Conditions: Severe Osteopetrosis
Keywords: osteopetrosis
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 7
Healthy volunteers: no

Brief summary:
The purpose of this research is to explore what we believe may be a safer and more effective means of performing stem cell transplantation in patients with Osteopetrosis, using chemotherapy and radiation designed to bring about engraftment and lessen transplant mortality. Prior multi-institutional data in past studies found that approximately 30% of Osteopetrosis patients do not engraft. Therefore, in this study, we utilize a reduced intensity design of pre-transplant drugs to try to make transplants safer for this disease, as well as to provide a second infusion of stem cells in patients with matched related or unrelated donors.

Detailed description:
This revised transplant protocol will test the following: 1) the ability to achieve engraftment with the reduced intensity protocol and a second infusion of stem cells on day 42, 2) the mortality associated with transplant by day 100, 3) patient outcomes, based on differential imaging and biologic evaluations prior to transplantation and at designated points after transplantation (day 100, 6 months, 1, 2 and 5 years). Additional biologic studies will include microarray analysis, and evaluation of blood parameters and genes that may be important in the disease process. In older patients, studies to evaluation osteoclast differentiation and function will also be offered.

Arms:
arm 1: Pre-transplant conditioning using Campath-1H, Busulfan, Fludarabine monophosphate, and total lymphoid irradiation followed by unrelated or matched related donor marrow graft transplantation (both peripheral blood and marrow) and a second CD34 cell infusion on Day 42. arm 2: Pre-transplant conditioning using Campath-1H, Busulfan and Cyclophosphamide followed by unrelated umbilical cord blood transplantation and a second smaller portion cord blood graft infusion on Day 42.

Interventions: intervention 1: umbilical cord blood transplantation intervention 2: Campath-1H intervention 3: Total Lymphoid Irradiation intervention 4: Cyclophosphamide intervention 5: Busulfan intervention 6: Fludarabine monophosphate intervention 7: marrow graft transplantation
Intervention descriptions: intervention 1: Umbilical cord blood will be collected, processed and shipped according to existing protocols. 2 cord blood units will be utilized if available. The choice of units will be based on the HLA typing standards of the University of Minnesota Blood and Marrow Program. If 2 units are not available, a single unit may be used. If a single unit is used, the unit should provide at least 10 x 107 nucleated cells/kg recipient body weight. intervention 2: Campath-1H will be administered 0.3 mg/kg subcutaneously per day for three days starting on Day -21 through Day -19. intervention 3: Dose 500 cGy via anteroposterior (AP) and posteroanterior(PA) fields (250 cGy AP and 250 cGy PA). intervention 4: Cyclophosphamide (50 mg/kg/dose) will be given IV on day -4, -3, -2 and -1 over 2 hours. The total dose to be given over 4 days is 200 mg/kg for cord blood grafts-receiving patients only. intervention 5: patients\<12 kg: 1.1 mg/kg/dose IV every 6 hours for 8 doses total; patients \>12 kg: 0.8 mg/kg/dose IV every 6 hours for 8 doses. on Day -8 to -7 for donor grafts-receiving patients, and on Day -9 to -6 for cord blood grafts-receiving patients. intervention 6: Fludarabine (35 mg/m2 daily for 5 days, 175 mg/m2 total) will be administered IV over 30 minutes on days -6, -5, -4, -3, and -2 for donor grafts-receiving patients only. intervention 7: Related donor marrow will be collected, processed and shipped according to existing protocols of the National Marrow Donor Program or other URD registry, with the goal of achieving a cell dose of ≥ 6.0 x 108 nucleated cells/kg. The proportion of cells that are CD34+ will be determined prior to the administration of the graft. This will allow a portion of the graft (2 x 106 CD34+ cells) to be frozen for a subsequent infusion on day +42.

Protocol document: