Palbociclib

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** An orally available cyclin-dependent kinase (CDK) inhibitor with potential antineoplastic activity. Palbociclib selectively inhibits cyclin-dependent kinase 4 (CDK4) and 6 (CDK6), thereby inhibiting retinoblastoma (Rb) protein phosphorylation early in the G1 phase leading to cell cycle arrest. This suppresses DNA replication and decreases tumor cell proliferation. CDK4 and 6 are serine/threonine kinases that are upregulated in many tumor cell types and play a key role in the regulation of cell cycle progression.

**Synonyms:** - 6-Acetyl-8-cyclopentyl-5-methyl-2-((5-(piperazin-1-yl)pyridin-2-yl)amino)-8h-pyrido(2,3-d)pyrimidin-7-one - Ibrance - PALBOCICLIB - PD 0332991 - PD 332991 - PD 991 - PD-0332991 - PD0332991 - Pyrido(2,3-d)pyrimidin-7(8H)-one, 6-Acetyl-8-cyclopentyl-5-methyl-2-((5-(1-piperazinyl)-2-pyridinyl)amino)-