If subjects are listed for kidney transplant and are considered sensitized, this means they have a high amount of antibodies in their blood that could react to a kidney transplant offered for them. Antibodies are protein substances made by the body that fight anything that the body considers as a threat to it, such as infection or a kidney transplant. Sensitization may be due to prior transplants, pregnancy, or blood transfusions. Being sensitized can increase the subject's kidney transplant waiting time as it is more difficult to find a suitable kidney transplant for them that their antibodies will not react to. The purpose of this research study is to see if giving the investigational drug belimumab up to one year pre-transplant can de-sensitize the subjects, or decrease the amount of antibodies in their blood. This may help make the subjects eligible to receive a kidney transplant more quickly. If after receiving belimumab, the subjects are compatible with a donor kidney offered and are medically suitable for transplant at that time, a kidney transplant will be performed.
Approximately one third of patients awaiting kidney transplant at our transplant center have significant levels of antibodies in their blood leading to a longer wait time for a kidney transplant and death. Antibodies in the blood may be due to prior transplants, pregnancy, or blood transfusions. These antibodies sensitize a patient and make it more difficult for the patient to get a compatible kidney transplant. The measure of these antibodies is called panel reactive antibodies (PRA) and can range from 0-100%, with 100% being most sensitized. The waiting time for patients with a PRA in the range of 20%-79% is over 5 years as compared to patients with low PRA (0%-19%) which is 3-4 years. Patients with a PRA greater than 80% are likely to be granted extra points to increase the chances of transplantation. Antibodies in these patients may be due to prior transplants, pregnancy, or blood transfusions. To date, no trials with belimumab have been performed in patients with pre-existing antibodies awaiting kidney transplantation. This study is undertaken to assess the effectiveness and safety of using belimumab to normalize antibody levels in sensitized patients awaiting kidney transplantation. It is hoped that decreasing these antibodies will decrease the waiting time on the kidney transplant list, and allow the patient to become compatible with a donor kidney for transplant.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
8
Belimumab is a fully human monoclonal antibody that recognizes and inhibits BLyS ®. BLyS ® is a B-lymphocyte stimulator protein which plays a role in the development of B lymphocyte cells into plasma B cells, which then produce antibodies that can sensitize a potential transplant recipient. At the time of this trial, belimumab was not yet FDA approved and was being studied in clinical trials for the treatment of systemic lupus erythematosus. Until this trial, it had not yet been used in the transplant setting.
University of Pennsyvlania Kidney Transplant Program
Philadelphia, Pennsylvania, United States
Effectiveness of Belimumab to Normalize Allo-antibody Levels in Sensitized Patients Awaiting Kidney Transplantation.
Before transplant it is necessary to measure antibodies that the recipient might have and compare them to the living or decease donor's immune make-up. Recipients with many antibodies or a specific antibody in a high concentration may have a more difficult time finding a compatible donor, and being transplanted. These recipients are referred to as sensitized patients. It is important that the sensitized recipient and the donor be compatible to prevent rejection after transplant. We measured antibodies levels in sensitized patients waiting for kidney transplant, to see if belimumab would decrease these antibody levels.
Time frame: up to one year pre-transplant
Successful Kidney Transplantation From a Cross-match Compatible Donor (as a Result of Belimumab Therapy)
In order for a sensitized recipient ( a recipient with antibodies) to be transplanted, the cross match with the donor has to be compatible. We wanted to study if belimumab reduced antibodies in sensitized patients and led those patients to subsequently become cross-match compatible with a donor and allow for successful transplant.
Time frame: one year pre-transplant
Pharmacokinetics of Belimumab Measured as Number of Participants With Specific Dilution Factors at Each Time Point.
We wanted to look at belimumab pharmacokinetics in sensitized patients awaiting kidney transplant. These are reported as number of participants with specific dilution factors at each studied time-point. Blood for these tests could be drawn pre dose as well as 0-4 hours after the dose was given. Belimumab dilutions factors were measured pre dose at timepoints 0 (first day of belimumab), days 56 and 364. Belimumab dilution factors were measured after the dose on days 14, and 168. Belimumab dilution factors were also measured at 8 weeks after completion of belimumab therapy and pre dose at any unscheduled visits if needed.
Time frame: Belimumab serum drug dilution factors were measured in patients at at timepoints 0 (first day of belimumab), day 14, day 56, day 168, 364, at any unscheduled visits, and at 8 weeks post completion of belimumab therapy.
B and T Lymphocyte Subsets
B and T Lymphocyte subsets were measured through flow cytometry pre-treatment and at months 1,2,12 and at 8 weeks after the last belimumab dose. We looked for clinically significant changes (as determined by Principal Investigator) in these subsets at each time-point.
Time frame: 8 weeks after the last dose of belimumab
BLyS Levels Before and After Treatment With Belimumab
We assessed for unexpected changes in bound and unbound BLyS levels before and after treatment with belimumab. These were measured from before treatment and at months 1,2,6,10 and 12 months after belimumab treatment and again at 8 weeks after belimumab treatment.
Time frame: up to 8 weeks after completion of therapy
Hepatitis B Vaccine Antibody Titers
We investigated if belimumab treatment would decrease Hepatitis B vaccine titers by 12 months after treatment with belimumab. All patients received Hepatitis B vaccine before beginning treatment with belimumab.
Time frame: up to 12 months of treatment with belimumab
Number of Participants With Treatment Related Serious Adverse Events
To assess the safety of belimumab in sensitized patients awaiting kidney transplant we evaluated the number of participants with serious adverse events possibly or definitely related to belimumab.
Time frame: up to one year pre-transplant
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