Aplastic Anaemia

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 prospective, single-center, observational cohort study aims to systematically observe and describe the clinical characteristics of adverse reactions in patients with aplastic anemia undergoing ATG (Anti-Thymocyte Globulin) /ALG (Anti-Lymphocyte Globulin) treatment, providing a data foundation for the development of relevant management strategies. This study plans to enroll 200 aplastic anemia patients undergoing ATG/ALG treatment

This study aims to compare the efficacy and safety of HLA-haploidentical hematopoietic stem cell transplantation (HLA-haplo HSCT) versus optimal immunosuppressive therapy (IST) as first-line treatments for severe aplastic anemia (SAA) through a real-world cohort design. The selection of treatment regimens for subjects is based on clinical decision-making in real-world practice, comprehensively considering factors including patient age, donor matching status, comorbidities, and treatment preferences, with non-randomized group allocation.

This is a single center, randomized, open-label, phase II study to compare the efficacy of sirolimus combined with cyclosporin A (CsA) to sirolimus alone in Chinese subjects with aplastic anemia refractory/intolerant to CsA. The safety would also be evaluated. Patients would be randomized to receive sirolimus alone or sirolimus combined with CsA at a 1:3 ratio. Treatment with sirolimus will be started at 1-3 mg once daily orally, with a target trough blood concentration of 4-12 ng/ml. CsA will be given at 25-150 mg orally every 12 hours, with the dose adjusted based on renal function and trough concentration. For patients with normal renal function, the target trough concentration is approximately 150 ng/ml. For patients with impaired renal function, the cyclosporine A dose is reduced to 25-50 mg every 12 hours, aiming for recovery or stabilization of renal function. The hematological response rate and safety will be recorded and compared at 3 and 6 months after starting the study treatment (Week 13 and 25).

The TBI-containing reduced-dose conditioning regimen was used to treat elderly patients with aplastic anemia who received hematopoietic stem cell transplantation. The overall survival rate, GVHD-free survival rate, all-cause mortality,et al were studied. The modified conditioning regimen included TBI 2Gy, -7d, busulfan 3.2mg / kg-6d ; fludarabine 30mg / m2 / d-5 \~ -1d ; cyclophosphamide 25-30mg / kg / d-5 \~ -2d ; ATG ( rabbit ) 2 mg / kg / d-5 \~ -1d.