Allogeneic Hemopoietic Stem Cell Transplants in Patients with Acute Myeloid Leukemia (AML) Prepared with Busulfan and Fludarabine (BUFLU) or Thiotepa, Busulfan, and Fludarabine (TBF): A Retrospective Study

Tacrolimus versus cyclosporine a combined with post-transplantation cyclophosphamide for AML In first complete remission: a study from the acute leukemia working party (EBMT)

Choice of calcineurin inhibitor may impact the outcome of patients undergoing T-cell replete hematopoietic cell transplantation (HCT) with post-transplant cyclophosphamide (PT-Cy) and mycophenolate mofetil (MMF) for prophylaxis of graft-versus-host disease (GVHD). We retrospectively analyzed 2427 patients with acute myeloid leukemia (AML) in first remission transplanted from a haploidentical (n = 1844) or unrelated donor (UD, n = 583) using cyclosporine A (CSA, 63%) or tacrolimus (TAC, 37%) and PT-Cy/MMF. In univariate analysis, CSA and TAC groups did not differ in 2-year leukemia-free or overall survival, cumulative incidence (CI) of relapse or non-relapse mortality. CI of severe grade III-IV acute GVHD was lower with TAC (6.6% vs. 9.1%, p = 0.02), without difference in grade II-IV acute GVHD or grade III-IV acute GVHD/severe chronic GVHD, relapse-free survival (GRFS). In multivariate analysis, TAC was associated with a lower risk of severe grade III-IV acute GVHD solely with haploidentical donors (HR 0.64 [95% CI, 0.42-0.98], p = 0.04), but not UD (HR 0.49 [95% CI, 0.2-1.21], p = 0.12). There was no significant difference for chronic GVHD. In conclusion, PT-Cy/MMF-based GVHD prophylaxis resulted in favorable OS and GRFS, irrespective of the CNI added. In haploidentical HCT, TAC seemed to prevent severe acute GVHD more effectively than CSA without impact on other outcome parameters.

Current challenges in conditioning regimens for MDS transplantation

Myelodysplastic syndrome (MDS) is a very heterogeneous clonal disorder. Patients with "higher-risk" MDS, defined by specific recurrent genetic abnormalities, have a poor prognosis because of a high risk of progression to secondary acute myeloid leukemia with low chemosensitivity. Allogeneic hematopoietic stem cell transplantation remains the only treatment that offers durable disease control because the donor immune system allows graft-versus-MDS effects. In terms of preparation steps before transplantation, targeting the malignant clone by increasing the conditioning regimen intensity is still a matter of intense debate. MDS is mainly diagnosed in older patients, and high toxicity related to common myeloablative conditioning regimens has been reported. Efforts to include new drugs in the conditioning regimen to achieve the best malignant clone control without increasing toxicity have been made over the past 20 years. We summarized these retrospective and prospective studies and evaluated the limitations of the available evidence to delineate the ideal conditioning regimen.

Fludarabine, busulfan, and melphalan conditioning regimen in allogeneic hematopoietic stem cell transplantation for adult patients with myeloid malignancies: A multicenter retrospective study

Relapse remains the main cause of treatment failure in patients with myeloid malignancies even after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We observed a particularly low incidence of relapse in patients prepared with fludarabine, busulfan and melphalan in our previous study and this multicenter retrospective analysis aimed to confirm the feasibility of the regimen and to identify the potential prognostic factors. This study was performed using registry data from adults patients with myeloid malignancies who underwent their first allo-HSCT following fludarabine(≥100 mg/m2), busulfan (≥3.2 mg/kg) and melphalan (≥100 mg/m2) based conditioning at nine transplantation centers in China between Jan. 2020 and Mar. 2022. A total of 221 consecutive patients (AML n = 171, MDS-IB-1 or 2 n = 44, CMML n = 6) with median age of 46 were enrolled in this study. The median follow-up was 507 days for survivors. The 2-year NRM, CIR, OS and DFS were 10.6% ± 2.2%, 14.8% ± 3.3%, 79.4% ± 3.7% and 74.6% ± 3.7%, respectively. In multivariate analyses, high HCT-CI (≥3) was the only independent factor for higher NRM [hazard ratio (HR), 2.96; 95% confidence interval (CI), 1.11 to 7.90; p = 0.030] and ECOG score ≥2 was the only independent factor for inferior OS (HR, 2.43; 95%CI, 1.15 to 5.16; p = 0.020) and DFS (HR, 2.12; 95%CI, 1.13 to 4.02; p = 0.020). AML diagnosis and positive measurable residual disease (MRD) at transplantation were predictors for higher CIR (HR = 7.92, 95%CI 1.05-60.03, p = 0.045; HR = 3.64, 95%CI 1.40-9.44, p = 0.008; respectively), while post-transplantation cyclophosphamide based graft-versus-host disease prophylaxis was associated with lower CIR (HR = 0.24 95%CI 0.11-0.54, p = 0.001). The intensity of conditioning regimen did not impact CIR, NRM, DFS and OS. These results supported that double alkylating agents of busulfan and melphalan based conditioning regimens were associated with low relapse rate and acceptable NRM in adult patients with myeloid malignancies. The optimal dose remained to be confirmed by further prospective studies.

