This is a single arm, phase I study to assess the tolerability of abatacept when combined with cyclosporine and mycophenolate mofetil as graft versus host disease prophylaxis in children undergoing unrelated hematopoietic stem cell transplant for serious non-malignant diseases as well as to assess the immunological effects of abatacept. Participants will be followed for 2 years.
Allogeneic hematopoietic stem cell transplantation (HSCT) represents the only viable cure for children who suffer from a wide variety of rare, serious non-malignant diseases, such as Fanconi Anemia, Hurler syndrome, and hemophagocytic lymphohistiocytosis. A major obstacle to the success of HSCT is morbidity and mortality from graft versus host disease (GVHD), driven by donor T cells recognizing and reacting against disparate host antigens. This trial is being conducted as a step toward testing the long-term hypothesis that the costimulation blockade agent abatacept can be added to a standard post-transplant GVHD prophylaxis regimen, cyclosporine and mycophenolate mofetil, to improve disease-free survival after unrelated hematopoietic stem cell transplantation (HSCT) using reduced intensity conditioning for children with non-malignant diseases (NMD). This study will have the following Specific Aims: Specific Aim #1: To conduct a multicenter pilot assessing the tolerability of abatacept (n=10). Patients will receive four doses (10 mg/kg IV on days -1, +5, +14 and +28), a schedule well tolerated by adolescents and adults with hematologic malignancies in a previous pilot. Abatacept will be combined with cyclosporine and mycophenolate mofetil. Specific Aim #2: To examine the immunological effects of abatacept in this setting. Three reduced intensity conditioning regimens that have been shown to be effective in achieving sustained engraftment in patients with non-malignant diseases are available for use, depending on the patient's disease: * Patients with Fanconi anemia will receive fludarabine, low dose cyclophosphamide, and anti-thymocyte globulin. * Patients with severe aplastic anemia will receive low dose total body irradiation, fludarabine, cyclophosphamide, and anti-thymocyte globulin. * Patients with other NMD will receive either the low dose total body irradiation regimen or an alemtuzumab, fludarabine, thiotepa, and melphalan regimen.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
10
All patients will receive 4 doses of abatacept in addition to standard GVHD prophylaxis with cyclosporine and mycophenolate mofetil.
Children's Healthcare of Atlanta
Atlanta, Georgia, United States
Tolerability of Abatacept
The primary endpoint for this trial will be tolerability, defined in terms of the success in administering all prescribed doses of abatacept. Abatacept will be deemed to be poorly tolerated if any of the following conditions are met: * More than one dose is withheld. * Death from an infection that occurs within 30 days of receiving the last prescribed dose of abatacept, but that is not preceded by systemic immunosuppressive therapy for GVHD * Post-transplant lymphoproliferative disorder (PTLD) that occurs within 100 days of receiving the last prescribed dose, but that is not preceded by systemic immunosuppressive therapy for GVHD. If less than 4 patients (of at least 18 evaluable patients) tolerate abatacept poorly, abatacept will be deemed tolerable. If there are fewer than 18 evaluable patients, if 3 of the first 10 patients treated tolerate abatacept poorly, abatacept will be deemed tolerable.
Time frame: 1 year post-transplant
Proportion of Participants Experiencing Regimen-related Toxicity (RRT)
Regimen-related toxicity is scored according to the Bearman scale. Major RRT, defined as grade 4 (causing death) in any organ system or grade 3 for pulmonary, cardiac, renal, oral mucosal, neurologic or hepatic, will be recorded.
Time frame: Day 42 post-transplant
Days until Neutrophil Recovery
Neutrophil recovery is defined as the first of 3 consecutive days following the nadir that the absolute neutrophil count is at least 500/µl.
Time frame: 1 year post-transplant
Days until Platelet Recovery
Platelet recovery is defined as the first day that the platelet count is at least 20 thousand/µl without a transfusion in the preceding 7 days.
Time frame: 1 year post-transplant
Number of Participants with Non-engraftment
Non-engraftment is defined as lack of neutrophil recovery (defined as absolute neutrophil count (ANC )\>0.5 \*109/L for three consecutive days) by 28 days post-transplant or neutrophil recovery with lack of myeloid donor chimerism.
Time frame: 1 year post-transplant
Number of Participants with Secondary Graft Failure
Secondary graft failure is defined by initial engraftment but subsequent development of an ANC \<0.5\*109/L for fourteen consecutive days.
Time frame: 1 year post-transplant
Number of Participants with Graft Loss
Graft loss is defined by initial engraftment (assessed by neutrophil recovery and donor chimerism) with the subsequent loss of donor myeloid chimerism (regardless whether persistent neutropenia develops).
Time frame: 1 year post-transplant
Number of Participants Experiencing Cytomegalovirus (CMV) Viremia
Cytomegalovirus (CMV) viremia is defined as positive blood antigen or polymerase chain reaction (PCR) test.
Time frame: Up to Day 180
Number of Participants Experiencing CMV Invasive Disease
CMV invasive disease is defined in accordance with the Blood and Marrow Transplant Clinical Trials Network Manual of Procedures.
Time frame: 1 year post-transplant
Number of Participants Experiencing Post-transplant Lymphoproliferative Disorder (PTLD)
Post-transplant lymphoproliferative disorder (PTLD) is defined in accordance with the Blood and Marrow Transplant Clinical Trials Network Manual of Procedures and the World Health Organization's Classification of Tumours of Haematopoietic and Lymphoid Tissues.
Time frame: 1 year post-transplant
Number of Participants Experiencing Other Infections
Infections other than CMV viremia, CMV invasive disease, and PTLD is defined in accordance with the Blood and Marrow Transplant Clinical Trials Network Manual of Procedures.
Time frame: 1 year post-transplant
Number of Participants Experiencing Immune Reconstitution
Immune reconstitution is assessed by the day 100 cluster of differentiation 4 (CD4+) T cell count and by the reaccumulation of natural killer (NK) cells, B cells, total T cells, and cluster of differentiation 8 (CD8+) T cells as assessed by multicolor flow cytometry.
Time frame: 1 year post-transplant
Number of Participants Experiencing Acute Graft Versus Host Disease (GVHD)
Early onset (before day 100) and late onset (after day 100) acute GVHD is assessed according to the Blood and Marrow Transplant Clinical Trials Network Manual of Procedures using the NIH consensus criteria.
Time frame: Up to 1 year post-transplant
Number of Participants Experiencing Chronic GVHD
Chronic GVHD, including overlap syndrome, is assessed according to the Blood and Marrow Transplant Clinical Trials Network Manual of Procedures using the NIH consensus criteria.
Time frame: 2 years post-transplant
Immune Suppression-Free Survival Rate
Participant survival while off of immunosuppressive agents.
Time frame: 1 year post-transplant
Immune Suppression-Free and Disease-Free Survival Rate
Participant disease-free survival while off of immunosuppressive agents.
Time frame: 1 year post-transplant
Disease-free Survival Rate
Disease-free survival is defined as survival without recurrence of underlying disease.
Time frame: 1 year post-transplant
Overall Survival Rate
Overall-survival is defined as survival with or without relapse of underlying disease
Time frame: 1 year post-transplant
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