Effects of Education and Income on Treatment and Outcome in Patients With Acute Myeloid Leukemia in a Tax-Supported Health Care System: A National Population-Based Cohort Study

Purpose Previous US studies have shown that socioeconomic status (SES) affects survival in acute myeloid leukemia (AML). However, no large study has investigated the association between education or income and clinical characteristics, treatment, and outcome in AML. Methods To investigate the effects of education and income in a tax-supported health care system, we conducted a population-based study using individual-level SES and clinical data on all Danish patients with AML (2000 to 2014). We compared treatment intensity, allogeneic transplantation, and response rates by education and income level using logistic regression (odds ratios). We used Cox regression (hazard ratios [HRs]) to compare survival, adjusting for age, sex, SES, and clinical prognostic markers. Results Of 2,992 patients, 1,588 (53.1%) received intensive chemotherapy. Compared with low-education patients, highly educated patients more often received allogeneic transplantation (16.3% v 8.7%). In intensively treated patients younger than 60 years of age, increased mortality was observed in those with lower and medium education (1-year survival, 66.7%; adjusted HR, 1.47; 95% CI, 1.11 to 1.93; and 1-year survival, 67.6%; adjusted HR, 1.55; CI, 1.21 to 1.98, respectively) compared with higher education (1-year survival, 76.9%). Over the study period, 5-year survival improvements were limited to high-education patients (from 39% to 58%), increasing the survival gap between groups. In older patients, low-education patients received less intensive therapy (30% v 48%; adjusted odds ratio, 0.65; CI, 0.44 to 0.98) compared with high-education patients; however, remission rates and survival were not affected in those intensively treated. Income was not associated with therapy intensity, likelihood of complete remission, or survival (high income: adjusted HR, 1.0; medium income: adjusted HR, 0.96; 95% CI, 0.82 to 1.12; low income: adjusted HR, 1.06; CI, .88 to 1.27). Conclusion In a universal health care system, education level, but not income, affects transplantation rates and survival in younger patients with AML. Importantly, recent survival improvement has exclusively benefitted highly educated patients.

Enasidenib in mutant IDH2 relapsed or refractory acute myeloid leukemia

Recurrent mutations in isocitrate dehydrogenase 2 (IDH2) occur in ∼12% of patients with acute myeloid leukemia (AML). Mutated IDH2 proteins neomorphically synthesize 2-hydroxyglutarate resulting in DNA and histone hypermethylation, which leads to blocked cellular differentiation. Enasidenib (AG-221/CC-90007) is a first-in-class, oral, selective inhibitor of mutant-IDH2 enzymes. This first-in-human phase 1/2 study assessed the maximum tolerated dose (MTD), pharmacokinetic and pharmacodynamic profiles, safety, and clinical activity of enasidenib in patients with mutant-IDH2 advanced myeloid malignancies. We assessed safety outcomes for all patients and clinical efficacy in the largest patient subgroup, those with relapsed or refractory AML, from the phase 1 dose-escalation and expansion phases of the study. In the dose-escalation phase, an MTD was not reached at doses ranging from 50 to 650 mg per day. Enasidenib 100 mg once daily was selected for the expansion phase on the basis of pharmacokinetic and pharmacodynamic profiles and demonstrated efficacy. Grade 3 to 4 enasidenib-related adverse events included indirect hyperbilirubinemia (12%) and IDH-inhibitor-associated differentiation syndrome (7%). Among patients with relapsed or refractory AML, overall response rate was 40.3%, with a median response duration of 5.8 months. Responses were associated with cellular differentiation and maturation, typically without evidence of aplasia. Median overall survival among relapsed/refractory patients was 9.3 months, and for the 34 patients (19.3%) who attained complete remission, overall survival was 19.7 months. Continuous daily enasidenib treatment was generally well tolerated and induced hematologic responses in patients for whom prior AML therapy had failed. Inducing differentiation of myeloblasts, not cytotoxicity, seems to drive the clinical efficacy of enasidenib. This trial was registered at www.clinicaltrials.gov as #NCT01915498.

Midostaurin plus Chemotherapy for Acute Myeloid Leukemia with a FLT3 Mutation

BACKGROUND

Patients with acute myeloid leukemia (AML) and a FLT3 mutation have poor outcomes. We conducted a phase 3 trial to determine whether the addition of midostaurin - an oral multitargeted kinase inhibitor that is active in patients with a FLT3 mutation - to standard chemotherapy would prolong overall survival in this population.

