Figures & data
Figure 1 Chemical structure of palbociclib (PD0332991).
Figure 2 Palbociclib mechanism of action.
Notes: Cyclin D1 activated CDK4 and then the resultant complex phosphorylates retinoblastoma protein. G1/S transition depends on the release of E2F family of transcription factors after RB is phosphorylated (P). Palbociclib blocks G1/S transition by ultimately inhibiting RB phosphorylation. Another suggested effect of palbociclib is decreasing metastasis by decreasing expression of COX-II enzyme, which contributes in EMT process. EMT gives cells invasive and metastatic properties. Also, by blocking CDK6 that was reported to have a role in angiogenesis, palbociclib is suggested to have antiangiogenesis effect.
Abbreviations: CDK, cyclin-dependent kinase; COX-II, cyclooxygenase-II; EMT, epithelial-to-mesenchymal transition; RB, retinoblastoma protein.
Abbreviations: CDK, cyclin-dependent kinase; COX-II, cyclooxygenase-II; EMT, epithelial-to-mesenchymal transition; RB, retinoblastoma protein.
Table 1 Palbociclib pharmacokinetic parameters for 2/1 schedule and 3/1 schedule
Table 2 Ongoing and future palbociclib trials