Small molecule
PubChem CID 5330286
Palbociclib
Ibrance
- Mechanism of action
- CDK4/6 inhibitor
- In plain language
- Slows the growth of certain breast cancer cells by blocking two proteins (CDK4 and CDK6) that cells need to divide and multiply.
- How it works
- Palbociclib is a selective, reversible small-molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which act downstream of growth-signaling pathways to drive cell-cycle progression from G1 into S phase. By inhibiting CDK4/6, palbociclib blocks retinoblastoma protein phosphorylation, reducing E2F-mediated transcription and halting proliferation of estrogen receptor-positive breast cancer cells. When combined with antiestrogen therapy, this produces greater growth arrest than either agent alone. Normal bone marrow progenitor cells exposed to palbociclib resume proliferation once the drug is withdrawn, consistent with its reversible, cytostatic mechanism.
- Therapeutic applications
- Indicated for adults with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer, in combination with an aromatase inhibitor or with fulvestrant; in combination with inavolisib and fulvestrant for endocrine-resistant, PIK3CA-mutated disease; and in combination with trastuzumab and endocrine therapy as maintenance treatment for HR-positive, HER2-positive advanced breast cancer.
- Class
- Small molecule
- Therapeutic area
- Oncology
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