Comparison of the clinical outcomes of hematologic malignancies after myeloablative haploidentical transplantation with G-CSF/ATG and posttransplant cyclophosphamide: results from the Chinese Bone Marrow Transplantation Registry Group (CBMTRG)

Triplet therapy with gilteritinib, venetoclax, and azacitidine for relapsed/refractory FLT3mut acute myeloid leukemia

The FMS-related tyrosine kinase 3 (FLT3) inhibitor gilteritinib is standard therapy for relapsed/refractory (R/R) FLT3-mutated (FLT3mut) acute myeloid leukemia (AML) but the overall survival (OS) is only approximately 20 % and few patients achieve deep and/ or durable response. We retrospectively analyzed 29 R/R FLT3mut AML patients treated on triplet regimens (gilteritinib+ venetoclax［VEN] +azacitidine［AZA]). Nineteen patients (65.5 %) had received prior FLT3 inhibitor therapy. The modified composite complete remission (mCRc) rate was 62.1 % (n = 18; CR, 4/29,13.8 %; CRi, 6/29, 20.7 %; MLFS, 8/29, 27.6 %). Among 18 patients achieved mCRc, FLT3-PCR negativity was 94.4 % (n=17), and flow-cytometry negativity was 77.7 % (n=14). The mCRc rate was 70 % (n=7) in 10 patients without prior FLT3 TKI exposure and 57.8 % (n=11) in 19 patients with prior FLT3 TKI exposure (P=0.52). At the end of the first cycle, the median time to ANC > 0.5× 109/L was 38 days and platelet > 50× 109/L was 31 days among responders, but 60-day mortality was 0 %. The estimated 2-year OS was 60.9 % for all R/R FLT3mut patients. The 1-year OS was 80 % and 58.8 % in patients without and with prior FLT3 TKI exposure, respectively (P=0.79). The estimated 2-year OS was 62 % in 19 (65.5 %) patients who received allo-HSCT after triplet therapy and 37 % in 10 patients who did not receive allo-HSCT (P=0.03). In conclusion, triplet therapy with gilteritinib, VEN, and AZA is effective and safe and an excellent frontline option for R/R FLT3mut AML.

Mesenchymal stromal cells plus basiliximab improve the response of steroid-refractory acute graft-versus-host disease as a second-line therapy: a multicentre, randomized, controlled trial

BACKGROUND

For patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD), effective second-line regimens are urgently needed. Mesenchymal stromal cells (MSCs) have been used as salvage regimens for SR-aGVHD in the past. However, clinical trials and an overall understanding of the molecular mechanisms of MSCs combined with basiliximab for SR-aGVHD are limited, especially in haploidentical haemopoietic stem cell transplantation (HID HSCT).

METHODS

The primary endpoint of this multicentre, randomized, controlled trial was the 4-week complete response (CR) rate of SR-aGVHD. A total of 130 patients with SR-aGVHD were assigned in a 1:1 randomization schedule to the MSC group (receiving basiliximab plus MSCs) or control group (receiving basiliximab alone) (NCT04738981).

RESULTS

Most enrolled patients (96.2%) received HID HSCT. The 4-week CR rate of SR-aGVHD in the MSC group was obviously better than that in the control group (83.1% vs. 55.4%, P = 0.001). However, for the overall response rates at week 4, the two groups were comparable. More patients in the control group used ≥ 6 doses of basiliximab (4.6% vs. 20%, P = 0.008). We collected blood samples from 19 consecutive patients and evaluated MSC-derived immunosuppressive cytokines, including HO1, GAL1, GAL9, TNFIA6, PGE2, PDL1, TGF-β and HGF. Compared to the levels before MSC infusion, the HO1 (P = 0.0072) and TGF-β (P = 0.0243) levels increased significantly 1 day after MSC infusion. At 7 days after MSC infusion, the levels of HO1, GAL1, TNFIA6 and TGF-β tended to increase; however, the differences were not statistically significant. Although the 52-week cumulative incidence of cGVHD in the MSC group was comparable to that in the control group, fewer patients in the MSC group developed cGVHD involving ≥3 organs (14.3% vs. 43.6%, P = 0.006). MSCs were well tolerated, no infusion-related adverse events (AEs) occurred and other AEs were also comparable between the two groups. However, patients with malignant haematological diseases in the MSC group had a higher 52-week disease-free survival rate than those in the control group (84.8% vs. 65.9%, P = 0.031).

CONCLUSIONS

For SR-aGVHD after allo-HSCT, especially HID HSCT, the combination of MSCs and basiliximab as the second-line therapy led to significantly better 4-week CR rates than basiliximab alone. The addition of MSCs not only did not increase toxicity but also provided a survival benefit.