Comparison of fludarabine/melphalan (FluMel) with fludarabine/melphalan/BCNU or thiotepa (FBM/FTM) in patients with AML in first complete remission undergoing allogeneic hematopoietic stem cell transplantation - a registry study on behalf of the EBMT Acute Leukemia Working Party

Conditioning protocols for patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) are being developed continuously to improve their anti-leukemic efficacy and reduce their toxicity. In this study, we compared the conditioning protocol of fludarabine with melphalan 140 mg/m2 (FluMel) with conditioning protocols based on this same backbone but with an additional alkylating agent i.e., either fludarabine/BCNU (also known as carmustine)/melphalan (FBM), or fludarabine/thiotepa/melphalan (FTM) 110 mg/m2. We included 1272 adult patients (FluMel, n = 1002; FBM/FTM, n = 270) with acute myeloid leukemia (AML) with intermediate/poor cytogenetic risk in first complete remission (CR) from the registry of the EBMT Acute Leukemia Working Party. Despite patients in the FBM/FTM group were older (64.1 years vs. 59.8 years, p < 0.001) and had a worse Karnofsky performance score (KPS < 90, 33% vs. 24%, p = 0.003), they showed a better overall survival (OS) (2 y OS: 68.3% vs. 58.1%, p = 0.02) and less non-relapse mortality (NRM) (2 y NRM: 15.8% vs. 22.2%, p = 0.009) compared to patients treated with FluMel. No significant differences were observed in relapse incidence (RI) (2 y RI: 24.9% vs. 23.7%, p = 0.62). In conclusion, the addition of a second alkylating agent (BCNU/carmustine or thiotepa) to FluMel as FBM/FTM conditioning, improves OS in AML patients in first CR with intermediate/poor risk cytogenetics after allo-HCT.

Busulfan Plus Fludarabine Compared With Busulfan Plus Cyclophosphamide for AML Undergoing HLA-Haploidentical Hematopoietic Cell Transplantation: A Multicenter Randomized Phase III Trial

PURPOSE

The busulfan plus fludarabine (BuFlu) conditioning regimen has lower transplant-related mortality (TRM) than busulfan plus cyclophosphamide (BuCy) in HLA-matched transplantation. We aimed to compare outcomes of the BuFlu regimen with those of the BuCy regimen in HLA-haploidentical hematopoietic cell transplantation (haplo-HCT).

METHODS

We performed an open-label, randomized phase III trial at 12 hospitals in China. Eligible patients with AML (18-65 years) were randomly assigned 1:1 to receive BuFlu (busulfan 0.8 mg/kg four times per day on days -6 to -3; fludarabine 30 mg/m2 once daily on days -7 to -3) or BuCy (same dose of busulfan; cyclophosphamide 60 mg/kg once daily on days -3 and -2). The primary end point was 1-year TRM in the intention-to-treat population and safety in the per-protocol population. This trial is registered with ClinicalTrials.gov (identifier: NCT02487069) and is complete.

