Patients with hematologic malignancies will receive myeloablative chemotherapy followed by stem cell rescue with bone marrow or hematopoietic peripheral blood stem cells collected by apheresis from a filgrastim- (G-CSF)-mobilized haploidentical related-donor, ie, hematopoietic peripheral blood stem cell transplant (HSCT).
This is dose-escalation study intended to evaluate the use of classification determinant 15-positive (CD15+), CD4+, CD127dim, and FoxP3+ regulatory T-cells (T-reg cells) supplemented by conventional T-cells (T-con cells), to enhance the efficacy of allogeneic (CliniMACS CD34+ selected) hematopoietic stem cell transplantation (allo-HSCT), in the setting of leukemia, lymphoma, and myelodysplastic syndrome (MDS). This study investigates amelioration of the impaired immune recovery and address the significant relapse incidence in the haploidentical HSCT setting. Pre-transplant myeloablative conditioning will be melphalan; thiotepa; fludarabine and rabbit antithymocyte globulin (rATG). Stem cell rescue will be with CD34+ selected cells. The rescue infusion will be supplemented with infusions of regulatory T-cells (T-reg) and conventional T-cells (T-con) from the same donor collection, on Treatment Days 14 and 16 respectively. CD34+ cell infusion day is Treatment Day 0. T-reg cells are those cells enriched by immunomagnetic selection of CD25+ cells, and further purified by flow cytometric cell sorting for the CD15+, CD4+, CD127dim, FoxP3+ cell population. These cells are an enriched but naturally-occurring T-cell population. T-con cells are unseparated/unfractionated cells, ie, as collected by the peripheral blood stem cells apheresis procedure. Post-transplant follow-up is for 5 years.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
10
To ameliorate the impaired immune recovery and address the significant relapse incidence in the haploidentical setting. Cells will be selected by a tandem selection process and infused on day +14. These are the enriched but naturally-occurring regulatory T cells. Possible dose cohorts and levels are: Cohort 1 * T-reg: 1 x 10e5/kg * T-con: 3 x10e5/kg Cohort 2 * T-reg: 3 x 10e5/kg * T-con: 1 x 10e6/kg Cohort 3 * T-reg: 1 x 10e6/kg * T-con: 3 x 10e6/kg Cohort 4 * T-reg: 3 x 10e6/kg * T-con: 1 x 10e7/kg
These are conventional (unselected) donor T-cells. Cell dosage of the infusion will be based on the CD3+ cell content and infused on day +16.
Anti-cancer chemotherapy drug administered IV at 140 mg/m² on Day -8 prior to HSCT (a component of the conditioning regiment prior to infusion of cells)
Anti-cancer chemotherapy drug administered IV at 10 mg/kg on Day -7 prior to HSCT (a component of the conditioning regiment prior to infusion of cells)
Anti-cancer chemotherapy drug administered IV at 160mg/m² on Days -6; -5; -4; and -3 prior to HSCT (a component of the conditioning regiment prior to infusion of cells
Rabbit-derived antibodies against human T-cells used as transplant rejection prophylaxis. Administered at 6 mg/kg IV on Days -6; -5; -4; and -3 prior to HSCT
An in vitro medical device system that uses antibodies conjugated to magnetic beads to select and enrich for CD34+ blood stem cells from the allogeneic donor apheresis product prior to HSCT, while removing other cells that can cause GvHD. CD34+ cell dosage will be based on the participant's body weight.
Stanford University School of Medicine
Stanford, California, United States
Maximum-tolerated Dose (MTD) of Regulatory and Conventional T-cells
The maximum-tolerated dose (MTD) was to be determined based on the safety and feasibility observed for a pre-determined set of cellular dose level combinations of regulatory T-cells (T-reg) and conventional T-cells (T-con).
Time frame: 30 days after HSCT infusion
Acute Graft-versus-Host-Disease (aGvHD)
The primary outcome was incidence of grade 3 or 4 acute graft-vs-host-disease (aGvHD), reported as the number of participants developing grade 3 or 4 aGvHD.
Time frame: 1 year
Overall Survival (OS), 1 Year
Assessed as subjects remaining alive 12 months after CD34+ cell infusion (ie, excludes death due to any cause)
Time frame: 1 year
Median Overall Survival (OS)
Reported as the median overall survival (OS) in months from infusion of the hematopoietic stem cells (HSCT)
Time frame: 25 months
To Measure the Incidence and Severity of Acute and Chronic GvHD
Population of participants that received HSCT and T-reg plus T-con, and developed actue, chronic, or any graft vs host disease (GvHD)
Time frame: 1 year
Serious Infections
Serious infections are reported as the number of participants experienced serious infections.
Time frame: 1 year
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