Palbociclib In Combination With Letrozole As Treatment Of Post-Menopausal Women With HR+, HER2- Advanced Breast Cancer

• Drug: Palbociclib
  
  125 mg/d capsules orally for 3 out of 4 weeks in repeated cycles
  Other Name: IBRANCE
• Drug: Letrozole
  
  2.5 mg/d tablets orally on a continuous regimen

Inclusion Criteria:

• Post-menopausal women (>=18 years of age) with proven diagnosis of advanced carcinoma of the breast (ER(+) and/or PgR(+) and HER2(-)) who are appropriate for letrozole therapy (in the first-line advanced/metastatic disease setting).
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
• Adequate bone marrow, liver, and renal function.

Exclusion Criteria:

• Prior treatment with any CDK inhibitor .
• QTc >480 msec; history of QT syndrome, Brugada syndrome or known history of QTc prolongation, or Torsade de Pointes.
• High cardiovascular risk, including, but not limited to myocardial infarction, severe/unstable angina, severe cardiac dysrhythmias, and symptomatic pulmonary embolism in the past 6 months of enrollment.