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).

Post-transplantation cyclophosphamide combined with tacrolimus and low-dose post-engraftment anti-thymoglobulin as GVHD prophylaxis for patients undergoing peripheral blood stem cell transplantation from haploidentical family donor: A single center analysis.

Introduction: Post-transplantation cyclophosphamide (PT-Cy) use is a recent graft-versus-host disease (GVHD) prophylaxis strategy for patients undergoing allogeneic stem cell transplantation (allo-HSCT). PT-Cy combined with two immunosuppressants is now widely used after haplo-identical (haplo) and HLA-matched peripheral blood stem cell (PBSC) transplantations with promising GVHD and relapsefree survival (GRFS) probabilities. Although appealing, these results may benefit from improvement notably outside matched sibling donor transplantation, and should be investigated in various ethnic populations. Methods: Therefore, we report our experience of GVHD prophylaxis regimen combining PT-Cy and tacrolimus with addition of post-engraftment low-dose anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation from haplo-identical donors (Haplo). Sixtyseven patients were included in the analysis. All patients received myeloablative or intensified sequential conditioning regimen. Results: The median follow-up was 521 (range, 10~991) days. The cumulative incidences of 100-day grade II-IV acute GVHD was 14.9±4.4%, and no case of grade III-IV acute GVHD was documented. The cumulative incidences of 2-yearchronic GVHD and moderate-to-severe chronic GVHD were 25.4±5.4% and 11.9±4%, respectively. The non-relapse mortality at day+100 and 2year were 7.5±3.2% and 9.0±3.5%, respectively. The cumulative incidence of relapse at 2year was 16±6.4%. The 2-year probability of DFS and OS were 73.8% (95%CI, 61.5~88.4%) and 72.5% (95% CI, 57.1~92.1%), respectively. The 2-year GRFS was estimated as 63.6% (95%CI, 50.6~80%). Discussion: Our results suggested that a combination of PT-Cy, tacrolimus, and low-dose post-engraftment ATG was a promising GVHD prophylaxis with low incidence of acute GVHD in the haplo-transplantation setting.

Chemotherapy or Allogeneic Stem Cell Transplantation as Salvage Therapy for Patients with Refractory Acute Myeloid Leukemia: A Multicenter Analysis.

INTRODUCTION: The overall outcome of patients with refractory AML (rAML) remains poor. Though allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered as the only curative therapy, it is routinely recommended only for patients after remission with salvage chemotherapy. OBJECTIVE: In this study, we evaluated the impact of salvage chemotherapy or allo-HSCT on the overall outcome in rAML. METHODS: We collected the clinical data of 220 patients from 4 medical centers and performed retrospective analysis of prognosis factors, including salvage chemotherapy, intensity of chemotherapy, and allo-HSCT. RESULTS: A total of 29 patients received allo-HSCT directly without salvage chemotherapy, 26 patients achieved complete remission (CR) or complete remission with incomplete hematological recovery (CRi) after transplantation and 4-year leukemia-free survival (LFS) and overall survival (OS) were 45.0 ± 10.7 and 51.0 ± 10.6%, respectively. Another 191 patients received salvage chemotherapy and 81 (42.2%) achieved CR or CRi. Thirty-four patients among them underwent subsequent allo-HSCT with 4-year LFS and OS of 46.0 ± 8.8 and 46.2 ± 9.0%. The 4-year LFS and OS in 26 patients who failed to obtain CR or CRi but received allo-HSCT with active disease were 32.9 ± 10.0 and 36.9 ± 10.8%, respectively. For patients who received salvage chemotherapy but not allo-HSCT, few of them became long-term survivors. In multivariate analysis, salvage chemotherapy and the intensity of chemotherapy failed to have significant impact on both OS and LFS. Allo-HSCT was the only prognostic factor for improved OS and LFS in multivariate analysis. CONCLUSIONS: These results indicate the benefit of allo-HSCT in patients with rAML and direct allo-HSCT without salvage chemotherapy could be treatment option.

