PENELOPE-B: This phase III trial is trying to demonstrate the effect of using palbociclib (a prescribed drug) in combination with anti-hormonal therapy for patients with hormone receptor positive / HER2 normal breast cancerPhase III Study Evaluating Palbociclib (PD-0332991), a Cyclin-Dependent Kinase (CDK) 4/6 Inhibitor in Patients With Hormone-receptor-positive, HER2-normal Primary Breast Cancer With High Relapse Risk After Neoadjuvant Chemotherapy.

Inclusion

1. Written informed consent prior to beginning specific protocol procedures, including expected cooperation of the patients for the treatment and follow-up, must be obtained and documented according to the local regulatory requirements.
2. Willingness and ability to provide archived formalin fixed paraffin embedded tissue block or a partial block from surgery after neoadjuvant chemotherapy and from core-biopsy before start of neoadjuvant chemotherapy, which will be used for centralized retrospective confirmation of hormone- and HER2-status and to evaluate correlation between genes, proteins, and mRNAs relevant to the endocrine and cell cycle pathways and sensitivity/resistance to the investigational agents. In case of bilateral breast cancer, tumor tissue of both sides needs to be assessable.
3. Histologically confirmed unilateral or bilateral primary invasive carcinoma of the breast.
4. Residual invasive disease post-neoadjuvant either in the breast or as residual nodal invasion.
5. Centrally confirmed hormone-receptor-positive (≥1% ER and/or PR positive stained cells) and HER2-normal (IHC score 0-1 or FISH negative (in-situ hybridization (ISH) ratio) <2.0 status) assessed preferably on tissue from post-neoadjuvant residual invasive disease or core biopsy of the breast, or if no other tissue is available, the residual tumor of the lymph node can be assessed. In case of bilateral breast cancer, hormone receptor positivity and HER2-normal status has to be centrally confirmed for both sides.
6. Centrally assessed Ki-67, pRB, and Cyclin D1 status assessed preferably on post-neoadjuvant residual invasive disease of the breast, or if not possible, of residual nodal invasion or core biopsy. In case of bilateral breast cancer, tumor tissue of both sides needs to be assessable.
7. Patients must have received neoadjuvant chemotherapy of at least 16 weeks. This period must include 6 weeks of a taxane-containing neoadjuvant therapy (Exception: For patients with progressive disease that occurred after at least 6 weeks of taxane-containing neoadjuvant treatment, a total treatment period of less than 16 weeks is also eligible).
8. Adequate surgical treatment including resection of all clinically evident disease and ipsilateral axillary lymph node dissection. Histologically complete resection (R0) of the invasive and ductal in situ tumor is required in case of breast conserving surgery as the final treatment. No evidence of gross residual disease (R2) is required after total mastectomy (R1 resection is acceptable). Axillary dissection is not required in patients with a negative sentinel-node biopsy before (pN0, pN+(mic)) or after (ypN0, ypN+(mic) neoadjuvant chemotherapy.
9. Less than 16 weeks interval since the date of final surgery or less than 10 weeks from completing radiotherapy (whichever occurs last) at date of randomization.
10. Completion of adjuvant radiotherapy according to standard guidelines (e.g. AGO Mamma, NCCN) is strongly recommended. If radiotherapy is not performed, the reason for this needs to be documented in the eCRF.
11. No clinical evidence for locoregional or distant relapse during or after preoperative chemotherapy. Local progression during chemotherapy is not an exclusion criterion.
12. A clinical-pathologic stage - estrogen/grade (CPS-EG) score of ≥3, or score 2 if nodal status at surgery is ypN+, calculated using local estrogen receptor status and grade assessed on either core biopsies taken before start of neoadjuvant treatment or surgical specimen (see chapter 21.1).
13. Age at diagnosis at least 18 years.
14. Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1.
15. Resolution of all acute toxic effects of prior anti cancer therapy or surgical procedures to NCI CTCAE version 4.0 Grade ≤1 (except alopecia or other toxicities not considered a safety risk for the patient at investigator's discretion).
16. Estimated life expectancy of at least 5 years irrespective of the diagnosis of breast cancer.
17. The patient must be accessible for scheduled visits, treatment and follow-up. Patients registered in this trial must be treated at the participating center which could be the Principal Investigator's or a Co-investigator's site.