Glucocorticoid and glycolysis inhibitors cooperatively abrogate acute graft-versus-host disease

Although glucorticosteroids (GCs) are the standard first-line therapy for acute graft-versus-host disease (aGvHD), nearly 50% of aGvHD patients have no response to GCs. The role of T cell metabolism in murine aGvHD was recently reported. However, whether GCs and metabolism regulators could cooperatively suppress T cell alloreactivity and ameliorate aGvHD remains to be elucidated. Increased glycolysis, characterized by elevated 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), and higher rates of glucose consumption and lactate production were found in T cells from aGvHD patients. Genetic upregulation of PFKFB3 induced T cell proliferation and differentiation into proinflammatory cells. In a humanized mouse model, PFKFB3-overexpressing or PFKFB3-silenced T cells aggravated or prevented aGvHD, respectively. Importantly, our integrated data from patient samples in vitro, in a humanized xenogeneic murine model of aGvHD and graft-versus-leukaemia (GVL) demonstrate that GCs combined with a glycolysis inhibitor could cooperatively reduce the alloreactivity of T cells and ameliorate aGvHD without loss of GVL effects. Together, the current study indicated that glycolysis is critical for T cell activation and induction of human aGvHD. Therefore, the regulation of glycolysis offers a potential pathogenesis-oriented therapeutic strategy for aGvHD patients. GCs combined with glycolysis inhibitors promises to be a novel first-line combination therapy for aGvHD patients.

The nuclear factor erythroid 2-related factor 2 agonist tert-butylhydroquinone improves bone marrow mesenchymal stromal cell function in prolonged isolated thrombocytopenia after allogeneic haematopoietic stem cell transplantation

Prolonged isolated thrombocytopenia (PT) is a life-threatening comorbidity associated with allogeneic haematopoietic stem cell transplantation (allo-HSCT). Our previous study indicated that dysfunctional bone marrow mesenchymal stromal cells (BM MSCs) played a role in PT pathogenesis and that reactive oxygen species (ROS) accumulation was related to BM MSC senescence and apoptosis. However, the mechanism of the increase in ROS levels in the BM MSCs of PT patients is unknown. In the current case-control study, we investigated whether nuclear factor erythroid 2-related factor 2 (NRF2), which is a central regulator of the cellular anti-oxidant response that can clear ROS in human BM MSCs, was associated with PT after allo-HSCT. We evaluated whether an NRF2 agonist (tert-butylhydroquinone, TBHQ) could enhance BM MSCs from PT patients in vitro. We found that BM MSCs from PT patients exhibited increased ROS levels and reduced NRF2 expression. Multivariate analysis showed that low NRF2 expression was an independent risk factor for primary PT [p = 0.032, Odds ratio (OR) 0.868, 95% confidence interval (CI) 0.764-0.988]. In-vitro treatment with TBHQ improved the quantity and function of BM MSCs from PT patients by downregulating ROS levels and rescued the impaired BM MSC support of megakaryocytopoiesis. In conclusion, these results suggested that NRF2 downregulation in human BM MSCs might be involved in the pathogenesis of PT after allo-HSCT and that BM MSC impairment could be improved by NRF2 agonist in vitro. Although further validation is needed, our data indicate that NRF2 agonists might be a potential therapeutic approach for PT patients after allo-HSCT.

Allogeneic stem cell transplantation in the treatment of acute myeloid leukemia: An overview of obstacles and opportunities

As an important treatment for acute myeloid leukemia, allogeneic hematopoietic stem cell transplantation (allo-HSCT) plays an important role in reducing relapse and improving long-term survival. With rapid advancements in basic research in molecular biology and immunology and with deepening understanding of the biological characteristics of hematopoietic stem cells, allo-HSCT has been widely applied in clinical practice. During allo-HSCT, preconditioning, the donor, and the source of stem cells can be tailored to the patient’s conditions, greatly broadening the indications for HSCT, with clear survival benefits. However, the risks associated with allo-HSCT remain high, i.e. hematopoietic reconstitution failure, delayed immune reconstitution, graft-versus-host disease, and post-transplant relapse, which are bottlenecks for further improvements in allo-HSCT efficacy and have become hot topics in the field of HSCT. Other bottlenecks recognized in the current treatment of individuals diagnosed with acute myeloid leukemia and subjected to allo-HSCT include the selection of the most appropriate conditioning regimen and post-transplantation management. In this paper, we reviewed the progress of relevant research regarding these aspects.

Reduced-dose post-transplant cyclophosphamide plus low-dose post-transplant anti-thymocyte globulin as graft-versus-host disease prophylaxis with fludarabine-busulfan-cytarabine conditioning in haploidentical peripheral blood stem cell transplantation: A multicentre, randomized controlled clinical trial

Anti-thymocyte globulin (ATG) or post-transplant cyclophosphamide (PTCy)-based regimens are widely used for graft-versus-host disease (GVHD) prophylaxis in haploidentical haematopoietic stem cell transplantation (haplo-HSCT). To improve the effectiveness of GVHD prophylaxis in haploidentical peripheral blood stem cell transplantation (haplo-PBSCT), we conducted a multicentre, randomized clinical trial to determine the efficacy of reduced-dose PTCy (40 mg/kg/d on days 3 and 4) combined with low-dose post-transplant ATG (2.5 mg/kg on day 8)-based GVHD prophylaxis (reduced-dose PTCy/ATG) with fludarabine-busulfan-cytarabine (FBA) conditioning for patients with haematological malignancies. From 2018 to 2022, 122 patients from four institutions were randomly assigned 1:1 to either a reduced-dose PTCy/ATG or a standard-dose ATG group ('Beijing Protocol', ATG: 10 mg/kg). All patients achieved myeloid engraftment. Cumulative incidences of grade II-IV (11.5% vs 39.3%, p = 0.001) and grade III-IV (6.6% vs 24.6%, p = 0.014) acute GVHD at day 100 were significantly reduced in the reduced-dose PTCy/ATG group. Furthermore, two-year overall survival, disease-free survival and GVHD-free/relapse-free survival were significantly improved in the reduced-dose PTCy/ATG group (75.4% vs 54.1%, p = 0.021; 72.7% vs 55.0%, p = 0.044; 61.3% vs 42.3%, p = 0.022 respectively). Our results demonstrate that the addition of low-dose ATG to reduced-dose PTCy with FBA conditioning is a promising strategy in haplo-PBSCT.

