Indications
Ribociclib is a kinase inhibitor used to treat adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer. It is given together with another medicine, in one of two ways. The first is with an aromatase inhibitor as the initial endocrine-based therapy. The second is with fulvestrant, either as the initial endocrine-based therapy or after the cancer has progressed on endocrine therapy, in postmenopausal women or in men.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Ribociclib blocks two enzymes called cyclin-dependent kinase (CDK) 4 and 6. These kinases switch on when they bind to D-cyclins, and they send signals that push a cell through the cell cycle so it can multiply. The cyclin D-CDK4/6 complex controls this progress by phosphorylating the retinoblastoma protein (pRb).
In laboratory (in vitro) tests on breast cancer cell lines, ribociclib reduced pRb phosphorylation. This stopped the cells in the G1 phase of the cell cycle and cut down cell proliferation. In vivo, ribociclib given alone to rats carrying human tumour cells (a xenograft model) led to smaller tumour volumes, and this matched the drop in pRb phosphorylation.
Studies in patient-derived estrogen receptor positive breast cancer xenograft models also looked at combinations. Ribociclib together with an antiestrogen (for example letrozole) slowed tumour growth more than either drug did alone. The combination of ribociclib and fulvestrant also slowed tumour growth in an estrogen receptor positive breast cancer xenograft model.
Pregnancy & Breastfeeding
Animal studies and the way ribociclib works suggest that it can harm the baby if a pregnant woman takes it. Females of reproductive potential should have a pregnancy test before starting treatment with ribociclib.
It isn't known whether ribociclib passes into human milk. There are also no data on how it affects a breastfed infant or milk production.
Ribociclib may impair fertility in males of reproductive potential.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.