Imatinib mesylate in patients with WHO B3 thymomas and thymic carcinomas

J Thorac Oncol. 2009 Oct;4(10):1270-3. doi: 10.1097/JTO.0b013e3181b6be57.


Thymic malignancies are rare tumors of the mediastinum. c-KIT is highly expressed in thymic carcinomas (TC) but infrequently in thymomas. Anecdotal experience suggests activity of imatinib mesylate in TC. Patients with unresectable World Health Organization B3 thymomas or TC, performance status 0 to 2, good organ function, and measurable disease were enrolled in this study. Imatinib was administered at 600 mg PO daily. Seven patients were recruited at one institution: two World Health Organization B3 thymomas and five TC. Imatinib treatment was generally well tolerated. Two patients had stable disease and five progressed. Median survival was 4 months, and median time to progression was 2 months. c-KIT expression was found in one of four samples by immunohistochemistry. No mutations were detected in the c-KIT or PDGFRA genes in three samples analyzed. Imatinib has no major activity in this rare tumor. Given the small number of patients treated in this study, selection based on presence of c-KIT mutations might be warranted.

Publication types

  • Clinical Trial, Phase II

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents / therapeutic use*
  • Benzamides
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism
  • Disease Progression
  • Female
  • Humans
  • Imatinib Mesylate
  • Immunoenzyme Techniques
  • Male
  • Middle Aged
  • Mutation / genetics
  • Neoplasm Recurrence, Local / drug therapy*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Staging
  • Piperazines / therapeutic use*
  • Polymerase Chain Reaction
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Proto-Oncogene Proteins c-kit / genetics
  • Proto-Oncogene Proteins c-kit / metabolism
  • Pyrimidines / therapeutic use*
  • Receptor, Platelet-Derived Growth Factor alpha / genetics
  • Receptor, Platelet-Derived Growth Factor alpha / metabolism
  • Survival Rate
  • Thymoma / drug therapy*
  • Thymoma / genetics
  • Thymoma / metabolism
  • Thymus Neoplasms / drug therapy*
  • Thymus Neoplasms / genetics
  • Thymus Neoplasms / metabolism
  • Treatment Outcome


  • Antineoplastic Agents
  • Benzamides
  • Biomarkers, Tumor
  • Piperazines
  • Pyrimidines
  • Imatinib Mesylate
  • Protein-Tyrosine Kinases
  • Proto-Oncogene Proteins c-kit
  • Receptor, Platelet-Derived Growth Factor alpha