Allogeneic stem cell transplantation for advanced acute promyelocytic leukemia in the ATRA and ATO era

The role of allogeneic stem cell transplant in advanced acute promyelocytic leukemia patients who received standard first- and second-line therapy is still unknown. We report the outcome of 31 acute promyelocytic leukemia patients (median age 39 years) who underwent allogeneic transplant in second remission (n=15) or beyond (n=16). Sixteen patients were real-time polymerase chain reaction positive and 15 negative for PML/RARA pre-transplant. The 4-year overall survival was 62% and 31% for patients transplanted in second remission and beyond, respectively (P=0.05), and 64% and 27% for patients with pre-transplant negative and positive real-time polymerase chain reaction, respectively (P=0.03). The 4-year cumulative incidence of relapse was 32% and 44% for patients transplanted in second remission and beyond, respectively (P=0.37), and 30% and 47% for patients transplanted with negative and positive real-time polymerase chain reaction, respectively (P=0.30). Transplant-related mortality was 19.6%. In conclusion, allogeneic transplant is effective in advanced acute promyelocytic leukemia in the all-trans-retinoic acid and arsenic trioxide era, and should be considered once relapse is diagnosed.Key words: allogeneic stem cell transplant, acute promyelocytic leukemia, acute promyelocytic leukemia relapse, alltrans retinoic acid, arsenic trioxide     

Monosomal karyotype as an adverse prognostic factor in patients with acute myeloid leukemia treated with allogeneic hematopoietic stem-cell transplantation in first complete remission: a retrospective survey on behalf of the ALWP of the EBMT

Despite the overall benefit from allogeneic hematopoietic stem cell transplantation observed in patients with poor cytogenetic risk acute myeloid leukemia in first complete remission, the precise effect of this procedure for different poor-risk subtypes has not been fully analyzed. This retrospective analysis was performed to investigate whether allogeneic hematopoietic stem cell transplantation performed in first complete remission in patients with monosomal karyotype can overcome the adverse prognosis associated with these patients. Of the 4635 patients included in the study, 189 (4%) harbored a monosomal karyotype. The presence of a monosomal karyotype was associated with a worse outcome, with an inferior leukemia-free survival and overall survival (5-year leukemia-free survival and overall survival: 24±3% and 26±3% vs. 53±1% and 57±1% in monosomal-karyotype and non-monosomal-karyotype, respectively; P<0.0001) and higher relapse risk after transplantation (cumulative incidence of relapse at 5 years: 56±4% in monosomal-karyotype vs. 28±1% in non-monosomal-karyotype; P<0.0001). The adverse negative impact of monosomal karyotype cytogenetics was confirmed in the entire cohort in a multivariate analysis [Hazard Ratio (HR): 1.88, 95% Confidence Interval (CI):1.29–2.73, P=0.001 for relapse incidence; HR:1.71, 95%CI:1.27–2.32, P<0.0001 for leukemia-free survival; HR:1.81, 95%CI:1.32–2.48, P=0.0002 for overall survival], and was independent of the presence of other poor-risk cytogenetic subtypes. In summary, monosomal karyotype arises as a strong negative prognostic feature in acute myeloid leukemia also in patients who undergo allogeneic hematopoietic stem cell transplantation in first complete remission, stressing the need to develop additional pre- and post-transplantation strategies aimed at improving overall results. Nonetheless, allogeneic hematopoietic stem cell transplantation in early phase is currently the best therapy for this very poor-risk acute myeloid leukemia subtype.     

Comparison of genetic and clinical aspects in patients with acute myeloid leukemia and myelodysplastic syndromes all with more than 50% of bone marrow erythropoietic cells

Background

The World Health Organization separates acute erythroid leukemia (erythropoiesis in ≥50% of nucleated bone marrow cells; ≥20% myeloblasts of non-erythroid cells) from other entities with increased erythropoiesis – acute myeloid leukemia with myelodysplasia-related changes (≥20% myeloblasts of all nucleated cells) or myelodysplastic syndromes – and subdivides acute erythroid leukemia into erythroleukemia and pure erythroid leukemia subtypes. We aimed to investigate the biological/genetic justification for the different categories of myeloid malignancies with increased erythropoiesis (≥50% of bone marrow cells).

Design and Methods

We investigated 212 patients (aged 18.5–88.4 years) with acute myeloid leukemia or myelodysplastic syndromes characterized by 50% or more erythropoiesis: 108 had acute myeloid leukemia (77 with acute erythroid leukemia, corresponding to erythroid/myeloid erythroleukemia, 7 with pure erythroid leukemia, 24 with acute myeloid leukemia with myelodysplasia-related changes) and 104 had myelodysplastic syndromes. Morphological and chromosome banding analyses were performed in all cases; subsets of cases were analyzed by polymerase chain reaction and immunophenotyping.

