between PD-L1 expression and OS when PD-L1 expression levels were stratified by the median or tertiles.

Conclusions

Using a preliminary IHC assay and cutoff, the results did not suggest that PD-L1 expression is a strong prognostic marker among advanced NSCLC patients treated with chemotherapy. The inconsistent results observed in previous studies may be due to different antibodies, cutoff values, or patient population characteristics.

Disclosure

W. Zhou: Full-time employment at Merck & Co., Inc., with stock ownership; M. Dolled-Filhart: Full-time employment at Merck & Co., Inc.; J.B. Georgsen: Corporate sponsored research–Merck Sharp & Dohme; Z. Wang: Full-time employment–Merck Sharp & Dohme; K. Emancipator: Full-time employment–Merck & Co., Inc.; D. Wu: Full-time employment at Merck & Co., Inc., with stock ownership; M. Busch-Sorensen: Full-time employment–Merck & Co., Inc. All other authors have declared no conflicts of interest.