Allogeneic Stem Cell Transplantation in Refractory Acute Myeloid Leukaemia.

Refractory acute myeloid leukaemia is very difficult to treat and represents an unmet clinical need. In recent years, new drugs and combinations of drugs have been tested in this category, with encouraging results. However, all treated patients relapsed and died from the disease. The only curative option is allogeneic transplantation through a graft from a healthy donor immune system. Using myeloablative conditioning regimens, the median overall survival regimens is 19%. Several so-called sequential induction chemotherapies followed by allogeneic transplantation conditioned by reduced intensity regimens have been developed, improving the overall survival to 25-57%. In the allogeneic transplantation field, continuous improvements in practices, particularly regarding graft versus host disease prevention, infection prevention, and treatment, have allowed us to observe improvements in survival rates. This is true mainly for patients in complete remission before transplantation and less so for refractory patients. However, full myeloablative regimens are toxic and carry a high risk of treatment-related mortality. In this review, we describe the results obtained with the different modalities used in more recent retrospective and prospective studies. Based on these findings, we speculate how allogeneic stem cell transplantation could be modified to maximise its therapeutic effect on refractory acute myeloid leukaemia.

Factors influencing overall survival and GvHD development after allogeneic hematopoietic stem cell transplantation - single centre experience.

BACKGROUNDS: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a substantial therapeutic procedure for the treatment of a wide spectrum of severe diseases. Despite advancements in treatment and supportive care, alloHSCT still carries a considerable mortality risk, primarily caused by graft-versus-host disease (GvHD). Our retrospective analysis aimed to identify the factors influencing overall survival and GvHD development in HLA-identical sibling alloHSCT. We have analyzed patients' and donors' age, AB0 compatibility, recipient-donor gender match, stem cell source, time from the diagnosis to alloHSCT, conditioning regimen type, GvHD prophylaxis, and relapse. PATIENTS AND METHODS: Our study included 96 patients (54 male, 42 female) who underwent HLA-identical sibling alloHSCT. The median follow-up was 64.5 months (range 1-218 months), and the median age of both recipients and donors was 34 years. Malignant hematological diseases were the most common indications for alloHSCT. RESULTS: GvHD and its complications accounted for the highest number of deaths (N = 24; 46.2%), followed by relapse (N = 18; 34.6%). Acute GvHD developed in 30 patients (31.3%), while chronic GvHD occurred in 25 patients (26.0%), resulting in a total of 45 patients (46.9%) experiencing GvHD. Male recipients with female donors had significantly worse overall survival compared to other patients (P = 0.01; HR = 2.33). Overall survival was better in patients transplanted within 1 year from the diagnosis compared to those transplanted after 1 year (P = 0.03; HR = 1.93). No factor reached statistical significance regarding the impact on acute GvHD, chronic GvHD, or overall GvHD. CONCLUSION: We confirmed that sex mismatch, specifically in the case of a female donor and a male recipient, significantly negatively affects overall survival after alloHSCT. Additionally, overall survival is significantly shorter when the interval between the diagnosis and alloHSCT exceeds one year.

Risk factors for hemorrhagic cystitis in children undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis.

