Study of Daratumumab for Decreasing Circulating Antibodies in Sensitized Patients Awaiting Heart Transplantation

Inclusion Criteria: * Participant is on an active list for a heart transplant. * Participant has a high level of allosensitization, defined as a calculated PRA (panel of reactive antibodies) of 50%, based on their antibody status at the time of entry into the study. * Ability to understand and willingness to sign an informed consent form prior to any study-related procedures. * Women of childbearing potential must have a negative pregnancy test at screening. * Both male and female patients must use effective methods of birth control, must not donate eggs or sperm during the course of the study and for 3 months after stopping daratumumab. Exclusion Criteria: * History of allergy or intolerance to daratumumab. * Prior diagnosis of myeloma or light chain amyloidosis. * Active infection. * Women who are pregnant or breastfeeding. * Ongoing desensitization treatment with another agent. Subjects are excluded if they have received: * a. IVIG within 30 days of enrollment. * b. Proteasome inhibitor within 60 days of enrollment. * c. Rituximab within 180 days of enrollment. * Any condition which could interfere with, or the treatment for which might interfere with, the conduct of the study or which would, in the opinion of the Investigator, unacceptably increase the subject's risk by participating in the study. * Contraindication to herpes zoster prophylaxis. * Known to be seropositive for human immunodeficiency virus (HIV). * Known to be seropositive for hepatitis B (defined…