Palbociclib is an endocrine-based chemotherapeutic agent used in combination with other antineoplastic agents to treat HER2-negative and HR-positive advanced or metastatic breast cancer. Palbociclib is a piperazine pyridopyrimidine that acts in the cell cycle machinery.
- Mechanism
- Curator reviewed · 3 references
Palbociclib is a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor that acts by binding to the ATP pocket with an IC50 in the range of 9-15 nmol/L. It is important to consider that it presents low to absent activity against other kinases.
The CDK4/6 kinase is involved, with coregulatory partner cyclin D, in the G1-S transition. Hence, inhibition of this step prevents cell cycle progression in cells in whose this pathway is functioning. This step includes the pathways of the phosphorylation of retinoblastoma protein and the E2F family of transcription factors.
- Primary indication
- Palbociclib is indicated in combination with letrozole as initial endocrine-based therapy for the treatment of human epidermal growth factor receptor type 2 (HER2)-negative and hormone receptor(HR)-positive tumors in adult patients with advanced/metastatic breast cancer.Curator reviewed · 14 structured indications
- Formula / weight
- C24H29N7O2 · 447.5328 g/mol (avg)
- First approval
- Canada, 2016 · United States, 2015 · European Union, 2020
- Also known as
- 6-Acetyl-8-cyclopentyl-5-methyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-8h-pyrido(2,3-d)pyrimidin-7-one
- Code names
- PD-0332991 · PD-332991 · PD 991
- Brand names
Resolves to
AHJRHEGDXFFMBM-UHFFFAOYSA-NSMILESCC(=O)C1=C(C)C2=CN=C(NC3=NC=C(C=C3)N3CCNCC3)N=C2N(C2CCCC2)C1=OWhat you can answer from here — as of September 23, 2026
Which drugs share a target with Palbociclib, and which of those have an active Phase 3 trial?
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