Post-transplantation Cyclophosphamide, Tacrolimus and Low-Dose ATG as GVHD Prophylaxis for Allogeneic Peripheral Stem Cell Transplantation for Adult Patients With Lymphoid Malignancies: A Single Arm Phase II Study.

The PT-Cy was considered as one of the mainstay protocol for graft verus host disease (GVHD) prophylaxis. Recent study demonstrated that PT-Cy combined with other immunosuppressants could further reduce the incidence of GVHD and improve the GVHD and relapse free survival (GRFS). In this prospective phase II study, we evaluated the effect of a new GVHD prophylaxis consist of PT-Cy combined with tacrolimus and low dose anti-thymoglobulin (ATG). A total of 23 patients were enrolled including 20 patients with acute lymphoblastic leukemia (ALL) and three patients with T cell lymphoma. The median age was 29 years (range, 16~58 years). Patients with HLA-matched related donor (MSD, n=7) received PT-Cy combined with tacrolimus, while patients with HLA matched unrelated (MUD, n = 2) or haplo-identical (Haplo, n = 14) donor received additional ATG at 2.5 mg/kg on day 15 or day 22 after engraftment of neutrophils. As to the acute GVHD (aGVHD), only three patients developed grade I (n = 1) or grade II (n = 2) aGVHD with 100-day incidence of all aGVHD and II-IV aGVHD at 13.0 ± 5.1% and 9.1 ± 6.1% respectively. Only two patients had mild and one had moderate chronic GVHD (cGVHD), with 1-year incidence of cGVHD and moderate/severe cGVHD at 15.2 ± 8.7% and 4.6 ± 4.4% respectively. A high incidence of CMV reactivation was documented (14/16 with MUD/Haplo donor and 2/7 with MSD) with only 1 CMV disease documented. There were two EBV reactivation without post-transplantation lymphoproliferative disease (PTLD) documented. With a median follow-up of 303 days (range, 75~700 days), three patients relapsed leading to 1-year cumulative incidence of relapse (CIR) at 12.8 ± 9.2%. Only one patient died of CMV pneumonia on day 91 with both 100-day and 1-year non-relapse mortality (NRM) at 4.6 ± 4.4%. The 1-year overall survival (OS), event-free survival (EFS) and GRFS were 95.5 ± 4.4%, 82.6 ± 9.5%, and 68.0 ± 11.3% respectively. Based on Simon's stage II design, our primary data showed that the PT-Cy+tacrolimus ± ATG protocol was promising in preventing aGVHD and cGVHD, which may translate into low NRM without increased CIR. Further clinical trial with large number of patients should be warranted. This trial was registered at www.clinicaltrials.gov as #NCT04118075.

Low-Dose Decitabine Monotherapy Reverses Mixed Chimerism in Adult Patients After Allogeneic Hematopoietic Stem Cell Transplantation With Myeloablative Conditioning Regimen: A Pilot Phase II Study.

T cell mixed chimerism (MC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) with myeloablative conditioning for hematological malignancies may indicate engraftment failure or disease relapse. Immune modulation, such as donor lymphocyte infusion (DLI) or the rapid tapering-off or stopping of immunosuppressive treatment, can reverse MC to full donor chimerism (FDC). However, the development or aggravation of graft-versus-host disease (GvHD) and the related mortality remain major concerns with immune modulation. In this prospective, single-arm study (NCT03663751), we tested the efficacy and safety of low-dose decitabine (LD-DAC, 5 mg/m2 daily for 5 days and repeated every 6-8 weeks) without immune modulation in the treatment of patients with MC to prevent MC-associated relapse and/or graft failure. A total of 14 patients were enrolled. All the patients received myeloablative conditioning regimens, and MC was documented from day +30 to day +180 after allo-HSCT with a donor chimerism level ranging from 59 to 97% without detectable measurable residual disease (MRD). Eleven patients (78.6%) responded favorably to treatment, showing increased levels of donor chimerism (≥95%), while nine achieved FDC. All of these patients maintained their responses for a median of 11 months (3-22). The three patients who failed to respond favorably eventually either relapsed or experienced graft failure. All three were alive and in remission at the last follow-up after the second allo-HSCT. LD-DAC monotherapy was well tolerated and exerted limited hematological and nonhematological toxicities. New-onset GvHD symptoms were observed only in two patients. Overall, the estimated 2-year overall survival (OS) and event-free survival (EFS) after allo-HSCT were 90.9 ± 8.7% and 67.0 ± 13.7%, respectively. In conclusion, LD-DAC alone could reverse MC in most patients after allo-HSCT with myeloablative conditioning, while those who achieved FDC enjoyed long-term EFS without major complications. Further prospective studies with larger sample sizes are warranted to confirm the benefits of LD-DAC.

