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Updated: Feb 5, 2026

Using 22C3 Anti-PD-L1 Antibody Concentrate on Biopsy and Cytology Samples from Non-small Cell Lung Cancer Patients
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PD-L1 expression, tumor mutational burden, and response to immunotherapy in patients with MET exon 14 altered lung

J K Sabari1, G C Leonardi2, C A Shu3

  • 1Thoracic Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, New York, USA.

Annals of Oncology : Official Journal of the European Society for Medical Oncology
|August 31, 2018
PubMed
Abstract

Insights

MET exon 14 alterations in lung cancer show modest responses to immunotherapy. While PD-L1 is expressed, tumor mutational burden is low, limiting overall clinical efficacy.

Area of Science:

  • Oncology
  • Genetics
  • Immunotherapy

Background:

  • MET exon 14 alterations are key drivers in lung cancer.
  • MET inhibitors show efficacy in clinical trials.
  • Immunotherapy activity and biomarkers in these tumors are not well understood.

Purpose of the Study:

  • To characterize PD-L1 expression and tumor mutational burden (TMB) in MET exon 14-altered lung cancers.
  • To analyze the response to immune checkpoint inhibition in this patient population.

Main Methods:

  • Retrospective analysis of 147 patients with MET exon 14-altered lung cancers.
  • Assessment of PD-L1 expression via immunohistochemistry.
  • Calculation of TMB from next-generation sequencing panels.

Main Results:

  • Median TMB was lower in MET exon 14-altered lung cancers compared to unselected NSCLCs.
  • Objective response rate to immunotherapy was 17%, with a median progression-free survival of 1.9 months.
  • Responses were not associated with high PD-L1 expression or TMB.

Conclusions:

  • MET exon 14-altered lung cancers often express PD-L1 but have low TMB.
  • Immunotherapy provides modest clinical benefit in this group, with occasional responses observed.

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