Lower dose of ATG combined with basiliximab for haploidentical hematopoietic stem cell transplantation is associated with effective control of GVHD and less CMV viremia

Currently, the graft-versus-host disease (GVHD) prophylaxis consists of an immunosuppressive therapy mainly based on antithymocyte globulin (ATG) or post-transplant cyclophosphamide (PTCy). GVHD remains a major complication and limitation to successful allogeneic haploidentical hematopoietic stem cell transplantation (haplo-HSCT). We modified the ATG-based GVHD prophylaxis with the addition of basiliximab in the setting of haplo-HSCT and attempted to explore the appropriate dosages. We conducted a retrospective analysis of 239 patients with intermediate- or high-risk hematologic malignancies who received haplo-HSCT with unmanipulated peripheral blood stem cells combined or not with bone marrow. All patients received the same GVHD prophylaxis consisting of the combination of methotrexate, cyclosporine or tacrolimus, mycofenolate-mofetil, and basiliximab with different doses of ATG (5-9mg/kg). With a median time of 11 days (range, 7-40 days), the rate of neutrophil engraftment was 96.65%. The 100-day cumulative incidences (CIs) of grade II-IV and III-IV aGVHD were 15.8 ± 2.5% and 5.0 ± 1.5%, while the 2-year CIs of total cGVHD and extensive cGVHD were 9.8 ± 2.2% and 4.1 ± 1.5%, respectively. The 3-year CIs of treatment-related mortality (TRM), relapse, overall survival (OS), and disease-free survival (DFS) were 14.6 ± 2.6%, 28.1 ± 3.4%, 60.9 ± 3.4%, 57.3 ± 3.4%, respectively. Furthermore, the impact of the reduction of the ATG dose to 6 mg/kg or less in combination with basiliximab on GVHD prevention and transplant outcomes among patients was analyzed. Compared to higher dose of ATG(>6mg/kg), lower dose of ATG (≤6mg/kg) was associated with a significant reduced risk of CMV viremia (52.38% vs 79.35%, P<0.001), while the incidences of aGVHD and cGVHD were similar between the two dose levels. No significant effect was found with regard to the risk of relapse, TRM, and OS. ATG combined with basiliximab could prevent GVHD efficiently and safely. The optimal scheme of using this combined regimen of ATG and basiliximab is that administration of lower dose ATG (≤6mg/kg), which seems to be more appropriate for balancing infection control and GVHD prophylaxis.

Haploidentical peripheral blood stem cell transplantation combined with unrelated cord blood in hematologic malignancy patients: A report of 80 cases

The outcomes of 80 patients with hematologic malignancies who received haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) combined with unrelated cord blood (UCB) from March 2017 to June 2020 were analyzed in this retrospective study. Anti-thymocyte globulin(ATG) was administered at a dose of 7.5 mg/kg. The median time for neutrophil and platelet engraftment was 13(range: 8-22) days and 14(range: 8-103) days, respectively. The 30-day cumulative incidence of neutrophil engraftment was 100%, and the 100-day cumulative incidence of platelet engraftment was 95%. All patients achieved complete haploidentical peripheral blood stem cell engraftment, and no cord blood chimerism was observed. The cumulative incidence of grades II-IV and grades III-IV acute graft-versus-host disease (aGVHD) on 100-day was 26.3%(95%CI: 17.2%–36.3%) and 5.0%(95%CI: 1.6%–11.4%), respectively. The estimated cumulative incidence of chronic GVHD (cGVHD) and moderate-severe cGVHD at 3-year was 43.3%(95%CI: 31.6%–54.4%) and 16.0%(95%CI: 8.7%–25.2%), respectively. The estimated 3-year cumulative incidence of relapse and non-relapse mortality was 18.8%(95%CI: 10.0%–29.7%) and 17.8%(95%CI: 9.9%–27.5%), respectively. The estimated 3-year probabilities of overall survival, disease-free survival, GVHD/relapse-free survival were 77.6%(95%CI: 68.3%–88.1%), 63.4%(95%CI: 52.6%–76.5%), and 55.5%(95%CI: 44.8%–68.7%), respectively. These satisfying results suggested that haplo-PBSCT combined with UCB is an alternative transplantation protocol for hematologic malignancies.

Current status and prospects of hematopoietic stem cell transplantation in China

ABSTRACT

Hematopoietic stem cell transplantation (HSCT) is a highly effective and unique medical procedure for the treatment of most hematological malignancies. The first allogeneic transplantation was performed by E. Donnall Thomas in 1957. Since then, the field has evolved and expanded worldwide. The first successful allogenic HSCT (allo-HSCT) in China was conducted in 1981. Although the development of allo-HSCT in China lagged, China has since made considerable contributions to the process of HSCT worldwide, with more than 10,000 HSCTs performed annually. In particular, haploid HSCT (haplo-HSCT) technology represented in the Beijing Protocol has demonstrated similar efficacy to human leukocyte antigen-matched HSCT and has gradually become the pre-dominant choice for allo-HSCT in China. Currently, the number of haplo-HSCT procedures exceeds 5000 per year, and the Beijing Protocol has been greatly improved by implementing updated individualized strategies for controlling complications, relapse, and infection management. In addition, innovative haplo-HSCT technologies developed by different medical transplantation centers, such as Soochow, Zhejiang, Fujian, Chongqing, and Anhui, have emerged, providing inspiration for the refinement of global practice. This review will focus on the current activity in this field and highlight important trends that are vital in China's allo-HSCT process, examining the current viewpoint and future directions.

