This is an international, randomized, open-label, controlled, multicenter phase II clinical
trial to investigate and compare the safety and efficacy of palbociclib combined with
fulvestrant or letrozole in women with ER+, HER2- locally advanced or metastatic breast
Women 18 years or older with metastatic or locally advanced disease, not amenable to
Confirmed diagnosis of HR+/HER2- breast cancer
No prior chemotherapy line in the metastatic setting
Measurable disease defined by RECIST version 1.1, or non-measurable disease
Eastern Cooperative Oncology Group (ECOG) PS 0-1
Adequate organ and marrow function, resolution of all toxic effects of prior therapy or
Confirmed diagnosis of HER2 positive disease
Patients with rapidly progressive visceral disease or visceral crisis.
Locally advanced breast cancer candidate for a radical treatment.
Prior (neo)adjuvant endocrine treatment with DFI 12-months from completion of treatment.
Major surgery within 4 weeks of start of study drug
Serious concomitant systemic disorder incompatible with the study
Known active uncontrolled or symptomatic CNS metastases
Minimum Eligible Age: 18 Years
Maximum Eligible Age: N/A
Eligible Gender: Female
Grade 3/4 adverse events, SAEs, deaths and discontinuations
Time to progression (TTP)
Overall survival (OS)
Clinical Benefit Rate
Overall Response Rate