This is a non-randomized, open label, multi-site, single-dose, phase 1/2 study in subjects with Transfusion-Dependent β-Thalassemia (TDT). The study will evaluate the safety and efficacy of autologous CRISPR-Cas9 modified CD34+ human hematopoietic stem and progenitor cells (hHSPCs) (BRL-101)

This clinical trial is a multi-center, single-arm, single-dose, open-label study without dose escalation. The proposed dose is ≥ 3 × 106 CD34 + cells/kg administered as a single intravenous infusion. The primary objective of Phase 1 is to explore the safety of the study drug in different age groups. For subjects of each age group, myeloablative conditioning and dosing of the remaining subjects was initiated only after completion of dosing and safety observations and assessments in sentinel subjects. The Phase 2 primary objective was to determine the effectiveness of BRL-101 administered intravenously to patients with TDT.

Key Inclusion Criteria:

• Fully understand and voluntarily sign informed consent. 3-35years old. At least one legal guardian and/or Subjects to sign informed consent.
• Clinically diagnosed as β-thalassemia major, phenotypes including β0β0, β+β+, β+β0, βEβ0 genotype.
• Subjects with no affection with HIV, TP, HBV, HCV, CMV and EBV.
• Subjects body condition eligible for autologous stem cell transplant.

Key Exclusion Criteria:

• Subjects acceptable for allogeneic hematopoietic stem cell transplantation and have an available fully matched related donor.
• Active bacterial, viral, or fungal infection.
• Treated with erythropoietin prior 3 months.
• Immediate family member with any known hematological tumor.
• Subjects with severe psychiatric disorders to be unable to cooperate.
• Prior hematopoietic stem cell transplant (HSCT).

Other protocol defined Inclusion/Exclusion criteria may apply.