bleselumab bleselumab bleselumab (inn; development code askp1240) is a human monoclonal antibody designed for the prevention of organ transplant rejection. bleselumabmonoclonal antibodytypewhole antibodysourcehumantargetcd40clinical dataother namesaskp1240atc codenoneidentifierscas number1453067-91-8chemspidernoneuniias3az5r46kkeggd11357chemical and physical dataformulac6412h9906n1690o2018s38molar mass144175.87 g·mol−1 this drug was developed by kyowa kirin pharmaceutical development inc.