Gemtuzumab ozogamicin in children and adolescents with de novo acute myeloid leukemia improves event-free survival by reducing relapse risk: results from the randomized phase III Children's Oncology Group trial AAML0531.

PURPOSE: To improve survival rates in children with acute myeloid leukemia (AML), we evaluated gemtuzumab-ozogamicin (GO), a humanized immunoconjugate targeted against CD33, as an alternative to further chemotherapy dose escalation. Our primary objective was to determine whether adding GO to standard chemotherapy improved event-free survival (EFS) and overall survival (OS) in children with newly diagnosed AML. Our secondary objectives examined outcomes by risk group and method of intensification. PATIENTS AND METHODS: Children, adolescents, and young adults ages 0 to 29 years with newly diagnosed AML were enrolled onto Children's Oncology Group trial AAML0531 and then were randomly assigned to either standard five-course chemotherapy alone or to the same chemotherapy with two doses of GO (3 mg/m2/dose) administered once in induction course 1 and once in intensification course 2 (two of three). RESULTS: There were 1,022 evaluable patients enrolled. GO significantly improved EFS (3 years: 53.1% v. 46.9%; hazard ratio [HzR], 0.83; 95% CI, 0.70 to 0.99; P.04) but not OS (3 years: 69.4% v. 65.4%; HzR, 0.91; 95% CI, 0.74 to 1.13; P = .39). Although remission was not improved (88% v. 85%; P = .15), posthoc analyses found relapse risk (RR) was significantly reduced among GO recipients overall (3 years: 32.8% v. 41.3%; HzR, 0.73; 95% CI, 0.58 to 0.91; P = .006). Despite an increased postremission toxic mortality (3 years: 6.6% v. 4.1%; HzR, 1.69; 95% CI, 0.93 to 3.08; P = .09), disease-free survival was better among GO recipients (3 years: 60.6% v. 54.7%; HzR, 0.82; 95% CI, 0.67 to 1.02; P = .07). CONCLUSION: GO added to chemotherapy improved EFS through a reduction in RR for children and adolescents with AML.

A Phase 2 study of bortezomib combined with either idarubicin/cytarabine or cytarabine/etoposide in children with relapsed, refractory or secondary acute myeloid leukemia: a report from the Children's Oncology Group.

BACKGROUND: This Phase 2 study tested the tolerability and efficacy of bortezomib combined with reinduction chemotherapy for pediatric patients with relapsed, refractory or secondary acute myeloid leukemia (AML). Correlative studies measured putative AML leukemia initiating cells (AML-LIC) before and after treatment. PROCEDURE: Patients with <400 mg/m(2) prior anthracycline received bortezomib combined with idarubicin (12 mg/m(2) days 1-3) and low-dose cytarabine (100 mg/m(2) days 1-7) (Arm A). Patients with ≥400 mg/m(2) prior anthracycline received bortezomib with etoposide (100 mg/m(2) on days 1-5) and high-dose cytarabine (1 g/m(2) every 12 hours for 10 doses) (Arm B). RESULTS: Forty-six patients were treated with 58 bortezomib-containing cycles. The dose finding phase of Arm B established the recommended Phase 2 dose of bortezomib at 1.3 mg/m(2) on days 1, 4, and 8 with Arm B chemotherapy. Both arms were closed after failure to meet predetermined efficacy thresholds during the first stage of the two-stage design. The complete response (CR + CRp) rates were 29% for Arm A and 43% for Arm B. Counting additional CRi responses (CR with incomplete neutrophil recovery), the overall CR rates were 57% for Arm A and 48% for Arm B. The 2-year overall survival (OS) was 39 ± 15%. Correlative studies showed that LIC depletion after the first cycle was associated with clinical response. CONCLUSION: Bortezomib is tolerable when added to chemotherapy regimens for relapsed pediatric AML, but the regimens did not exceed preset minimum response criteria to allow continued accrual. This study also suggests that AML-LIC depletion has prognostic value.

Outcome of transplantation for acute lymphoblastic leukemia in children with Down syndrome.

