Description

What is Ibrance (palbociclib) for?

Palbociclib is indicated for the treatment of postmenopausal women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer as initial endocrine-based therapy for their metastatic disease^[1]. It is indicated in combination with an aromatase inhibitor (an hormonal therapy) as initial endocrine based therapy in postmenopausal women or fulvestrant in women with disease progression following endocrine therapy

How does Ibrance (palbociclib) work?

Palbociclib is an inhibitor of cyclin-dependent kinase (CDK) 4 and 6.

Before a cell can divide, it has to go through four phases. The first phase is a growth phase (G1-phase), the second a synthesis phase (S-phase), the third another growth phase (G2-phase) and the last phase, where the cell divides (M-phase). Cancer cells divide exceedingly fast, passing through these 4 phases rapidly. Palbociclib blocks the progression from the first G1-phase, into the second S-phase. It does this by inhibiting the cyclin-dependent kinases 4 and 6 (CDK4 and CDK6)—two proteins that are involved in entering the S-phase