In a clinical context, there is a lack of molecular compounds with demonstrated clinical activity in delaying/reversing resistance to endocrine agents. CDK 4/6 inhibitors may represent a biologically-driven option in this context.
With the present study investigators aim to complement the ongoing trial on PD0332991 by acquiring information on its clinical activity in post-menopausal patients with ER positive, Her2 negative advanced breast cancer patients already pretreated with a first-line or second line endocrine therapy.
