Etesevimab

ABSTRACT

Etesevimab is a monoclonal antibody given together with bamlanivimab. Both are directed against the SARS-CoV-2 virus that causes COVID-19. No information is available on the clinical use of etesevimab during breastfeeding. Because etesevimab is a large protein molecule with a molecular weight of 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. Until more data become available, etesevimab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. Etesevimab is a human immunoglobulin G1 (IgG1) 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 IgG1 activity decreasing by about 37%.[3] None of the studies measured IgG activity.