Results

Unfavorable karyotypes were more frequent in patients with acute myeloid leukemia than in those with myelodysplastic syndromes (42.6% versus 13.5%; P<0.0001), but their frequency did not differ significantly between patients with acute erythroid leukemia (39.0%), pure erythroid leukemia (57.1%), and acute myeloid leukemia with myelodysplasia-related changes (50.0%). The incidence of molecular mutations did not differ significantly between the different categories. The 2-year overall survival rate was better for patients with myelodysplastic syndromes than for those with acute myeloid leukemia (P<0.0001), without significant differences across the different acute leukemia subtypes. The 2-year overall survival rate was worse in patients with unfavorable karyotypes than in those with intermediate risk karyotypes (P<0.0001). In multivariate analysis, only myelodysplastic syndromes versus acute myeloid leukemia (P=0.021) and cytogenetic risk category (P=0.002) had statistically significant effects on overall survival.

Conclusions

The separation of acute myeloid leukemia and myelodysplastic syndromes with 50% or more erythropoietic cells has clinical relevance, but it might be worth discussing whether to replace the subclassifications of different subtypes of acute erythroid leukemia and acute myeloid leukemia with myelodysplasia-related changes by the single entity, acute myeloid leukemia with increased erythropoiesis ≥50%.     

Prognosis of patients with core binding factor acute myeloid leukemia after first relapse

Core binding factor acute myeloid leukemia is known to have a favorable prognosis, however, there have been no detailed analyses on prognostic factors after first relapse. Using a nationwide database, we retrospectively analyzed core binding factor acute myeloid leukemia patients who relapsed after being treated with chemotherapy alone during their first complete remission. Of a total of 397 patients who were diagnosed with core binding factor acute myeloid leukemia, 208 experienced a first relapse, and analyses were performed in 139 patients for whom additional data were available. In the entire cohort, the overall survival rate after relapse was 48% at 3 years. By multivariate analysis, younger age at diagnosis, a longer interval before relapse, and inv(16) were shown to be independently associated with better survival after relapse. Although there was no significant difference in survival after relapse between patients who underwent allogeneic hematopoietic cell transplantation and those who did not in the overall series of relapsed patients, we found that transplantation significantly improved survival among patients who had t(8;21) (54% versus 26% at 3 years, P=0.002). In addition, among patients with t(8;21), those who had different cytogenetics at relapse had a significantly improved survival after transplantation, while those who had same cytogenetics did not. We showed that the prognosis differs significantly and optimal treatment strategies may vary between groups of patients with core binding factor acute myeloid leukemia with different cytogenetic profiles at relapse. These findings may help to guide therapeutic decisions after first relapse.     

Gemtuzumab ozogamicin in combination with vorinostat and azacitidine in older patients with relapsed or refractory acute myeloid leukemia: a phase I/II study

Epigenetic therapeutics such as the histone deacetylase inhibitor, vorinostat, and the DNA methyltransferase I inhibitor, azacitidine, enhance gemtuzumab ozogamicin efficacy in vitro. We therefore investigated vorinostat/azacitidine/gemtuzumab ozogamicin in 52 adults aged 50 years or over with acute myeloid leukemia requiring therapy for first relapse (remission duration ≤12 months) or primary refractory disease in a phase I/II trial. Vorinostat and gemtuzumab ozogamicin were escalated step-wise during the phase I portion of the trial. Vorinostat (400 mg/day orally from Days 1–9), azacitidine (75 mg/m²/day intravenously or subcutaneously from Days 1–7), and gemtuzumab ozogamicin (3 mg/m²/day intravenously on Days 4 and 8) were identified as the maximum tolerated dose. Among the 43 patients treated at this dose, 10 achieved a complete remission and 8 achieved a complete remission with incomplete blood count recovery, for an overall response rate of 41.9% (exact 95% confidence interval (CI): 27.0–57.9%). Four of these 18 patients (2 with complete remission and 2 with complete remission with incomplete blood count recovery) had persistence of minimal residual disease by flow cytometry at the time of best response. Four patients died within 28 days of treatment initiation. Median overall survival for the 18 patients achieving complete remission/complete remission with incomplete blood count recovery was significantly longer than for those 21 patients who failed therapy but lived at least 29 days after treatment initiation (224.5 days (range 70–798) vs. 95 days (range 36–900); P=0.0023). These data indicate that vorinostat/azacitidine/gemtuzumab ozogamicin has activity in this difficult-to-treat acute myeloid leukemia patient subset. (ClinicalTrials.gov: identifier 00895934).     