METHODS

We screened 3277 patients, 18 to 59 years of age, who had newly diagnosed AML for FLT3 mutations. Patients were randomly assigned to receive standard chemotherapy (induction therapy with daunorubicin and cytarabine and consolidation therapy with high-dose cytarabine) plus either midostaurin or placebo; those who were in remission after consolidation therapy entered a maintenance phase in which they received either midostaurin or placebo. Randomization was stratified according to subtype of FLT3 mutation: point mutation in the tyrosine kinase domain (TKD) or internal tandem duplication (ITD) mutation with either a high ratio (>0.7) or a low ratio (0.05 to 0.7) of mutant to wild-type alleles (ITD [high] and ITD [low], respectively). Allogeneic transplantation was allowed. The primary end point was overall survival.

RESULTS

A total of 717 patients underwent randomization; 360 were assigned to the midostaurin group, and 357 to the placebo group. The FLT3 subtype was ITD (high) in 214 patients, ITD (low) in 341 patients, and TKD in 162 patients. The treatment groups were well balanced with respect to age, race, FLT3 subtype, cytogenetic risk, and blood counts but not with respect to sex (51.7% in the midostaurin group vs. 59.4% in the placebo group were women, P=0.04). Overall survival was significantly longer in the midostaurin group than in the placebo group (hazard ratio for death, 0.78; one-sided P=0.009), as was event-free survival (hazard ratio for event or death, 0.78; one-sided P=0.002). In both the primary analysis and an analysis in which data for patients who underwent transplantation were censored, the benefit of midostaurin was consistent across all FLT3 subtypes. The rate of severe adverse events was similar in the two groups.

CONCLUSIONS

The addition of the multitargeted kinase inhibitor midostaurin to standard chemotherapy significantly prolonged overall and event-free survival among patients with AML and a FLT3 mutation. (Funded by the National Cancer Institute and Novartis; ClinicalTrials.gov number, NCT00651261 .).

Abstract 532: Identification of unpaired cysteine-mediated gain and loss of function CSF3R extracellular mutations

Mutations in the CSF3R extracellular domain have been reported so far only in neutropenia patients. These extracellular mutations are loss of function mutations, which interrupt ligand binding. Here we screened CSF3R extracellular domain variants in a variety of hematological malignances and described for the first time the identification of an activating CSF3R extracellular mutation W341C in a leukemia patient. Functional assays revealed that this mutation conferred Ba/F3 cell cytokine-independent growth and induced constitutive JAK-STAT activation. 

We further characterized that cysteine substitutions at other amino acid positions (342, 356 and 477) and other amino acid substitutes of W341 (A/G/K/R/S) did not transform cells, indicating that both the amino acid position and cysteine substitution are essential for the transforming capacity. In agreement, increased dimer formation of W341C was observed in the co-immunoprecipitation assay and non-reducing condition immunoblot, which could be abrogated in an immunoblot run under reducing conditions, highly suggesting that dimerization is mediated by the formation of intermolecular disulfide bonds. Surprisingly, W356C demonstrated loss of function properties, however, showed increased dimer formation similar to W341C, indicating that only the increased dimerization is not sufficient for transforming capacity. Computational modeling based on IL6ST showed opposite directions of W341 and W356, which may orientate the cytoplasmic domain towards or away from one another.

Interestingly, a CSF3R cytoplasmic truncation mutation at amino acid W791 was found to be on the same allele as W341C in this patient. The W341C/W791X compound mutation transformed Ba/F3 with faster kinetics comparing to the W341C single mutation. Furthermore, the compound mutation, but not W341C alone demonstrated delayed receptor degradation, indicating enhanced oncogenic potential. Notably, the primary patient sample and the Ba/F3 cells transformed by W341C or the compound mutation were all sensitive to JAK inhibitors. The patient harboring these CSF3R mutations displayed myelodysplastic morphology with BCOR mutation at disease diagnosis, and showed good response to Azacytidine treatment. However her white blood count (mature neutrophils in particular) increased after 15-18 months’ treatment, which was concomitant with the acquisition and expansion of CSF3R W341C and W791X and disease progression. We further investigated the oncogenic potential of disrupting original cysteine pairs in the CSF3R extracellular domain. Increased dimers are observed in these mutations, whereas two functional consequences were observed: loss of function and constitutive activity. This, therefore, represents the first characterization of unpaired cysteines that mediate both loss and gain of function phenotypes. This paradigm may apply to other cytokine receptors.