RESULTS

From November 20, 2015, to September 30, 2019, 386 patients were randomly assigned to receive the BuFlu (n = 194) or BuCy (n = 192) regimen. The median follow-up was 55.0 (IQR, 46.5-69.0) months after random assignment. The 1-year TRM was 7.2% (95% CI, 4.1 to 11.4) and 14.1% (95% CI, 9.6 to 19.4; hazard ratio [HR], 0.51; 95% CI, 0.27 to 0.97; P = .041), the 5-year relapse was 17.9% (95% CI, 9.6 to 28.3) and 14.2% (95% CI, 9.1 to 20.5; HR, 1.12; 95% CI, 0.65 to 1.95; P = .670), and the 5-year overall survival was 72.5% (95% CI, 62.2 to 80.4) and 68.2% (95% CI, 58.9 to 75.9; HR, 0.84; 95% CI, 0.56 to 1.26; P = .465) in two groups, respectively. Grade 3 regimen-related toxicity (RRT) was reported for 0 of 191 patients following the BuFlu regimen and 9 (4.7%) of 190 patients following the BuCy regimen (P = .002). At least one type of grade 3-5 adverse event was reported for 130 (68.1%) of the 191 patients and 147 (77.4%) of the 190 patients in two groups, respectively (P = .041).

CONCLUSION

The BuFlu regimen has a lower TRM and RRT and similar relapse for patients with AML undergoing haplo-HCT compared with the BuCy regimen.

Thiotepa-busulfan-fludarabine Compared to Treosulfan-based Conditioning for Haploidentical Transplant With Posttransplant Cyclophosphamide in Patients With Acute Myeloid Leukemia in Remission: A Study From the Acute Leukemia Working Party of the EBMT

We conducted a registry analysis including adult acute myeloid leukemia (AML) patients in remission who had received thiotepa, busulfan, and fludarabine (TBF) or treosulfan-based (Treo) conditioning for haplo-hematopoietic stem cell transplant (HSCT) with posttransplant cyclophosphamide (PTCy) between 2010 and 2020. A total of 1123 patients met the inclusion criteria (968 received TBF and 155 received Treo). A 1:1 matched-pair analysis was performed on 142 TBF and 142 Treo patients. In the Treo group, 68% of patients received treosulfan at a dose ≥36 g/m2 and 54% of patients received a second alkylator (thiotepa or melphalan). We observed a trend toward increased incidence of grade II-IV acute (a) graft-versus-host disease (GVHD) at 180 days in the TBF group compared with Treo (29% versus 20%; P = 0.08), while incidence of grade III-IV aGVHD was not statistically different. Similarly, the incidence of chronic (c) GVHD was not statistically different in the 2 groups. Incidence of nonrelapse mortality at 2 years was 19% in TBF and 14% in Treo (P = 0.4). Relapse incidence at 2 years was not statistically different in the 2 groups (16% and 18% in TBF and Treo, respectively; P = 0.9). Leukemia-free survival, overall survival, and GVHD-free, relapse-free survival was 65% versus 68% (P = 0.6), 73% versus 76% (P = 0.5), and 54% versus 53% (P = 0.8) in TBF versus Treo, respectively. In conclusion, we did not find a significant difference between the 2 conditioning in the present study; Treo and TBF represent 2 valid alternative regimens for haplo-HSCT with PTCy for AML in remission.

Low Incidence of Relapse with a Moderate Conditioning Regimen of Fludarabine, Busulfan, and Melphalan for Patients with Myeloid Malignancies: A Single-Center Analysis of 100 Patients

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) with standard myeloablative conditioning regimens such as fludarabine (Flu) and busulfan (Bu) remains a major concern in patients with myeloid malignancies. A low relapse rate has been reported when thiotepa or melphalan (Mel) is added to Flu-Bu, but at a possible increased risk of nonrelapse mortality (NRM). Here we evaluated the outcomes of 100 patients (70 with acute myeloid leukemia, 23 with myelodysplastic syndrome, 4 with chronic myelomonocytic leukemia, and 3 with granulocytic sarcoma) who underwent their first allo-HSCT after a moderate-dose FBM conditioning regimen consisting of Flu 150 mg/m2, Bu 6.4 mg/kg, and Mel 140 mg/m2 (n = 69), with Mel 100 mg/m2 for patients age >55 years and/or with a Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) ≥3 (n = 31). Donors were HLA-matched siblings (n = 19), matched unrelated donors (n = 4), and haploidentical donors (n = 77). The majority of patients (88%) had an intermediate or high Disease Risk Index. Out of 96 evaluable patients, 94 achieved neutrophil engraftment and had full donor chimerism on day +30 post-transplantation. After a median follow-up of 468 days (range, 55 to 1039 days), only 4 patients relapsed, with a 2-year cumulative incidence of relapse (CIR) of 5.3% ± 3.6%. The 100-day and 2-year NRM were 6.8% ± 4.4% and 12.3% ± 3.6%, respectively. At the last follow-up, the 2-year disease-free survival (DFS) and overall survival (OS) were 82.4% ± 4.2% and 80.3% ± 6.0%, respectively. Comparing the transplantation outcomes between patients receiving Mel 100 mg/m2 and those receiving Mel 140 mg/m2, showed no significant differences in NRM and CIR between the 2 groups and similar 2-year DFS and OS in the 2 groups, although the Mel 100 group had a higher median age (58 years versus 42 years; P < .001) and a higher percentage of patients with an HCT-CI ≥3 (P = .005). In the total cohort, the sole independent factor associated with transplantation outcomes was HCT-CI ≥3, which correlated with higher NRM and inferior DFS and OS. Our study suggests that moderate-intensity FBM conditioning is feasible for patients with myeloid malignancies, with a low relapse rate without increased NRM. A lower Mel dose of 100 mg/m2 maintained the low risk of relapse without excess NRM in older adults. However, the FBM regimen should be used with caution in patients with high-risk HCT-CI (≥3).

