No information is available on the clinical use of acalabrutinib during breastfeeding. Because acalabrutinib is over 97% bound to plasma proteins, and the half-life of the drug and metabolite are less than 7 hours, the amount in milk is likely to be low. However, the protein binding of the active metabolite is not known and the manufacturer recommends that breastfeeding be discontinued during acalabrutinib therapy and for at least 2 weeks after the final dose.