BACKGROUND: The risk factors for hemorrhagic cystitis (HC) in children undergoing hematopoietic stem cell transplantation (HSCT) are unclear. Therefore, we conducted this systematic review and meta-analysis to investigate the risk factors for HC in children undergoing HSCT. METHODS: We performed this meta-analysis by retrieving studies from PubMed, EMBASE, and the Cochrane Library up to October 10, 2023, and analyzing those that met the inclusion criteria. I2 statistics were used to evaluate heterogeneity. RESULTS: Twelve studies, including 2,764 patients, were analyzed. Male sex (odds ratio [OR] = 1.52; 95% confidence interval [CI], 1.16-2.00; p = 0.003, I2 = 0%), allogeneic donor (OR = 5.28; 95% CI, 2.60-10.74; p < 0.00001, I2 = 0%), human leukocyte antigen (HLA) mismatched donor (OR = 1.86; 95% CI, 1.00-3.44; p = 0.05, I2 = 31%), unrelated donor (OR = 1.58; 95% CI, 1.10-2.28; p = 0.01, I2 = 1%), myeloablative conditioning (MAC) (OR = 3.17; 95% CI, 1.26-7.97; p = 0.01, I2 = 0%), busulfan (OR = 2.18; 95% CI, 1.33-3.58; p = 0.002, I2 = 0%) or anti-thymoglobulin (OR = 1.65; 95% CI, 1.07-2.54; p = 0.02, I2 = 16%) use, and cytomegalovirus (CMV) reactivation (OR = 2.64; 95% CI, 1.44-4.82; p = 0.002, I2 = 0%) were risk factors for HC in children undergoing HSCT. CONCLUSIONS: Male sex, allogeneic donor, HLA-mismatched, unrelated donor, MAC, use of busulfan or anti-thymoglobulin, and CMV reactivation are risk factors for HC in children undergoing HSCT.

Comparison of upfront haploidentical hematopoietic stem cell transplantation and salvage haploidentical hematopoietic stem cell transplantation after immunosuppressive therapy in children with acquired severe aplastic anemia - a multicenter study.

Background: For children with severe aplastic anemia, if the first immunosuppressive therapy (IST) fails, it is not recommended to choose a second IST. Therefore, for patients without matched sibling donor (MSD) and matched unrelated donor (MUD), haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) can be chosen as a salvage treatment. This article aims to explore the comparison between upfront Haplo-HSCT and salvage Haplo-HSCT after IST. Methods: 29 patients received salvage Haplo-HSCT, and 50 patients received upfront Haplo-HSCT. The two groups received Bu (Busulfan, 3.2mg/kg/d*2d on days -9 to-8), CY (Cyclophosphamide, 60mg/kg/d*2d on days -4 to-3), Flu (fludarabine, 40mg/m2/d*5d on days -9 to -5) and rabbit ATG (Anti-thymocyte globulin, total dose 10mg/kg divided into days -4 to -2). Results: The OS of the salvage Haplo-HSCT group showed no difference to the upfront Haplo-HSCT group (80.2 ± 8.0% vs. 88.7 ± 4.8%, p=0.37). The FFS of the salvage Haplo-HSCT group also showed no difference to the frontline Haplo-HSCT group (75 ± 8.2% vs. 84.9 ± 5.3%, p=0.27). There was no significant difference in the incidence of other complications after transplantation between the two groups, except for thrombotic microangiopathy (TMA). In the grouping analysis by graft source, the incidence of II-IV aGVHD in patients using PBSC ± BM+UCB was lower than that in the PBSC ± BM group (p=0.010). Conclusion: Upfront Haplo-HSCT and salvage Haplo-HSCT after IST in children with acquired severe aplastic anemia have similar survival outcomes. However, the risk of TMA increases after salvage Haplo-HSCT. This article provides some reference value for the treatment selection of patients. In addition, co-transplantation of umbilical cord blood may reduce the incidence of GVHD.

[Efficacy of allogeneic hematopoietic stem cell transplantation based on a total body irradiation conditioning treatment regimen for adult acute lymphocytic leukemia].