Is Haploidentical Hematopoietic Cell Transplantation Using Post-Transplantation Cyclophosphamide Feasible in Sub-Saharan Africa?

Identifying a suitable volunteer unrelated donor (UD) in South Africa is challenging due to the highly diverse ethnic groups and mixed-race populations in this region. Haploidentical hematopoietic cell transplantation (haploHCT) is thus an attractive procedure for patients with high-risk hematologic malignancies. This study was conducted to assess the safety and feasibility of haploHCT in South Africa. We retrospectively analyzed the outcome of 134 patients with hematologic malignancies who received unmanipulated haploHCT with post-transplantation cyclophosphamide at 2 high-volume HCT centers between 2014 and 2019. We assessed overall survival (OS), disease-free survival (DFS), nonrelapse mortality (NRM), relapse incidence (RI), and incidence of acute GVHD. The median recipient age was 44 years (range, 15 to 73 years) and the median donor age was 36 years (range, 9 to 68 years). Acute myelogenous leukemia or myelodysplastic syndrome (AML/MDS) and acute lymphoblastic leukemia (ALL) were the most common indications for haploHCT (61.2%). The European Society for Blood and Marrow Transplantation risk score was ≥5 in 44 patients (32.8%). Seventy-seven patients (57.4%) received a myeloablative conditioning regimen. The majority of patients received a sex-matched transplant (57.4%) and had peripheral blood stem cells (PBSCs) as the stem cell source (70.9%). Sixteen patients (11.9%) had an incongruent cytomegalovirus serostatus at transplantation. The median duration of follow-up was 10.8 months (range, 0.36 to 70.8 months). OS was 56% (95% confidence interval [CI], 47% to 64%) at 1 year and 37% (95% CI, 28% to 47%) at 3 years. DFS was 47% (95% CI, 38% to 55%) at 1 year and 32% (95% CI, 24% to 41%) at 3 years. The 100-day and 3-year cumulative incidence of NRM was 18% (95% CI, 11% to 25%) and 41% (95% CI, 32% to 50%), respectively, and the 1- and 3-year cumulative RI was 16% (95% CI, 11% to 24%) and 21% (95% CI, 14% to 29%), respectively. The 1-year OS was 55% (95% CI, 40% to 67%) for the patients with AML/MDS versus 41% (95% CI, 21% to 60%) for those with ALL. Forty-five patients (41.7%) developed acute GVHD by day +100; of these, 80% had grade I-II disease. Fifty patients (37.5%) developed cytomegalovirus infection that required therapy. On multivariable analysis, older donor age was an independent risk factor for lower DFS. RI was higher for diagnoses other than acute leukemia/MDS (relative risk [RR], 2.62; 95% CI, 1.12 to 6.15; P = .027), decreased for PBSC versus bone marrow (RR, 0.43; 95% CI, 0.19 to 0.95; P = .038) and decreased for offspring donors (RR, 0.25; 95% CI, 0.09 to 0.67; P = .006). These data support the feasibility of haploHCT and suggest that unmanipulated haploHCT using a younger parent or offspring donor is a viable option for adults in sub-Saharan Africa with acute leukemia and MDS who lack a suitable related or unrelated donor.

Haploidentical Stem Cell Transplantation for Acute Myeloid Leukemia: Current Therapies, Challenges and Future Prospective

Haploidentical stem cell transplantation (haplo-SCT), an alternative donor source, offers a curative therapy for patients with acute myeloid leukemia (AML) who are transplant candidates. Advances in transplantation techniques, such as donor selection, conditioning regimen modification, and graft-versus-host disease prophylaxis, have successfully improved the outcomes of AML patients receiving haplo-SCT and extended the haploidentical transplant indictions for AML. Presently, treating de novo AML, secondary AML, therapy-related AML and refractory and relapsed AML with haplo-SCT can achieve comparable outcomes to those of human leukocyte antigen (HLA)-matched sibling donor transplantation (MSDT), unrelated donor transplantation or umbilical cord blood transplantation. For some subgroups of AML subjects, such as patients with positive pretransplantation minimal/measurable residual disease, recent studies suggest that haplo-SCT might be superior to MSDT in decreasing relapse and improving survival. Unfortunately, for patients with AML after haplo-SCT, relapse and infections remain the causes of death that restrict further improvement in clinical outcomes. In this review, we discuss the recent advances and challenges in haplo-SCT for AML treatment, mainly focusing on unmanipulated haplo-SCT protocols. We provide an outlook on future prospects and suggest that relapse prophylaxis, intervention, and treatment, as well as infection prevention and therapy, are areas of active research in AML patients who receive haploidentical allografts.

