No information is available on the clinical use of midostaurin during breastfeeding. Because midostaurin and its active metabolites are 99.8% bound to plasma proteins, the amount in milk is likely to be low. The manufacturer recommends that breastfeeding be discontinued during midostaurin therapy and for 4 months after the last dose. Avoiding breastfeeding is particularly important when midostaurin is given with other cancer chemotherapy agents.