Phase II study of tosedostat with cytarabine or decitabine in newly diagnosed older patients with acute myeloid leukaemia or high-risk MDS.

Tosedostat, an oral aminopeptidase inhibitor, has synergy with cytarabine and hypomethylating agents. We performed a Phase II trial to determine rates of complete remission (CR) and survival using tosedostat with cytarabine or decitabine in older patients with untreated acute myeloid leukaemia (AML) or high-risk myelodysplastic syndrome (MDS). Thirty-four patients ≥60 years old (median age 70 years; range, 60-83) were randomized to receive tosedostat (120 mg on days 1-21 or 180 mg continuously) with 5 d of either cytarabine (1 g/m2 /d) or decitabine (20 mg/m2 /d) every 35 d. Twenty-nine patients (85%) had AML, including 15 (44%) with secondary AML/MDS, and 5 (15%) had MDS-refractory anaemia with excess blasts type 2. The CR/CR with incomplete count recovery (CRi) rate was 53% [9 in each arm; 14 CR (41%) and 4 CRi (12%)], attained in 6 of 14 patients with adverse cytogenetics and 4 of 7 with FLT3-internal tandem duplication mutations. Median follow-up was 11.2 months (range, 0.5-22.3), and median survival was 11.5 months (95% confidence interval, 5.2-16.7). Twenty-three patients (67.6%) were treated as outpatients and 10 of these patients required hospitalization for febrile neutropenia. No Grade 3-4 non-haematological toxicities required withdrawal from study. Tosedostat with cytarabine or decitabine is tolerated in older patients with untreated AML/MDS, results in a CR/CRi rate of >50%, and warrants further study in larger trials.

Prognostic significance of acquired copy-neutral loss of heterozygosity in acute myeloid leukemia.

BACKGROUND: Chromosomal abnormalities are important in the diagnosis and prognosis of patients with acute myeloid leukemia (AML). Genomic microarray techniques detect recurrent copy-neutral loss of heterozygosity (cnLOH) in addition to copy number aberrations. However, the clinical utility has not been fully established. Therefore, in the current study, the authors examined the prognostic impact of acquired cnLOH in patients with AML, including complete remission (CR) rate, duration of CR, and overall survival (OS). METHODS: A total of 112 consecutive patients with AML who were undergoing chromosome genomic array testing (CGAT) at the Seattle Cancer Care Alliance were included in the current study. DNA from the bone marrow or blood was analyzed with a microarray platform with both single-nucleotide polymorphism (SNP) probes and non-SNP probes to identify acquired cnLOH. Results were correlated with cytogenetic, molecular, immunophenotypic, and other clinicopathological findings. RESULTS: Patients with cnLOH demonstrated a shorter duration of CR (hazard ratio, 1.87; P =.04) and worse OS (HR, 1.82; P = .03). Multivariate analyses confirmed the independent predictive value of cnLOH for early disease recurrence (P =.02). These results largely reflected those in patients with intermediate and unfavorable cytogenetics. Most strikingly, 13q cnLOH was found to demonstrate a 6.64-fold higher rate of disease recurrence (P =.006) and 3.45-fold worse OS (P = .02) and was enriched with the FLT3-ITD (Fms-related tyrosine kinase 3-internal tandem duplication) mutation. CONCLUSIONS: CnLOH has important prognostic significance in patients with AML. CGAT can replace imbalance fluorescence in situ hybridization and the authors recommend the routine use of CGAT to detect cnLOH, particularly among patients with intermediate-risk cytogenetics.

A phase I/II study of oral clofarabine plus low-dose cytarabine in previously treated acute myeloid leukaemia and high-risk myelodysplastic syndrome patients at least 60 years of age.