Influence of molecular subgroups on outcome of acute myeloid leukemia with normal karyotype in 141 patients undergoing salvage allogeneic stem cell transplantation in primary induction failure or beyond first relapse

Based on molecular aberrations, in particular the NPM1 mutation (NPM1^mut) and the FLT3 internal tandem duplication (Flt3-ITD), prognostic subgroups have been defined among patients with acute myeloid leukemia with normal karyotype. Whereas these subgroups are known to play an important role in outcome in first complete remission, and also in the indication for allogeneic stem cell transplantation, data are limited on their role after transplantation in advanced disease. To evaluate the role of molecular subgroups of acute myeloid leukemia with normal karyotype after allogeneic stem cell transplantation beyond first complete remission, we analyzed the data from 141 consecutive adults (median age: 51.0 years, range 18.4-69.3 years) who had received an allogeneic transplant either in primary induction failure or beyond first complete remission. A sequential regimen of cytoreductive chemotherapy (fludarabine, high-dose AraC, amsacrine) followed by reduced intensity conditioning (FLAMSA-RIC), was uniformly used for conditioning. After a median follow up of three years, overall survival from transplantation was 64±4%, 53±4% and 44±5% at one, two and four years, respectively. Forty patients transplanted in primary induction failure achieved an encouraging 2-year survival of 69%. Among 101 patients transplanted beyond first complete remission, 2-year survival was 81% among patients with the NPM1^mut/FLT3^wt genotype in contrast to 43% in other genotypes. Higher numbers of transfused CD34⁺ cells (hazard ratio 2.155, 95% confidence interval 0.263-0.964, P=0.039) and favorable genotype (hazard ratio 0.142, 95% confidence interval: 0.19-0.898, P=0.048) were associated with superior overall survival in multivariate analysis. In conclusion, patients with acute myeloid leukemia with normal karyotype can frequently be rescued after primary induction failure by allogeneic transplantation following FLAMSA-RIC. The prognostic role of NPM1^mut/FLT3-ITD based subgroups was carried through after allogeneic stem cell transplantation beyond first complete remission.     

Reduced-toxicity conditioning prior to allogeneic stem cell transplantation improves outcome in patients with myeloid malignancies

The introduction of reduced intensity/toxicity conditioning regimens has allowed allogeneic hematopoietic cell transplantation to be performed in patients who were previously considered too old or otherwise unfit. Although it led to a reduction in non-relapse mortality, disease control remains a major challenge. We studied the outcome of 165 patients with acute myeloid leukemia (n=124) or myelodysplastic syndrome (n=41) transplanted after conditioning with fludarabine (30 mg/m²/day for 5 days), intravenous busulfan (either 260 mg/m²: reduced intensity conditioning, or 390–520 mg/m²: reduced toxicity conditioning), and rabbit anti-thymoglobulin (2.5 mg/kg/day for 2 days). The median age of the patients at transplantation was 56.8 years. The 2-year relapse incidence was 29% (23% versus 39% for patients transplanted in first complete remission and those transplanted beyond first complete remission, respectively; P=0.008). The 2-year progression-free survival rate was 57% (95% CI: 49.9–65). It was higher in the groups with favorable or intermediate cytogenetics than in the group with unfavorable cytogenetics (72.7%, 60.5%, and 45.7%, respectively; P=0.03). The cumulative incidence of grades 2–4 and 3–4 acute graft-versus-host disease at day 100 was 19.3% and 7.9%, respectively. The cumulative incidence of chronic graft-versus-host disease at 1 year was 21.6% (severe forms: 7.8%). Non-relapse mortality at 1 year reached 11%. The 2-year overall survival rate was 61.8% (95% CI: 54.8–69.7). Unfavorable karyotype and disease status beyond first complete remission were associated with a poorer survival. This well-tolerated conditioning platform can lead to long-term disease control and offers possibilities of modulation according to disease stage or further development.     

Tyrosine kinase inhibitors improve long-term outcome of allogeneic hematopoietic stem cell transplantation for adult patients with Philadelphia chromosome positive acute lymphoblastic leukemia