Objective: To analyze the efficacy of allo-HSCT with total body irradiation (TBI) and chemotherapy alone in the treatment of adult ALL and to explore the factors affecting prognosis. Methods: The clinical data of 95 adult patients with ALL who underwent allo-HSCT from January 2015 to August 2022 were included. According to the conditioning regimen, the patients were divided into two groups: the TBI plus cyclophosphamide (TBI/Cy) group (n=53) and the busulfan plus cyclophosphamide (Bu/Cy) group (n=42). Hematopoietic reconstitution after transplantation, GVHD, transplantation-related complications, relapse rate (RR), non-relapse mortality (NRM), OS, and LFS were compared, and the factors related to prognosis were analyzed. Results: The median time of neutrophil engraftment was 14 (10-25) days in the TBI/Cy group and 14 (10-24) days in the Bu/Cy group (P=0.106). The median time of megakaryocyte engraftment was 17 (10-42) days in the TBI/Cy group and 19 (11-42) days in the Bu/Cy group (P=0.488). The incidence of grade Ⅱ-Ⅳ acute GVHD (aGVHD) in the TBI/Cy and Bu/Cy groups was 41.5% and 35.7%, respectively (P=0.565). The incidence of grade Ⅲ-Ⅳ aGVHD in these two groups was 24.5% and 4.8%, respectively (P=0.009). The incidence of severe chronic GVHD in the two groups was 16.7% and 13.5%, respectively (P=0.689). The incidence of cytomegalovirus infection, Epstein-Barr virus infection, severe infection, and hemorrhagic cystitis in the two groups was 41.5% and 35.7% (P=0.565), 34.0% and 35.7% (P=0.859), 43.4% and 33.3% (P=0.318), and 20.8% and 50.0% (P=0.003), respectively. The median follow-up time was 37.1 months and 53.3 months in the TBI/Cy and Bu/Cy groups, respectively. The 2-year cumulative RR was 17.0% in the TBI/Cy group and 42.9% in the Bu/Cy group (P=0.017). The 2-year cumulative NRM was 24.5% and 7.1%, respectively (P=0.120). The 2-year LFS was 58.5% and 50.0%, respectively (P=0.466). The 2-year OS rate was 69.8% and 64.3%, respectively (P=0.697). In the multivariate analysis, the conditioning regimen containing TBI was a protective factor for relapse after transplantation (HR=0.304, 95% CI 0.135-0.688, P=0.004), whereas the effect on NRM was not significant (HR=1.393, 95% CI 0.355-5.462, P=0.634). Infection was an independent risk factor for OS after allo-HSCT in adult patients with ALL. Conclusion: allo-HSCT based on TBI conditioning regimen had lower relapse rate and lower incidence of hemorrhagic cystitis for adult ALL, compared with chemotherapy regimen. While the incidence o grade Ⅲ/Ⅳ aGVHD was hgher in TBI conditioning regimen than that in chemotherapy regimen.

Continuously improving outcome over time after second allogeneic stem cell transplantation in relapsed acute myeloid leukemia: an EBMT registry analysis of 1540 patients.

Second allogeneic stem cell transplantation (alloSCT2) is among the most effective treatments for acute myeloid leukemia (AML) relapse after first alloSCT (alloSCT1). Long-term EBMT registry data were used to provide large scale, up-to-date outcome results and to identify factors for improved outcome. Among 1540 recipients of alloSCT2, increasing age, better disease control and performance status before alloSCT2, more use of alternative donors and higher conditioning intensity represented important trends over time. Between the first (2000-2004) and last (2015-2019) period, two-year overall and leukemia-free survival (OS/LFS) increased considerably (OS: 22.5-35%, LFS: 14.5-24.5%). Cumulative relapse incidence (RI) decreased from 64% to 50.7%, whereas graft-versus-host disease and non-relapse mortality (NRM) remained unchanged. In multivariable analysis, later period of alloSCT2 was associated with improved OS/LFS (HR = 0.47/0.53) and reduced RI (HR = 0.44). Beyond, remission duration, disease stage and patient performance score were factors for OS, LFS, RI, and NRM. Myeloablative conditioning for alloSCT2 decreased RI without increasing NRM, leading to improved OS/LFS. Haploidentical or unrelated donors and older age were associated with higher NRM and inferior OS. In summary, outcome after alloSCT2 has continuously improved over the last two decades despite increasing patient age. The identified factors provide clues for the optimized implementation of alloSCT2.