Citation Format: Haijiao Zhang, Sophie Means, Anna R. Schultz, Kevin Watanabe-Smith, Bruno C. Medeiros, Tim Kükenshöner, Oliver Hantschel, Daniel Bottomly, Beth Wilmot, Shannon K. McWeeney, Jeffrey W. Tyner. Identification of unpaired cysteine-mediated gain and loss of function CSF3R extracellular mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 532. doi:10.1158/1538-7445.AM2017-532

Unpaired Extracellular Cysteine Mutations of CSF3R Mediate Gain or Loss of Function

Exclusive of membrane-proximal mutations seen commonly in chronic neutrophilic leukemia (e.g., T618I), functionally defective mutations in the extracellular domain of the G-CSF receptor (CSF3R) have been reported only in severe congenital and idiopathic neutropenia patients. Here, we describe the first activating mutation in the fibronectin-like type III domain of the extracellular region of CSF3R (W341C) in a leukemia patient. This mutation transformed cells via cysteine-mediated intermolecular disulfide bonds, leading to receptor dimerization. Interestingly, a CSF3R cytoplasmic truncation mutation (W791X) found on the same allele as the extracellular mutation and the expansion of the compound mutation was associated with increased leukocytosis and disease progression of the patient. Notably, the primary patient sample and cells transformed by W341C and W341C/W791X exhibited sensitivity to JAK inhibitors. We further showed that disruption of original cysteine pairs in the CSF3R extracellular domain resulted in either gain- or loss-of-function changes, part of which was attributable to cysteine-mediated dimer formation. This, therefore, represents the first characterization of unpaired cysteines that mediate both gain- and loss-of-function phenotypes. Overall, our results show the structural and functional importance of conserved extracellular cysteine pairs in CSF3R and suggest the necessity for broader screening of CSF3R extracellular domain in leukemia patients. Cancer Res; 77(16); 4258-67. ©2017 AACR.

Enasidenib in mutant-IDH2 relapsed or refractory acute myeloid leukemia (R/R AML): Results of a phase I dose-escalation and expansion study

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Background: Recurrent mutations in isocitrate dehydrogenase 2 (m IDH2) occur in 8-15% of AML pts. mIDH2 proteins synthesize an oncometabolite, 2-hydroxyglutarate (2HG), causing DNA and histone hypermethylation and blocked myeloid differentiation. Enasidenib (AG-221) is an oral, selective, small-molecule inhibitor of mIDH2 protein. Methods: This phase 1/2 study assessed the maximum tolerated dose (MTD), pharmacokinetic and pharmacodynamic profiles, safety, and clinical activity of enasidenib in pts with m IDH2 myeloid malignancies. Safety for all pts and efficacy outcomes for R/R AML pts from the phase 1 dose-escalation and expansion phases are reported. Results: In all, 239 pts received enasidenib. In the dose-escalation (n=113), the MTD was not reached at doses up to 650 mg daily. Median 2HG reductions from baseline were 92%, 90%, and 93% for pts receiving <100 mg, 100 mg, and >100 mg daily, respectively. Enasidenib 100 mg QD was chosen for the expansion phase (n=126) based on PK/PD profiles and demonstrated efficacy. Median number of enasidenib cycles was 5 (range 1–25). Grade 3-4 drug-related investigator reported AEs included indirect hyperbilirubinemia (12%) and IDH-inhibitor-associated differentiation syndrome (ie, retinoic acid syndrome; 7%). For R/R AML pts, overall response rate (ORR) was 40.3%, including 34 (19.3%) complete remissions (CR; Table). Response was associated with cellular differentiation, typically with no evidence of aplasia. Median overall survival (OS) for R/R AML pts was 9.3 months (mos). For pts who attained CR, OS was 19.7 mos. Pts who had received ≥2 prior AML regimens (n=94; 53%) had median OS of 8.0 mos. Conclusions: Enasidenib was well tolerated, induced CRs, and was associated with OS of >9 mos in pts who had failed prior AML therapies. Differentiation of myeloblasts, not cytotoxicity, appears to drive the clinical efficacy of enasidenib. Clinical trial information: NCT01915498. [Table: see text]

Correlation between mutation clearance and clinical response in elderly patients with acute myeloid leukemia (AML) treated with azacitidine and pracinostat

