Idarubicin-intensified BUCY2 conditioning regimen improved survival in high-risk acute myeloid, but not lymphocytic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: A retrospective comparative study

Comparative analysis of hypomethylating agents as maintenance therapy after allogeneic hematopoietic stem cell transplantation for high-risk acute leukemia

We retrospectively analyzed the outcomes of 136 consecutive patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) at our center. Among them, 76 cases used hypomethylating agents (decitabine, n = 40; azacitidine, n = 36) as post-transplant maintenance therapy, whereas 60 contemporaneous patients did not adopt maintenance therapy. The 3-year incidences of relapse in two groups were 16.6% and 39.2% (p = .001). The 3-year OS and DFS in maintenance group were 84.0% and 78.6%, which were remarkably improved than in control group (60.0% and 58.0%) (p = .004, p = .011). Moreover, the 3-year relapse rates for patients receiving decitabine and azacitidine therapy were 8.5% and 25.0%, respectively (p = .019). Patients utilizing decitabine had more common possibility of grade 3-4 neutropenia than azacitidine (20.0% vs. 2.8%, p = .031). These results indicate that maintenance therapies using hypomethylating agents could reduce the risk of post-transplant recurrence, resulting into remarkable superior survival. Decitabine might lower relapse after allo-HSCT with somewhat more severe myelosuppression when being compared to azacitidine.

Comparison of efficacies of haploidentical transplantation and matched sibling donor transplantation in treating T-cell lymphoblastic lymphoma

OBJECTIVE

To investigate the differences in efficacy and safety between haploidentical donor hematopoietic stem cell transplantation (HID-HSCT) and matched sibling donor HSCT (MSD-HSCT) in patients with T-cell lymphoblastic lymphoma (T-LBL).

METHODS

In this retrospective analysis, we enrolled 38 patients who had undergone allogeneic HSCT at our institution between 2013 and 2021. The study participants included 28 patients who underwent HID-HSCT and 10 patients who underwent MSD-HSCT. We compared the patient characteristics and treatment effectiveness and safety between the two groups and evaluated potential prognostic variables for patients with T-LBL.

RESULTS

The median follow-up durations in the HID-HSCT and MSD-HSCT groups were 23.5 (range: 4-111) and 28.5 (range: 13-56) months, respectively. All patients showed full-donor chimerism after hematopoietic stem cell transplantation (HSCT). Except for two patients in the HID-HSCT cohort who developed poor graft function, all patients showed neutrophil and platelet engraftments after HSCT. The cumulative incidences of grades III-IV acute graft-versus-host disease were 37.5% and 28.57% in the HID-HSCT and MSD-HSCT groups, respectively (p = 0.84). The cumulative incidences of limited (34.13% vs. 28.57%, p = 0.82) and extensive (31.22% vs. 37.50%, p = 0.53) chronic graft-versus-host disease did not differ between the two cohorts. In the HID-HSCT and MSD-HSCT cohorts, the estimated 2-year overall survival rates were 70.3% (95% confidence interval [CI]: 54.9%-90.0%) and 56.2% (95% CI: 31.6%-100%), respectively (p = 1.00), and the estimated 2-year progression-free survival (PFS) rates were 48.5% (95% CI: 32.8%-71.6%) and 48.0% (95% CI: 24.6%-93.8%), respectively (p = 0.94). Furthermore, the Cox proportional-hazards model showed that a positive positron emission tomography/computed tomography (PET/CT) status before HSCT in patients who had completed chemotherapy was an independent risk factor for PFS in the multivariate analysis (p = 0.0367).

CONCLUSION

This study showed that HID-HSCT had comparable effectiveness and safety to MSD-HSCT in treating T-LBL. HID-HSCT could serve as an alternate treatment option for T-LBL in patients without an eligible identical donor. Achievement of the PET/CT-negative status before HSCT may contribute to better survival.

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.

Influence of graft composition in patients with hematological malignancies undergoing ATG-based haploidentical stem cell transplantation