Myeloablative conditioning regimens in adult patients with acute myeloid leukemia undergoing allogeneic hematopoietic stem cell transplantation in complete remission: a systematic review and network meta-analysis

The optimal myeloablative conditioning (MAC) regimens in adult patients with acute myeloid leukemia (AML) undergoing allogeneic hemopoietic stem cell transplantation (allo-HSCT) in complete remission (CR) remain unclear. We performed a systematic review and network meta-analysis to compare the effects of different MAC regimens. Bayesian network meta-analysis was performed using WinBUGS version 1.4.3. The commonly used MAC regimen Bu/Cy (4-day busulfan for toal 16 mg/kg orally or 12.8 mg/kg intravenously, plus 2-day cyclophosphamide for toal 120 mg/kg intravenously) is chosen as the common comparator. Pooled hazard ratios (HRs) with the associated 95% credibility interval (95% CrI) are obtained for all comparisons. We included 19 eligible studies, involving 8104 AML patients and 9 MAC regimens. Compared with Bu/Cy, 3-day busulfan plus fludarabine and thiotepa (Bu3/Flu/TT) is associated with significantly better overall survival (HR, 0.70; 95% CrI, 0.51 to 0.96) and lower risk of relapse (HR, 0.59; 95% CrI, 0.35 to 0.98). Bu3/Flu/TT is also associated with superior overall survival than Cy/TBI (cyclophosphamide plus total body irradiation), and lower risk of relapse than Bu4/Flu (4-day busulfan plus fludarabine). These results suggest that thiotepa-based new MAC regimen Bu3/Flu/TT is associated with improved outcomes in AML patients undergoing allo-HSCT in CR and worth further investigation.

Individualized busulfan dosing improves outcomes compared to fixed-dose administration in pre-transplant minimal residual disease-positive acute myeloid leukemia patients with intermediate-risk undergoing allogeneic stem cell transplantation in CR

Pre-transplant minimal residual disease (MRD) impacts negatively on post-transplant relapse risk in acute myeloid leukemia (AML). Therapeutic drug monitoring by calculating area under the curve (AUC) was developed to optimize busulfan (Bu) exposure. Here, we compared post-transplant outcomes after individualized versus fixed busulfan dosage in intermediate-risk AML who achieved CR prior to allograft focusing on pre-transplant flow-MRD. Eighty-seven patients (median, 56 years) with intermediate-risk AML and pre-transplant flow-MRD ("different from normal") were included. Thirty-two patients received individualized busulfan; 54 fixed dosages. Individualized dosage was adjusted in 25/32 patients: increased, n = 18/25 (72%); decreased: n = 7/25 (28%). After median follow-up of 27 months, we observed lower 3-year relapses (6%, 2%-19% vs. 35%, 23%-49% p = 0.02), improved 3-year leukemia-free survival (LFS) (78%, 54%-91% vs. 55%, 40%-70% p = 0.009) and - overall survival (OS) (82%, 60%-93% vs. 69%, 54%-81% p = 0.05) after individualized compared to fixed Bu. Non-relapsed mortality (NRM) and acute graft versus host disease (GvHD) were not different. In multivariate analysis, fixed Bu showed unfavorable impact on OS (hazard ratio [HR] 4.6, p = 0.044), LFS (HR 3.6, p = 0.018) and relapses (HR 3.6, p = 0.033). Fixed Bu also had unfavorable impact on LFS (3.6, 1.1-12.6, p = 0.041) in pre-transplant MRD-positive patients. Individualized, AUC-based, busulfan is associated with lower relapses in intermediate-risk AML patients allografted in CR and may overcome pre-transplant MRD-positivity.