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Background: In a phase II study in 50 elderly patients (pts) with AML who were not eligible for intensive chemotherapy, treatment with pracinostat + azacitidine (AZA) was well tolerated, led to 42% complete remission (CR) rate and a median overall survival (OS) of 19.1 months (Blood 2016: 128;100). Here we investigate the impact of somatic mutations and their clearance on disease response and patient outcomes. Methods: 88 samples from 41 study pts were sequenced. All 41 pts were analyzed pre-treatment, and a median of 3 longitudinal samples were analyzed from 19 pts between Cycle 2 and 9. Mutations were assayed by SureSelect targeted capture exon sequencing (Agilent) of 295 genes that are recurrently mutated in hematologic malignancies. Longitudinal mutation clearance was analyzed by plotting variant allele frequency (VAF). Results: At baseline, 96 mutations in 28 genes were detected in 38 pts, with the most frequent being in SRSF2 (27%), DNMT3A (20%), IDH2 (17%), RUNX1 (17%), and TET2(17%). Mutations associated with CR rate and OS are indicated in the Table. A CR was achieved in 10/19 pts that had longitudinal sequencing analysis and at the time of CR, 9 (90%) had persistently detectable mutations in their bone marrow. In 7 of them, continued exposure to pracinostat + AZA lowered the VAF or cleared residual mutations. In 2 pts, relapsed samples showed re-expansion of the founder clone. Conclusions: Mutations in NPM1, and DNA methylation pathway were associated with a better response to pracinostat + AZA, while TP53 mutation was associated with a poor response. Persistent mutation at the time of CR suggests residual preleukemic clonal hematopoiesis in this elderly population. Benefit of prolonged exposure to pracinostat + AZA was also confirmed at molecular level where continued decline of mutation VAF was seen after achieving CR. Clinical trial information: NCT01912274. [Table: see text]

Quality of life of acute myeloid leukemia patients in a real-world setting

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Background: There is currently limited data on the quality-of-life (QoL) of patients with acute myeloid leukemia (AML) in the real-world setting. The objective of this analysis was to understand the impact of AML on patients receiving first-line treatment vs those who were relapsed/refractory to first-line treatment and therefore on later lines of therapy. Methods: The Adelphi AML Disease-Specific Programme, a real-world, cross-sectional survey involving 61 US hematologists/hemato-oncologists and their consulting AML patients, was conducted between February–May 2015. Physicians provided details on patient demographics and clinical information. Each patient was asked to complete both the EQ-5D-3L and Functional Assessment of Cancer Therapy Leukemia (FACT-Leu). Scores range from −1.09–1 (EQ-5D-3L) and 0–176 (FACT-Leu), where a higher score indicates a better QoL. Data from physician-completed record forms and corresponding patient self-completion forms on a matched sample of 75 patients were analyzed. Results: Of the patients who took part in the survey, 75% (n = 56) were receiving first-line treatment for AML and 25% (n = 19) were relapsed/refractory to first-line treatment and had progressed to later lines of therapy. The first-line patients had a mean age of 56.6 years and an average of 2.1 symptoms whereas the relapsed/refractory patients had a mean age of 56.9 years and an average of 2.4 symptoms, according to the physician. First-line patients may have a directionally better QoL scores than those on later lines of therapy, according to both the EQ-5D (0.75 and 0.71 respectively, P= .51) and the FACT-Leu (103.7 and 92.5 respectively, P= .098) measures. Results from the FACT-Leu-Physical Well-Being sub-domain show that relapsed/refractory patients were significantly more likely than first-line patients to be affected physically by their AML condition (13.0 and 17.6 respectively, P= .005). Conclusions: AML patients who have relapsed or become refractory to first-line treatment report worse QoL than those still on first-line treatments. These observational data shows a need for effective and tolerable treatments that can maintain or improve patients’ QoL, especially for patients with relapsed or refractory disease.