We report on 27 patients with Down syndrome (DS) and acute lymphoblastic leukemia (ALL) who received allogeneic hematopoietic cell transplantation (HCT) between 2000 and 2009. Seventy-eight percent of patients received myeloablative conditioning and 52% underwent transplantation in second remission. Disease-free survival (DFS) was 24% at a median of 3 years. Post-transplant leukemic relapse was more frequent than expected for children with DS-ALL (54%) than for non-DS ALL. These data suggest leukemic relapse rather than transplant toxicity is the most important cause of treatment failure. Advancements in leukemia control are especially needed for improvement in HCT outcomes for DS-ALL.

Oxandrolone for the treatment of bone marrow failure in Fanconi anemia.

BACKGROUND: A majority of Fanconi anemia (FA) patients will experience bone marrow failure (BMF) and androgen therapy (most often oxymetholone) may be utilized as a treatment to improve BMF-related cytopenias. However, oxymetholone is associated with toxicities making identification of other agents of interest. In this study we aimed to evaluate the toxicity profile and hematologic response in patients with FA who are treated with low-dose oxandrolone, a synthetic non-fluorinated anabolic steroid, similar to oxymetholone, with known dosing thresholds for virilization. PROCEDURE: A single arm, Phase I/II study was designed to treat patients on low-dose oxandrolone. If no toxicity or hematologic response was noted at 16 weeks, a single dose escalation was offered. Subjects were regularly assessed for toxicity, including determinations of virilization, behavioral changes, and liver and kidney function. At 32 weeks, those who demonstrated hematologic response were allowed to continue study treatment, and those without improvement were deemed non-responsive. RESULTS: Nine subjects completed the study and were followed for a median of 99 weeks (46-136 weeks). Three (33.3%) subjects developed mild sub-clinical virilization and continued treatment with a dose reduction. None (0%) had adverse behavioral changes. Two (22.2%) developed elevated liver function tests at 42 and 105 weeks. Seven (77.8%) subjects had a hematologic response. CONCLUSION: Oxandrolone appears to be well-tolerated, has limited toxicities at the administered doses in FA with patients, and may be an alternative androgen for the treatment of BMF in FA.

Outcome of transplantation for acute myelogenous leukemia in children with Down syndrome.

Data on outcomes of allogeneic transplantation in children with Down syndrome and acute myelogenous leukemia (DS-AML) are scarce and conflicting. Early reports stress treatment-related mortality as the main barrier; a recent case series points to posttransplantation relapse. We reviewed outcome data for 28 patients with DS-AML reported to the Center for International Blood and Marrow Transplant Research between 2000 and 2009 and performed a first matched-pair analysis of 21 patients with DS-AML and 80 non-DS AML controls. The median age at transplantation for DS-AML was 3 years, and almost half of the cohort was in second remission. The 3-year probability of overall survival was only 19%. In multivariate analysis, adjusting for interval from diagnosis to transplantation, risks of relapse (hazard ratio [HR], 2.84; P < .001; 62% versus 37%) and transplant-related mortality (HR, 2.52; P = .04; 24% versus 15%) were significantly higher for DS-AML compared to non-DS AML. Overall mortality risk (HR, 2.86; P < .001; 21% versus 52%) was significantly higher for DS-AML. Both transplant-related mortality and relapse contribute to higher mortality. Excess mortality in DS-AML patients can only effectively be addressed through an international multicenter effort to pilot strategies aimed at lowering both transplant-related mortality and relapse risks.

Transient myeloproliferative disorder in children with Down syndrome: clarity to this enigmatic disorder.

Children with trisomy 21 have a unique predisposition to develop a megakaryoblastic proliferative disease of varying severity during their first 3 months of life. This disorder exists in no other children or adults without the presence of trisomy 21 and only occurs in the fetal or neonatal period of life. Its spontaneous resolution in most cases further delineates it from otherwise indistinguishable neonatal leukaemias. The identification that GATA1 mutations are the leukaemogenic source along with three recently reported prospective clinical trials now provide a clearer understanding of this haematopoietic disorder. These recent advances in this enigmatic disorder, now known as Transient Myeloproliferative Disorder, are reviewed here in order to bring clarity to the breadth of organ involvement, the range of severity, the risk factors for mortality, the therapeutic options for severe manifestations, the natural course of spontaneous resolution regardless of therapy, and the elucidation of the subsequent risk for myeloid leukaemia.