FLT3 inhibition upregulates HDAC8 via FOXO to inactivate p53 and promote maintenance of FLT3-ITD+ acute myeloid leukemia.

Internal tandem duplication (ITD) mutations within the FMS-like receptor tyrosine kinase-3 (FLT3) can be found in up to 25% to 30% of acute myeloid leukemia (AML) patients and confer a poor prognosis. Although FLT3 tyrosine kinase inhibitors (TKIs) have shown clinical responses, they cannot eliminate primitive FLT3-ITD+ AML cells, which are potential sources of relapse. Therefore, elucidating the mechanisms underlying FLT3-ITD+ AML maintenance and drug resistance is essential to develop novel effective treatment strategies. Here, we demonstrate that FLT3 inhibition induces histone deacetylase 8 (HDAC8) upregulation through FOXO1- and FOXO3-mediated transactivation in FLT3-ITD+ AML cells. Upregulated HDAC8 deacetylates and inactivates p53, leading to leukemia maintenance and drug resistance upon TKI treatment. Genetic or pharmacological inhibition of HDAC8 reactivates p53, abrogates leukemia maintenance, and significantly enhances TKI-mediated elimination of FLT3-ITD+ AML cells. Importantly, in FLT3-ITD+ AML patient-derived xenograft models, the combination of FLT3 TKI (AC220) and an HDAC8 inhibitor (22d) significantly inhibits leukemia progression and effectively reduces primitive FLT3-ITD+ AML cells. Moreover, we extend these findings to an AML subtype harboring another tyrosine kinase-activating mutation. In conclusion, our study demonstrates that HDAC8 upregulation is an important mechanism to resist TKIs and promote leukemia maintenance and suggests that combining HDAC8 inhibition with TKI treatment could be a promising strategy to treat FLT3-ITD+ AML and other tyrosine kinase mutation-harboring leukemias.

[The clinical evaluation of preemptive treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To retrospectively analyze the effect of preemptive treatment on cytomegalovirus (CMV) infection in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The data of one hundred and three patients who underwent allo-HSCT with preemptive treatment to prevent CMV associated diseases were retrospectively analyzed. Fluorescence quantitative PCR was used to detect CMV-DNA. The incidences of CMV viremia and CMV associated diseases were analyzed. RESULTS: CMV viremia was confirmed 63 times in 51 of the 103 patients. The incidence of CMV viremia was 49.5% and the median time of onset was 40 days after transplantation. All the patients with CMV viremia received preemptive antiviral therapy and 19 of them developed CMV associated diseases, including 14 hemorrhagic cystitis, 3 CMV associated pneumonia and 2 CMV associated enteritis. The total incidence of CMV associated diseases was 18.4%. After treatment with ganciclovir and/or foscarnet, 60 of the 63 times of CMV viremia disappeared. One patient was not included in the analysis because he died of intracranial hemorrhage and GVHD only 3 days after the treatment. The total response rate was 96.8% (60/62). The remaining two cases who did not respond to treatment died of CMV associated pneumonia in combination with acute GVHD. The direct mortality rate of CMV infection was 1.9% (2/103). CONCLUSION: The incidences of CMV viremia and CMV associated diseases do not increase in patients receiving preemptive therapy as compared with those receiving prophylaxis therapy. Preemptive treatment can not only prevent the progression of CMV viremia to CMV associated diseases in majority of the cases but also control CMV associated diseases effectively.