Thiotepa-busulfan-fludarabine-based conditioning as a promising approach prior to allogeneic hematopoietic stem cell transplantation in patients with blastic plasmacytoid dendritic cell neoplasm.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive myeloid malignancy associated with a poor prognosis. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) has emerged as a potential treatment strategy for BPDCN, standardized conditioning regimens remain lacking. In this manuscript, we present two cases of BPDCN that were treated with a thiotepa-busulfan-fludarabine (TBF)-based conditioning regimen prior to allo-HSCT. Both cases demonstrated complete remission post-transplantation, sustained donor chimerism, and remission maintenance, suggesting the potential efficacy of the TBF conditioning regimen for BPDCN transplantation. Given the small sample size in our study, we emphasize caution and advocate for larger studies to confirm the efficacy of TBF in the treatment of BPDCN.

Graft failure after allogeneic hematopoietic stem cell transplantation in pediatric patients with acute leukemia: autologous reconstitution or second transplant?

BACKGROUND: Graft failure (GF) is a rare but serious complication after allogeneic hematopoietic stem cell transplantation (HSCT). Prevention of graft failure remains the most advisable approach as there is no clear recommendation for the best strategies for reversing this complication. Administration of growth factor, additional hematopoietic progenitor boost, or a salvage HSCT are current modalities recommended for the treatment of GF. Autologous recovery without evidence of disease relapse occurs rarely in patients with GF, and in the absence of autologous recovery, further salvage transplantation following a second conditioning regimen is a potential treatment option that offers the best chances of long-term disease-free survival. The preconditioning regimens of second HSCT have a significant impact on engraftment and outcome, however, currently there is no consensus on optimal conditioning regimen for second HSCT in patients who have developed GF. Furthermore, a second transplant from a different donor or the same donor is still a matter of debate. OBSERVATIONS: We present our experience in managing pediatric patients with acute leukemia who encountered graft failure following stem cell transplantation. CONCLUSIONS AND RELEVANCE: Although a second transplantation is almost the only salvage method, we illustrate that some pediatric patients with acute leukemia who experience graft failure after an allogeneic stem cell transplant using Myeloablative conditioning (MAC) regimen may achieve long-term disease-free survival through autologous hematopoiesis recovery.

Unrelated umbilical cord blood transplantation with low-dose anti-thymocyte globulin for children with severe aplastic anemia: A case series.

OBJECTIVE: This study aimed to investigate the prognosis of unrelated umbilical cord blood transplantation (UCBT) using low-dose anti-thymocyte globulin (ATG) in children diagnosed with severe aplastic anemia (SAA). METHODS: This retrospective case series study was conducted involving pediatric SAA patients treated at the Capital Institute of Pediatrics from January 2020 to February 2023. All patients underwent a reduced-intensity conditioning (RIC) regimen alongside low-dose ATG. RESULTS: The study comprised nine patients (five males) with a median age of 5 years (range: 1.7 to 7 years). The median follow-up duration was 799 days (range: 367 to 1481 days), during which all patients survived. The median time interval from diagnosis to transplantation was 3 months (range: 1 to 9 months). The median dosage of ATG administered was 5 mg/kg (range: 2.5 to 7.5 mg/kg). The median durations for granulocyte and platelet engraftment were 15 days (range: 12 to 23 days) and 26 days (range: 12 to 41 days), respectively. Three patients experienced grade 2-4 acute graft-versus-host disease (aGVHD). Epstein-Barr virus (EBV) reactivation was observed in three patients, while cytomegalovirus (CMV) reactivation occurred in seven patients, with no cases of CMV disease or post-transplant lymphoproliferative disorder (PTLD). One patient experienced recurrence 15 months after transplantation due to influenza A infection. CONCLUSION: These findings indicate that SAA patients may attain a favorable prognosis following UCBT with a RIC regimen combined with low-dose ATG.

Comparable outcomes of allogeneic peripheral blood versus bone marrow hematopoietic stem cell transplantation from a sibling donor for pediatric patients.

