Safety & Tolerability of Berinert® (C1 Inhibitor) Therapy to Prevent Rejection

Single center, Phase I/II, randomized The trial will examine the safety and efficacy of human C1 INH given post-transplant to reduce or prevent complement-dependent, antibody-mediated rejection (AMR) in 20 subjects (adult) who are highly-HLA sensitized (HS),(Panel Reactive Antibodies \>30% (PRA), have undergone desensitization with intravenous immunoglobin (IVIG) + rituximab and/or plasmapheresis and are awaiting Living donor (LD)/ Deceased Donor (DD) kidney transplant. Once transplant offers are entertained, a donor-specific crossmatch will be performed to detect anti-HLA antibodies and donor-specific anti-HLA antibodies (DSA) which are associated with acute rejection or graft loss. (These anti-HLA (anti-Human Leukocyte Antigen antibodies) antibodies may result naturally or from previous pregnancy, transfusions, or prior transplants.) If acceptable crossmatches and Donor Specific Antibody levels are seen after desensitization, the patients will proceed to Living Donor/Deceased Donor transplantation. Patients receiving transplants will have pre-transplant labs obtained for C1 INH levels, Complement 3 (C3) and Complement 4 (C4) at transplant. In addition to the standard post-transplant immunosuppressive protocol, participating patients will receive placebo or 20 Units/kg C1 INH twice weekly X 4 weeks. At the end of the treatment, a protocol biopsy will be performed to assess the allograft for evidence of Antibody Mediated Rejection, including C4d staining. Since \~25% of highly sensitized patients experience Antibody Mediated Rejection post-transplant and 85% of these Antibody Mediated Rejection episodes occur in the 1st post-transplant month, we feel the assessment of the potential impact of C1 INH therapy is best assessed in this time period. After completion of the C1 INH therapy, patients will be followed for an additional 6 month to assess allograft function and Antibody Mediated Rejection episodes as well as Donor Specific Antibodies. The subjects will be followed to determine the proportion who develop evidence of Antibody Mediated Rejection within 6 month of completion of the study. In addition we will asses the transplanted patients to determine the number who sustain a viable and functioning kidney allograft for 6 months. All subjects will be evaluated on an intent-to-treat basis. The subject accrual rate will be limited to no more than five subjects per month in the initial three months to assure safety to all subjects. Repeat laboratories will be performed at the completion of C1 INH therapy to determine effect on levels and correlation with any potential events.