[The role of FDG-PET in staging of lymphoma and evaluation of therapeutic efficiency].

OBJECTIVE: To evaluate the application of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to the staging and detecting residual masses of lymphoma. METHODS: The clinical data of 179 patients with lymphoma were analyzed retrospectively. The results of FDG-PET, computed tomography (CT) and bone marrow biopsy (BMB) were compared for detection of lymph node/extranodal lymphoid tissue and bone marrow infiltration. Therapeutic efficiency was assessed by International Workshop Criteria (IWC) and Revised Integrated International Workshop Criteria (IWC + PET). RESULTS: In the detection of 286 disease focuses in 98 patients before chemotherapy, the sensitivities of FDG-PET and CT were 73% and 70% (P < 0.01) in detecting nodal focus,and 87% and 45% (P < 0.01) in detecting extranodal lymphoma respectively. In detection of 104 lesions in 81 patients after chemotherapy,the sensitivities of FDG-PET and CT were 81% and 55% respectively (P < 0.01), and the specificities were 68% and 33%, respectively (P < 0.01) in detecting residual masses. According to IWC criteria, 33 patients achieved complete response/unconfirmed complete response (CR/CRu) , and 8 (24%) relapsed. Patients with PET-positive residual masses had a relapse rate of 40%, whereas only 21% of those with no such masses relapsed. Based on IWC + PET criteria, 25 patients achieved CR, with a relapse rate of 20%. Both FDG-PET and BMB produced positive results in 133/179 (74%) patients. Twenty-two patients with positive FDG-PET results were not detected by BMB. The sensitivities and specificities of FDG-PET for BM infiltration were 52% and 83%, respectively. CONCLUSIONS: FDG-PET is a high sensitive and specific technique in staging and detecting residual masses of lymphoma.

[Allogeneic hematopoietic stem cell transplantation following reduced intensity conditioning regimen for treatment of refractory leukemia].

OBJECTIVE: To evaluate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) following reduced intensity conditioning (RIC) regimen for treatment of refractory leukemia. METHODS: Twenty patients with refractory leukemia received allo-HSCT following RIC regimen consisting of fludarabine plus small or moderate dose total body irradiation (TBI). Graft versus host disease (GVHD) prophylaxis was CsA plus mycophenolate mofetil (MMF) or short-term MTX, or these three drugs combination; CD25 monoclone antibody(McAb) and ATG were also used in some of the patients. RESULTS: Seventeen patients engrafted successfully, the median time for ANC > 0.5 x 10(9)/L was 13 (11 - 17) days, and for BPC > 50 x 10(9)/L 19 (12 -42) days. Detected by short tandem repeat (STR)-PCR, complete donor chimerism was confirmed in 16 patients with a median of 14 (7 -35) days. The incidence of acute and chronic GVHD was 47.1% (8/17) and 38.5% (5/13) respectively. The transplant related mortality (TRM) was 25.0% (5/20), mainly from graft failure, intracranial hemorrhage and severe infection. Up to now, 7 patients relapsed and 9 were alive with leukemia free. The overall survival (OS) at 2 year was (35. 3 +/- 14.2)% for all patients and (52.5 +/- 18.6)% for acute non-lymphocytic leukemia (ANLL) patients. CONCLUSION: Allo-HSCT following fludarabine and TBI based RIC regimen can be used for treatment of refractory leukemia with well tolerance and low TRM and there is a better prognosis for ANLL patients than that for acute lymphocytic leukemia patients.

