No information is available on the clinical use of glofitamab during breastfeeding. Because glofitamab is a large protein molecule with a molecular weight of 197,000 Da, the amount in milk is likely to be very low.[1] It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[2] Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[3] The manufacturer recommends avoiding breastfeeding during glofitamab use and for 1 month after the last dose.