Busulfan, fludarabine, and melphalan are effective conditioning for pediatric and young adult patients with myeloid malignancies underdoing matched sibling or alternative donor transplantation

BACKGROUND

Allogeneic hematopoietic cell transplantation (allo-HCT) remains a curative option for patients with high-risk myeloid malignancies.

PROCEDURE

We present our 10-year experience (October 2012 to October 2021) of consecutive allo-HCT in patients with myeloid malignancies treated on the pediatric HCT service and conditioned with myeloablative targeted dose-busulfan (BU), fludarabine (FLU), and melphalan (MEL). Twenty-three children, adolescents, and young adult patients (CAYA) (median age 15.4 years) with acute myeloid leukemia (AML, n = 17), myelodysplastic syndrome (MDS, n = 4), or chronic myeloid leukemia (CML, n = 2) underwent allo-HCT post-BU-FLU-MEL. Four patients had treatment-related AML/MDS. Donor/stem cell source was matched sibling donor (MSD) PBSC (n = 7), matched unrelated donor (MUD) PBSC (n = 2), umbilical cord blood (UCB) (n = 3), or haploidentical-BMT (n = 11). Risk stratification was low (n = 2), intermediate (n = 15), high (n = 3), and very high risk (n = 1). The two patients with CML had failed tyrosine kinase inhibitor therapies.

RESULTS

With a median follow-up of 41.6 months, the relapse rate is only 4.5% with an overall survival (OS) 100%, progression-free survival (PFS) 95.5%, and graft-versus-host-free-relapse-free survival (GRFS) 67.8%. The donor source and the acute graft-versus-host disease (GvHD) prophylaxis regimen significantly impacted grade II-IV aGvHD 66.7% versus 19.2% (p = .039) and chronic graft-versus-host-disease (cGvHD) 66.7% versus 0% (p = .002) in the patients receiving MSD or MUD PBSC compared to haplo-BMT, respectively, resulting in improved GRFS in haplo-BMT, 83.3% compared to 40% matched donor peripheral blood stem cell transplant (PBSCT) (p = .025).

CONCLUSIONS

Our results demonstrate that BU-FLU-MEL is efficacious conditioning for disease control in young patients with myeloid malignancies undergoing MSD or alternative donor allo-HCT, but in the setting of PBSC grafts with cyclosporine A-methotrexate (CSA-MTX) GvHD prophylaxis, it results in an unacceptably high incidence of GvHD.

Reduced intensity versus non-myeloablative conditioning regimen for haploidentical transplantation and post-transplantation cyclophosphamide in complete remission acute myeloid leukemia: a study from the ALWP of the EBMT

The optimal conditioning regimen prior haploidentical stem cell transplantation (Haplo-SCT) with post transplantation cyclophosphamide (PT-Cy) for acute myeloid leukemia (AML) remains unknown. A non-myeloablative conditioning (NMAC) regimen (cyclophosphamide + fludarabine + TBI 2 Gy [CyFluTBI]) is a safe approach, but relapse incidence remains high in this setting. Alternatively, a reduced intensity conditioning (RIC) regimen combining thiotepa and reduced-dose busulfan with fludarabine (TBF) may decrease AML relapse. However, an excess of toxicity may counterbalance this potential benefit. We retrospectively compared CyFluTBI vs. TBF in CR AML patients who underwent Haplo-SCT with PT-Cy, in two different populations based on age. We analyzed 490 patients. In patients aged <60 years (n = 203), we observed a higher RI (HR = 3.59, 95% CI = 1.75-7.37, p < 0.01), lower LFS (HR = 1.98, 95% CI = 1.22-3.22, p < 0.01) and lower OS (HR = 1.73, 95% CI = 1.04-2.88, p = 0.04) in the CyFluTBI group, without significant difference in NRM. In older patients (n = 287), we observed that conditioning regimen did not significantly influence LFS (HR = 0.90, 95% CI = 0.56-1.44, p = 0.65), OS (HR = 0.81, 95% CI = 0.49-1.32, p = 0.39) and RI (HR = 1.78, 95% CI = 0.90-3.50, p = 0.10), but showed that CyFluTBI was associated with a significantly lower risk of NRM (HR = 0.48, 95% CI = 0.25-0.92, p = 0.03). Thus, younger patients seem to benefit from conditioning intensification from CyFluTBI to TBF regimens prior PT-Cy Haplo-SCT for CR AML, while older ones do not.

