Although one breastfed infant apparently experienced no adverse effects during maternal use of dasatinib, no long-term data are available. Because dasatinib and its metabolite are more than 90% bound to plasma proteins, the amounts in milk are likely to be low. However, there is little published experience with dasatinib during breastfeeding, and an alternate drug may be preferred, especially while nursing a newborn or preterm infant. National Comprehensive Cancer Network guidelines recommend avoiding breastfeeding during dasatinib therapy and the manufacturer recommends withholding breastfeeding until 2 weeks following the last dose.[1]