This study aimed to determine the impact of tyrosine kinase inhibitors given pre- and post-allogeneic stem cell transplantation on long-term outcome of patients allografted for Philadelphia chromosome-positive acute lymphoblastic leukemia. This retrospective analysis from the EBMT Acute Leukemia Working Party included 473 de novo Philadelphia chromosome-positive acute lymphoblastic leukemia patients in first complete remission who underwent an allogeneic stem cell transplantation using a human leukocyte antigen-identical sibling or human leukocyte antigen-matched unrelated donor between 2000 and 2010. Three hundred and ninety patients received tyrosine kinase inhibitors before transplant, 329 at induction and 274 at consolidation. Kaplan-Meier estimates of leukemia-free survival, overall survival, cumulative incidences of relapse incidence, and non-relapse mortality at five years were 38%, 46%, 36% and 26%, respectively. In multivariate analysis, tyrosine-kinase inhibitors given before allogeneic stem cell transplantation was associated with a better overall survival (HR=0.68; P=0.04) and was associated with lower relapse incidence (HR=0.5; P=0.01). In the post-transplant period, multivariate analysis identified prophylactic tyrosine-kinase inhibitor administration to be a significant factor for improved leukemia-free survival (HR=0.44; P=0.002) and overall survival (HR=0.42; P=0.004), and a lower relapse incidence (HR=0.40; P=0.01). Over the past decade, administration of tyrosine kinase inhibitors before allogeneic stem cell transplantation has significantly improved the long-term allogeneic stem cell transplantation outcome of adult Philadelphia chromosome-positive acute lymphoblastic leukemia. Prospective studies will be of great interest to further confirm the potential benefit of the prophylactic use of tyrosine kinase inhibitors in the post-transplant setting.     

Hematopoietic stem cell transplantation for children with high-risk acute lymphoblastic leukemia in first complete remission: a report from the AIEOP registry

Children with high-risk acute lymphoblastic leukemia in first complete remission can benefit from allogeneic hematopoietic stem cell transplantation. We analyzed the outcome of 211 children with high-risk acute lymphoblastic leukemia in first complete remission who were given an allogeneic transplant between 1990 and 2008; the outcome of patients who, despite having an indication for transplantation and a suitable donor, did not receive the allograft for different reasons in the same time period was not analyzed. Sixty-nine patients (33%) were transplanted between 1990 and 1999, 58 (27%) between 2000 and 2005, and 84 (40%) between 2005 and 2008. A matched family donor was employed in 138 patients (65%) and an unrelated donor in 73 (35%). The 10-year probabilities of overall and disease-free survival were 63.4% and 61%, respectively. The 10-year cumulative incidences of transplantation-related mortality and relapse were 15% and 24%, respectively. After 1999, no differences in either disease-free survival or transplant-related mortality were observed in patients transplanted from unrelated or matched family donors. In multivariate analysis, grade IV acute graft-versus-host disease was an independent factor associated with worse disease-free survival. By contrast, grade I acute graft-versus-host disease and age at diagnosis between 1 and 9 years were favorable prognostic variables. Our study, not intended to evaluate whether transplantation is superior to chemotherapy for children with acute lymphoblastic leukemia in first complete remission and high-risk features, shows that the allograft cured more than 60% of these patients; in the most recent period, the outcome of recipients of grafts from matched family and unrelated donors was comparable.     

The role of matched sibling donor allogeneic stem cell transplantation in pediatric high-risk acute myeloid leukemia: results from the AML-BFM 98 study

Background

The role of allogeneic stem cell transplantation in post-remission management of children with high-risk acute myeloid leukemia remains controversial. In the multi-center AML-BFM 98 study we prospectively evaluated the impact of allogeneic stem cell transplantation in children with high-risk acute myeloid leukemia in first complete remission.

Design and Methods

HLA-typed patients with high-risk acute myeloid leukemia, who achieved first complete remission (n=247), were included in this analysis. All patients received double induction and consolidation. Based on the availability of a matched-sibling donor, patients were allocated by genetic chance to allogeneic stem cell transplantation (n=61) or chemotherapy-only (i.e. intensification and maintenance therapy; n=186). The main analysis was done on an intention-to-treat basis according to this allocation.

Results

Intention-to-treat analysis did not show a significantly different 5-year disease-free survival (49±6% versus 45±4%, P_{log rank}=0.44) or overall survival (68±6% versus 57±4%, P_{log rank}=0.17) between the matched-sibling donor and no-matched-sibling donor groups, whereas late adverse effects occurred more frequently after allogeneic stem cell transplantation (72.5% versus 31.8%, P_Fischer<0.01). These results were confirmed by as-treated analysis corrected for the time until transplantation (5-year overall survival: 72±8% versus 60±4%, P_Mantel-Byar 0.21). Subgroup analysis demonstrated improved survival rates for patients with 11q23 aberrations allocated to allogeneic stem cell transplantation (5-year overall survival: 94±6% versus 52±7%, P_log-rank=0.01; n=18 versus 49) in contrast to patients without 11q23 aberrations (5-year overall survival: 58±8% versus 55±5%, P_log-rank=0.66).