Outcomes for older adults with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) are generally poor, and new effective therapies are needed. We investigated oral clofarabine combined with low-dose cytarabine (LDAC) in patients aged 60 years and above with relapsed or refractory AML or high-risk MDS in a phase I/II trial. A 3 + 3 dose escalation of oral clofarabine was followed by a phase II expansion with the aim of obtaining a complete response (CR) rate ≥30%. We identified 20 mg/d for 5 d as the maximum tolerated dose (MTD) of oral clofarabine. A total of 35 patients, with a median age of 72 years, were treated. Of 26 patients enrolled at the MTD, 4 had treatment-related grade 3-4 non-haematological toxicities, but none died within 28 d. The observed CR rate and median survival were 34% [95% confidence interval (CI), 18-50%] and 6.8 months overall and 38% [95% CI, 19-57%] and 7.2 months at the MTD. The median disease-free survival was 7.4 months. Fifty-two percent (23/44) of cycles administered at the MTD were done without hospital admission. This combination of oral clofarabine and LDAC demonstrated efficacy with a CR rate of >30% and acceptable toxicity in older patients.

Idarubicin, cytarabine, and pravastatin as induction therapy for untreated acute myeloid leukemia and high-risk myelodysplastic syndrome.

Previous studies suggest that idarubicin/cytarabine(ara-C)/pravastatin (IAP) is an active salvage regimen for patients with AML. We therefore investigated this regimen in patients with newly-diagnosed AML or MDS (≥10% blasts). Patients were eligible if the anticipated treatment-related mortality (TRM) was <10%. Patients received pravastatin (1,280 mg/day po; days 1-8), cytarabine (1.5 g/m(2) /day; days 4-7), and idarubicin (12 mg/m(2) /day, days 4-6). Up to 3 cycles of consolidation with a shortened course was permitted. The primary endpoints were "good CR" rate (CR on day 35 without minimal residual disease) and TRM in the first 28 days. The study was to stop if after each cohort of 5 patients (a) the Bayesian posterior probability was < 5% that the true "good CR rate" was ≥ 70% or (b) the posterior probability was >25% that the TRM rate was ≥5%. Twenty-four patients were included. Conventional CR was achieved in 15 (63%) patients but only 12 (50%) achieved "good CR". 4 of 12 (33%) patients with "good CR" relapsed at median of 16 weeks (10.5-19). Five (21%) patients had refractory disease. Survival probability at 1 year was 72% (48.7-64). Two (8.3%) patients died within 28 days from multiorgan failure. The most common grade 3-4 adverse effects were febrile neutropenia (75%) and diarrhea (25%). Based on the stopping rules accrual ceased after entry of these 24 patients. IAP did not meet the predefined efficacy criteria for success. Therefore, we would not recommend this regimen for phase three testing in this patient subset.

Outpatient bendamustine and idarubicin for upfront therapy of elderly acute myeloid leukaemia/myelodysplastic syndrome: a phase I/II study using an innovative statistical design.

Combinations of agents may improve outcomes among elderly acute myeloid leukaemia (AML) and high-risk myelodysplastic syndrome (MDS) patients. We performed an adaptive phase I/II trial for newly-diagnosed AML or high-risk MDS patients aged ≥50 years using a Bayesian approach to determine whether 1 of 3 doses of bendamustine (45, 60, 75 mg/m(2) days 1-3), together with idarubicin (12 mg/m(2) days 1-2), might provide a complete response (CR) rate ≥40% with <30% grade 3-4 non-haematological toxicity. We treated 39 patients (34 AML; five MDS with >10% marrow blasts; median age 73 years). None of the three bendamustine doses in combination with idarubicin met the required CR and toxicity rates; the 75 mg/m(2) dose because of excess toxicity (two of three patients) and the 60 mg/m(2) dose because of low efficacy (CR rate 10/33), although no grade 3-4 non-haematological toxicity was seen at this dose. Median survival was 7·2 months. All patients began treatment as outpatients but hospitalization was required in 90% (35/39). Although we did not find a dose of bendamustine combined with idarubicin that would provide a CR rate of >40% with acceptable toxicity, bendamustine may have activity in AML/MDS patients, suggesting its addition to other regimens may be warranted.

Infusion of a non-HLA-matched ex-vivo expanded cord blood progenitor cell product after intensive acute myeloid leukaemia chemotherapy: a phase 1 trial.

