A Multicenter, Randomized, Open-Label Study of Haplo-Cord HSCT for the Treatment of Aplastic Anemia

A Multicenter, Randomized, Open-Label Study to Analyze the Efficacy of Unrelated Cord Blood Combined With Haploidentical Stem Cell Transplantation in Patients With Aplastic Anemia

Aplastic anemia (AA) is a bone marrow failure disorder characterized by pancytopenia and hypoplastic bone marrow caused by the decrease of hematopoietic stem cells. The pathogenesis of AA is complex and involves an abnormal hematopoietic microenvironment, hematopoietic stem cell/progenitor cell deficiencies and immunity disorders.

Currently, the standard treatment for AA includes immunosuppressive therapy (IST) based on anti-thymocyte/lymphocyte globulin (ATG/ALG) and cyclosporine A (CsA) or hematopoietic stem cell transplantation (HSCT). Although HLA-identical sibling allogeneic hematopoietic stem cell transplantation is considered the preferred transplant option for patients with severe aplastic anemia (SAA), only less than 30% of patients have an available HLA-matched sibling donor. In recent years, haploidentical hematopoietic cell transplantation (Haplo-HCT) has developed rapidly and has become an important alternative. However, graft failure and graft-versus-host disease (GVHD) remain significant factors limiting its efficacy.

Umbilical cord blood (UCB) contains a diverse population of hematopoietic stem cells. Compared with other sources, cord blood-derived hematopoietic stem cells are more primitive, more viable, and possess higher proliferative capacity. Therefore, cord blood transplantation, with its notable clinical therapeutic effects, has become an effective and reliable alternative to peripheral blood or bone marrow transplantation.

Currently, some transplant centers worldwide have adopted the coinfusion of UCB units with haplo-HCT (haplo-cord HCT) achieving preliminary efficacy in promoting engraftment and reducing the incidence of GVHD. A retrospective comparative study of haplo-cord HCT versus IST in patients with SAA identified haplo-cord HCT as the sole independent predictor for superior health-related quality of life (HRQoL) (P < 0.0001).

Based on existing research and clinical experience, this study plans to investigate and further evaluate the safety and efficacy of haplo-cord HCT in the treatment of aplastic anemia. Primary endpoints will include overall survival, engraftment rate, disease-free survival, incidence of GVHD, CMV/EBV reactivation rate, donor chimerism dynamics, and immune reconstitution.

This study is designed to assess the safety and efficacy of haplo-cord HCT versus haplo HCT in patients with aplastic anemia, with particular emphasis on factors associated with treatment outcome and adverse events.

Inclusion Criteria: (1)Aged ≥14 years. (2) Patients diagnosed with aplastic anemia meeting the diagnostic criteria of the Chinese Guidelines for the Diagnosis and Management of Aplastic Anemia (2024 Edition). (3) Patients who were eligible for allogeneic bone marrow or peripheral blood hematopoietic stem cell transplantation in accordance with the Clinical Application and Management Specifications for Allogeneic Hematopoietic Stem Cell Transplantation Technology (2022 Edition). (4) The patient understands the study protocol and voluntarily signs the informed consent form. (5) Life expectancy of ≥3 months; (6) Pre-transplant assessment meets the following criteria: Karnofsky Performance Status (KPS) score≥70, Eastern Cooperative Oncology Group Performance Status (ECOG PS) score≤2, and Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) score≤2.

Exclusion Criteria: (1)Patients with aplastic anemia secondary to malignancy treatment or those with concurrent active malignancy. (2) Women who are pregnant or lactating. (3) Patients with psychiatric or psychological disorders that preclude adequate compliance with the treatment protocol. (4) Patients with positive serologic testing for any of the four major infectious diseases (hepatitis B, hepatitis C, syphilis, HIV). (5) Patients with systemic infection or localized severe infection requiring active antimicrobial therapy. (6) Patients with significant dysfunction of major organs (e.g., heart, lung, liver, kidney). (7) Patients with a known allergy or hypersensitivity to any drug or component used in this study. (8) Patients who are currently participating in or plan to participate in any other clinical trial. (9) Any other condition deemed by the investigator to render the patient unsuitable for study participation.