The consensus from The Chinese Society of Hematology on indications, conditioning regimens and donor selection for allogeneic hematopoietic stem cell transplantation: 2021 update

The consensus recommendations in 2018 from The Chinese Society of Hematology (CSH) on indications, conditioning regimens and donor selection for allogeneic hematopoietic stem cell transplantation (allo-HSCT) facilitated the standardization of clinical practices of allo-HSCT in China and progressive integration with the world. There have been new developments since the initial publication. To integrate recent developments and further improve the consensus, a panel of experts from the CSH recently updated the consensus recommendations, which are summarized as follows: (1) there is a new algorithm for selecting appropriate donors for allo-HSCT candidates. Haploidentical donors (HIDs) are the preferred donor choice over matched sibling donors (MSDs) for patients with high-risk leukemia or elderly patients with young offspring donors in experienced centers. This replaces the previous algorithm for donor selection, which favored MSDs over HIDs. (2) Patients with refractory/relapsed lymphoblastic malignancies are now encouraged to undergo salvage treatment with novel immunotherapies prior to HSCT. (3) The consensus has been updated to reflect additional evidence for the application of allo-HSCT in specific groups of patients with hematological malignancies (intermediate-risk acute myeloid leukemia (AML), favorable-risk AML with positive minimal residual disease, and standard-risk acute lymphoblastic leukemia). (4) The consensus has been updated to reflect additional evidence for the application of HSCT in patients with nonmalignant diseases, such as severe aplastic anemia and inherited diseases. (5) The consensus has been updated to reflect additional evidence for the administration of anti-thymocyte globulin, granulocyte colony-stimulating factors and post-transplantation cyclophosphamide in HID-HSCT.

Comparison of the clinical outcomes between NIMA-mismatched and NIPA-mismatched haploidentical hematopoietic stem cell transplantation for patients with hematological malignancies

The objective of this study was to compare clinical outcomes between noninherited maternal antigen (NIMA)-mismatched and noninherited paternal antigen (NIPA)-mismatched haploidentical hematopoietic stem cell transplantation (haplo-HSCT) among patients with hematological malignancies and perform a subgroup analysis. We retrospectively analyzed 378 patients with hematological malignancies who received haplo-HSCT from NIMA-mismatched (n = 201) and NIPA-mismatched (n = 177) donors between January 2012 and December 2017. The cumulative incidence of 100-d grades II-IV acute graft-versus-host disease (aGVHD) (19.2% vs. 32.8%, P = 0.003) was significantly lower in NIMA mismatch. Multivariate analysis showed that NIMA mismatch was associated with lower incidence of grades II-IV aGVHD and better overall survival (OS) and disease-free survival (DFS). According to the subgroup analysis, the clinical outcomes of older and/or female NIMA mismatches were comparable to those of younger and/or male NIPA mismatches with respect to grades II-IV aGVHD, chronic GVHD (cGVHD), nonrelapse mortality (NRM), relapse, DFS, and OS. In conclusion, this study confirmed the NIMA effect on aGVHD and demonstrated that NIMA mismatch was associated with better survival. In the NIMA mismatch context, donor age and sex did not seem to influence haplo-HSCT, which provides a basis for the selection of sibling donors.

[Comparison of the clinical outcomes of haploidentical and matched-sibling donor stem cell transplantation for T cell acute lymphoblastic leukemia in complete remission]

目的

比较亲缘单倍型造血干细胞移植（HIDT）和同胞相合造血干细胞移植（MSDT）治疗完全缓解期（CR）急性T淋巴细胞白血病（T-ALL）的疗效。

方法

回顾性分析2012年5月至2017年5月间在河北燕达陆道培医院接受HIDT（81例）和MSDT（17例）的CR期T-ALL患者的临床特点和预后。

结果

HIDT组、MSDT组移植后100 d Ⅱ～Ⅳ度急性GVHD发生率分别为51.9％（95％CI42.0％～64.0％）、29.4％（95％CI 14.1％～61.4％）（P＝0.072），Ⅲ/Ⅳ度急性GVHD发生率分别为9.8％（95％CI 5.1％～19.1％）、11.8％（95％CI 3.2％～43.3％）（P＝1.000），巨细胞病毒（CMV）血症发生率分别为53.1％（95％CI 43.3％～65.2％）、29.4％（95％CI 14.1％～61.4％）（P＝0.115），EB病毒（EBV）血症发生率分别为35.8％（95％CI 26.8％～47.9％）、11.8％（95％CI 3.2％～43.3％）（P＝0.048）。HIDT、MSDT两组移植后5年总生存（OS）率分别为60.5％（95％CI 5.4％～49.0％）、68.8％（95％CI 11.8％～40.0％）（P＝0.315），无白血病生存（LFS）率分别为58.0％（95％CI 5.5％～46.5％）、68.8％（95％CI11.8％～40.0％）（P＝0.258），累积复发率分别为16.1％（95％ CI 9.8％～26.4％）、11.8％（95％ CI3.2％～43.3％）（P＝0.643），非复发死亡率（NRM）分别为25.9％（95％CI 17.9％～37.5％）、19.4％（95％CI6.9％～54.4％）（P＝0.386）。

结论

对于CR期T-ALL患者，当缺乏合适供者时，HIDT可作为替代选择。

Overcoming graft failure after haploidentical transplantation: Is this a possibility?