[Clinical significance of dynamic monitoring of cell chimerism following allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To evaluate the relationship of chimerism status of cell subsets with engraftment, occurrence of acute graft versus host disease (aGVHD), graft rejection and disease relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Chimerism status in peripheral blood (PB) and bone marrow (BM) of 65 patients received allo-HSCT were monitored at regular intervals post-transplant. Fluorescence-activated cell sorter (FACS) was used to sort CD3(+)T lymphocytes in 65 cases, CD3(-)CD56(+)CD16(+)NK cells in 52 cases, CD15(+) granulocytes in 32 cases and CD19(+)B lymphocytes in 20 cases post transplants. The chimerism status of different lineage cells was analyzed by polymerase chain reaction amplification of short tandem repeats (PCR-STR). RESULTS: On day +7, NK-cells donor chimerism (DC 55.5%) was higher than other cell subsets. T lymphocyte was the latest one to reach complete donor chimerism (CDC) with a median on day +21. Patients whose T lymphocytes donor chimerism was more than 70% on day +7 and more than 95% on day +14 had a high risk for acute aGVHD. In all cases except those with ALL, the decreased DC of T lymphocytes were observed before molecular or hematological relapse occurred. CONCLUSION: Serial and quantitative T cell chimerism analysis provides a reliable and rapid screening method for the early detection of engraftment, graft rejection, disease relapse and occurrence of aGVHD, therefore, is a prognostic tool to identify patients at high risk of aGVHD and disease relapse following allo-HSCT.

[Prognostic factor analysis of 77 old patients with acute myelogenous leukemia].

BACKGROUND & OBJECTIVE: The manifestations of old acute myelogenous (AML) patients have their special biological and clinical characteristics, with lower response rate to therapy and shorter survival time. This study was to investigate the prognostic factors of elderly patients with AML retrospectively. METHODS: 77 patients aged> or =60 years with AML from 1994 to 2005 were admitted to our study and all the possible prognostic factors were analyzed with Kaplan-Meier survival analysis. The significant factors were further analyzed by Cox proportional hazard model analysis. RESULTS: Seventy-two patients were evaluated. The patients aged 60-70 (median survival time was 350 days) had significantly longer survival time than those aged more than 70 (median survival time is 60 days)(P<0.001), which their CR ratios were 71.4% and 29.4% (P=0.001). The patients with performance status 0 or 1 (median survival time was 402 days) had significantly longer survival time than those with performance status 2, 3 or 4 (median survival time was 31 days)(P<0.001), which their CR ratios were 75% and 15% (P<0.001). The patients with primary AML (median survival time was 98 days) had significantly longer survival time than those with secondary AML (median survival time was 32 days)(P=0.007), which their CR ratios were 50% and 0% (P=0.023). The patients treated with sub-standard dosage of anthracycline (median survival time was 293 days) had significantly longer survival time than those treated with reduced dosage of anthracycline (median survival time was 35 days)(P=0.006), which their CR ratios were 63.6% and 33.3% (P=0.02). The patients with bone marrow blast cell ratio< or =50% (median survival time was 98 days ) had significantly longer survival time than those with bone marrow blast cell ratio >50% (median survival time was 55 days)(P=0.006). The patients with favorable karyotype (median survival time was 293 days) had significantly longer survival time than those with unfavorable or normal karyotype (median survival time was 31 days)(P=0.005). The patients without CD34 expression (median survival time was 201 days) had significantly longer survival time than those with CD34 expression(median survival time was 36 days)(P<0.001). The patients with the peripheral blood white blood cell count (PBWBC)>10x10(9)/L (50%) had significantly higher CR ratio than those with PBWBC< or =10x10(9)/L (25%)(P=0.043). The patients received chemotherapy (50%) had significantly higher CR ratio than those received supportive therapy (0%)(P=0.001). In the stepwise COX proportional hazard regression model, all the seven factors related to OS remained independent and significant. CONCLUSIONS: Factors, including age >70, PS 2 to 4, percentage of blasts in bone marrow >50%, secondary AML, unfavorable karyotype, expression of CD34, lower dosage.