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 by a positive test for hepatitis B
   surface antigen [HBsAg]). Subjects with resolved infection (ie, subjects who are HBsAg
   negative but positive for antibodies to hepatitis B core antigen [anti-HBc] and/or
   antibodies to hepatitis B surface antigen [anti-HBs]) must be screened using real-time
   polymerase chain reaction (PCR) measurement of hepatitis B virus (HBV) DNA levels.
   Those who are PCR positive will be excluded. EXCEPTION: Subjects with serologic
   findings suggestive of HBV vaccination (anti-HBs positivity as the only serologic
   marker) AND a known history of prior HBV vaccination, do not need to be tested for HBV
   DNA by PCR.

   - Known to be seropositive for hepatitis C (except in the setting of a sustained
   virologic response (SVR), defined as aviremia at least 12 weeks after completion of
   antiviral therapy).

   - Known chronic obstructive pulmonary disease (COPD) with a forced expiratory volume in
   1 second (FEV1) <50% of predicted normal. Note that FEV1 testing is required for
   subjects suspected of having COPD and subjects must be excluded if FEV1 is <50% of
   predicted normal.

   - Known moderate or severe persistent asthma within the past 2 years, or uncontrolled
   asthma of any classification.