Conclusions

Our analyses defined a genetic subgroup of children with high-risk acute myeloid leukemia who benefited from allogeneic stem cell transplantation in the prospective multi-center AML-BFM 98 study. For the remainder of the pediatric high-risk acute myeloid leukemia patients the prognosis was not improved by allogeneic stem cell transplantation, which was, however, associated with a higher rate of late sequelae.     

Prognostic factors and outcomes of adult patients with acute myeloid leukemia after first relapse

Background

Patients with acute myeloid leukemia who are treated with conventional chemotherapy still have a substantial risk of relapse; the prognostic factors and optimal treatments after relapse have not been fully established. We, therefore, retrospectively analyzed data from patients with acute myeloid leukemia who had achieved first complete remission to assess their prognosis after first relapse.

Design and Methods

Clinical data were collected from 70 institutions across the country on adult patients who were diagnosed with acute myeloid leukemia and who had achieved a first complete remission after one or two courses of induction chemotherapy.

Results

Among the 1,535 patients who were treated with chemotherapy alone, 1,015 relapsed. Half of them subsequently achieved a second complete remission. The overall survival was 30% at 3 years after relapse. Multivariate analysis showed that achievement of second complete remission, salvage allogeneic hematopoietic cell transplantation, and a relapse-free interval of 1 year or longer were independent prognostic factors. The outcome after allogeneic transplantation in second complete remission was comparable to that after transplantation in first complete remission. Patients with acute myeloid leukemia and cytogenetic risk factors other than inv(16) or t(8;21) had a significantly worse outcome when they did not undergo salvage transplantation even when they achieved second complete remission.

Conclusions

We found that both the achievement of second complete remission and the application of salvage transplantation were crucial for improving the prognosis of patients with acute myeloid leukemia in first relapse. Our results indicate that the optimal treatment strategy after first relapse may differ according to the cytogenetic risk.     

Factors predicting long-term survival after T-cell depleted reduced intensity allogeneic stem cell transplantation for acute myeloid leukemia

Background

Reduced intensity conditioning regimens permit the delivery of a potentially curative graft-versus-leukemia effect in older patients with acute myeloid leukemia. Although T-cell depletion is increasingly used to reduce the risk of graft-versus-host disease its impact on the graft-versus-leukemia effect and long-term outcome post-transplant is unknown.

Design and Methods

We have characterized pre- and post-transplant factors determining overall survival in 168 patients with acute myeloid leukemia transplanted using an alemtuzumab based reduced intensity conditioning regimen with a median duration of follow-up of 37 months.

Results

The 3-year overall survival for patients transplanted in CR1 or CR2/CR3 was 50% (95% CI, 38% to 62%) and 44% (95% CI, 31% to 56%), respectively compared to 15% (95% CI, 2% to 36%) for patients with relapsed/refractory disease. Multivariate analysis demonstrated that both survival and disease relapse were influenced by status at transplant (P=0.008) and presentation cytogenetics (P=0.01). Increased exposure to cyclosporine A (CsA) in the first 21 days post-transplant was associated with an increased relapse risk (P<0.0001) and decreased overall survival (P<0.0001).

Conclusions

Disease stage, presentation karyotype and post-transplant CsA exposure are important predictors of outcome in patients undergoing a T-cell depleted reduced intensity conditioning allograft for acute myeloid leukemia. These data confirm the presence of a potent graft-versus-leukemia effect after a T-cell depleted reduced intensity conditioning allograft in acute myeloid leukemia and identify CsA exposure as a manipulable determinant of outcome in this setting.     

Results from a clofarabine-busulfan-containing,reduced-toxicity conditioning regimen prior to allogeneic stem cell transplantation: the phase 2 prospective CLORIC trial

We prospectively evaluated the safety and efficacy of a clofarabine, intravenous busulfan and antithymocyte globulin-based reduced-toxicity conditioning (CloB2A2) regimen before allogeneic stem cell transplantation. Thirty high-risk patients (median age: 59 years; acute myeloid leukemia n=11, acute lymphoblastic leukemia n=13; myelodysplastic syndrome n=5, bi-phenotypic leukemia n=1) were included in this phase 2 study. At time of their transplant, 20 and seven patients were in first and second complete remission, respectively, while three patients with myelodysplastic syndrome were responding to chemotherapy or who had not been previously treated. The CloB2A2 regimen consisted of clofarabine 30 mg/m²/day for 4 days, busulfan 3.2 mg/kg/day for 2 days and antithymocyte globulin 2.5 mg/kg/day for 2 days. The median follow-up was 23 months. Engraftment occurred in all patients. The 1-year overall survival, leukemia-free survival, relapse incidence and non-relapse mortality rates were 63±9%, 57±9%, 40±9%, and 3.3±3%, respectively. Comparing patients with acute myeloid leukemia/myelodysplastic syndrome versus those with acute lymphoblastic leukemia/bi-phenotypic leukemia, the 1-year overall and leukemia-free survival rates were 75±10% versus 50±13%, respectively (P=0.07) and 69±12% versus 43±13%, respectively (P=0.08), while the 1-year relapse incidence was 25±11% versus 57±14%, respectively (P=0.05). The CloB2A2 regimen prior to allogeneic stem cell transplantation is feasible, allowing for full engraftment and low toxicity. Disease control appears to be satisfactory, especially in patients with acute myeloid leukemia/myelodysplastic syndrome. The trial was registered at www.clinicaltrials.gov no. {"type":"clinical-trial","attrs":{"text":"NCT00863148","term_id":"NCT00863148"}}NCT00863148.     

