Treosulfan-based conditioning regimen in a second matched unrelated peripheral blood stem cell transplantation for a pediatric patient with CGD and invasive aspergillosis, who experienced initial graft failure after RIC

Busulfan-Based and Treosulfan-Based Myeloablative Conditioning for Allogeneic Transplantation in Children with Thalassemia Major: a Single-Center Experience From Southern Turkey

OBJECTIVES

Allogeneic hematopoietic stem cell transplant is the only curative treatment for patients with transfusion-dependent thalassemia major. In recent years, a number of novel approaches have improved patient outcomes and quality of life by minimizing the toxicity of conditioning regimens. The objective of this study was to compare the role of treosulfan- and busulfan-based conditioning in transfusion-dependent thalassemia.

MATERIALS AND METHODS

Data were collected retrospectively on 121 children with beta thalassemia major who underwent hematopoietic stem cell transplant using treosulfan-based (n = 37) or busulfan-based (n = 84) conditioning regimens between 2012 and 2022.

RESULTS

Two-year overall survival was 87.5% in the busulfan-based conditioning group and 91.1% in the treosulfan-based conditioning group.The group given the busulfan regimen compared with treosulfan regimen had significantly increased number of side effects (58.3% vs 21.6%, respectively; P < .001). When the busulfan-based regimen by level was evaluated, we observed no significant differences between the frequency of side effects according to drug serum levels. In addition, no significant differences were shown between the 2 regimen groups for cumulative incidence of acute and chronic graft-versus-host disease.

CONCLUSIONS

The safety and effectiveness of a treosulfan-based myeloablative conditioning regimen has been confirmed by ourretrospective investigation of pediatric patients with beta thalassemia.

Hematopoietic Stem Cell Transplantation Cures Therapy-refractory Aspergillosis in Chronic Granulomatous Disease

BACKGROUND

Pulmonary invasive aspergillosis is a frequent and life-threatening complication for patients with chronic granulomatous disease (CGD). Despite combined treatment with several groups of antifungal agents, conservative treatment of invasive aspergillosis often remains refractory. Pulmonary invasive aspergillosis is often treated by surgical resection of consolidated lobes or segments, donor granulocyte transfusions and allogeneic hematopoietic stem cell transplantation (HSCT). These options are not mutually exclusive and often combined.

METHODS AND RESULTS

We here describe the treatment of 3 patients with CGD who received HSCT upon active pulmonary invasive aspergillosis: Two of them received HSCT as salvage therapy for refractory aspergillosis, and 1 patient received elective HSCT in infancy but developed pulmonary aspergillosis during secondary graft failure. Based on our experience and available literature, we discuss indication as well as timing of HSCT, granulocyte transfusions and surgery in patients with CGD and pulmonary invasive aspergillosis.

CONCLUSIONS

Upon diagnosis with invasive aspergillosis in CGD, we propose to start antifungal treatment and preparation for HSCT at the same time. Remission of pulmonary invasive aspergillosis before HSCT remains preferable but is not mandatory. When pulmonary aspergillosis in patients with CGD remains refractory for longer than 3 months on conservative treatment, HSCT without prior surgery or accompanying granulocyte transfusions is a feasible option.

Treosulfan and Fludarabine Conditioning for Hematopoietic Stem Cell Transplantation in Children with Primary Immunodeficiency: UK Experience

We previously published results for 70 children who received conditioning with treosulfan and cyclophosphamide (n = 30) or fludarabine (n = 40) before undergoing hematopoietic stem cell transplantation (HSCT) for primary immunodeficiency (PID). Toxicity was lower and T cell chimerism was better in the patients receiving fludarabine, but cohort numbers were relatively small and follow-up was short. Here we report outcomes of 160 children who received homogeneous conditioning with treosulfan, fludarabine, and, in most cases, alemtuzumab (n = 124). The median age at transplantation was 1.36 years (range, .09 to 18.25 years). Donors included 73 matched unrelated, 54 1 to 3 antigen-mismatched unrelated, 12 matched sibling, 17 other matched family, and 4 haploidentical donors. Stem cell source was peripheral blood stem cells (PBSCs) in 70, bone marrow in 49, and cord blood in 41. Median duration of follow-up was 4.3 years (range, .8 to 9.4 years). Overall survival was 83%. No patients had veno-occlusive disease. Seventy-four patients (46%) had acute GVHD, but only 14 (9%) greater than grade II. Four patients underwent successful retransplantation for graft loss or poor immune reconstitution. Another patient experienced graft rejection and died. There was no association between T cell chimerism >95% and stem cell source, but a significant association was seen between myeloid chimerism >95% and use of PBSCs without an increased risk of significant GVHD compared with other sources. All 11 patients with severe combined immunodeficiency diagnosed at birth were alive at up to 8.7 years of follow-up. Long-term studies are needed to determine late gonadotoxic effects, and pharmacokinetic studies are needed to identify whether specific targeting is advantageous. The combination of treosulfan, fludarabine, and alemtuzumab is associated with excellent results in HSCT for PID.