Traditionally, bone marrow (BM) has been preferred as a source of stem cells (SCs) in pediatric hematopoietic SC transplantation (HSCT); however, the use of peripheral blood SCs (PBSC) has recently increased. With advancing graft-versus-host disease (GVHD) prophylaxis, whether the BM is still a better SC source than PB in sibling donor HSCT remains controversial. Here, we compared the results of BM transplantation (BMT) and PBSC transplantation (PBSCT) in pediatric patients with malignant or non-malignant diseases receiving sibling HSCT using a total of 7.5 mg/kg of anti-thymocyte globulin (ATG). We retrospectively reviewed children who received HSCT from a sibling donor between 2005 and 2020 at Seoul National University Children's Hospital. Of the 86 patients, 40 underwent BMT, and 46 underwent PBSCT. Fifty- six patients had malignant diseases, whereas thirty patients had non-malignant diseases. All conditioning regimens comprised ATG. Busulfan-based myeloablative conditioning regimens were administered to patients with malignant diseases and approximately half of those with non-malignant diseases. The remaining half of the patients with non-malignant diseases were administered cyclophosphamide-based reduced- intensity conditioning regimens. According to studies conducted at our center, all BM donors received G-CSF before harvest to achieve early engraftment. In all 86 patients (47 males and 39 females), the median age at the time of HSCT was 11.4 (range, 0.7 - 24.6) years. The median follow-up period was 57.9 (range, 0.9-228.6) months, and the corresponding values for those with BM and PBSC were 77 (range, 2.4-228.6) months and 48.7 (range, 0.9-213.2) months, respectively. Engraftment failure occurred in one patient with BM and no patient with PBSC. The cumulative incidence of acute GVHD with grades II-IV was higher in PBSC (BM 2.5%, PBSC 26.1%, p = 0.002), but there was no significant difference in those with grades III-IV acute GVHD (BM 0%, PBSC 6.5%, p = 0.3703) and extensive chronic GVHD (BM 2.5%, PBSC 11.6%, p = 0.1004). There were no significant differences in treatment-related mortality (TRM) (BM 14.2%, PBSC 6.8%, p = 0.453), 5-year event-free survival (EFS) (BM 71.5%, PBSC 76.2%, p = 0.874), and overall survival (OS) rates (BM 80.8%, PBSC 80.3%, p = 0.867) between BM and PBSC in the univariate analysis. In the multivariate analysis, which included all factors with p < 0.50 in the univariate analysis, there was no significant prognostic factor for EFS or OS. There was no significant difference in the relapse incidence between BM and PBSC among patients with malignant diseases (BM 14.2%, PBSC 6.8%, p = 0.453). Additionally, there were no significant differences in the TRM, 5-year EFS, and OS rates between malignant and non-malignant diseases nor between the busulfan-based myeloablative regimen and reduced-intensity chemotherapy using cyclophosphamide. In this study, we showed no significant differences in EFS, OS, TRM, and GVHD, except for acute GVHD grades II-IV, between BMT and PBSCT from sibling donors, using ATG (a total of 7.5 mg/kg). Therefore, PB collection, which is less invasive for donors and less labor-intensive for doctors, could also be considered an acceptable SC source for sibling donor HSCT in children.

Implementation of a light therapy team to administer photobiomodulation therapy: A standardized protocol to prevent and treat oral mucositis in the pediatric hematopoietic stem cell transplant population.

BACKGROUND: Oral mucositis (OM) is a painful and common complication of hematopoietic stem cell transplant (HSCT). The Children's Oncology Group recently published guidelines recommending photobiomodulation (PBM) for preventing and treating OM in pediatric HSCT patients. However, this is a rarely used intervention in pediatric hospitals. PROCEDURE: Patients undergoing allogeneic HSCT, or autologous HSCT for a neuroblastoma diagnosis, had PBM administered from the first day of conditioning to transplant Day +20. We successfully developed a standardized treatment protocol and workflow to ensure consistent and uniform delivery of PBM. In addition, clinical patient data were compared before and after PBM implementation. RESULTS: The administration of PBM at our center was feasible, but required dedicated staff. A registered nurse (RN) was determined to be the best fit to deliver PBM. Sixty-two patients received PBM from October 2022 to September 2023; patients from 2021 before PBM implementation were used for comparison. Patients receiving PBM were more likely (p = .03) to engage in teeth brushing (56/62 = 90%) compared to baseline (61/81 = 75%). Mean days of OM decreased from 11.3 to 9 days; patients who received PBM were less likely (p < .001) to be discharged on total parental nutrition (TPN) (11/62 = 18%) compared to baseline (50/82 = 61%). OM-related supportive care costs (TPN and patient-controlled anesthesia [PCA]) were lower (p = .02) for those who received PBM (median cost = $31,229.87 vs. $37,370.66). CONCLUSION: PBM, as the standard of care in the pediatric HSCT population, is safe, feasible, and well-tolerated. At our center, a dedicated RN was critical to providing standardized treatment and ensuring sustainability.