Hemorrhagic cystitis in allogeneic stem cell transplantation: a role for age and prostatic hyperplasia

PURPOSE

Hemorrhagic cystitis (HC) is a frequent complication of allogeneic hematopoietic stem-cell transplantation (HSCT). HC worsens transplant outcomes and patient wellbeing in terms of pain, hospitalization, and need for supportive care. A deeper understanding of the risk factors of HC may lead to more intensive prevention in high-risk patients.

METHODS

In this report, we analyzed 237 consecutive patients who received HSCT with the aim of identifying possible risk factors for HC and their consequences, with a particular focus on transplant- and gender-related risk factors.

RESULTS

HC occurred in 17% of patients, with a higher incidence in males (21% vs 11%, p = 0.03). Risk factors identified for HC included age over 55 years, male recipient, HLA mismatch, reduced intensity conditioning, and cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. Increased HC was seen in patients with grade II-IV acute GVHD and detectable BKV and JCV viruria. In a multivariate model, increased age remained significant (p = 0.013). Patients with HC had longer hospitalizations and increased non-relapse mortality (NRM). Among male recipients, independent risk factors for HC included age (p = 0.016) and prostate volume (p = 0.016). Prostatic hyperplasia (volume more than 40 cm³) occurred in 33% of male patients, of which 32% developed HC (compared with 16% of patients without prostatic hyperplasia; p = 0.032).

CONCLUSIONS

Age is the most important risk factor for HC. Additional potential risk factors include cyclophosphamide-based GVHD prophylaxis and HLA mismatch. Among male recipients, prostatic hyperplasia is an additional independent risk factor. As HC is common and associated with prolonged hospitalization, more intensive prophylactic strategies should be considered in high-risk patients.

Changing trends in the therapy of acute myeloid leukemia

There has been remarkable progress in the treatment of acute myeloid leukemia (AML) which has spanned 5 decades. The changing trends have led to new approaches and significant improvement in outcomes. This review has summarized the historical insights that have shaped the current treatment paradigms of AML.

Is Allogeneic Transplantation an Option in Patients Affected by Concurrent Myelofibrosis and Chronic Myeloid Leukemia (CML)?

Classification of myeloproliferative neoplasms is based on hematologic, histopathologic, and molecular characteristics, including the BCR-ABL1 and JAK2 V617F or MPL and CALR. Although the different gene mutations ought to be mutually exclusive, several cases with co-occurring BCR-ABL1 and JAK2 V617F or CALR have been identified with a frequency of 0.2–2.5% in the European population. The tyrosine kinase abnormalities appeared to affect independent subclones because imatinib mesylate (IM) treatment induced Ph+-CML remission, whereas the JAK2V617F clone either persisted or clinically expanded after a major response of Ph+-clone.

Allogeneic stem cell transplantation is at present the only potentially curative therapy for these patients after therapy with ruxolitinib and TKI inhibitor. We describe the case of 3 young people treated in our institution for the coexistence of BCR/ABL chronic myeloid leukemia and another Philadelphia chromosome-negative (Ph−) Chronic myeloproliferative disease. They received ruxolitinib, imatinib/nilotinib, and allogeneic transplantation with safe and efficient results.

Personalized prediction of overall survival in patients with AML in non-complete remission undergoing allo-HCT