Identification of regulators of polyploidization presents therapeutic targets for treatment of AMKL.

The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. Our study implicates five networks of kinases that regulate the switch to polyploidy. Moreover, we find that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. An integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora kinase A (AURKA). We further find that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in acute megakaryocytic leukemia (AMKL) blasts and displayed potent anti-AMKL activity in vivo. Our findings provide a rationale to support clinical trials of MLN8237 and other inducers of polyploidization and differentiation in AMKL.

Favorable survival maintained in children who have myeloid leukemia associated with Down syndrome using reduced-dose chemotherapy on Children's Oncology Group trial A2971: a report from the Children's Oncology Group.

BACKGROUND: Children who are treated for myeloid leukemia associated with Down syndrome (DS) experience superior survival compared with children who have myeloid leukemia without DS. To maintain excellent outcomes while avoiding toxicity, the Children's Oncology Group (COG) conducted the phase 3 trial COG A2971, the first trial solely designed to provide uniform treatment of myeloid leukemia in North American children with DS. A2971 eliminated 2 induction drugs and 3 months of maintenance therapy from the standard-timing regimen of dexamethasone, cytarabine, 6-thioguanine, etoposide, and rubidomycin/daunomycin (DCTER) used in the previous study (Children's Cancer Group [CCG] 2891). METHODS: COG A2971 was a multi-institutional, nonrandomized, clinical trial that enrolled 132 patients who had DS with either acute myeloid leukemia (n = 91) or myelodysplastic syndrome (n = 41). RESULTS: The median follow-up was 4.8 years (range, 0.8-8.6 years), the median age at diagnosis was 1.7 years (range, 0.3-13.6 years), and the median white blood cell count was 6200/µL (range, 900-164,900/µL). The remission rate (92.7% ± 6%) was similar to that reported in the CCG 2891 study (91.3% ± 5%; P = .679). The 5-year event free survival (EFS) rate was 79% ± 7% (vs 77% ± 7% in CCG 2891; P = .589), the disease-free survival (DFS) rate was 89% ± 6% (vs 85% ± 6% in CCG 2891; P = .337), and the overall survival rate was 84% ± 6% (vs 79% ± 7% in CCG 2891; P = .302). Induction day-14 bone marrow response trended toward a more favorable outcome (EFS: P = .12). Age >4 years was an adverse risk factor (5-year EFS rate: 33% ± 38% for children aged >4 years [median, 8.5 years; n = 6] vs 81% ± 7% for children ages 0-4 years [median, 1.7 years; n = 126]; P = .001). CONCLUSIONS: The COG A2971 trial reduced the chemotherapy dose and maintained survival to that achieved by the CCG 2891 trial in children who had myeloid leukemia associated with DS.

AAML03P1, a pilot study of the safety of gemtuzumab ozogamicin in combination with chemotherapy for newly diagnosed childhood acute myeloid leukemia: a report from the Children's Oncology Group.

BACKGROUND: The development of antigen-targeted therapies may provide additional options to improve outcomes in children with acute myeloid leukemia (AML). The Children's Oncology Group AAML03P1 trial sought to determine the safety of adding 2 doses of gemtuzumab ozogamicin, a humanized anti-CD33 antibody-targeted agent, to intensive chemotherapy during remission induction and postremission intensification for children with de novo AML. METHODS: AAML03P1 enrolled 350 children with previously untreated AML. Patients with a matched family donor received 3 courses of chemotherapy followed by hematopoietic stem cell transplantation; those without a matched family donor received 5 courses of chemotherapy. Gemtuzumab ozogamicin 3 mg/m(2)/dose was administered on Day 6 of Course 1 and Day 7 of Course 4. RESULTS: Toxicities observed in all courses of therapy were typical of AML chemotherapy regimens, with infection being most common. Patients achieved a complete remission rate of 83% after 1 course and 87% after 2 courses. The mortality rate was 1.5% after the first gemtuzumab ozogamicin-containing induction course and 2.6% after 2 induction courses. The 3-year event-free survival and overall survival rates were 53 ± 6% and 66 ± 5%, respectively. CONCLUSIONS: This trial determined that it is safe and feasible to include gemtuzumab ozogamicin in combination with intensive chemotherapy. The survival rates compare favorably with the recently published results of clinical trials worldwide.