[Clinical study of the efficacies of ruxolitinib plus low-dose PTCY for acute GVHD prevention after haploidentical transplantation in malignant hematological diseases].

Objective: To investigate and verify a novel acute graft versus host disease (aGVHD) prevention protocol in the context of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: Patients who underwent haplo-HSCT in our center between January 2022 and December 2022 were included. All patients received reduced doses of cyclophosphamide, Rabbit anti-human tymoglobulin, ruxolitinib, methotrexate, cyclosporine, and MMF to prevent aGVHD. The transplantation outcomes, complications, and survival rate of all patients were investigated. Results: A total of 52 patients with haplo-HSCT were enrolled, 29 (55.8%) male and 23 (44.2%) female, with a median age of 28 (5-59) years. There were 25 cases of acute myeloid leukemia, 17 cases of acute lymphocyte leukemia, 6 cases of myelodysplastic syndrome, 2 cases of chronic myeloid leukemia and 2 cases of myeloproliferative neoplasms. 98.1% of patients had successful engraftment. The incidence of Ⅱ-Ⅳ aGVHD and Ⅲ-Ⅳ aGVHD was 19.2% (95% CI 8.2% -30.3% ) and 7.7% (95% CI 0.2% -15.2% ), respectively. No patients experienced severe gastrointestinal mucositis. The Epstein-Barr virus and CMV reactivation rates were 40.4% and 21.3%, respectively. 9.6% of patients relapsed during followup, with 1-year overall survival, progression-free survival, and non-relapse mortality rates of 86.5% (95% CI 76.9% -96.1% ), 78.8% (95% CI 67.4% -90.3% ) and 11.5% (95% CI 2.6% -20.5% ), respectively. Conclusion: Ruxolitinib combined with a low dose of PTCY is a safe and effective first-line aGVHD prevention strategy.

Hematopoietic Stem Cell Transplantation in Sickle Cell Disease: A Multidimentional Review.

While exagamglogene autotemcel (Casgevy) and lovotibeglogene autotemcel (Lyfgenia) have been approved by the US Food and Drug Administration (FDA) as the first cell-based gene therapies for the treatment of patients 12 years of age and older with sickle cell disease (SCD), this treatment is not universally accessible. Allogeneic hematopoietic stem cell transplant (HSCT) has the potential to eradicate the symptoms of patients with SCD, but a significant obstacle in HSCT for SCD is the availability of suitable donors, particularly human leukocyte antigen (HLA)-matched related donors. Furthermore, individuals with SCD face an elevated risk of complications during stem cell transplantation due to SCD-related tissue damage, endothelial activation, and inflammation. Therefore, it is imperative to consider optimal conditioning regimens and investigate HSCT from alternative donors. This review encompasses information on the use of HSCT in patients with SCD, including the indications for HSCT, conditioning regimens, alternative donors, and posttransplant outcomes.

Impact of prophylactic echinocandin on the development of neurological complications in patients receiving busulfan-containing conditioning regimens for stem cell transplantation: A single-center retrospective study.

