effectiveness of the investigational drug campath-1h in preventing rejection of transplanted kidneys

Conditions: Graft Rejection; Kidney Disease

Summary: this protocol will test a humanized monoclonal antibody known as campath-1h for its ability to induce a state of permanent allograft acceptance, or tolerance, when administered in combination with a brief course of the immunosuppressive drug deoxyspergualin (dsg) at the time of human renal allotransplantation. campath-1h is specific for the common lymphocyte and monocyte antigen cd52. its administration temporarily depletes mature lymphocytes and some monocytes without altering neutrophils or hematopoietic stem cells. deoxyspergualin inhibits the nfkb pathway thus preventing monocyte and macrophage activation. recipients of living or cadaveric donor kidneys will be treated with one dose of campath-1h prior to transplantation to insure that peripheral depletion is achieved at the time of graft reperfusion. three subsequent doses of campath-1h will be administered on the first, third and fifth days after the transplant to deplete passenger donor leukocytes and residual recipient cells that mobilize in response to the allograft. in addition, patients will be treated with dsg for 14 days beginning on the day prior to surgery. this trial expands on pilot studies at the nih of 15 patients in which campath was given alone at the time of transplantation. in those studies, excellent peripheral depletion occurred after just one dose of campath though central depletion required additional dosing. this allowed for greatly reduced immunosuppression to be used to prevent rejection, but to date, all patients have required some immunosuppressive medication. it is hoped that the addition of dsg will eliminate the need for long-term immunosuppression. patients will be followed closely in the post transplant period. if patients experience rejection, they will be treated with methylprednisolone and have immunosuppression added using sirolimus as the predominant immunosuppressive agent. in the previous phase of this study without dsg, this maneuver has in all cases been successful in returning the allograft to normal function. in addition to evaluating graft function following transplantation, this protocol will also characterize and evaluate the function of the immune system and the composition of the t cell repertoire following the administration of campath-1h and dsg, and during immune system recovery after transplantation.

this protocol will test a humanized monoclonal antibody known as campath-1h for its ability to induce a state of permanent allograft acceptance, or tolerance, when administered in combination with a brief course of the immunosuppressive drug deoxyspergualin (dsg) at the time of human renal allotransplantation. campath-1h is specific for the common lymphocyte and monocyte antigen cd52. its administration temporarily depletes mature lymphocytes and some monocytes without altering neutrophils or hematopoietic stem cells. deoxyspergualin inhibits the rel-b/ nfkb pathway thus preventing monocyte and macrophage activation. extensive preliminary data have been accumulated in humans using campath-1h and its non-humanized predecessors. additionally, data have been generated using a similar depleting scheme with and without dsg in non-human primates. both the human and non-human primate data suggest that profound mature mononuclear cell depletion establishes a window of opportunity during which foreign tissue can be transplanted without the need for additional immunosuppression. regulatory events occuring during mature cell repopulation in the presence of allografted tissue created a state in which the graft may not be rejected even in the absence of chronic immunosuppression. recipients of living or cadaveric donor kidneys will be treated with one dose of campath-1h prior to transplantation to insure that peripheral depletion is achieved at the time of graft reperfusion. three subsequent doses of campath-1h will be administered on the first, third and fifth days after the transplant to deplete passenger donor leukocytes and residual recipient cells that mobilize in response to the allograft. in addition, patients will be treated with dsg 4mg/kg/d x 1 beginning on day 12 and then 2.5 mg/kg/d for an additional 13 days. this trial expands on pilot studies at the nih of 17 patients in which campath was dosed both prior to and after transplantation with and without dsg. in those studies, excellent peripheral depletion occured after just one dose of campath though central depletion required additional dosing. thus, the goal of pre-reperfusion depletion can be achieved with a single pre-operative dose but thorough depletion requires additional post-operative dosing. lasting rejection-free survival was not realized without the addition of some, albeit reduced immunosuppression. this is thought to be due to residual post-operative monocytes that infiltrated the allograft causing modest reversible allograft dysfunction. the current dosing regimen with dsg is thus designed to accomplish both pre-operative depletion, and more thorough post operative elimination of donor and recipient cells mobilizing as a result of reperfusion, combined with therapy aimed at preventing the activation of monocytes that escape depletion. the timing of the dsg is meant to correspond with the peripheral repopulation of monocytes seen in previous patients. patients will be followed closely in the post transplant period for evidence of a detrimental immune response to the allograft. in the previous patients experiencing graft directed immunity the graft dysfunction was preceded by a rise in activated monocytes in the peripheral blood and augmented transcription of the cytokine tumor necrosis factor-alpha (tnf-a) in the allograft. this syndrome has been resistant to treatment with the tnf-a sequestrant infliximab and is now thought to require more comprehensive monocyte directed therapy. if patients progress and graft dysfunction occurs, patients will be treated with methylprednisolone and have immunosuppression added using sirolimus as the predominant immunosuppressive agent. this maneuver has in all cases been successful in returning the allograft to normal function. sirolimus has been chosen since it does not act by interfering with specific t cell receptor function, and thus, provides immunosuppressive coverage during cell repopulation without interfering with the antigen specific t cell events important for tolerance induction. non-human primate and human clinical data support both of these approaches. in addition to evaluating graft and patient outcome following transplantation, this protocol will also characterize and evaluate the function of the immune system and the composition of the t cell repertoire following the administration of campath-1h and dsg, and during immune system recovery after transplantation.

Eligibility criteria:
* inclusion criteria: candidates for a kidney transplant performed at the warren g. magnuson clinical center. willingness and legal ability to give informed consent, or permission from a legal guardian. willingness to travel to the clinical center for protocol specific samples to be taken, or in some cases, the ability to send samples via overnight mail. availability of donor tissue for testing. this could include splenic or peripheral blood lymphocytes from a cadaveric donor or a willing living donor enrolled on the clinic center living donor protocol who consents to periodic phlebotomy for peripheral blood lymphocyte isolation. exclusion criteria: immunosuppressive drug therapy at the time of or 2 months prior to enrollment. specifically, candidates must not be taking prednisone, cyclosporine, tacrolimus, azathioprine, mycophenolate mofetil, antilymphocyte agents, cyclophosphamide, methotrexate, or other agents whose therapeutic effect is immunosuppressive. any condition that precludes serial follow-up. any active malignancy or any history of a hematogenous malignancy or lymphoma. patients with primary, cutaneous basal cell or squamous cell cancers may be enrolled providing the lesions are appropriately treated prior to transplant. significant coagulopathy or requirement for anticoagulation therapy that would contraindicate protocol allograft biopsies. platelet count less than 100,000/mm(3). hemoglobin less than 9.0 mg/dl. patients may be on erythropoietin therapy, but will not be placed on therapy solely to facilitate research sample acquisition. any known immunodeficiency syndrome. hla identical status with a living donor. any history of uncompensated cardiac insufficiency, major vascular disease, or symptomatic coronary artery disease. systemic or pulmonary edema. inability to be effectively dialyzed. chronic hypotension (sbp less than 100 mmhg). any condition that would likely increase the risk of protocol participation or confound the interpretation of the data. cmv negative status receiving an organ from a known cmv positive donor. ebv negative status receiving an organ from a known ebv positive donor. panel reactive antibody greater than 20% due to hla antibodies.

Keywords: immunosuppression tolerance dsg alemtuzumab