BACKGROUND: The intensive chemotherapy regimens used to treat acute myeloid leukaemia routinely result in serious infections, largely due to prolonged neutropenia. We investigated the use of non-HLA-matched ex-vivo expanded cord blood progenitor cells to accelerate haemopoietic recovery and reduce infections after chemotherapy. METHODS: We enrolled patients with a diagnosis of acute myeloid leukaemia by WHO criteria and aged 18-70 years inclusive at our institution (Fred Hutchinson Cancer Research Center) into this phase 1 trial. The primary endpoint of the study was safety of infusion of non-HLA-matched expanded cord blood progenitor cells after administration of clofarabine, cytarabine, and granulocyte-colony stimulating factor priming. The protocol is closed to accrual and analysis was performed per protocol. The trial is registered with ClinicalTrials.gov, NCT01031368. FINDINGS: Between June 29, 2010, and June 26, 2012, 29 patients with acute myeloid leukaemia (19 newly diagnosed, ten relapsed or refractory) were enrolled. The most common adverse events were fever (27 [93%] of 29 patients) and infections (25 [86%] of 29 patients). We observed one case of acute infusional toxicity (attributed to an allergic reaction to dimethyl sulfoxide) in the 29 patients enrolled, who received 42 infusions of expanded progenitor cells. The following additional serious but expected adverse events were observed (each in one patient): grade 4 atrial fibrillation, grade 4 febrile neutropenia, lung infection with grade 4 absolute neutrophil count, colon infection with grade 4 absolute neutrophil count, grade 4 changed mental status, and one death from liver failure. No unexpected toxicity or graft-versus-host disease was observed. There was no evidence of in-vivo persistence of the expanded progenitor cell product in any patient beyond 14 days or induced alloimmunisation. INTERPRETATION: Infusion of the expanded progenitor cell product seemed safe and might provide a promising treatment method for patients with acute myeloid leukaemia. FUNDING: Biomedical Advanced Research and Development Authority in the US Department of Health and Human Services and Genzyme (Sanofi).

Elevated lymphocyte count at time of acute myeloid leukemia diagnosis is associated with shorter remission.

In solid tumors, decreased absolute lymphocyte count (ALC) at diagnosis was found to be associated with poorer outcome, but there is only limited data on the impact of ALC in acute myeloid leukemia (AML). In this study we evaluated the prognostic value of ALC on outcome in 259 adult patients with AML who responded to induction therapy. Higher than normal ALC at diagnosis was associated with shorter remission (HR 4.06; p < 0.001), and decreased relapse free and overall survival (HR 3.47; p < 0.001 and HR 3.85; p < 0.001 respectively). Flow cytometry showed low frequency of natural killer (NK) cells and high frequency of CD4+ T cells (which includes the subset of T regulatory cells) in the high ALC group. Low frequency of NK cells and potentially high frequency of inhibitory T regulatory cells may result in weaker immune responses against residual leukemia and may explain the poorer outcome of the high ALC group.

Relation of clinical response and minimal residual disease and their prognostic impact on outcome in acute myeloid leukemia.

PURPOSE: Both presence of minimal residual disease (MRD) and achievement of complete remission (CR) with incomplete platelet recovery (CRp) rather than CR after induction therapy predict relapse in acute myeloid leukemia (AML). These results suggest a correlation between response (peripheral count recovery) and MRD at the time of morphologic remission. Here we examine this hypothesis and whether MRD and response provide independent prognostic information after accounting for other relevant covariates. PATIENTS AND METHODS: We retrospectively analyzed data from 245 adults with AML who achieved CR, CRp, or CR with incomplete blood count recovery (CRi) after induction therapy. Bone marrow samples were collected on or closest to the first date of blood count recovery, and MRD was determined by 10-color multiparameter flow cytometry. RESULTS: The 71.0% of patients who achieved CR had MRD less frequently and had lower levels of MRD than the 19.6% of patients achieving CRp and 9.4% achieving CRi. Although pretreatment covariates such as cytogenetics, monosomal karyotype, relapsed or refractory rather than newly diagnosed AML, and FLT3 internal tandem duplication were associated with relapse, their prognostic effect was much lower once MRD and response were taken into account, the univariable statistical effect of which was not materially affected by inclusion of pretreatment covariates. CONCLUSION: Our data indicate that post-therapy parameters including MRD status and response are important independent prognostic factors for outcome in patients with AML achieving remission. MRD status and type of response (CR v CRp or CRi) should play important, and perhaps dominant, roles in planning postinduction therapy.

