This study will be intented to evaluate the safety, tolerability, and engraftment efficacy after myeloablative preconditioning and transplantation of autologous CD34+ hematopoietic stem cells transduced with a lentiviral vector encoding the human βA-T87Q-globin gene in patients with transfusion-dependent (TDT) β-thalassemia.
This is an open-label, single-dose study of BD211 in patients with transfusion-dependent β-thalassemia aged 6 to 35 years. It is estimated that 10 subjects will be enrolled. BD211 is a gene modified gene therapy product designed to produce healthy β-globin in red blood cells in beta-thalassemia patients. The total follow-up duration was 24 months, the safe endpoints and effectiveness endpoints will be used to assess the safety and efficacy profiles in patients with transfusion-dependent β-thalassemia.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
10
Genetically modified CD34+ autologous stem cells were transfused intravenously with single dosing.
Shanghai Ruijin Hospital
Shanghai, China
RECRUITINGRed blood cell (RBCs) transfusion requirements, whether reaching TI
Comparison of blood volume and number of transfusions in the 2 years prior to participants enrolment as baseline with blood volume and number of transfusions up to months 6, 12, and 24 after receiving transfusion of the BD211. TI defined as peripheral blood weighted average hemoglobin (Hb) \> or = 9 g/dL without pRBCs transfusion for 60 days after BD211 treatment, and transfusion is continuously halted for 12 months.
Time frame: 24 months
Total hospitalizing days at 6, 12, and 24 months (discharge after transplant)
Total hospitalizing days at 6, 12, and 24 months after transplantation were counted.
Time frame: 24 months
Percentage of treated participants with Transfusion-Dependent β-Thalassemia (TDT) who achieved transfusion independence for at least 6 months
TI defined as peripheral blood weighted average hemoglobin (Hb) \> or = 9 g/dL without pRBCs transfusion for 60 days after BD211 treatment, and transfusion is continuously halted for 12 months.
Time frame: 24 months
Change in RBCs infusion from baseline at 6 to 24 months
The quantity of RBCs transfusions at 6 to 24 months will be measured and compared with baseline level.
Time frame: 24 months
Mean Hb (g/dL) at 6, 12 and 24 months after treatment
Mean Hb (g/dL) in 6, 12, and 24 months after drug product infusion are tested and calculated.
Time frame: 24 months
Change in ferritin/liver iron levels from baseline
The Ferritin/liver iron levels are assayed per protocol plan, and evaluate the changes from those baseline level.
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Time frame: 24 months
Neutrophil engraftment, platelet engraftment and vector copy number
Neutrophil engraftment was defined as the first of absolute neutrophil count (ANC) \> or = 0.5 ×10\^9/ L for 3 consecutive days (or 3 consecutive measurements done on separate days), after a post-transplant value less than (\<) 0.5 × 10\^9/L. Platelet engraftment was defined as the first of 3 consecutive platelet values \> or =20 × 10\^9/L for participants on different days with no platelet transfusionsadministered for 7 days immediately preceding. The day of engraftment is the first day of the 3 consecutive platelet measurements. Vector copy number will be detected per investigating time schedule.
Time frame: 24 months
Transplant-related mortality in 3 months and 12 months
Transplant related mortality was definedas any death occurring in the study post drug product infusion deemed related to the transplant bythe investigator.
Time frame: 12 months
Overall survival
Overall survival was defined as time from date of BD211 Drug Product infusion (Day 1) to date of death. Overall survival was censored at the date of last visit if the participant was still alive.
Time frame: 24 months
RCL incidence
Subjects blood RCL was detected with specific assay method, and the incidence was calculated at different scheduled timeslots.
Time frame: 24 months
Characterized insertion mutagenesis events that lead to clonal dominance or leukemia
The number of insertion mutagenesis events that characterized clonal dominance or leukemia was collected.
Time frame: 24 months
Frequency and severity of AE
An AE was any untoward medical occurrence associated with the use of a drug in participants, whether or not considered drug related. An AE may include a change in physical signs, symptoms, and/or clinically significant laboratory change occurring in any phase of a clinical study.
Time frame: 24 months