Non-myeloablative conditioning with allogeneic hematopoietic cell transplantation for the treatment of high-risk acute lymphoblastic leukemia

Background

Allogeneic hematopoietic cell transplantation is a potentially curative treatment for patients with acute lymphoblastic leukemia. However, the majority of older adults with acute lymphoblastic leukemia are not candidates for myeloablative conditioning regimens. A non-myeloablative preparative regimen is a reasonable treatment option for this group. We sought to determine the outcome of non-myeloablative conditioning and allogeneic transplantation in patients with high-risk acute lymphoblastic leukemia.

Design and Methods

Fifty-one patients (median age 56 years) underwent allogeneic hematopoietic cell transplantation from sibling or unrelated donors after fludarabine and 2 Gray total body irradiation. Twenty-five patients had Philadelphia chromosome-positive acute lymphoblastic leukemia. Eighteen of these patients received post-grafting imatinib.

Results

With a median follow-up of 43 months, the 3-year overall survival was 34%. The 3-year relapse/progression and non-relapse mortality rates were 40% and 28%, respectively. The cumulative incidences of grades II and III-IV acute graft-versus-host disease were 53% and 6%, respectively. The cumulative incidence of chronic graft-versus-host disease was 44%. Hematopoietic cell transplantation in first complete remission and post-grafting imatinib were associated with improved survival (P=0.005 and P=0.03, respectively). Three-year overall survival rates for patients with Philadelphia-negative acute lymphoblastic leukemia in first remission and beyond first remission were 52% and 8%, respectively. For patients with Philadelphia chromosome-positive acute lymphoblastic leukemia in first remission who received post-grafting imatinib, the 3-year overall survival rate was 62%; for the subgroup without evidence of minimal residual disease at transplantation, the overall survival was 73%.

Conclusions

For patients with high-risk acute lymphoblastic leukemia in first complete remission, non-myeloablative conditioning and allogeneic hematopoietic cell transplantation, with post-grafting imatinib for Philadelphia chromosome-positive disease, can result in favorable long-term survival. (Clinicaltrials.gov identifier: NCT0036738)     

Treatment and outcomes for chronic myelomonocytic leukemia compared to myelodysplastic syndromes in older adults

Prior studies have investigated patients'' characteristics, treatments, and outcomes for older adults with myelodysplastic syndromes, but most failed to distinguish chronic myelomonocytic leukemia. Recognizing potentially important differences between the diseases, we undertook a population-based comparison of baseline characteristics, treatments, and outcomes between older adults with chronic myelomonocytic leukemia and myelodysplastic syndromes. The patients'' data were obtained from Surveillance Epidemiology and End Results registry data from 2001-2005, linked to Medicare claims. Baseline characteristics, treatment (red blood cell transfusions, hematopoietic growth factors, hypomethylating agents, chemotherapy or transplantation), progression to acute myeloid leukemia, and overall survival were compared using bivariate techniques. Multivariate logistic regression estimated differences in treatments received. Cox proportional hazard models estimated the effects of chronic myelomonocytic leukemia relative to myelodysplastic syndromes on progression-free survival. A larger proportion of patients with chronic myelomonocytic leukemia (n=792), compared to patients with myelodysplastic syndromes (n=7,385), failed to receive any treatment (25% versus 15%; P<0.0001), or only received red blood cell transfusions (19.8% versus 16.7%; P=0.037). A larger percentage of patients with chronic myelomonocytic leukemia progressed to acute myeloid leukemia (42.6% versus 15.5%, respectively; P<0.0001), with shorter time to progression. Chronic myelomonocytic leukemia patients had a shorter median survival (13.3 versus 23.3 months; P<0.0001) and lower 3-year survival rate (19% versus 36%; P<0.0001). Adjusted estimates, controlling for baseline characteristics and selected treatments, indicate that chronic myelomonocytic leukemia was associated with an increased risk of progression to acute myeloid leukemia or death (HR 2.22; P<0.0001), compared to myelodysplastic syndromes. In conclusion, chronic myelomonocytic leukemia is less frequently treated in older adults and is associated with worse outcomes, even after controlling for the patients'' baseline characteristics and selected treatments. Our data suggest the need for continued evaluation of the biological differences between these diseases and clinical trials targeting chronic myelomonocytic leukemia.     