BACKGROUND: Although neurotoxicity is a major adverse event associated with busulfan, little information is available regarding the association between drug interactions and neurological symptoms during busulfan-based regimens. This study evaluated the association between prophylactic echinocandins and neurological complications in patients receiving busulfan-containing conditioning regimens for stem cell transplantation. METHODS: We retrospectively included consecutive patients who administered intravenous busulfan as a conditioning regimen at our facility between 2007 and 2022. Prophylactic echinocandin use was defined as the use of an echinocandin antifungal drug to prevent invasive fungal disease in SCT recipients. The primary outcome was the incidence of neurological complications within 7 days of busulfan initiation and was compared between the echinocandin group (patients received prophylactic echinocandin) and nonechinocandin group (patients received prophylactic antifungal drugs other than echinocandin and those without antifungal prophylaxis). RESULTS: Among the 59 patients included in this study, the incidence of neurological complications in the echinocandin (n = 26) and nonechinocandin groups (n = 33) was 30.8% and 63.6%, respectively. We observed a negative association between prophylactic echinocandin use and the development of neurological complications after adjusting for the propensity score for receiving prophylactic echinocandins (adjusted odds ratio 0.294, 95% confidence interval 0.090 to 0.959). We observed a lower incidence of neurological complications in the echinocandin group than in the nonechinocandin group. CONCLUSION: Our results suggested that the choice of antifungal prophylaxis is associated with busulfan neurotoxicity.

Haploidentical hematopoietic stem cell transplantation with busulfan, cyclophosphamide, and fludarabine conditioning for X-linked adrenal cerebral leukodystrophy.

OBJECTIVE: We investigated the safety and efficacy of haploidentical stem cell transplantation (SCT) in pediatric patients with X-linked adrenoleukodystrophy (ALD). METHODS: A retrospective analysis of transplantation data from 29 cases of ALD, treated between December 2014 and April 2022, was conducted. Neurologic function scores (NFS) were assessed. The conditioning regimen was busulfan 9.6 mg/kg, cyclophosphamide 200 mg/kg, and fludarabine 90 mg/m2 (BFC). Graft-versus-host disease prophylaxis consisted of anti-human thymocyte globulin, cyclosporine A, mycophenolate mofetil, and short course of methotrexate. RESULTS: Among the 29 cases, 14 cases (NFS = 0) were asymptomatic, and 15 (NFS ≥ 1) were symptomatic. The median age at SCT was 8 years (range: 4-16 years); the median follow-up time was 1058 days (range: 398-3092 days); 28 cases were father donors and 1 case was a grandfather donor. Hematopoietic reconstitution was successful in all patients, and all of them achieved complete donor chimerism at the time of engraftment. The leading cause of death was still primary disease progression (n = 4). Survival free of major functional disabilities was 100% in asymptomatic patients versus 66.67% in the symptomatic group (p = .018). CONCLUSION: BFC regimen used in haploidentical SCT was administered safely without major transplant-related complications even in symptomatic patients, and neurological symptoms were stabilized after SCT.

Exagamglogene Autotemcel for Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs). METHODS: We conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent ß-thalassemia and a ß0/ß0, ß0/ß0-like, or non-ß0/ß0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed. RESULTS: A total of 52 patients with transfusion-dependent ß-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred. CONCLUSIONS: Treatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent ß-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.).

Exagamglogene Autotemcel for Severe Sickle Cell Disease.

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis by means of ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) at the erythroid-specific enhancer region of BCL11A. METHODS: We conducted a phase 3, single-group, open-label study of exa-cel in patients 12 to 35 years of age with sickle cell disease who had had at least two severe vaso-occlusive crises in each of the 2 years before screening. CD34+ HSPCs were edited with the use of CRISPR-Cas9. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was freedom from severe vaso-occlusive crises for at least 12 consecutive months. A key secondary end point was freedom from inpatient hospitalization for severe vaso-occlusive crises for at least 12 consecutive months. The safety of exa-cel was also assessed. RESULTS: A total of 44 patients received exa-cel, and the median follow-up was 19.3 months (range, 0.8 to 48.1). Neutrophils and platelets engrafted in each patient. Of the 30 patients who had sufficient follow-up to be evaluated, 29 (97%; 95% confidence interval [CI], 83 to 100) were free from vaso-occlusive crises for at least 12 consecutive months, and all 30 (100%; 95% CI, 88 to 100) were free from hospitalizations for vaso-occlusive crises for at least 12 consecutive months (P<0.001 for both comparisons against the null hypothesis of a 50% response). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No cancers occurred. CONCLUSIONS: Treatment with exa-cel eliminated vaso-occlusive crises in 97% of patients with sickle cell disease for a period of 12 months or more. (CLIMB SCD-121; ClinicalTrials.gov number, NCT03745287.).

