Haploidentical Hematopoietic Stem Cell Transplantation

Phase 1

Completed

Interventions: Drug: peripheral blood stem cell graft that are CD34+ selected

Brief Summary: The study is designed as a Pilot/Phase 1 trial of reduced intensity Haploidentical HSCT in patients with sickle cell disease and thalassemia. The purpose of the study is to assess the safety and toxicity of reduced intensity conditioning haploidentical hematopoietic stem cell transplantation.

Detailed Description: Research subjects will undergo reduced intensity conditioning (Hydroxyurea, ATG, Fludarabine, Thiotepa, Melphalan) followed by infusion of a peripheral blood stem cell graft collected from haploidentical family donors that are CD34+ positively selected using the CliniMACS device. Sirolimus will be used for GVHD prophylaxis and given for 9 months post-transplant and then tapered off by one year

The use of the CliniMACS device for CD34 selection will be performed at CNMC through cross-reference of the master file for CliniMACS CD34+ Reagent by Milteyni Biotech (BB-MF 8061).

CliniMACs is an electromechanical device intended to isolate certain cell subsets from mixed cell populations. When used in combination with the CliniMACs CD34 reagent, it is possible to prepare extremely pure populations of CD34+ cells with upwards of 5 logs depletion of contaminating T cells within a closed and sterile system.

We intend to use this system to select cells from HLA haploidentical related donors who have been mobilized with G-CSF prior to stem cell collection. Since previous investigations of this strategy in adult patients have not translated into enhanced long term survival, we intend to limit this protocol to patients under the age of 22 as they have more rapid immune reconstitution.

Recruitment & Eligibility

Inclusion Criteria

First allogeneic transplant
Age up to 22 years
Patients with severe sickle cell disease (stroke, elevated TCD velocities, >2 acute chest syndrome, ongoing chronic red cell transfusion > 6 months)
Patients with transfusion dependent thalassemia and evidence of iron overload
Patients must have a related donor that is HLA-matched at >/=4 of 8 but <8/8 HLA-A, -B, -C and -DRB1
Cardiac function: Shortening fraction >25%; ejection fraction >40%
Estimated creatinine clearance greater than 50 mL/minute
Pulmonary function: DLCO ≥40% (adjusted for hemoglobin) and FEV1≥50% in patients 7 years and older with normal cognitive function and able to perform the test adequately. If not able to complete the testing a CT chest will be required., oxygen saturation>91%
Liver function: direct (conjugated) bilirubin < 2x the upper limit of normal and ALT/AST < 2.5x the upper normal limit.
Signed informed consent.

Exclusion Criteria

Life expectancy less than 6 months
Patients with uncontrolled bacterial, viral or fungal infections (undergoing appropriate treatment and with progression of clinical symptoms) within 1 month prior to conditioning. Patients with febrile illness or suspected minor infection should await clinical resolution prior to starting conditioning.
Pregnant or breastfeeding patients
Patients seropositive for the human immunodeficiency virus (HIV)
Patient with active Hepatitis B or C determined by serology and/or NAAT
Active hepatitis, bridging fibrosis or cirrhosis on liver biopsy (biopsy required for patients on chronic transfusion therapy for > 1 year and evidence of iron overload with ferritin >1000 ng/mL)
Patients with suitable 8/8 HLA matched related and unrelated donors
Patients who have an intolerance to or have received alemtuzumab in the prior 6 months will be excluded from enrollment unless alemtuzumab is replaced with rabbit ATG in the conditioning regimen

Arm && Interventions

Group	Intervention	Description
peripheral blood stem cell graft that are CD34+ selected	peripheral blood stem cell graft that are CD34+ selected	peripheral blood stem cell graft that are CD34+ selected. All patients will undergo reduced intensity conditioning regimen which followed by infusion of a peripheral blood stem cell graft collected from haploidentical family donors that are CD34+ positively selected using the CliniMACS device and Sirolimus will be used for GVHD prophylaxis and given for 9 months post-transplant and then tapered off by one year (see intervention).

Primary Outcome Measures

Name	Time	Method
Incidence of transplant related adverse outcomes	60 days	The primary endpoint of this trial is safety. Transplant related adverse outcomes and non-hematological toxicity will be measured through Day +60 on this objective to include: * Non-hematological severe (Grade IV and V) organ specific toxicity according to the Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0) * Rates of non-engraftment * Severe acute (Grade III-IV) * Veno-occlusive disease of the liver * Idiopathic pneumonia syndrome * Seizures/Posterior reversible encephalopathy syndrome (PRES)

Secondary Outcome Measures

Name	Time	Method
Overall survival	2 years	Overall survival upto 2 years

Locations (1): Childrens National Medical Center
🇺🇸
Washington, District of Columbia, United States