Ibrance (palbociclib) is used for the treatment of breast cancer that is hormone receptor-positive (estrogen or progesterone receptor positive), is HER2 negative, and is metastatic (has spread to other parts of the body). Ibrance is used in combination with other drugs. For example, in postmenopausal people, it is used with an aromatase inhibitor. It may also be used with a drug called Faslodex (fulvestrant) in people who have previously received hormonal therapy for breast cancer.