Identification of GDC-0810 (ARN-810), an Orally Bioavailable Selective Estrogen Receptor Degrader (SERD) that Demonstrates Robust Activity in Tamoxifen-Resistant Breast Cancer Xenografts

J Med Chem. 2015 Jun 25;58(12):4888-904. doi: 10.1021/acs.jmedchem.5b00054. Epub 2015 May 22.


Approximately 80% of breast cancers are estrogen receptor alpha (ER-α) positive, and although women typically initially respond well to antihormonal therapies such as tamoxifen and aromatase inhibitors, resistance often emerges. Although a variety of resistance mechanism may be at play in this state, there is evidence that in many cases the ER still plays a central role, including mutations in the ER leading to constitutively active receptor. Fulvestrant is a steroid-based, selective estrogen receptor degrader (SERD) that both antagonizes and degrades ER-α and is active in patients who have progressed on antihormonal agents. However, fulvestrant suffers from poor pharmaceutical properties and must be administered by intramuscular injections that limit the total amount of drug that can be administered and hence lead to the potential for incomplete receptor blockade. We describe the identification and characterization of a series of small-molecule, orally bioavailable SERDs which are potent antagonists and degraders of ER-α and in which the ER-α degrading properties were prospectively optimized. The lead compound 11l (GDC-0810 or ARN-810) demonstrates robust activity in models of tamoxifen-sensitive and tamoxifen-resistant breast cancer, and is currently in clinical trials in women with locally advanced or metastatic estrogen receptor-positive breast cancer.

MeSH terms

  • Administration, Oral
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacokinetics
  • Antineoplastic Agents / therapeutic use*
  • Breast / drug effects
  • Breast / metabolism
  • Breast / pathology
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Dogs
  • Drug Discovery
  • Drug Resistance, Neoplasm / drug effects
  • Estrogen Receptor alpha / metabolism*
  • Female
  • Heterografts
  • Humans
  • Mice
  • Proteolysis / drug effects*
  • Rats
  • Selective Estrogen Receptor Modulators / pharmacology*
  • Small Molecule Libraries / administration & dosage
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacokinetics
  • Small Molecule Libraries / therapeutic use*
  • Tamoxifen / pharmacology*


  • Antineoplastic Agents
  • Estrogen Receptor alpha
  • Selective Estrogen Receptor Modulators
  • Small Molecule Libraries
  • Tamoxifen