Summary of Use during Lactation

No information is available on the clinical use of mosunetuzumab during breastfeeding. Because mosunetuzumab is a large protein molecule with a molecular weight of 146,000 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] The manufacturer recommends that breastfeeding be discontinued during mosunetuzumab therapy and for 3 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.

References

1.

Stratigakis A, Paty D, Zou P, et al. A regression approach for assessing large molecular drug concentration in breast milk. Reprod Breed 2023;3:199-207. doi:10.1016/j.repbre.2023.10.003 [CrossRef]

2.

Anderson PO. Monoclonal antibodies during breastfeeding. Breastfeed Med 2021;16:591-3. [PubMed: 33956488]

Substance Name

Mosunetuzumab

CAS Registry Number

1905409-39-3

Drug Class

Breast Feeding

Lactation

Milk, Human

Monoclonal Antibodies, Humanized

Antineoplastic Agents