Allogeneic hematopoietic stem cell transplantation (allo-HSCT), including haploidentical HSCT (haplo-HSCT), is a potentially curative treatment for several hematologic disorders. However, the occurrence of poor graft function (PGF) can lead to mortality. Advances in the use of novel conditioning regimens and strategies to improve engraftment while reducing PGF, are expected to improve outcomes. This review has examined recent evidence that will provide insights into reducing graft failure in haplo-HSCT.

Haploidentical stem cell transplantation vs matched unrelated donor transplantation in adults with hematologic malignancies: a systematic review and meta-analysis

OBJECTIVES

Haploidentical hematopoietic stem cell transplantation (Haplo-SCT) and matched unrelated donor transplantation (MUD-SCT) are two important options when a matched sibling donor (MSD) is unavailable. Several studies comparing Haplo-SCT and MUD-SCT have reported inconsistent clinical outcomes. Therefore, it is necessary to synthesize the existing evidence regarding outcomes of stem cell transplantations comparing Haplo-SCT with MUD-SCT.

METHODS

We searched for titles of articles in MEDLINE (PubMed), Cochrane library, EMBASE database that compared transplantation with Haplo-SCT versus MUD-SCT. To compare clinical outcomes between Haplo-SCT and MUD-SCT, we performed a meta-analysis of 17 studies and reported the pooled odd ratios (OR) of 6 endpoints including overall survival (OS), progression free survival (PFS), non-relapse mortality (NRM), relapse rate (RR), acute graft-versus-host disease (aGVHD) and chronic graft- versus-host disease (cGVHD).

RESULTS

We found that Haplo-SCT was associated with a comparable OS (pooled OR of 0.99, 95% Confidence Interval (CI) 0.86-1.14), PFS (OR 1.00, 95% CI 0.88-1.15), NRM (OR 0.83, 95% CI 0.65-1.04) and RR (OR 1.08, 95% CI 0.95-1.22) compared to MUD-SCT. We also found a significantly decreased risk of aGVHD (OR 0.74, 95% CI 0.62-0.88) and cGVHD (OR 0.50, 95% CI 0.38-0.66) in Haplo-SCT group.

CONCLUSION

Results of this meta-analysis demonstrates that Haplo-SCT achieves comparable clinical outcomes compared to MUD-SCT in terms of OS, PFS, TRM and RR, but is better than MUD-SCT in terms of decreased aGVHD and cGVHD risk. Haplo-SCT is a valid option for patient needing urgent transplantation.

T-Cell-Replete Versus ex vivo T-Cell-Depleted Haploidentical Haematopoietic Stem Cell Transplantation in Children With Acute Lymphoblastic Leukaemia and Other Haematological Malignancies

Allogeneic haematopoietic stem cell transplantation (HSCT) represents a potentially curative option for children with high-risk or refractory/relapsed leukaemias. Traditional donor hierarchy favours a human leukocyte antigen (HLA)-matched sibling donor (MSD) over an HLA-matched unrelated donor (MUD), followed by alternative donors such as haploidentical donors or unrelated cord blood. However, haploidentical HSCT (hHSCT) may be entailed with significant advantages: besides a potentially increased graft-vs.-leukaemia effect, the immediate availability of a relative as well as the possibility of a second donation for additional cellular therapies may impact on outcome. The key question in hHSCT is how, and how deeply, to deplete donor T-cells. More T cells in the graft confer faster immune reconstitution with consecutively lower infection rates, however, greater numbers of T-cells might be associated with higher rates of graft-vs.-host disease (GvHD). Two different methods for reduction of alloreactivity have been established: in vivo T-cell suppression and ex vivo T-cell depletion (TCD). Ex vivo TCD of the graft uses either positive selection or negative depletion of graft cells before infusion. In contrast, T-cell-repleted grafts consisting of non-manipulated bone marrow or peripheral blood grafts require intense in vivo GvHD prophylaxis. There are two major T-cell replete protocols: one is based on post-transplantation cyclophosphamide (PTCy), while the other is based on anti-thymocyte globulin (ATG; Beijing protocol). Published data do not show an unequivocal benefit for one of these three platforms in terms of overall survival, non-relapse mortality or disease recurrence. In this review, we discuss the pros and cons of these three different approaches to hHSCT with an emphasis on the significance of the existing data for children with acute lymphoblastic leukaemia.

HLA-Haploidentical Family Donors: The New Promise for Childhood Acute Lymphoblastic Leukaemia?

Allogeneic haematopoietic stem cell transplantation (HSCT) is indicated in children with high-risk, relapsed or refractory acute lymphoblastic leukaemia (ALL). HLA-matched grafts from cord blood and stem cell repositories have allowed patients without suitable sibling donors to undergo HSCT. However, challenges in procuring matched unrelated donor (MUD) grafts due to high cost, ethnic disparity and time constraints have led to the exponential rise in the use of stem cells from human leukocyte antigen (HLA)-haploidentical family donors. Whilst HLA-haploidentical HSCT (hHSCT) performed in adult patients with acute leukaemia has produced outcomes similar to MUD transplants, experience in children is limited. Over the last 5 years, more data have emerged on hHSCT in the childhood ALL setting, allowing comparisons with matched donor transplants. The feasibility of hHSCT using adult family donors in childhood ALL may also address the ethical issues related to selection of minor siblings in matched sibling donor transplants. Here, we review hHSCT in paediatric recipients with ALL and highlight the emergence of hHSCT as a promising therapeutic option for patients lacking a suitable matched donor. Recent issues related to conditioning regimens, donor selection and graft-vs.-host disease prophylaxis are discussed. We also identify areas for future research to address transplant-related complications and improve post-transplant disease-free survival.