Galactomannan Antigen Testing for Diagnosis of Invasive Aspergillosis in Pediatric Hematology Patients.

OBJECTIVE: Invasive aspergillosis (IA) can cause significant morbidity and mortality in immunocompromised children. The galactomannan (GM) enzyme immunoassay (EIA) has been shown in adult studies to be a useful adjunct in diagnosing IA. Data on this assay in children are limited by small sample sizes and conflicting results; false-positive assays were a concern in historical studies. We sought to evaluate the GM EIA in a large cohort of children who received intensive chemotherapy and/or hematopoietic stem cell transplant. A focus was placed on evaluating the assay specificity, and the potential of measuring GM antigen in urine. METHODS: A multicenter prospective observational study in children with anticipated prolonged neutropenia was performed. Serum specimens were collected twice weekly, and urine was collected once weekly during neutropenic periods. Operating characteristics were calculated using the GM EIA optical density index cutoffs of 0.5 and 1.0 for both serum and urine specimens. RESULTS: At least one serum or urine specimen was tested from 198 patients. Ten patients had one or more repeatedly positive serum specimens, while 37 patients had one or more repeatedly positive urine specimens. The specificity of serum and urine testing was 95% and 80%, respectively. Although the urine test resulted in a higher false positivity rate, it successfully identified the only case of probable IA. CONCLUSIONS: Data suggest that the serum GM EIA does not provide frequent false-positive results as previously reported. Screening for galactomannan, or a related antigen in urine, needs to be further evaluated as it may be amenable to development of surveillance strategies.

Effect of donor-recipient HLA matching at HLA A, B, C, and DRB1 on outcomes after umbilical-cord blood transplantation for leukaemia and myelodysplastic syndrome: a retrospective analysis.

BACKGROUND: The importance of matching at the HLA C locus has not been well defined for unrelated umbilical-cord blood transplantation. The selection algorithm for umbilical-cord blood units generally considers intermediate resolution HLA typing at A and B and allele-level typing at DRB1. We aimed to establish the relative importance of additional matching at HLA C. METHODS: We used Cox regression to assess retrospectively the effect of donor-recipient HLA matching on outcomes of single umbilical-cord blood transplantations for leukaemia and myelodysplastic syndrome. Our primary endpoint was transplant-related mortality. HLA typing was done with molecular techniques with a minimum of intermediate resolution for HLA A, B, and C, and at the allele-level for DRB1. FINDINGS: The median age of our study population was 10 years (range <1-62) and 552 (69%) of 803 patients were aged 16 years or younger at transplantation. Compared with transplantations matched at HLA A, B, C, and DRB1 (n=69), transplant-related mortality risk was higher after transplantations matched at HLA A, B, and DRB1 and mismatched at HLA C (n=23; HR 3·97, 95% CI 1·27-12·40; p=0·018). Transplant-related mortality risk was also higher after transplantations with a single mismatch at HLA A, B, or DRB1 and mismatched at HLA C (n=234; 1·70, 1·06-2·74; p=0·029) compared with transplantations matched at HLA C with a single mismatch at HLA A, B, or DRB1 (n=127). Assessing the overall effect of HLA disparity on transplant-related mortality, risks were higher with units mismatched at two (n=259; 3·27, 1·42-7·54; p=0·006), three (n=253; 3·34, 1·45-7·71; p=0·005), or four (n=75; 3·51, 1·44-8·58; p=0·006) loci compared with matched units (n=69). INTERPRETATION: Our data suggest that the present strategy for umbilical-cord blood unit selection should be reassessed; matching at HLA C for units that are matched at HLA A, B, or DRB1 or in the presence of a single locus mismatch at HLA A, B, or DRB1 should be included to minimise mortality risks. FUNDING: National Cancer Institute, National Heart Lung and Blood Institute, National Institute for Allergy and Infectious Diseases, Leukemia and Lymphoma Society, US Department of the Navy, Children's Leukemia Research Association, and INSERM.

