Ibalizumab and Breastfeeding

Summary of use during lactation

No published information is available on the use of ibalizumab during breastfeeding. Because ibalizumab 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, ibalizumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. Achieving and maintaining viral suppression with antiretroviral therapy decreases breastfeeding transmission risk to less than 1%, but not zero. Individuals with HIV who are on antiretroviral therapy with a sustained undetectable viral load and who choose to breastfeed should be supported in this decision. If a viral load is not suppressed, banked pasteurized donor milk or formula is recommended.[3,4]

Drug levels in milk and infant serum

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
2. Anderson PO. Monoclonal antibodies during breastfeeding. Breastfeed Med 2021;16:591-3.33956488 PubMed
3. Department of Health and Human Services. Recommendations for the use of antiretroviral drugs during pregnancy and interventions to reduce perinatal HIV transmission in the United States. 2024. https://clinicalinfo.hiv.gov/sites/default/files/guidelines/documents/perinatal-hiv/guidelines-perinatal.pdf
4. World Health Organization. Consolidated guidelines on HIV prevention, testing, treatment, service delivery and monitoring: Recommendations for a public health approach. 2021. https://www.who.int/publications/i/item/9789240031593 PubMed