No information is available on the clinical use of toripalimab during breastfeeding. Because toripalimab is a large protein molecule with a molecular weight of 150,000 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] Until more data become available, toripalimab should be used with caution or avoided during breastfeeding, especially while nursing a newborn or preterm infant. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[3] The manufacturer recommends that breastfeeding be discontinued during toripalimab therapy and for 4 months after the last dose.