POETIC-A is a phase III, multi-centre, biomarker-stratified randomised trial, which draws on the results of the POETIC trial, to provide a novel but simple mechanism to detect those post-menopausal women with ER+/HER2- primary breast cancer who are at high (20%) 5-year risk of relapse on standard-of-care therapy, and then tests whether a molecular algorithm can identify groups of women who derive greatest benefit from adjuvant treatment with abemaciclib.

The trial is in two parts:

1) A registration part where patients receive between 10 days and 6 months of an aromatase inhibitor (AI) prior to surgery.

 2) A randomisation part where patients whose centrally assessed Ki67 remained high at surgery are randomised between standard adjuvant endocrine therapy (ET) alone vs. ET + abemaciclib for two years. Randomisation takes place following completion of standard of care non-endocrine therapy adjuvant treatment.  

POETIC-A is open to recruitment and plans to open across 80 UK centres.  It is anticipated that approximately 8000 patients will be registered in order to randomise 2500 patients.



The primary aim of POETIC-A is to determine the benefit of adding abemaciclib to standard adjuvant ET in a sub-population of ER+/HER2- breast cancer who exhibit early evidence suggestive of sub-optimal endocrine responsiveness and high risk of disease relapse.

A key secondary aim is to determine whether a molecular algorithm (Aromatase Inhibitor Resistant-CDK4/6 Inhibitor Sensitive [“AIR-CIS”]) can identify those women who may derive greatest benefit from additional adjuvant therapy with abemaciclib.


Inclusion criteria:

Key Registration criteria:

  • Post-menopausal women
  • Operable invasive breast cancer with a clinical/radiological tumour size of ≥1.5cm
  • ER+, HER2- or HER2 status unknown (only confirmed HER2 status negative will be eligible for randomisation)
  • Received or planned to receive 10 days to 6 months of AI prior to surgery
  • No evidence of metastatic disease

Key Randomisation criteria:

  • Centrally confirmed Ki67 ≥8% following pre-surgical AI.
  • Patient must have undergone definitive surgery for the primary breast tumour with clear radial margins as judged by MDT.
  • Patient must have recovered from acute effects of completed adjuvant chemotherapy and/or radiotherapy


Update from the POETIC-A Chief Investigator - November 2021






ICR-CTSU Poetic-A Trial Manager

Telephone: +44 203 437 6858