Pembrolizumab

The Basics

What is Pembrolizumab?

Used in cancer immunotherapy.

Brand names for Pembrolizumab

Keytruda

How Pembrolizumab is classified

Antibodies – Monoclonal (Humanized), Antineoplastic Agents, Biological Response Modifiers, Immunologic Adjuvants, Immune Checkpoint Inhibitors

Pembrolizumab During Pregnancy

Pembrolizumab pregnancy category

Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Pembrolizumab while pregnant

Based on its mechanism of action, KEYTRUDA can cause fetal harm when administered to a pregnant woman. There are no available human data informing the risk of embryo-fetal toxicity. In animal models, the PD-1/PD-L1 signaling pathway is important in the maintenance of pregnancy through induction of maternal immune tolerance to fetal tissue (see Data). Human IgG4 (immunoglobulins) are known to cross the placenta; therefore, pembrolizumab has the potential to be transmitted from the mother to the developing fetus. Advise pregnant women of the potential risk to a fetus. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Taking Pembrolizumab While Breastfeeding

What are recommendations for lactation if you're taking Pembrolizumab?

No information is available on the clinical use of pembrolizumab during breastfeeding. Because pembrolizumab is a large protein molecule with a molecular weight of about 149,000, the amount in milk is likely to be very low and absorption is unlikely because it is probably destroyed in the infant’s gastrointestinal tract. Until more data become available, pembrolizumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. The manufacturer recommends that breastfeeding be discontinued during pembrolizumab therapy and for 4 months after the last dose.

Maternal / infant drug levels

No information is available on the clinical use of pembrolizumab during breastfeeding. Because pembrolizumab is a large protein molecule with a molecular weight of about 149,000, the amount in milk is likely to be very low and absorption is unlikely because it is probably destroyed in the infant’s gastrointestinal tract. Until more data become available, pembrolizumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. The manufacturer recommends that breastfeeding be discontinued during pembrolizumab therapy and for 4 months after the last dose.

Possible effects of Pembrolizumab on milk supply

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

Possible alternatives to Pembrolizumab

None listed