Heparin cofactor II is more sensitive than antithrombin to secretory impairment arising from mutations introduced into its carboxy-terminal region.

INTRODUCTION: Antithrombin (AT) and heparin cofactor II (HCII) are plasma glycoproteins and serpins that inhibit thrombin. We showed [Blood 86 (1995) 3461] that recombinant rabbit AT containing the Utah mutation of AT, P407L, was inefficiently secreted by transfected primate and rodent cultured cells. In the current study, the effects of P407L and related substitutions in human AT and human HCII were investigated. MATERIALS AND METHODS: Cultured cells were transfected transiently (COS-1) or permanently (CV-1) with AT and HCII expression vectors encoding the wild type or mutant serpins. The amount of protein secreted was determined immunologically, while RNA levels were assessed by reverse-transcription-PCR (RT-PCR). The kinetics of secretion were investigated by pulse-chase experiments, supplemented by endoglycosidase H or lactacystin treatment. RESULTS AND CONCLUSIONS: The F450L, P455L, P477L, P477*, and T446* (*=stop codon) mutations reduced HCII secretion 6.6- to 24-fold, while the F402L, A404T, and P407L mutations reduced AT secretion in COS-1 cells 1.7- to 5.2-fold. Homologous mutants HCII (P455L) and AT (P407L) were transcribed at similar levels in COS-1 cells, but were secreted less rapidly and less efficiently than their wild-type counterparts. HCII (P455L) exhibited intracellular proteasomal degradation in permanently transfected CV-1 cells, while AT (P407L) secretion was unaffected in this milieu. HCII secretion is thus more sensitive than that of AT to C-terminal mutations, as shown in two primate cell lines, likely reflecting a greater tendency to misfold during synthesis. We speculate that this difference may arise due to an interstrand s1C/s4B loop that is shorter in HCII than in AT.

Frequency of allogeneic hematopoietic cell transplantation among patients with high- or intermediate-risk acute myeloid leukemia in first complete remission.

PURPOSE: To determine the frequency of allogeneic hematopoietic cell transplantation (HCT) for patients with acute myeloid leukemia (AML) in first complete remission (CR1). PATIENTS AND METHODS: Between January 1, 2008, and March 1, 2011, 212 newly diagnosed patients with AML received treatment at our center. Ninety-five patients age less than 75 years with intermediate- or high-risk AML achieved a complete remission, and 21 patients achieved a morphologic remission with incomplete blood count recovery. RESULTS: Seventy-eight (67%; 95% CI, 58% to 76%) of 116 patients received HCT at a median of 2.8 months (range, 0.5 to 19 months) from their CR1 date. The median age was 57 years in both the HCT patient group (range, 18 to 75 years) and the non-HCT patient group (range, 24 to 70 years; P = .514). Between the HCT patients and the non-HCT patients, the mean Eastern Cooperative Oncology Group performance status was 1.1 compared with 1.5, respectively (P = .005), and the average HCT comorbidity score within 60 days of CR1 was 1.7 and 2.1, respectively (P = .68). Twenty-nine (76%) of 38 non-HCT patients were HLA typed, and matched donors were found for 13 of these 29 patients (34% of all non-HCT patients). The most common causes for patients not receiving transplantation in CR1 were early relapse (within 6 months) in 12 patients (32%), poor performance status in eight patients (21%), and physician decision in five patients (13%). CONCLUSION: HCT can be performed in CR1 in the majority of patients with AML for whom it is currently recommended. The main barriers to HCT were early relapse and poor performance status, highlighting the need for improved therapies for patients with AML of all ages.