Preemptive interferon-α treatment could protect against relapse and improve long-term survival of ALL patients after allo-HSCT

Relapse was the major cause of treatment failure in patients with acute lymphoblastic leukemia (ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aimed to identify the efficacy and safety of preemptive interferon-α (IFN-α) treatment in ALL patients who had minimal residual disease (MRD) after allo-HSCT. Multiparameter flow cytometry and polymerase chain reaction assays were applied for MRD monitoring. Recombinant human IFN-α-2b injections were administered subcutaneously twice weekly in every 4 weeks cycle. Twenty-four (35.3%), 5 (7.4%), 6 (8.8%), and 13 (19.1%) patients achieved MRD negativity at 1, 2, 3, and > 3 months, respectively, after treatment. Seven patients showed grade ≥ 3 toxicities after IFN-α treatment. The 4-year cumulative incidence of total acute graft-versus-host disease (aGVHD), severe aGVHD, total chronic GVHD (cGVHD), and severe cGVHD after treatment was 14.7%, 2.9%, 40.0%, and 7.5%, respectively. The 4-year cumulative incidences of relapse and non-relapse mortality after treatment was 31.9% and 6.0%, respectively. The 4-year probabilities of disease-free survival and overall survival after IFN-α treatment were 62.1% and 71.1%, respectively. Thus, preemptive IFN-α treatment could protect against relapse and improve long-term survival for ALL patients who had MRD after allo-HSCT. The study was registered at https://clinicaltrials.gov as #NCT02185261 (09/07/2014).

Ruxolitinib is an effective salvage treatment for multidrug-resistant graft-versus-host disease after haploidentical allogeneic hematopoietic stem cell transplantation without posttransplant cyclophosphamide

The purpose of our study is to identify the efficacy of ruxolitinib in human leukocyte antigen (HLA) haploidentical hematopoietic stem cell transplantation (haplo-HSCT) recipients with multidrug-resistant (MDR)-graft-versus-host disease (GVHD, n = 34). MDR-GVHD was defined as GVHD showing no improvement after at least 3 types of treatments. The median number of previous GVHD-therapies was 4 for both MDR-acute GVHD (aGVHD) and MDR-chronic GVHD (cGVHD). For MDR-aGVHD (n = 15), the median time to response was 10 days (range 2 to 65), and the overall response rate (ORR) was 60.0% (9/15), including 40.0% (6/15) complete response (CR) and 20.0% (3/15) partial response (PR). The 1-year probability of overall survival after ruxolitinib was 66.7%. The rates of hematologic and infectious toxicities were 73.3% and 46.7% after ruxolitinib treatment. For MDR-cGVHD (n = 19), the median time to response was 29 days (range 6 to 175), and the ORR was 89.5% (17/19), including 26.3% (5/19) CR and 63.2% (12/19) PR. All patients remained alive until our last follow-up. The rates of hematologic and infectious toxicities were 36.8% and 47.4% after ruxolitinib treatment. Ruxolitinib is an effective salvage treatment for MDR-GVHD in haplo-HSCT recipients.

The incidence, risk factors, and outcomes of acute graft-vs-host disease in pediatric T-cell-replete haploidentical hematopoietic stem cell transplantation

The specific description, risk factors, and outcomes of aGVHD in pediatric haplo-HSCT using TCR protocols without PT-Cy have not been well described previously. We evaluated the incidence, risk factors, and outcomes of aGVHD in 350 consecutive pediatric patients receiving TCR haplo-HSCT without PT-Cy according to the Glucksberg and NIH aGVHD classifications between January 2015 and December 2017 at Peking University Institute of Hematology. The cumulative incidences of grade I, II, III, and IV aGVHD were 28%, 29.7%, 8.3%, and 5.1%, respectively. The type of aGVHD onset was classic in 243 patients (97.2%), and persistent/recurrent/late-onset aGVHD was in seven patients (2.8%). None of the considered variables significantly influenced the incidence of grade III-IV aGVHD. The 3-year OS, DFS, cumulative incidence of NRM, and relapse in malignant disease between severe aGVHD (III-IV) group and grade 0-II aGVHD group were 61.5% vs 77.2% (P = .027), 58.6% vs 75.1% (P = .014), 19.8% vs 5.3% (P = .002), and 21.6% vs 19.6% (P = .59), respectively; in non-malignant diseases, the 3-year OS, DFS, and NRM were 81.8% vs 97.4% (P = .05), 81.8% vs 97.4% (P = .05), and 18.2% vs 2.6% (P = .05), respectively. Under the protocol of pediatric TCR haplo-HSCT without PT-Cy, the persistent/recurrent/late-onset aGVHD was rare, and the incidence of severe aGVHD was acceptable and significantly contributed to NRM and lower survival in both malignant disease and non-malignant diseases.