Natural history of transient myeloproliferative disorder clinically diagnosed in Down syndrome neonates: a report from the Children's Oncology Group Study A2971.

Transient myeloproliferative disorder (TMD), restricted to newborns with trisomy 21, is a megakaryocytic leukemia that although lethal in some is distinguished by its spontaneous resolution. Later development of acute myeloid leukemia (AML) occurs in some. Prospective enrollment (n = 135) elucidated the natural history in Down syndrome (DS) patients diagnosed with TMD via the use of uniform monitoring and intervention guidelines. Prevalent at diagnosis were leukocytosis, peripheral blast exceeding marrow blast percentage, and hepatomegaly. Among those with life-threatening symptoms, most (n = 29/38; 76%) received intervention therapy until symptoms abated and then were monitored similarly. Organomegaly with cardiopulmonary compromise most frequently led to intervention (43%). Death occurred in 21% but only 10% were attributable to TMD (intervention vs observation patients: 13/14 vs 1/15 because of TMD). Among those solely observed, peripheral blasts and all other TMD symptoms cleared at a median of 36 and 49 days from diagnosis, respectively. On the basis of the diagnostic clinical findings of hepatomegaly with or without life-threatening symptoms, 3 groups were identified with differing survival: low risk with neither finding (38%), intermediate risk with hepatomegaly alone (40%), and high risk with both (21%; overall survival: 92% ± 8%, 77% ± 12%, and 51% ± 19%, respectively; P ≤ .001). Among all, AML subsequently occurred in 16% at a median of 441 days (range, 118-1085 days). The trial is registered at http://www.clinicaltrials.gov as NCT00003593.

A phase II study of amifostine in children with myelodysplastic syndrome: a report from the Children's Oncology Group study (AAML0121).

Based on its potential role in adult myelodysplastic syndrome (MDS), the Children's Oncology Group (COG) embarked on a phase II study using amifostine in pediatric MDS (WHO 2001 criteria) patients. Responses were evaluated after two cycles. Ten patients were enrolled; five were deemed ineligible, and four withdrew after the first course. Only one patient completed two courses, and was found to be in complete remission. The study was closed after being open for 2 years due to slow accrual. Studying a rare disease like MDS may pose insurmountable obstacles even in a large clinical trials group such as COG, in part because of the changing definitions of MDS and the rarity of adult type MDS in children. The role of amifostine in pediatric MDS was not known at the time of study.

Prognostic significance of additional cytogenetic aberrations in 733 de novo pediatric 11q23/MLL-rearranged AML patients: results of an international study.

We previously demonstrated that outcome of pediatric 11q23/MLL-rearranged AML depends on the translocation partner (TP). In this multicenter international study on 733 children with 11q23/MLL-rearranged AML, we further analyzed which additional cytogenetic aberrations (ACA) had prognostic significance. ACAs occurred in 344 (47%) of 733 and were associated with unfavorable outcome (5-year overall survival [OS] 47% vs 62%, P < .001). Trisomy 8, the most frequent specific ACA (n = 130/344, 38%), independently predicted favorable outcome within the ACAs group (OS 61% vs 39%, P = .003; Cox model for OS hazard ratio (HR) 0.54, P = .03), on the basis of reduced relapse rate (26% vs 49%, P < .001). Trisomy 19 (n = 37/344, 11%) independently predicted poor prognosis in ACAs cases, which was partly caused by refractory disease (remission rate 74% vs 89%, P = .04; OS 24% vs 50%, P < .001; HR 1.77, P = .01). Structural ACAs had independent adverse prognostic value for event-free survival (HR 1.36, P = .01). Complex karyotype, defined as ≥ 3 abnormalities, was present in 26% (n = 192/733) and showed worse outcome than those without complex karyotype (OS 45% vs 59%, P = .003) in univariate analysis only. In conclusion, like TP, specific ACAs have independent prognostic significance in pediatric 11q23/MLL-rearranged AML, and the mechanism underlying these prognostic differences should be studied.

Bone mineral density is normal in children with Fanconi anemia.