Real-world prescribing patterns in acute myeloid leukemia in the United States

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Background: The effective treatment of patients with acute myeloid leukemia (AML) remains a challenge in clinical practice. This analysis describes the patient characteristics and real-world use of AML treatments in the United States for patients on high- and low-intensity treatment. Methods: Data from the Adelphi AML Disease-Specific Programme, a real-world, cross-sectional survey conducted between February–May 2015, were analysed. A total of 61 hematologist/hem-oncologists, across academic, non-academic and office-based practice locations, provided data on 457 AML patients. Patient characteristics were derived from physician-completed patient record forms where each physician was asked to provide treatment details, including the treatment intensity, for each line of therapy. Results: A total of 91% (n = 415) of patients included in this analysis were previously untreated for AML. Patients had a mean age of 60 years and been diagnosed with AML for a median of 5.0 months. At first-line induction therapy, over half (53%; n = 241) of the patients were initiated on a high-intensity treatment, the most common regimen being cytarabine plus anthracycline (61%; n = 147). The remaining 47% (n = 216) of patients received a low-intensity induction therapy such as low dose cytarabine monotherapy (28%, n = 61), azacitidine monotherapy (25%, n = 54), or decitabine monotherapy (21%, n = 45). Over half (55%, n = 62) of patients suited to high intensity treatment went on to receive cytarabine monotherapy during the consolidation phase of their first-line treatment. Conclusions: According to treating physicians, the large majority of patients receive traditional, well-established therapies at first-line induction for AML. Whilst cytarabine combinations dominate the high-intensity treatment setting, the hypomethylating agents, azacitidine and decitabine, are frequently used for those more suited to low-intensity treatment.

Overall survival (OS) and stem cell transplant (SCT) in patients with FLT3 mutations treated with CPX-351 versus 7+3: Subgroup analysis of a phase III study of older adults with newly diagnosed, high-risk acute myeloid leukemia (AML)

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Background: FLT3+ AML patients (pts; 20%-30% of AML pts) often have rapid post-induction relapse, highlighting the need for therapies that improve the bridge to SCT. CPX-351 is a liposomal formulation that delivers a synergistic 5:1 molar ratio of cytarabine (C) and daunorubicin (D). CPX-351 demonstrated efficacy versus 7+3 in a randomized, open-label, controlled phase III trial in pts aged 60-75 years with newly diagnosed, high-risk AML; our analysis investigated outcomes in the subset of FLT3+ pts. Methods: Pts were randomized 1:1 to induction with 1-2 cycles of CPX-351 (100 u/m2 [C 100 mg/m2 + D 44 mg/m2] on Days 1, 3, and 5 [2nd induction: Days 1 and 3]) or 7+3 (C 100 mg/m2/day x 7 days [2nd induction: x 5 days] + D 60 mg/m2on Days 1, 2, and 3 [2nd induction: Days 1 and 2]). Pts with complete remission (CR) or CR with incomplete platelet or neutrophil recovery (CRi) could receive up to 2 consolidation cycles. Results: Of the pts who had FLT3 mutations assessed and received study treatment, 22/138 (16%) pts in the CPX-351 arm and 20/136 (15%) pts in the 7+3 arm had baseline FLT3 mutations. AML subtypes in FLT3+ pts were: tAML (19%); AML after MDS with (38%) or without (10%) prior hypomethylating agents; AML after CMMoL (12%); and de novo AML with MDS karyotype (21%). In FLT3+ pts, median OS was longer with CPX-351 (10.25 mo) versus 7+3 (4.55 mo; HR = 0.57 [95% CI: 0.24, 1.33]; P= 0.093) and the rate of CR+CRi was higher (68% vs 25%). A greater number of FLT3+ pts treated with CPX-351 were able to undergo SCT (n = 10/22 [45%]; 4 pts were alive as of this analysis, after a median post-SCT follow up of 692 days [range: 96-769]) compared with 7+3 (n = 2/20 [10%]; neither pt still alive). The on-study safety profile of CPX-351 in FLT3+ pts was comparable to 7+3 and consistent with the overall study population. Serious adverse events were experienced by 7 (32%) FLT3+ pts in the CPX-351 arm and 10 (50%) in the 7+3 arm. Conclusions: CPX-351 demonstrated numerical improvement in median OS in older pts with newly diagnosed, FLT3+ high-risk AML and allowed more pts to undergo SCT. The analysis was limited by small number of pts. Clinical trial information: NCT01696084.

