Ipilimumab and Breastfeeding

Summary of use during lactation

The amount of ipilimumab in breastmilk appears to be very low, but it may increase with subsequent doses during a treatment cycle. It is likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[1] Until more data become available, ipilimumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. The manufacturer recommends that breastfeeding be discontinued during ipilimumab therapy and for 3 months after the last dose.

Drug levels in milk and infant serum

Maternal Levels. A woman with recurrent malignant melanoma was treated with ipilimumab 3 mg/kg intravenously over 90 minutes once every 3 weeks for 4 doses, beginning soon after delivery. Breast milk and serum samples were collected before she began therapy and at various times over the first 2 dosage intervals. A total of 26 daily breastmilk samples were obtained. Breastmilk levels of ipilimumab were at their highest of about 90 mcg/L at 10 days after the first infusion, and were lowest at 41 mcg/L at the time of the second infusion, 19 days after the first infusion. A peak milk level of 147 mcg/L was reached 4 days after the second infusion. It was apparent that accumulation took place after the second dose. The authors estimated that a fully breastfed infant would ingest a total of 4.5 mg of ipilimumab over a 4 month treatment cycle.[2] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

A woman with recurrent malignant melanoma was treated with ipilimumab 3 mg/kg intravenously over 90 minutes once every 3 weeks for 4 doses, beginning soon after delivery. She began breastfeeding 21 days after her 12 weeks of therapy was completed. At 30 weeks after treatment she was well, but no mention was made of the duration of breastfeeding or the health of her infant.[4]

Effects on lactation and breastmilk

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

References

1. Anderson PO. Monoclonal antibodies during breastfeeding. Breastfeed Med 2021;16:591-3.33956488 PubMed
2. Ross E, Robinson SE, Amato C, et al. Therapeutic monoclonal antibodies in human breast milk: A case study. Melanoma Res 2014;24:177-80.24476799 PubMed