To determine the influence of graft composition in haplo-HSCT, we summarized the long-term consequences of 251 consecutive transplantations from haploidentical donors. For donor-recipient HLA3/6-matched setting, 125 cases used G-CSF-mobilized BM and PBSCs mixtures, while 126 cases only used G-CSF-mobilized PBSCs in HLA4/6-matched transplantation. On the one hand, we wanted to explore the effect of harvests (CD34+ cells and TNCs dosages) on transplantation outcome in the context of haplo-HSCT no matter HLA4/6 or HLA3/6-matched setting. On the other hand, for patients using G-CSF-mobilized BM and PBSCs combination in HLA3/6-matched setting, we attempted to analyze whether TNCs or CD34+ cells from G-CSF-mobilized BM or G-CSF-mobilized PBSCs play the most paramount role on transplantation prognosis. Collectively, patients with hematologic malignancies receiving G-CSF-primed BM and PBSCs harvests had comparable consequences with patients only receiving G-CSF-mobilized PBSCs. Moreover, when divided all patients averagely according to the total amount of transfused nucleated cells, 3-year TRM of the intermediate group (13.06-18.05×10⁸/kg) was only 4.9%, which was remarkably reduced when compared to lower and higher groups with corresponding values 18.3%, 19.6% (P=0.026). The 3-year probabilities of OS and DFS of this intermediate group were 72.6% and 66.5%, which were slightly improved than the lower and higher groups. Most importantly, these data suggest that the transfused nucleated cells from G-CSF-primed BM above than 5.20×10⁸/kg could achieve remarkably lower TRM in haplo-HSCT receiving G-CSF-mobilized BM and PBSCs harvests. These encouraging results suggested that we could improve the efficacy of haplo-HSCT by adjusting the component and relative ratio of transfused graft cells. Nevertheless, the above findings should be confirmed in a randomized prospective comparative research with adequate follow-up.

Comparative analysis of Decitabine intensified BUCY2 and BUCY2 conditioning regimen for high-risk MDS patients undergoing allogeneic hematopoietic stem cell transplantation

The optimal conditioning regimen for high-risk myelodysplastic syndrome (MDS) patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains elusive. This study aimed to explore the anti-leukemic efficacy and toxicity of Decitabine (Dec, 20 mg/m²/day, day -11 to -7) intensified BUCY2 vs. traditional regimen in high-risk MDS population. We retrospectively evaluated 93 consecutive high-risk MDS patients undergoing allo-HSCT in our institution, comparing discrepancies in clinical characteristics and outcomes between cases using Dec-intensified BUCY2 (n = 52) and traditional BUCY2 regimen (n = 41). Three-year cumulative incidence of relapse after Dec-intensified BUCY2 conditioning was remarkably lower than that of patients using BUCY2 regimen (20.2% vs. 39.0%, p = 0.034). Overall survival and disease-free survival at 3 years for Dec-intensified BUCY2 group were 70.2% and 64.9%, respectively, which were significantly improved when compared with BUCY2 group (51.1% and 43.9%, p = 0.031 and p = 0.027). Furthermore, overall survival and disease-free survival for MDS cases receiving cytoreduction therapy were dramatically better than patients in non-cytoreduction group (p = 0.041, p = 0.047). In summary, the Dec-intensified conditioning regimen could be effective and feasible, providing prominent recurrence control with moderate toxicity for high-risk MDS patients. These patients might also benefit from pre-transplant cytoreductive therapeutic schedules. Larger randomized controlled trials are still needed to further confirm these conclusions.

Decitabine-Intensified Modified Busulfan/Cyclophosphamide Conditioning Regimen Improves Survival in Acute Myeloid Leukemia Patients Undergoing Related Donor Hematopoietic Stem Cell Transplantation: A Propensity Score Matched Analysis

To identify the benefit of decitabine (Dec)-intensified myeloablative conditioning on the outcomes of patients with acute myeloid leukemia (AML) after related donor hematopoietic stem cell transplantation (HSCT), we performed a retrospective matched-pair study from a pool of 156 patients to evaluate Dec [20 mg/m²/day intravenously (i.v.) on days -11 to -7]-intensified modified busulfan/cyclophosphamide (mBuCy) conditioning regimen vs. mBuCy regimen in 92 AML patients, with 46 patients in each cohort. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was lower in the Dec group (15.2% ± 0.3% vs. 32.6% ± 0.5%, P = 0.033). Compared with mBuCy group (15.5% ± 0.3%), a significantly higher proportion of limited chronic GVHD (cGVHD) in Dec group (35% ± 0.6%) was observed (P = 0.025). Dec-intensified mBuCy conditioning was associated with better 2-year overall survival (OS) and GVHD-free relapse-free survival (GRFS) (81% ± 6.2% vs. 59.4% ± 7.5%, P = 0.03; 58.7% ± 8.1% vs. 40.9% ± 7.3%, P = 0.042; respectively). Our results also elucidated that the Dec group had better 2-year OS and lower 2-year cumulative incidence of relapse (CIR) in patients acquiring haploidentical HSCT than that of the mBuCy group (84.8% ± 7.1% vs. 58.2% ± 10.3%, P = 0.047; 17.9% ± 0.8% vs. 40.0% ± 1.0%, P = 0.036; respectively), which did not increase the treatment-related mortality and regimen-associated toxicities. Dec-intensified myeloablative regimen and high-risk stratification were the variables associated with OS, leukemia-free survival (LFS), and GRFS in multivariate analysis. In high-risk patients, no differences were found in CIR, OS, LFS, and GRFS between the two groups. These data indicated that Dec-intensified mBuCy conditioning regimen was associated with better survival than mBuCy regimen in AML patients, especially in patients undergoing haploidentical HSCT.

