Is Durvalumab Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Durvalumab? Is Durvalumab safe for nursing mother and child? Does Durvalumab extracts into breast milk? Does Durvalumab has any long term or short term side effects on infants? Can Durvalumab influence milk supply or can Durvalumab decrease milk supply in lactating mothers?

No information is available on the clinical use of durvalumab during breastfeeding. Because durvalumab 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. Until more data become available, durvalumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. The manufacturer recommends that mothers not breastfeed during treatment and for at least 3 months after the last dose of durvalumab. Durvalumab is a human immunoglobulin G1 (IgG1) kappa 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.