Guselkumab

Abstract

No information is available on the clinical use of guselkumab during breastfeeding. Because guselkumab is a large protein molecule with a molecular weight of about 144,000 Da, 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, guselkumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. Guselkumab is a human immunoglobulin G1 (IgG1) lambda 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.