The Basics
What is Cemiplimab?
Monoclonal antibody drug for the treatment of squamous cell skin cancer, myeloma, and lung cancer.
Brand names for Cemiplimab
Libtayo
How Cemiplimab is classified
Antibodies – Monoclonal, Antineoplastic Agents
Cemiplimab During Pregnancy
Cemiplimab 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 Cemiplimab while pregnant
N/A
Taking Cemiplimab While Breastfeeding
What are recommendations for lactation if you're taking Cemiplimab?
No information is available on the clinical use of cemiplimab during breastfeeding. Because cemiplimab is a large protein molecule with a molecular weight of about 146,000, 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. The manufacturer recommends that breastfeeding be discontinued during cemiplimab therapy and for 4 months after the last dose. Cemiplimab is a human immunoglobulin G4 (IgG4) antibody. Holder pasteurization (62.5 degrees C for 30 minutes) decreases the concentration of endogenous immunoglobulin G by up to 79%.[1][2] A study of 67 colostrum samples that underwent Holder pasteurization found that IgG amounts decreased by 34 to 40%. Specific IgG subclasses decreased by different amounts, with Holder pasteurization having little effect on IgG4 activity.[3] None of the studies measured IgG activity.
Maternal / infant drug levels
No information is available on the clinical use of cemiplimab during breastfeeding. Because cemiplimab is a large protein molecule with a molecular weight of about 146,000, 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. The manufacturer recommends that breastfeeding be discontinued during cemiplimab therapy and for 4 months after the last dose. Cemiplimab is a human immunoglobulin G4 (IgG4) antibody. Holder pasteurization (62.5 degrees C for 30 minutes) decreases the concentration of endogenous immunoglobulin G by up to 79%.[1][2] A study of 67 colostrum samples that underwent Holder pasteurization found that IgG amounts decreased by 34 to 40%. Specific IgG subclasses decreased by different amounts, with Holder pasteurization having little effect on IgG4 activity.[3] None of the studies measured IgG activity.
Possible effects of Cemiplimab on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Cemiplimab
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Koenig A, de Albuquerque Diniz EM, Barbosa SF et al. Immunologic factors in human milk: The effects of gestational age and pasteurization. J Hum Lact. 2005;21:439-43. PMID: 16280560
2. Adhisivam B, Vishnu Bhat B, Rao K et al. Effect of Holder pasteurization on macronutrients and immunoglobulin profile of pooled donor human milk. J Matern Fetal Neonatal Med. 2018;1-4. PMID: 29587541
3. Rodriguez-Camejo C, Puyol A, Fazio L et al. Antibody profile of colostrum and the effect of processing in human milk banks: Implications in immunoregulatory properties. J Hum Lact. 2018;34:137-47. PMID: 28586632
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