Digital droplet PCR-based absolute quantification of pre-transplant <Emphasis Type="Italic">NPM1</Emphasis> mutation burden predicts relapse in acute myeloid leukemia patients

Allogeneic hematopoietic stem cell transplantation is an established consolidation therapy for patients with acute myeloid leukemia. However, relapse after transplantation remains a major clinical problem resulting in poor prognosis. Thus, detection of measurable (“minimal”) residual disease to identify patients at high risk of relapse is essential. A feasible method to determine measurable residual disease may be digital droplet PCR (ddPCR) that allows absolute quantification with high sensitivity and specificity without the necessity of standard curves. Using ddPCR, we analyzed pre-transplant peripheral blood and bone marrow of 51 NPM1-mutated acute myeloid leukemia patients transplanted in complete remission or complete remission with incomplete recovery. Mutated NPM1 measurable residual disease-positive patients had higher cumulative incidence of relapse (P?<?0.001) and shorter overall survival (P?=?0.014). Restricting the analyses to patients receiving non-myeloablative conditioning, mutated NPM1 measurable residual disease positivity is associated with higher cumulative incidence of relapse (P?<?0.001) and shorter overall survival (P?=?0.006). Positive mutated NPM1 measurable residual disease status determined by ddPCR before allogeneic stem cell transplantation is associated with worse prognosis independent of other known prognostic markers—also for those receiving non-myeloablative conditioning. In the future, mutated NPM1 measurable residual disease status determined by ddPCR might guide treatment and improve patients’ outcomes.     

Intravenous busulfan for autologous stem cell transplantation in adult patients with acute myeloid leukemia: a survey of 952 patients on behalf of the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Oral busulfan is the historical backbone of the busulfan+cyclophosphamide regimen for autologous stem cell transplantation. However intravenous busulfan has more predictable pharmacokinetics and less toxicity than oral busulfan; we, therefore, retrospectively analyzed data from 952 patients with acute myeloid leukemia who received intravenous busulfan for autologous stem cell transplantation. Most patients were male (n=531, 56%), and the median age at transplantation was 50.5 years. Two-year overall survival, leukemia-free survival, and relapse incidence were 67±2%, 53±2%, and 40±2%, respectively. The non-relapse mortality rate at 2 years was 7±1%. Five patients died from veno-occlusive disease. Overall leukemia-free survival and relapse incidence at 2 years did not differ significantly between the 815 patients transplanted in first complete remission (52±2% and 40±2%, respectively) and the 137 patients transplanted in second complete remission (58±5% and 35±5%, respectively). Cytogenetic risk classification and age were significant prognostic factors: the 2-year leukemia-free survival was 63±4% in patients with good risk cytogenetics, 52±3% in those with intermediate risk cytogenetics, and 37 ± 10% in those with poor risk cytogenetics (P=0.01); patients ≤50 years old had better overall survival (77±2% versus 56±3%; P<0.001), leukemia-free survival (61±3% versus 45±3%; P<0.001), relapse incidence (35±2% versus 45±3%; P<0.005), and non-relapse mortality (4±1% versus 10±2%; P<0.001) than older patients. The combination of intravenous busulfan and high-dose melphalan was associated with the best overall survival (75±4%). Our results suggest that the use of intravenous busulfan simplifies the autograft procedure and confirm the usefulness of autologous stem cell transplantation in acute myeloid leukemia. As in allogeneic transplantation, veno-occlusive disease is an uncommon complication after an autograft using intravenous busulfan.     

Prognosis of acute myeloid leukemia harboring monosomal karyotype in patients treated with or without allogeneic hematopoietic cell transplantation after achieving complete remission

To evaluate the prognostic impact of monosomal karyotype on post-remission outcome in acute myeloid leukemia, we retrospectively analyzed 2,099 patients who had achieved complete remission. Monosomal karyotype was noted in 73 patients (4%). Of these, the probability of overall survival from first complete remission was 14% at four years, which was significantly lower than that reported in patients without monosomal karyotype, primarily due to a high relapse rate (86%). Monosomal karyotype remained significantly associated with worse overall survival among patients with unfavorable cytogenetics or complex karyotype, and even in patients who underwent allogeneic hematopoietic cell transplantation during first complete remission. These findings confirm that monosomal karyotype has a significantly adverse effect on post-remission outcome in patients with acute myeloid leukemia treated with and without allogeneic hematopoietic cell transplantation in first complete remission, emphasizing the need for the development of alternative therapies for this patient population.     

