Bone Marrow Transplant Rejection

This research is being done to investigate the safety and effectiveness of Darzalex Faspro (daratumumab and hyaluronidase-fihj) (a monoclonal antibody that targets plasma cells that make antibodies) and whether it can lower donor specific antibodies (DSA) levels to low enough levels to permit patients to proceed with allogeneic peripheral blood transplant (alloBMT). Those being asked to participate have high DSA levels that puts those being asked to participate at high risk of rejecting the available donor's blood stem cells and making those being asked to participate ineligible to receive a stem cell transplant.