A drug used to treat hormone-receptor positive (HR+), HER2 negative (HER2-) breast cancer that is advanced or has spread to other parts of the body. It is used with an aromatase inhibitor (a type of hormone therapy) in women who have not been treated with hormone therapy. It is used with fulvestrant in postmenopausal women who have not been treated with hormone therapy or whose cancer got worse during treatment with hormone therapy. It is also being studied in the treatment of other types of cancer. Ribociclib succinate blocks certain proteins, which may help keep cancer cells from growing. It is a type of cyclin-dependent kinase inhibitor. Also called Kisqali.