IDH1 mutations in patients with myelodysplastic syndromes are associated with an unfavorable prognosis

Background

Myelodysplastic syndromes are a heterogeneous group of hematopoietic stem cell disorders with a high propensity to transform into acute myeloid leukemia. Heterozygous missense mutations in IDH1 at position R132 and in IDH2 at positions R140 and R172 have recently been reported in acute myeloid leukemia. However, little is known about the incidence and prognostic impact of IDH1 and IDH2 mutations in myelodysplastic syndromes.

Design and Methods

We examined 193 patients with myelodysplastic syndromes and 53 patients with acute myeloid leukemia arising from myelodysplastic syndromes for mutations in IDH1 (R132), IDH2 (R172 and R140), and NPM1 by direct sequencing.

Results

We found that mutations in IDH1 occurred with a frequency of 3.6% in myelodysplastic syndromes (7 mutations in 193 patients) and 7.5% in acute myeloid leukemia following myelodysplastic syndromes (4 mutations in 53 patients). Three mutations in codon R140 of IDH2 and one mutation in codon R172 were found in patients with acute myeloid leukemia following myelodysplastic syndromes (7.5%). No IDH2 R140 or R172 mutations were identified in patients with myelodysplastic syndromes. The presence of IDH1 mutations was associated with a shorter overall survival (HR 3.20; 95% CI 1.47–6.99) and a higher rate of transformation into acute myeloid leukemia (67% versus 28%, P=0.04). In multivariate analysis when considering karyotype, transfusion dependence and International Prognostic Scoring System score, IDH1 mutations remained an independent prognostic marker in myelodysplastic syndromes (HR 3.57; 95% CI 1.59–8.02; P=0.002).

Conclusions

These results suggest that IDH1 mutations are recurrent molecular aberrations in patients with myelodysplastic syndromes, and may become useful as a poor risk marker in these patients. These findings await validation in prospective trials.     

Therapy-related myeloid neoplasms following treatment with radioiodine

Background

Few data are available on therapy-related myelodysplastic syndromes and acute myeloid leukemia developing after radioiodine treatment.

Design and Methods

We retrospectively analyzed 39 patients with myeloid neoplasms following radioiodine treatment, whose data were reported to the Duesseldorf Myelodysplastic Syndromes Register (8 of 3814 patients) and five other German Myelodysplastic Syndromes centers (n=31) between 1982 and 2011. These data were compared with those from 165 patients from our Myelodysplastic Syndromes Register with therapy-related myeloid neoplasms following chemotherapy (n=90), radiation (n=30), or radiochemotherapy (n=45).

Results

With a median latency of 79 months, 18 patients developed therapy-related acute myeloid leukemia and 21 presented with therapy-related myelodysplastic syndromes (8 refractory anemia with excess blasts I/II, 6 refractory anemia with multilineage dysplasia, 3 myelodysplastic syndromes with del(5q), 1 refractory anemia, 1 refractory anemia with ring sideroblasts, 1 chronic myelomonocytic leukemia II, 1 myelodysplastic/myeloproliferative neoplasm unclassifiable). Risk assessment according to the International Prognostic Scoring System was low-risk in 23%, intermediate-1 in 29%, intermediate-2 in 35%, and high-risk in 13%. Karyotype was abnormal in 68%, with chromosomes 7 (30%), 5 (26%), 8 (26%) and 3 (17%) being most frequently affected. No differences in the distribution of gender, World Health Organization subtype, acute myeloid leukemia progression, International Prognostic Scoring System score, and cytogenetic risk were observed between patients with therapy-related myeloid neoplasms following radioiodine or other treatment modalities. Of 17 patients who received induction chemotherapy, 71% were refractory to this treatment or died from treatment-related toxicity. The median overall survival in the entire group was 21.7 months (95%-CI 10.5–33 months) and did not differ significantly in comparison to the survival of patients with therapy-related myeloid neoplasms following other cytotoxic treatments. Patients with therapy-related acute myeloid leukemia had significantly inferior overall survival (12.4 versus 28.7 months, P=0.002).

Conclusions

Patients developing a therapy-related myeloid neoplasm after radioiodine treatment usually present with biological characteristics similar to those seen in patients with therapy-related myeloid neoplasms following other cytotoxic treatment modalities, associated with a low response rate to induction chemotherapy and poor prognosis.