Bannerbild German Brest Group

April 2021: First results of the rendomized phase III PenelopeB trial


April 2021: First results of the rendomized phase III PenelopeB trial

We are delighted to inform you that the first results of the randomized phase III PenelopeB trial have been published in Journal of Clinical Oncology.

About one third of patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer who have residual invasive disease after neoadjuvant chemotherapy will relapse. Thus, additional therapy is needed. Palbociclib is a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor demonstrating efficacy in the metastatic setting. The randomized phase III PenelopeB study evaluated the addition of the CDK4/6 inhibitor palbociclib to endocrine therapy as post-neoadjuvant treatment for HR-positive/HER2-negative, breast cancer patients with high risk of relapse (clinical pathological staging-estrogen receptor grading score ≥ 3 or 2 and ypN+) after neoadjuvant chemotherapy. Patients received either palbociclib 125 mg orally once daily for 21 days followed by 1 week off treatment for a total duration of 13 4-week cycles or matching placebo in addition to standard adjuvant endocrine therapy at the discretion of the investigator given for at least 5 years. The primary endpoint was invasive disease-free survival (iDFS). Secondary endpoints included iDFS excluding second primary invasive nonbreast cancers, distant disease-free survival, overall survival, locoregional relapse-free interval, safety, and compliance. After a median follow-up of 43 months the addition of 1 year palbociclib to standard adjuvant endocrine therapy did not significantly improve iDFS. The estimated 3-year iDFS was 81.2% (95%CI 77.8%-84.1%) with palbociclib and 77.7% (95%CI 74.1%-80.9%) with placebo. No new safety signals were observed. PenelopeB is the first study showing mature iDFS results on a CDK4/6 inhibitor as part of (post-neo)adjuvant therapy in early breast cancer. Further translational research and subgroup analyses are ongoing.

Loibl S, Marmé F, Martin M, et al. Palbociclib for Residual High-Risk Invasive HR-Positive and HER2-Negative Early Breast Cancer-The Penelope-B Trial. J Clin Oncol. 2021 Apr 1:JCO2003639. doi: 10.1200/JCO.20.03639.

PubMed Link


GBG Forschungs GmbH
Martin-Behaim-Str. 12 | 63263 Neu-Isenburg | Fax +49 6102 7480-440

+49 6102 7480-0 | nfGBGd