Safety and efficacy of chimeric antigen receptor T-cell therapy for acute myeloid leukemia: A subgroup based meta-analysis.

INTRODUCTION: Acute myeloid leukemia (AML) is a significant hematological malignancy in the United States, with a high mortality rate and limited treatment options. CAR T-cell therapy, a new and promising treatment, is being investigated for its efficacy and safety in AML. This meta-analysis aims to assess the safety and efficacy of CAR T-cell therapy in AML, considering various subgroups such as study location, study design, prior transplantation status, conditioning regimen, and CAR T-cell source. METHODS: We conducted a comprehensive literature review across multiple databases, adhering to PRISMA guidelines and focusing on studies concerning CAR T-cell therapy in AML. We included original articles in English and excluded non-original reviews, abstracts, and non-English studies. The risk of bias was assessed using the Cochrane ROBINS-I tool. Statistical analysis involved meta-analysis with Cochrane's Q-test and I² statistic, using both fixed-effect and random-effects models, and assessed for publication bias. RESULTS: Our search yielded studies encompassing 57 AML patients treated with CAR T-cell therapy. The meta-analysis revealed a 48% incidence of complete remission with CAR T-cell therapy, varying significantly across subgroups based on study design, location, prior transplantation, conditioning regimen, and CAR T-cell source. The highest complete remission rates were observed in patients from China, those who had undergone prior hematopoietic cell transplantation, and those treated with fludarabine and cyclophosphamide conditioning regimen. Adverse events included graft-versus-host disease (7%) and cytokine release syndrome (53%). CONCLUSIONS: This meta-analysis highlights the potential of CAR T-cell therapy in AML treatment, especially when integrated with certain prior treatments and conditioning regimens. The findings suggest a higher efficacy in patients with previous hematopoietic cell transplantation and specific conditioning regimens. Further large-scale, randomized trials are essential to confirm these findings and establish CAR T-cell therapy as a standard treatment for AML.

Favorable outcome of non-myeloablative allogeneic transplantation in adult patients with severe sickle cell disease: A single center experience of 200 patients.

Allogeneic hematopoietic stem cell transplant (HSCT) for adults with severe sickle cell disease (SCD) is potentially curative but not commonly utilized therapy due to complications such as graft failure (GF) and organ toxicity. Herein, we are reporting our long-term outcome data of non-myeloablative (NMA) HSCT in adults with severe SCD with emphasis on factors predicting event free survival (EFS). Adults with severe SCD undergoing NMA match-related donor allogeneic HSCT from 2015 to 2021 with at least 12 months of follow-up were included. A total of 200 patients were included with a median age of 26 years (14-43) and 56% were male. The median infused CD34 dose was 13.7 (5.07-25.8), respectively. Median absolute neutrophil count engraftment was 19 (13-39) days with 51% of patients receiving GCSF to expedite recovery. A total of 17 patients experienced GF; 3 as primary and 14 as secondary within a median time of 204 days (40-905). A 76% successfully discontinued sirolimus at the last follow-up. Median follow-up for the cohort is 29.2 (2.1-71.4) months. Estimated 3-year EFS and OS were 88.2% (81.9-92.5) and 94.6% (89.2-97.3). At multivariable analysis, minor ABC incompatibility hazard ratio (HR) 4 (1.3-12.1; 0.014) and allo-antibody against non-ABO donor antigens HR 4.3 (1.3-14.1; 0.016) were significant for EFS. No clonal evolution or myeloid malignancies were seen. This largest single-center report of NMA HSCT in adults with severe SCD further delineated its feasibility, potential toxicities, and fertility outcomes. GF remains a major impediment and appears dependent on ABO matching and non-ABO antibodies.