Efficacy by consolidation administration site: Subgroup analysis of a phase III study of CPX-351 versus 7+3 in older adults with newly diagnosed, high-risk acute myeloid leukemia (AML)

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Background: The CPX-351 liposomal formulation delivers a synergistic 5:1 molar ratio of cytarabine (C) and daunorubicin (D) preferentially to leukemia cells. CPX-351 has demonstrated significantly improved overall survival (OS) versus 7+3 in a randomized, open-label, phase III study in patients (pts) aged 60-75 years with newly diagnosed, high-risk AML. In contrast to 7+3, which includes C continuous infusion, CPX-351 is administered as a 90-minute infusion and has the potential to be given in the outpatient setting. The current analysis of the phase III trial assessed the setting of consolidation therapy. Methods: Pts were randomized 1:1 to 1-2 induction cycles of CPX-351 or 7+3; pts with complete remission (CR) or CR with incomplete platelet or neutrophil recovery (CRi) could receive up to 2 consolidation cycles (CPX-351: 65 u/m2 [C 65 mg/m2 + D 28.6 mg/m2] on Days 1 and 3; 7+3: C 100 mg/m2/day x 5 days + D 60 mg/m2 on Days 1 and 2). Site of administration was not protocol defined. Results: Few pts received induction as outpatient therapy (CPX-351 n = 3/153 and 7+3 n = 1/151 in each cycle). 49/153 CPX-351 pts and 32/151 7+3 pts received consolidation, with a substantial proportion of pts receiving CPX-351 as outpatients (consolidation 1: 51%; consolidation 2: 61%). CPX-351 consolidation was associated with substantial improvement in median OS versus 7+3 irrespective of inpatient/outpatient status (Table). Median OS was not diminished with CPX-351 administration in the outpatient versus inpatient setting (consolidation 1: 25.43 and 14.72, respectively; consolidation 2: 26.32 and not reached). Conclusions: Some pts can successfully receive CPX-351 consolidation as outpatients without diminished efficacy, potentially reducing hospitalizations associated with treatment administration. Clinical trial information: NCT01696084. [Table: see text]

Identification of Interleukin-1 by Functional Screening as a Key Mediator of Cellular Expansion and Disease Progression in Acute Myeloid Leukemia

Secreted proteins in the bone marrow microenvironment play critical roles in acute myeloid leukemia (AML). Through an ex vivo functional screen of 94 cytokines, we identified that the pro-inflammatory cytokine interleukin-1 (IL-1) elicited profound expansion of myeloid progenitors in ∼67% of AML patients while suppressing the growth of normal progenitors. Levels of IL-1β and IL-1 receptors were increased in AML patients, and silencing of the IL-1 receptor led to significant suppression of clonogenicity and in vivo disease progression. IL-1 promoted AML cell growth by enhancing p38MAPK phosphorylation and promoting secretion of various other growth factors and inflammatory cytokines. Treatment with p38MAPK inhibitors reversed these effects and recovered normal CD34+ cells from IL-1-mediated growth suppression. These results highlight the importance of ex vivo functional screening to identify common and actionable extrinsic pathways in genetically heterogeneous malignancies and provide impetus for clinical development of IL-1/IL1R1/p38MAPK pathway-targeted therapies in AML.

Isocitrate dehydrogenase mutations in myeloid malignancies

Alterations to genes involved in cellular metabolism and epigenetic regulation are implicated in the pathogenesis of myeloid malignancies. Recurring mutations in isocitrate dehydrogenase (IDH) genes are detected in approximately 20% of adult patients with acute myeloid leukemia (AML) and 5% of adults with myelodysplastic syndromes (MDS). IDH proteins are homodimeric enzymes involved in diverse cellular processes, including adaptation to hypoxia, histone demethylation and DNA modification. The IDH2 protein is localized in the mitochondria and is a critical component of the tricarboxylic acid (also called the ‘citric acid' or Krebs) cycle. Both IDH2 and IDH1 (localized in the cytoplasm) proteins catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG). Mutant IDH enzymes have neomorphic activity and catalyze reduction of α-KG to the (R) enantiomer of 2-hydroxyglutarate, which is associated with DNA and histone hypermethylation, altered gene expression and blocked differentiation of hematopoietic progenitor cells. The prognostic significance of mutant IDH (mIDH) is controversial but appears to be influenced by co-mutational status and the specific location of the mutation (IDH1-R132, IDH2-R140, IDH2-R172). Treatments specifically or indirectly targeted to mIDH are currently under clinical investigation; these therapies have been generally well tolerated and, when used as single agents, have shown promise for inducing responses in some mIDH patients when used as first-line treatment or in relapsed or refractory AML or MDS. Use of mIDH inhibitors in combination with drugs with non-overlapping mechanisms of action is especially promising, as such regimens may address the clonal heterogeneity and the multifactorial pathogenic processes involved in mIDH myeloid malignancies. Advances in mutational analysis have made testing more rapid and convenient, and less expensive; such testing should become part of routine diagnostic workup and repeated at relapse to identify patients who may benefit from treatments that target mIDH.