Treosulfan-based conditioning for allogeneic HSCT in children with chronic granulomatous disease: a multicenter experience

Chronic granulomatous disease (CGD) can be cured by allogeneic hemopoietic stem cell transplantation (HSCT). Complications include graft failure, graft-versus-host disease (GVHD), infection, and transplant-related mortality; therefore, reduced-intensity conditioning regimens are being used to improve outcomes. In this retrospective study, the aim was to determine the outcome of treosulfan-based conditioning in HSCT for pediatric patients with CGD. The following data were collected: risk features pre-HSCT, additional conditioning agents, donor type and stem cell source, toxicity, engraftment, GVHD, chimerism, viral reactivation, post-HSCT complications, length of follow-up, and outcome. Seventy patients (median age, 107 months; interquartile range [IQR], 46-232 months) from 16 centers worldwide were transplanted between 2006 and 2015. Ninety-one percent had high-risk features. Fifty-seven HLA-matched donors, 12 HLA-mismatched donors, and 1 CD3(+)TCR αβ/CD19 depleted parental haploidentical transplants were performed. No major toxicity was reported. Median times to neutrophil and platelet engraftment were 17 (IQR, 15-35) and 16 (IQR, 13-50) days. At a median follow-up of 34 months (IQR, 13-102 months), the overall survival was 91.4%, and event-free survival was 81.4%. The cumulative incidence of acute grade III-IV GVHD was 12%. Nine patients developed chronic GVHD. When split cell chimerism was available, 95% or more myeloid donor chimerism was documented in 80% of surviving patients. Secondary graft failure occurred in 12% of patients. Treosulfan-containing conditioning regimens can be used safely in HSCT for children with CGD and high-risk clinical features, achieving excellent survival with high myeloid chimerism. Further studies are needed to compare with other regimens and evaluate the long-term outcome, particularly on fertility.

Chronic granulomatous disease: a review of the infectious and inflammatory complications

Chronic Granulomatous Disease is the most commonly encountered immunodeficiency involving the phagocyte, and is characterized by repeated infections with bacterial and fungal pathogens, as well as the formation of granulomas in tissue. The disease is the result of a disorder of the NADPH oxidase system, culminating in an inability of the phagocyte to generate superoxide, leading to the defective killing of pathogenic organisms. This can lead to infections with Staphylococcus aureus, Psedomonas species, Nocardia species, and fungi (such as Aspergillus species and Candida albicans). Involvement of vital or large organs can contribute to morbidity and/or mortality in the affected patients. Major advances have occurred in the diagnosis and treatment of this disease, with the potential for gene therapy or stem cell transplantation looming on the horizon.

Chronic granulomatous disease: overview and hematopoietic stem cell transplantation

Chronic granulomatous disease (CGD) still causes significant morbidity and mortality. The difficulty in considering high-risk yet curative treatments, such as allogeneic bone marrow transplantation, lies in the unpredictable courses of both CGD and bone marrow transplantation in different patients. Some patients with CGD can have frequent infections, granulomatous or autoimmune disorders necessitating immunosuppressive therapy, or both but also experience long periods of relative good health. However, the risk of death is clearly higher in patients with CGD of all types, and the complications of CGD short of death can still cause significant morbidity. Therefore, with recent developments and improvements, bone marrow transplantation, previously considered an experimental or high-risk procedure, has emerged as an important option for patients with CGD. We will discuss the complications of CGD that result in significant morbidity and mortality, particularly the most common infections and autoimmune/inflammatory complications, as well as their typical management. We will then discuss the status of bone marrow transplantation.

Treosulfan-based conditioning regimens for hematopoietic stem cell transplantation in children with primary immunodeficiency: United Kingdom experience

Children with primary immunodeficiency diseases, particularly those less than 1 year of age, experience significant toxicity after hematopoietic stem cell transplantation, with busulfan- or melphalan-based conditioning. Treosulfan causes less veno-occlusive disease than busulfan and does not require pharmacokinetic monitoring. We report its use in 70 children. Children received 42 g/m(2) or 36 g/m(2) with cyclophosphamide 200 mg/kg (n = 30) or fludarabine 150 mg/m(2) (n = 40), with alemtuzumab in most. Median age at transplantation was 8.5 months (range, 1.2-175 months); 46 (66%) patients were 12 months of age or younger. Donors were as follows: matched sibling donor, 8; matched family donor, 13; haploidentical, 4; and unrelated, 45. Median follow-up was 19 months (range, 1-47 months). Overall survival was 81%, equivalent in those age less or greater than 1 year. Skin toxicity was common. Veno-occlusive disease occurred twice with cyclophosphamide. Eighteen patients (26%) had graft-versus-host disease, and only 7 (10%) greater than grade 2. Two patients rejected; 24 of 42 more than 1 year after transplantation had 100% donor chimerism. The remainder had stable mixed chimerism. T-cell chimerism was significantly better with fludarabine. Long-term follow-up is required, but in combination with fludarabine, treosulfan is a good choice of conditioning for hematopoietic stem cell transplantation in primary immunodeficiency disease.