Allogenic hematopoietic stem cell transplantation (allo‐HCT) is the standard treatment for acute myeloid leukemia (AML) in non‐complete remission (non‐CR); however, the prognosis is inconsistent. This study aimed to develop and validate nomograms and a web application to predict the overall survival (OS) of patients with non‐CR AML undergoing allo‐HCT (cord blood transplantation [CBT], bone marrow transplantation [BMT], and peripheral blood stem cell transplantation [PBSCT]). Data from 3052 patients were analyzed to construct and validate the prognostic models. The common significant prognostic factors among patients undergoing allo‐HCT were age, performance status, percentage of peripheral blasts, cytogenetic risk, chemotherapy response, and number of transplantations. The conditioning regimen was a significant prognostic factor only in patients undergoing CBT. Compared with cyclophosphamide/total body irradiation, a conditioning regimen of ≥3 drugs, including fludarabine, with CBT exhibited the lowest hazard ratio for mortality (0.384; 95% CI, 0.266–0.554; p < 0.0001). A conditioning regimen of ≥3 drugs with CBT also showed the best leukemia‐free survival among all conditioning regimens. Based on the results of the multivariable analysis, we developed prognostic models showing adequate calibration and discrimination (the c‐indices for CBT, BMT, and PBSCT were 0.648, 0.600, and 0.658, respectively). Our prognostic models can help in assessing individual risks and designing future clinical studies. Furthermore, our study indicates the effectiveness of multi‐drug conditioning regimens in patients undergoing CBT.

Astaxanthin Relieves Busulfan-Induced Oxidative Apoptosis in Cultured Human Spermatogonial Stem Cells by Activating the Nrf-2/HO-1 pathway

Many child cancer patients endure anticancer therapy containing alkylating agents before sexual maturity. Busulfan (BU), as an alkylating agent, is a chemotherapy drug, causing DNA damage and cytotoxicity in germ cells. In the present study, we aimed to investigate the protective effect of astaxanthin (AST), as a potent antioxidant and powerful reactive oxygen species (ROS) scavenger, on BU-induced toxicity in human spermatogonial stem cells. For this purpose, testes were obtained from four brain-dead donors. After tissue enzymatic digestions, testicular cells were cultured for 3 weeks for spermatogonial stem cell (SSC) isolation and purification. K562 cell line was cultured to survey the effect of AST on cancer treatment. The cultured SSCs and K562 cell line were finally treated with AST (10μM), BU (0.1nM), and AST+BU. The expression of NRF-2, HO-1, SOD2, SOD3, TP53, and apoptotic genes, including CASP9, CASP3, BCL2, and BAX, were assayed using real-time PCR. Moreover, ROS level in different groups and malondialdehyde level and total antioxidant capacity in cell contraction of SSCs were measured using ELISA. Data showed that AST significantly upregulated the expression of NRF-2 gene (P<0.001) and protein (P<0.005) and also significantly decreased the production of BU-induced ROS (P<0.001). AST activated the NRF-2/HO-1 pathway that could remarkably restrain BU-induced apoptosis in SSCs. Interestingly, AST upregulated the expression level of apoptosis genes in the K562 cell line. The results of this study indicated that AST reduces the side effects of BU on SSCs without interference with its chemotherapy effect on cancerous cells through modulation of the NRF-2/HO-1 and mitochondria-mediated apoptosis pathways.

Adding melphalan to fludarabine and a myeloablative dose of busulfan improved survival after allogeneic hematopoietic stem cell transplantation in a propensity score-matched cohort of hematological malignancies

Fludarabine and a myeloablative dose of busulfan (Flu/Bu4) can improve prognosis after allogeneic hematopoietic stem cell transplantation (HSCT) with melphalan (Mel). We investigated the prognostic impact of adding Mel to Flu/Bu4 by comparing between Flu/Bu4/Mel and Flu/Bu4 groups. This study included 846 propensity score (PS)-matched patients who received either Flu/Bu4/Mel (n = 423) or Flu/Bu4 (n = 423) from 2394 patients enrolled in a multicenter prospective registry, from January 2010 to December 2016. The primary endpoint (5-year overall survival [OS]), and the prognostic impact of adding Mel was evaluated using Cox regression analysis. The study population median age was 58 (interquartile 50-64) years and 61.0% were male. Patient characteristics were well-balanced between groups. Five-year OS was 34.2% (95% confidence interval [CI]: 27.3-41.1%) and 30.1% (24.8-35.6%) in the Flu/Bu4/Mel and Flu/Bu4 groups, respectively (log-rank P = 0.019). The adjusted hazard ratio of adding Mel was 0.77 (95% CI: 0.62-0.96) (P = 0.022) for the 5-year OS, and this attributed to a lower incidence of 5-year relapse (0.71, 0.56-0.90, P = 0.005) and relapse associated mortality (0.73, 0.57-0.95, P = 0.018). There was no statistical difference in 5-year non-relapse mortality between groups (log-rank P = 0.855). Flu/Bu4/Mel was associated with better 5-year OS compared to Flu/Bu4 in a PS-matched cohort after allogeneic HSCT.