Efficacy of pembrolizumab for patients with both high PD-L1 expression and an MET exon 14 skipping mutation: A case report

Thorac Cancer. 2019 Feb;10(2):369-372. doi: 10.1111/1759-7714.12939. Epub 2019 Jan 2.


Pembrolizumab has become the standard first-line treatment for non-small cell lung cancer (NSCLC) patients with high PD-L1expression. MET exon 14 skipping is a rare mutation typically found in older, female, and non-smoking patients with NSCLC. Herein, we report the case of a 71-year-old non-smoking woman who was diagnosed with NSCLC in the left lung. EGFR mutation and ALK fusion were not detected. Because the biopsy specimen showed high PD-L1 expression with a tumor proportion score of 95%, pembrolizumab was introduced as first-line therapy, but resulted in no clinical benefit. The patient was subsequently administered chemotherapy with carboplatin and pemetrexed, leading to remarkable tumor shrinkage. A next-generation sequencing panel analysis revealed a MET exon 14 skipping mutation. Thus, pembrolizumab might not be effective for NSCLC patients with MET exon 14 skipping mutations, even if PD-L1 expression is high.

Keywords: MET exon 14 skipping mutation; non-small cell lung cancer; pembrolizumab; pemetrexed; programmed death-ligand 1.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Antineoplastic Agents, Immunological / therapeutic use
  • B7-H1 Antigen / metabolism*
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Exons / genetics*
  • Female
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Mutation*
  • Prognosis
  • Proto-Oncogene Proteins c-met / genetics*


  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents, Immunological
  • B7-H1 Antigen
  • CD274 protein, human
  • pembrolizumab
  • MET protein, human
  • Proto-Oncogene Proteins c-met