No information is available on the clinical use of ribociclib during breastfeeding. Because protein binding of ribociclib is 70%, clinically important amounts of the drug might pass into breastmilk. The manufacturer recommends that breastfeeding be discontinued during ribociclib therapy and for at least 3 weeks after the final dose. Ribociclib is also given in combination with fulvestrant, which may increase the risk to the infant.