Haploidentical related donor vs matched sibling donor allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia and myelodysplastic syndrome aged over 50 years: A single-center retrospective study

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapeutic option for patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Increasing data suggest that haploidentical donor (HID) transplantation achieve comparable outcomes with HLA-matched sibling donor (MSD) in adult AML/MDS. This retrospective study compared the outcomes of AML or MDS patients age ≥50 years underwent HID and MSD transplantation. One hundred and fifty-six patients were enrolled in this study, including 75 HID and 81 MSD transplantation. The 100-day cumulative incidence of II-IV° acute graft-versus-host disease (GVHD) was 33.3 ± 5.4% vs 22.2 ± 4.6%, respectively, in HID and MSD groups (P = .066), and III-IV° acute GVHD was not significantly different between two groups (5.3%±2.6% vs 6.2%±2.7%, respectively, P = .823). The 2-year cumulative incidence of limited and extensive chronic GVHD was not statistically different in HID and MSD groups (20.9 ± 5.5% vs 18.9 ± 4.8% and 13.0 ± 4.7% vs 19.7 ± 5.0%, P = .889 and P = .269, respectively). The 2-year cumulative incidences of relapse (27.0 ± 5.6% vs 22.7 ± 5.1%, P = .509), 2-year overall survival (63.0 ± 5.8% vs 66.7 ± 5.4%, P = .454), 2-year transplant-related mortality (17.2 ± 4.6% vs 17.4 ± 4.4%, P = .847), 2-year progression-free survival (59.3 ± 5.8% vs 64.5 ± 5.4%, P = .437), 2-year GVHD-free relapse-free survival (42.6 ± 5.9% vs 40.9 ± 5.6%, P = .964) were not significantly different in the two groups. The present data showed equivalent outcomes in AML or MDS patients age ≥50 years underwent HID and MSD transplantation.

Incidence, Risk Factors, and Outcomes of Chronic Graft-versus-Host Disease in Pediatric Patients with Hematologic Malignancies after T Cell-Replete Myeloablative Haploidentical Hematopoietic Stem Cell Transplantation with Antithymocyte Globulin/Granulocyte Colony-Stimulating Factor

The specific description, risk factors, and outcomes of chronic graft-versus-host disease (cGVHD) in pediatric patients with hematologic malignancies after T cell-replete (TCR) myeloablative haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with antithymocyte globulin (ATG)/granulocyte colony-stimulating factor (G-CSF) have not been previously well described. We retrospectively analyzed the incidence, risk factors, and outcomes of cGVHD documented according to the 2014 National Institutes of Health consensus criteria (NIH-CC) in 292 consecutive pediatric patients with hematologic malignancies after TCR myeloablative haplo-HSCT with ATG/G-CSF between January 2015 and December 2017. A total of 170 patients experienced cGVHD. The 3-year cumulative incidence of total cGVHD and mild, moderate, and severe cGVHD was 57.9%, 27.5%, 18.8%, and 11.9%, respectively. Multivariate analysis showed that acute GVHD (aGVHD) grade II-IV (hazard ratio, 1.578; P = .002) was an independent risk factor for cGVHD. Compared to patients without cGVHD, patients with cGVHD demonstrated a lower 3-year relapse (17.6% versus 27.2%; P = .009), a similar 3-year nonrelapse mortality (NRM) (5.9% versus 5.4%; P = .79), and better 3-year disease-free survival (DFS) (77.8% versus 66.9%; P = .007) and overall survival (OS) (81.3% versus 68.6%; P = .001), particularly those with mild or moderate cGVHD; however, no significant impact of severe cGVHD on relapse, NRM, DFS, or OS was seen. In conclusion, the incidence of severe cGVHD in pediatric patients with hematologic malignancies after TCR myeloablative haplo-HSCT with ATG/G-CSF was acceptable. Previous aGVHD grade II-IV was a risk factor for the occurrence of cGVHD. Only mild or moderate cGVHD was associated with a lower risk of relapse, translating into improved DFS and OS in pediatric patients with hematologic malignancies after TCR myeloablative haplo-HSCT with ATG/G-CSF.

Haploidentical transplantation might have superior graft-versus-leukemia effect than HLA-matched sibling transplantation for high-risk acute myeloid leukemia in first complete remission: a prospective multicentre cohort study

This study aimed to investigate graft-versus-leukemia (GVL) of haploidentical donor (HID) compared with HLA-matched sibling donor (MSD) for high-risk acute myeloid leukemia (H-AML) in first complete remission (CR1). One hundred and eighty-nine patients with H-AML in CR1 were enrolled in this multicentre prospective cohort study. Patients were assigned to groups transplanted with HID (n = 83) or MSD (n = 106) based on donor availability (biological randomization). The primary endpoint was the incidence of MRD positivity posttransplantation (post-MRD+). All post-MRD+ patients received preemptive interventions. The cumulative incidences of post-MRD+ were 18 and 42% in HID and MSD groups, respectively, (p < 0.001). Fifty-two patients received preemptive DLI, including 13 (16%) in HID and 39 cases (37%) in MSD groups (p = 0.001). Among HID and MSD groups, the 3-year cumulative incidence of relapse were 14 and 24% (p = 0.101); the 3-year cumulative incidence of treatment-related mortality were 15 and 10% (p = 0.368); the 3-year overall survival rates were 72 and 68% (p = 0.687); the 3-year disease-free-survival were 71 and 66% (p = 0.579); the 3-year graft-versus-host disease and relapse free survival were 63 and 43% (p = 0.035), respectively. HID might have a stronger GVL than MSD in H-AML patients. HID transplantation as postremission therapy should be recommended as one of the optimal choices for H-AML patients in CR1.