Comparing the outcomes between TMLI and non-TMLI conditioning regimens for adult high-risk acute lymphoblastic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: a single-center experience

This study aimed to retrospectively evaluate the outcomes of adult patients with high-risk acute lymphoblastic leukemia (ALL) who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) with either total marrow and lymphoid irradiation (TMLI)-containing or non-TMLI conditioning regimen. Seventy adult patients with high-risk ALL who received allo-HSCT were enrolled in this study and divided into two groups based on the conditioning regimen type (TMLI group: n = 29 and non-TMLI group: n = 41). We noted significant statistical differences in the 1-year estimated cumulative incidence of relapse (25% vs. 46.5%, p = 0.018), the 1-year estimated overall survival (73.1% vs. 52.6%, p = 0.033) and disease-free survival (65.2% vs. 48.2%, p = 0.026) but found no considerable difference in transplant-related mortality (12% vs. 13.4%, p = 0.619) between patients in the TMLI and non-TMLI groups. The TMLI-containing regimen is safe and alternative for patients with high-risk ALL undergoing allo-HSCT.

Idarubicin-Intensified Hematopoietic Cell Transplantation Improves Relapse and Survival of High-Risk Acute Leukemia Patients with Minimal Residual Disease

The optimal conditioning regimen of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for high-risk patients with minimal residual disease (MRD) remains controversial. We studied the results in 98 high-risk acute leukemia patients transplanted with idarubicin (IDA)-intensified conditioning regimens between 2012 January and 2017 January. Among these patients, 31 (31.6%) had more than 5% marrow blasts at time of transplantation and 67 patients were in morphologic remission: MRD negative status at time of conditioning was achieved in 39 patients (39.8%), whereas 28 (28.6%) remained carriers of any other positive MRD level in the bone marrow. Three-year relapse estimates of patients with MRD-positive remission was 22.0%, which was remarkably lower than patients with active disease (45.4%, P = .027) but approximate to that of patients in MRD-negative remission (15.5%, P = .522). There were no significant differences in terms of 3-year estimated overall survival (OS) and disease-free survival (DFS) between MRD-positive remission and MRD-negative remission groups (71.4% versus 79.1% [P = .562] and 67.9% versus 76.9% [P = .634], respectively). Moreover, the estimated rates of 3-year OS and DFS of patients in MRD-positive remission were significantly better than those in patients with active disease (71.4% versus 41.9% [P = .033] and 67.9% versus 38.7% [P = .037], respectively). These data indicate that IDA-intensified conditioning allo-HSCT could overcome the negative prognostic impact of MRD.

Idarubicin-intensified haploidentical HSCT with GvHD prophylaxis of ATG and basiliximab provides comparable results to sibling donors in high-risk acute leukemia

We designed a novel haploidentical hematopoietic stem cell transplantation (haplo-HSCT) system using idarubicin (IDA) intensified conditioning regimens and combination of antithymocyte globulin and basiliximab for GvHD prophylaxis. The outcomes of 110 high-risk acute leukemia patients undergoing haplo-HSCT were compared with 69 contemporaneous high-risk patients receiving HLA-matched sibling transplantation using uniform IDA-intensified regimens. The relapse incidence of haplo-HSCT was 23.4%, and 3-year overall survival (OS) and disease-free survival (DFS) achieved 62.9%, 59.1%, respectively. The cumulative incidences of II-IV and III-IV aGvHD were 28.6 and 14.3%, while limited and extensive cGvHD were 19.4, 13.8%. All these results were equivalent to those of concurrent identical sibling transplantation. Three-year OS and DFS for patients in advance stage reached 48.5, 47.3%. Furthermore, the relapse, 3-year OS of positive minimal residual disease (MRD) patients did not differ from negative MRD patients (18.9% vs 11.5%, 63.6% vs 69.6%), indicating our intensified haplo-HSCT technique could circumvent the dismal prognosis of MRD. These data provide reinforcing evidence that our haplo-HSCT system could dramatically improve the survival of high-risk acute leukemia with low relapse and acceptable transplantation-related mortality, and might be a promising therapeutic option for high-risk patients.