PALbociclib CoLlaborative Adjuvant Study

Official Title

PALbociclib CoLlaborative Adjuvant Study: A Randomized Phase III Trial of Palbociclib With Standard Adjuvant Endocrine Therapy Versus Standard Adjuvant Endocrine Therapy Alone for Hormone Receptor Positive (HR+) / Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Early Breast Cancer


This is a prospective, two arm, international, multicentre, randomized, open-label Phase III study evaluating the addition of 2 years of palbociclib to standard adjuvant endocrine therapy for patients with HR+ / HER2- early breast cancer (EBC). The purpose of the PALLAS study is to determine whether the addition of palbociclib to adjuvant endocrine therapy will improve outcomes over endocrine therapy alone for HR+/HER2- early breast cancer. Assessment of a variety of correlative analysis, including evaluation of the effect of palbociclib in genomically defined tumour subgroups, is planned.

Trial Description

Primary Outcome:

  • Invasive Disease Free Survival (iDFS)
Secondary Outcome:
  • To compare the safety of 2 years of palbociclib with adjuvant endocrine therapy versus adjuvant endocrine therapy alone. (distant recurrence-free survival (DRFS), locoregional recurrences-free survival (LRRFS), and overall survival (OS)

View this trial on

Interested in this trial?

Print this page and take it to your doctor to discuss your eligibilty and treatment options. Only your doctor can refer you to a clinical trial.


Canadian Cancer Society

These resources are provided in partnership with the Canadian Cancer Society