Ribociclib (1 brand name, 1 dosage form, 1 route)
Available dosage forms: TABLET.
Routes of administration: ORAL.
Brand Names
- RIBOCICLIB
Contraindications
None.
Adverse Reactions
The following adverse reactions are discussed in greater detail in other sections of the labeling: Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.1)] Severe Cutaneous Adverse Reactions [see Warnings and Precautions (5.2)] QT Interval Prolongation [see Warnings and Precautions (5.3, 5.4)] Hepatotoxicity [see Warnings and Precautions (5.5)] Neutropenia [see Warnings and Precautions (5.6)]
Mechanism of Action
Ribociclib is an inhibitor of cyclin-dependent kinase (CDK) 4 and 6. These kinases are activated upon binding to D-cyclins and are downstream of signaling pathways which lead to cell cycle progression and cellular proliferation. The cyclin D-CDK4/6 complex regulates cell cycle progression through phosphorylation of the retinoblastoma protein (pRb). In vitro, ribociclib decreased pRb phosphorylation, resulting in arrest in the G1 phase of the cell cycle and reduced proliferation in breast cancer-derived models. In vivo, treatment with single agent ribociclib in a rat xenograft model with human tumor cells led to decreased tumor volumes, which correlated with inhibition of pRb phosphorylation. In studies using patient-derived estrogen receptor positive breast cancer xenograft models, combination of ribociclib and antiestrogen (e.g., letrozole) therapies resulted in increased tumor growth inhibition compared to each drug alone. Additionally, the combination of ribociclib and fulvestrant resulted in tumor growth inhibition in an estrogen receptor positive breast cancer xenograft model.