Activating ESR1 mutations differentially affect the efficacy of ER antagonists Journal Article


Authors: Toy, W.; Weir, H.; Razavi, P.; Lawson, M.; Goeppert, A. U.; Mazzola, A. M.; Smith, A.; Wilson, J.; Morrow, C.; Wong, W. L.; De Stanchina, E.; Carlson, K. E.; Martin, T. S.; Uddin, S.; Li, Z.; Fanning, S.; Katzenellenogen, J. A.; Greene, G.; Baselga, J.; Chandarlapaty, S.
Article Title: Activating ESR1 mutations differentially affect the efficacy of ER antagonists
Abstract: Recent studies have identified somatic ESR1 mutations in patients with metastatic breast cancer and found some of them to promote estrogen-independent activation of the receptor. The degree to which all recurrent mutants can drive estrogen-independent activities and reduced sensitivity to ER antagonists like fulvestrant is not established. In this report, we characterize the spectrum of ESR1 mutations from more than 900 patients. ESR1 mutations were detected in 10%, with D538G being the most frequent (36%), followed by Y537S (14%). Several novel, activating mutations were also detected (e.g., L469V, V422del, and Y537D). Although many mutations lead to constitutive activity and reduced sensitivity to ER antagonists, only select mutants such as Y537S caused a magnitude of change associated with fulvestrant resistance in vivo. Correspondingly, tumors driven by Y537S, but not D5358G, E380Q, or S463P, were less effectively inhibited by fulvestrant than more potent and bioavailable antagonists, including AZD9496. These data point to a need for antagonists with optimal pharmacokinetic properties to realize clinical efficacy against certain ESR1 mutants. SIGNIFICANCE: A diversity of activating ESR1 mutations exist, only some of which confer resistance to existing ER antagonists that might be overcome by next-generation inhibitors such as AZD9496. © 2017 American Association for Cancer Research.
Journal Title: Cancer Discovery
Volume: 7
Issue: 3
ISSN: 2159-8274
Publisher: American Association for Cancer Research  
Date Published: 2017-03-01
Start Page: 277
End Page: 287
Language: English
DOI: 10.1158/2159-8290.cd-15-1523
PROVIDER: scopus
PMCID: PMC5340622
PUBMED: 27986707
DOI/URL:
Notes: Article -- Export Date: 3 April 2017 -- Source: Scopus
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MSK Authors
  1. Weiyi Toy
    19 Toy
  2. Zhiqiang Li
    10 Li
  3. Jose T Baselga
    483 Baselga
  4. Pedram Razavi
    144 Razavi
  5. Sharmeen Yeasmin Uddin
    5 Uddin