Summary of Use during Lactation

No information is available on the clinical use of trastuzumab deruxtecan during breastfeeding. Because trastuzumab is a large protein molecule with a molecular weight of 145,531 Da, the amount in milk is likely to be very low. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. However, deruxtecan (DXd) is a small-molecule topoisomerase 1 inhibitor, which might be excreted into milk. The manufacturer recommends that breastfeeding be discontinued during trastuzumab deruxtecan therapy and for 7 months after the last dose.

Drug Levels

Maternal Levels. Relevant published information was not found as of the revision date.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

Substance Name

Trastuzumab Deruxtecan

CAS Registry Number

1826843-81-5

Drug Class

Breast Feeding

Lactation

Milk, Human

Antibodies, Monoclonal

Antineoplastic Agents

Immunoconjugates

Topoisomerase I Inhibitors