Neoplasms

Skin and Connective Tissue Diseases

All Conditions

Breast Neoplasms

Breast Diseases

Skin Diseases

Antineoplastic Agents

All Drugs and Chemicals

Capecitabine

Fulvestrant

Exemestane

Palbociclib

Aromatase Inhibitors

Antimetabolites

Antineoplastic Agents, Hormonal

Estrogens

Estrogen Antagonists

Estrogen Receptor Antagonists

Hormones

Hormone Antagonists

Protein Kinase Inhibitors

Enzyme Inhibitors

Palbociclib 125 mg orally once daily on Day 1 to Day 21 followed by 7 days off treatment on every 28 days cycles in combination with

* Cohort 1: Exemestane 25 mg orally once daily.
* Cohort 2: Fulvestrant 500 mg on Days 1 and 15 of Cycle 1, and Day 1 of each subsequent 28 days Cycle.

Capecitabine, 1,250 mg/m2 twice daily for 2 weeks followed by a 1 week rest period, given as 3 weeks cycles. Capecitabine must be administered at a dose of 1,000 mg/m2 twice daily for 2 weeks followed by a 1 week of rest period, given as 3 weeks cycles, in patients over 70 years of age.

Study Director

This is an international (4 countries) randomized phase III study with 2 cohorts, patients will be randomized 1:1 to endocrine therapy (cohort 1: exemestane 25 mg daily, cohort 2: fulvestrant 500mg days 1 and 15 cycle 1 and then day 1 every 4 weeks) plus palbociclib (125 mg daily x3 weeks every 4 weeks) vs. capecitabine (1,250 mg/m2 twice daily x2 weeks every 3 weeks). Postmenopausal patients with HR+/HER2 MBC are eligible if resistant to previous nonsteroidal aromatase inhibitors (NSAI) (letrozole or anastrozole) in cohort 1 or previous aromatase inhibitors (AI) (letrozole, anastrozole or exemestane) in cohort 2 defined as: recurrence while on or within 12 months after the end of adjuvant treatment with NSAI/AI or progression while on or within 1 month after the end of treatment with NSAI/AI for MBC. Previous chemotherapy is permitted either in the (neo)adjuvant setting and/or as first line for MBC. Patients must have measurable disease according to RECIST 1.1 or bone lesions, lytic or mixed, in the absence of measurable disease.

296 patients have been randomized 1:1 between the experimental arm (Arm A: approximately 125 patients treated with palbociclib plus exemestane) and the control arm (Arm B: approximately 125 patients treated with capecitabine) before the approval of this protocol version (Cohort 1).

Approximately 300 patients will be randomized 1:1 between the experimental arm (Arm A: approximately 150 patients treated with palbociclib plus fulvestrant) and the control arm (Arm B: approximately 150 patients treated with capecitabine) from the approval of this protocol version (Cohort 2).

Phase III Palbociclib With Endocrine Therapy vs. Capecitabine in HR+/HER2- MBC With Resistance to Aromatase Inhibitors

Phase III Study of Palbociclib in Combination With Exemestane or Fulvestrant vs. Chemotherapy (Capecitabine) in Hormonal Receptor Positive/HER2 Negative Metastatic Breast Cancer Patients With Resistance to Aromatase Inhibitors

Baseline biomarker values from most recently obtained tumor tissue (deeply recommended from metastatic tumor) will be used for central assessment of biomarkers related to breast tumor sensitivity and/or resistance to palbociclib (e.g., Ki67, p16/CDKN2A, pRb, CyclinD and others) or breast cancer (e.g. PTEN, ERBB2, BRCA1 and BRCA2). A whole blood sample will be collected for potential pharmacogenomic analyses related to drug response or adverse drug reactions. For example, putative safety biomarkers, drug metabolizing enzyme genes, drug transport protein genes, or genes thought to be related to the drug mechanism of action may be examined. Correlative plasma samples will be collected for exploratory analysis to analyze the pharmacodynamic (PD) treatment effects on circulating free DNA or RNA and explore specific breast cancer and efficacy predictive biomarkers (e.g. PIK3CA mutation). Sample will be collected from all patients, unless prohibited by local regulations.

The primary efficacy variable is PFS based on the investigator's assessment. PFS is defined as the time from randomization to the first documented progressive disease based on the investigator's assessment, using RECIST version 1.1, or death from any cause, whichever occurs first. Estrogen Receptor 1 (ESR1) mutational status will be determined in circulating free DNA (cDNA) obtained from baseline plasma samples and will be prospectively determined before the interims or final analyses. ESR1 mutational status will be blinded to the patients, investigators and study team.

Complete Response (CR) plus Partial Response (PR) based on the investigator's assessment according to the RECIST version 1.1 in patients randomized with measurable disease.

Tumor assessment will be performed at baseline, the same method of measurement used at baseline will be used for further evaluations, that will be conducted every 8 weeks (±7days). The best response across treatment will be recorded. OR is defined as the complete plus partial responses out of the patients who had measurable disease at baseline.

CB is defined as complete response (CR), partial response (PR), or stable disease (SD) based on the investigator´s assessment lasting more than 24 weeks according to the RECIST version 1.1 in all randomized patients (ITT population)

RD is defined as the time from the first documentation of objective tumor response (CR or PR) to the first documented progressive disease using RECIST version 1.1 and based on the investigator's assessment, or to death due to any cause, whichever occurs first.

OS is defined as the time from the date of randomization to the date of death from any cause.

Safety will be assessed by standard clinical and laboratory tests (hematology, serum chemistry). Adverse events grade will be defined by the NCI CTCAE v4.0.

Spots Global Cancer Trial Database for hormonal receptor positive