Adjuvant CDK4/6 Inhibitor in High-Risk Early-Stage Breast Cancer

In the PENELOPE-B trial, adding palbociclib to adjuvant endocrine therapy did not improve invasive-disease–free survival in patients with ER+/HER2− breast cancer and residual disease after neoadjuvant chemotherapy.

Approximately one third of patients with early-stage, hormone receptor–positive breast cancer who are deemed at high enough risk to warrant neoadjuvant chemotherapy (NACT) have residual disease at the time of surgery and remain at high risk for recurrence. In the phase 3, industry-funded PENELOPE-B trial, researchers evaluated whether a more intense postoperative endocrine therapy approach could impact risk for recurrence.

A total of 1250 patients with ER+/HER2− breast cancer and residual disease following NACT were randomized to receive adjuvant endocrine therapy alone or with the cyclin-dependent kinase (CDK) 4/6 inhibitor palbociclib (3 weeks on/1 week off) for 1 year. Endocrine therapy was intended to be given for at least 5 years, and t…

Reviewing Author

William J. Gradishar, MD

Disclosures

Consultant/Advisory BoardLilly; AstraZeneca; Gilead

Grant/Research SupportBreast Cancer Research Foundation

Editorial BoardsClinical Breast Cancer; Oncology; Annals of Surgery; Breast Cancer Research and Treatment

Leadership Positions in Professional SocietiesNational Comprehensive Cancer Network (Chair, Breast Cancer Panel); American Board of Internal Medicine (Medical Oncology Board)