Cell Reports Medicine (Apr 2020)

Clonal Evolution and Heterogeneity of Osimertinib Acquired Resistance Mechanisms in EGFR Mutant Lung Cancer

  • Nitin Roper,
  • Anna-Leigh Brown,
  • Jun S. Wei,
  • Svetlana Pack,
  • Christopher Trindade,
  • Chul Kim,
  • Olivia Restifo,
  • Shaojian Gao,
  • Sivasish Sindiri,
  • Farid Mehrabadi,
  • Rajaa El Meskini,
  • Zoe Weaver Ohler,
  • Tapan K. Maity,
  • Abhilash Venugopalan,
  • Constance M. Cultraro,
  • Elizabeth Akoth,
  • Emerson Padiernos,
  • Haobin Chen,
  • Aparna Kesarwala,
  • DeeDee K. Smart,
  • Naris Nilubol,
  • Arun Rajan,
  • Zofia Piotrowska,
  • Liqiang Xi,
  • Mark Raffeld,
  • Anna R. Panchenko,
  • Cenk Sahinalp,
  • Stephen Hewitt,
  • Chuong D. Hoang,
  • Javed Khan,
  • Udayan Guha

Journal volume & issue
Vol. 1, no. 1
p. 100007

Abstract

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Summary: Clonal evolution of osimertinib-resistance mechanisms in EGFR mutant lung adenocarcinoma is poorly understood. Using multi-region whole-exome and RNA sequencing of prospectively collected pre- and post-osimertinib-resistant tumors, including at rapid autopsies, we identify a likely mechanism driving osimertinib resistance in all patients analyzed. The majority of patients acquire two or more resistance mechanisms either concurrently or in temporal sequence. Focal copy-number amplifications occur subclonally and are spatially and temporally separated from common resistance mutations such as EGFR C797S. MET amplification occurs in 66% (n = 6/9) of first-line osimertinib-treated patients, albeit spatially heterogeneous, often co-occurs with additional acquired focal copy-number amplifications and is associated with early progression. Noteworthy osimertinib-resistance mechanisms discovered include neuroendocrine differentiation without histologic transformation, PD-L1, KRAS amplification, and ESR1-AKAP12, MKRN1-BRAF fusions. The subclonal co-occurrence of acquired genomic alterations upon osimertinib resistance will likely require targeting multiple resistance mechanisms by combination therapies.

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