A phase 1, open-label, dose-escalation study of pralatrexate in combination with bortezomib in patients with relapsed/refractory multiple myeloma

Pralatrexate inhibits folic acid metabolism, and preclinical studies have shown that it is cytotoxic to multiple myeloma cells. This phase 1 study investigated the safety and efficacy of pralatrexate in combination with bortezomib in adults with relapsed or refractory multiple myeloma. A standard 3 + 3 design was used. Patients received intravenous pralatrexate at doses ranging from 10 to 30 mg/m(2) and intravenous bortezomib at a dose of 1·3 mg/m(2) on days 1, 8 and 15 of each 4-week cycle. Eleven patients were enrolled and completed a median of two cycles. The maximum tolerated dose was 20 mg/m(2) . Two patients experienced dose-limiting toxicity of mucositis. The most frequent non-haematological toxicities were fatigue (55%) and mucositis (45%). There were three serious adverse events in three patients: rash, sepsis and hypotension. One patient (9%) had a very good partial response, 1 (9%) had a partial response, 1 (9%) had minimal response and two (18%) had progressive disease. The median duration of response was 4 months, the median time to next treatment was 3·4 months and the median time to progression was 4 months. Pralatrexate, in combination with bortezomib, was generally safe and demonstrated modest activity in relapsed or refractory multiple myeloma. Clinicaltrials.gov identifier: NCT01114282.

Predictors of early death and survival among children, adolescents and young adults with acute myeloid leukaemia in California, 1988-2011: a population-based study

A better understanding of factors associated with early death and survival among children, adolescents and young adults with acute myeloid leukaemia (AML) may guide health policy aimed at improving outcomes in these patients. We examined trends in early death and survival among 3935 patients aged 0-39 years with de novo AML in California during 1988-2011 and investigated the associations between sociodemographic and selected clinical factors and outcomes. Early death declined from 9·7% in 1988-1995 to 7·1% in 2004-2011 (P = 0·062), and survival improved substantially over time. However, 5-year survival was still only 50% (95% confidence interval 47-53%) even in the most recent treatment period (2004-2011). Overall, the main factors associated with poor outcomes were older age at diagnosis, treatment at hospitals not affiliated with National Cancer Institute-designated cancer centres, and black race/ethnicity. For patients diagnosed during 1996-2011, survival was lower among those who lacked health insurance compared to those with public or private insurance. We conclude that mortality after AML remained strikingly high in California and increased with age. Possible strategies to improve outcomes include wider insurance coverage and treatment at specialized cancer centres.

Hematopoietic Cell Transplantation Outcomes in Monosomal Karyotype Myeloid Malignancies

The presence of monosomal karyotype (MK+) in acute myeloid leukemia (AML) is associated with dismal outcomes. We evaluated the impact of MK+ in AML (MK+AML, n = 240) and in myelodysplastic syndrome (MDS) (MK+MDS, n = 221) on hematopoietic cell transplantation outcomes compared with other cytogenetically defined groups (AML, n = 3360; MDS, n = 1373) as reported to the Center for International Blood and Marrow Transplant Research from 1998 to 2011. MK+ AML was associated with higher disease relapse (hazard ratio, 1.98; P < .01), similar transplantation-related mortality (TRM) (hazard ratio, 1.01; P = .90), and worse survival (hazard ratio, 1.67; P < .01) compared with those outcomes for other cytogenetically defined AML. Among patients with MDS, MK+ MDS was associated with higher disease relapse (hazard ratio, 2.39; P < .01), higher TRM (hazard ratio, 1.80; P < .01), and worse survival (HR, 2.02; P < .01). Subset analyses comparing chromosome 7 abnormalities (del7/7q) with or without MK+ demonstrated higher mortality for MK+ disease in for both AML (hazard ratio, 1.72; P < .01) and MDS (hazard ratio, 1.79; P < .01). The strong negative impact of MK+ in myeloid malignancies was observed in all age groups and using either myeloablative or reduced-intensity conditioning regimens. Alternative approaches to mitigate disease relapse in this population are needed.