BACKGROUND: Conflicting data exist regarding whether low bone mineral density (BMD) is associated with Fanconi anemia (FA). The current study identified the frequency of low BMD in FA, expecting low BMD even in childhood and before HCT. PROCEDURE: Thirty-seven FA patients (18 prior HCT, 19 no prior HCT), participating in an IRB-approved database, had clinical assessment of DXA of lumbar spine BMD. Four had used androgens, one later underwent HCT. Most had used glucocorticoids after HCT (prolonged in five), and one more with no HCT. BMD [in standard deviation units from mean for age (SD), gender, and ethnicity (BMD Z-score)] was then adjusted for height age, and separately for bone maturation (BA). Data were collected for height SD, pubertal stage, and duration since HCT. RESULTS: BMD Z-score (without adjustment) was <-1 SD in half of FA children. BA-adjusted BMD Z-score was similar. (BA was not usually delayed, although most patients were short.) In contrast, height age-adjusted BMD Z-score was normal in most with FA (only below -2.0 in one child after prolonged glucocorticoids). Mean duration after HCT until DXA test was 6.2 years (median 4.2 years, range 1-18 years). CONCLUSIONS: Children and adolescents with FA have normal BMD prior to and after HCT, when DXA results are adjusted for bone size/height age. In contrast, BA-adjustment of BMD was not useful in this population. Individual BMD results may be influenced by gonadal function, transplantation status, and prolonged glucocorticoid therapy.

Higher dose imatinib for children with de novo chronic phase chronic myelogenous leukemia: a report from the Children's Oncology Group.

PURPOSE: To determine the efficacy of imatinib in children with newly diagnosed chronic phase (CP) chronic myelogenous leukemia (CML). METHODS: This was an open label, multi-center phase II clinical trial. Courses were defined as consecutive 28-day intervals. Oral imatinib was administered daily at 340 mg/m² without interruption in the absence of toxicity. RESULTS: Fifty-one children received 978 28-day courses of imatinib. The most common toxicities encountered were hematologic. Forty-one patients (80%) achieved a complete hematologic response by the end of course 2. Nineteen children (38%) obtained a complete cytogenetic response (CCyR) at the end of course 3. Overall, 72% achieved CCyR at a median time of 5.6 months. The rate of complete molecular response (>3 log reduction) was 27%. Progression-free and overall survival at 3 years were 72% ± 6.4% and 92% ± 3.9%, respectively. CONCLUSIONS: Daily oral imatinib at a dose of 340 mg/m² is well tolerated in children. In addition, imatinib therapy is effective in inducing a high percent of hematologic, cytogenetic and molecular responses, comparable to adults with CML. (This study was registered at ClinicalTrials.gov under identifier NCT00030394.).

Reducing the risk for transplantation-related mortality after allogeneic hematopoietic cell transplantation: how much progress has been made?

PURPOSE: Transplantation-related mortality (TRM) is a major barrier to the success of allogeneic hematopoietic cell transplantation (HCT). PATIENTS AND METHODS: We assessed changes in the incidence of TRM and overall survival from 1985 through 2004 in 5,972 patients younger than age 50 years who received myeloablative conditioning and HCT for acute myeloid leukemia (AML) in first complete remission (CR1) or second complete remission (CR2). RESULTS: Among HLA-matched sibling donor transplantation recipients, the relative risks (RRs) for TRM were 0.5 and 0.3 for 2000 to 2004 compared with those for 1985 to 1989 in patients in CR1 and CR2, respectively (P < .001). The RRs for all causes of mortality in the latter period were 0.73 (P = .001) and 0.60 (P = .005) for the CR1 and CR2 groups, respectively. Among unrelated donor transplantation recipients, the RRs for TRM were 0.73 (P = .095) and 0.58 (P < .001) for 2000 to 2004 compared with those in 1990 to 1994 in the CR1 and CR2 groups, respectively. Reductions in mortality were observed in the CR2 group (RR, 0.74; P = .03) but not in the CR1 group. CONCLUSION: Our results suggest that innovations in transplantation care since the 1980s and 1990s have reduced the risk of TRM in patients undergoing allogeneic HCT for AML and that this reduction has been accompanied by improvements in overall survival.