Casirivimab

Casirivimab is a monoclonal antibody given together with imdevimab. The distribution of casirivimab and imdevimab was stopped in January of 2022 because of a lack of efficacy against COVID-19 variants. Both are directed against the SARS-CoV-2 virus that causes COVID-19. No information is available on the clinical use of casirivimab during breastfeeding. Because casirivimab is a large protein molecule with a molecular weight of over 145,000 Da, the amount in milk is likely to be very low. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. Until more data become available, casirivimab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant.