Identification of Hetero-aggregates in Antibody Co-formulations by Multi-dimensional Liquid Chromatography Coupled to Mass Spectrometry.

Antibody combination therapies have become viable therapeutic treatment options for certain severe diseases such as cancer. The co-formulation production approach is intrinsically associated with more complex drug product variant profiles and creates more challenges for analytical control of drug product quality. In addition to various individual quality attributes, those arising from the interactions between the antibodies also potentially emerge through co-formulation. In this study, we describe the development of a widely applicable multi-dimensional liquid chromatography coupled to tandem mass spectrometry method for antibody homo- versus hetero-aggregate characterization. The co-formulation of trastuzumab and pertuzumab was used, a challenging model system, comprising two monoclonal antibodies with very similar physicochemical properties. The data presented demonstrate the high stability of the co-formulation, where only minor aggregate formation is observed upon product storage and accelerated temperature or light-stress conditions. The results also show that the homo- and hetero-aggregates, formed in low and comparable proportions, are only marginally impacted by the formulation and product storage conditions. No preferential formation of hetero-aggregates, in comparison to the already existing pertuzumab and trastuzumab homo-aggregates, was observed.

The hypomorphic TERT A1062T variant is associated with increased treatment-related toxicity in acute myeloid leukemia.

Hypomorphic germline variants in TERT, the gene encoding the reverse transcriptase component of the human telomerase complex, occur with a frequency of 3-5% in acute myeloid leukemia. We analyzed the clinical and prognostic impact of the most common TERT A1062T variant in younger patients with acute myeloid leukemia intensively treated within two prospective multicenter trials. Four hundred and twenty patients (age 17-60 years) were analyzed for the TERT A1062T variant by direct sequencing. Fifteen patients (3.6%) carried the TERT A1062T variant. Patients with the TERT A1062T variant had a trend towards less favorable and more intermediate 2/adverse karyotypes/genotypes according to the European Leukemia Net classification. In univariate and multivariate analysis, patients with the TERT A1062T variant had a significantly inferior overall survival compared to wild-type patients (6-year overall survival 20 vs. 41%, p = 0.005). Patients with the TERT A1062T variant showed a high rate of treatment-related mortality: 5/15 (33%) died during induction therapy or in complete remission as compared to 62/405 (15%) of the wild-type patients. In patients with the TERT variant, 14/15 (93%) suffered from non-hematological/non-infectious grade 3/4 adverse events (mostly hepatic and/or mucosal) as compared to 216/405 (53%) wild-type patients (p = 0.006). In multivariate analysis, the TERT A1062T variant was an independent risk factor predicting for adverse events during induction chemotherapy. In conclusion, the TERT A1062T variant is an independent negative prognostic factor in younger patients with acute myeloid leukemia and seems to predispose those patients to treatment-related toxicity.

Hydrophobins in the Life Cycle of the Ectomycorrhizal Basidiomycete Tricholoma vaccinum.

Hydrophobins-secreted small cysteine-rich, amphipathic proteins-foster interactions of fungal hyphae with hydrophobic surfaces, and are involved in the formation of aerial hyphae. Phylogenetic analyses of Tricholoma vaccinum hydrophobins showed a grouping with hydrophobins of other ectomycorrhizal fungi, which might be a result of co-evolution. Further analyses indicate angiosperms as likely host trees for the last common ancestor of the genus Tricholoma. The nine hydrophobin genes in the T. vaccinum genome were investigated to infer their individual roles in different stages of the life cycle, host interaction, asexual and sexual development, and with respect to different stresses. In aerial mycelium, hyd8 was up-regulated. In silico analysis predicted three packing arrangements, i.e., ring-like, plus-like and sheet-like structure for Hyd8; the first two may assemble to rodlets of hydrophobin covering aerial hyphae, whereas the third is expected to be involved in forming a two-dimensional network of hydrophobins. Metal stress induced hydrophobin gene hyd5. In early steps of mycorrhization, induction of hyd4 and hyd5 by plant root exudates and root volatiles could be shown, followed by hyd5 up-regulation during formation of mantle, Hartig' net, and rhizomorphs with concomitant repression of hyd8 and hyd9. During fruiting body formation, mainly hyd3, but also hyd8 were induced. Host preference between the compatible host Picea abies and the low compatibility host Pinus sylvestris could be linked to a stronger induction of hyd4 and hyd5 by the preferred host and a stronger repression of hyd8, whereas the repression of hyd9 was comparable between the two hosts.

Expression of Hedgehog Pathway Mediator GLI Represents a Negative Prognostic Marker in Human Acute Myeloid Leukemia and Its Inhibition Exerts Antileukemic Effects.

PURPOSE: The Hedgehog pathway plays an important role in stem-cell biology and malignant transformation. Therefore, we investigated the expression and prognostic impact of Hedgehog pathway members in acute myeloid leukemia (AML). EXPERIMENTAL DESIGN: Pretreatment samples from 104 newly diagnosed AML patients (AMLSG 07-04 trial) were analyzed by qPCR, and expression of Hedgehog family members was correlated with clinical outcome. Inhibition of GLI by GANT61 or shRNA was investigated in AML cells in vitro and in vivo. RESULTS: Expression of receptors Smoothened and Patched-1 and their downstream mediators, GLI1, GLI2, and GLI3, was found in AML patients in contrast to Hedgehog ligands. GLI2 expression had a significant negative influence on event-free survival (EFS), relapse-free survival (RFS), and overall survival (OS; P = 0.037, 0.026, and 0.013, respectively) and was correlated with FLT3 mutational status (P < 0.001). Analysis of a second, independent patient cohort confirmed the negative impact of GLI2 on EFS and OS (P = 0.007 and 0.003, respectively; n = 290). Within this cohort, GLI1 had a negative prognostic impact (P < 0.001 for both EFS and OS). Although AML cells did not express Hedgehog ligands by qPCR, AML patients had significantly increased Desert Hedgehog (DHH) plasma levels compared with healthy subjects (P = 0.002), in whom DHH was presumably provided by bone marrow niche cells. Moreover, the GLI inhibitor GANT61 or knockdown of GLI1/2 by shRNA caused antileukemic effects, including induction of apoptosis, reduced proliferation, and colony formation in AML cells, and a survival benefit in mice. CONCLUSIONS: GLI expression is a negative prognostic factor and might represent a novel druggable target in AML.

Lack of noncanonical RAS mutations in cytogenetically normal acute myeloid leukemia.

Transforming mutations in RAS genes are commonly found in human malignancies, including myeloid leukemias. To investigate the incidence, spectrum, and distribution of activating K- and N-RAS mutations in cytogenetically normal acute myeloid leukemia (CN-AML) patients, 204 CN-AML patients were screened. Activating K- and N-RAS mutations were detected in 3 of 204 (1.5 %) and 22 of 204 (10.8 %) CN-AML samples, respectively. RAS mutated patients presented with a lower percentage of bone marrow blasts (65 vs 80 %, P = 0.022). RAS mutations tended to occur with nucleophosmin-1 (NPM1) mutations (P = 0.079), and all three samples containing K-RAS mutations had concomitant NPM1 mutations. There was no significant overlap between K-RAS mutations and N-RAS, FLT3, CEBPA, IDH1/2, WT1 or MLL mutations. RAS mutation status did not impact relapse-free or overall survival of CN-AML patients. In contrast to reports of noncanonical RAS mutations in other cancers, including some leukemia subtypes, we only observed K- and N-RAS mutations in codons 12, 13, or 61 in CN-AML samples. Our findings suggest that while K-RAS mutations are infrequent in CN-AML, activating K-RAS mutations may cooperate with mutated NPM1 to induce leukemia.

Prognostic significance of expression levels of stem cell regulators MSI2 and NUMB in acute myeloid leukemia.

Deregulation of the hematopoietic stem cell (HSC) compartment represents a hallmark of acute myeloid leukemia (AML). Recently, in vivo screening for genes that are involved in the regulation of HSCs has led to the discovery of Musashi-2 (MSI2) as a key regulator of HSCs and as a suppressor of NUMB. In order to analyze the prognostic importance of MSI2 and NUMB expression in AML, MSI2 and NUMB transcript levels from 454 AML patients treated in multicenter trials AML SHG 0199 (ClinicalTrials Identifier NCT00209833) and 0295, and 38 healthy volunteers were analyzed by reverse transcriptase PCR in the context of other molecular markers (NPM1, FLT3, CEBPA, IDH1/IDH2, DNMT3A, NRAS, WT1, KIT, MN1, BAALC, ERG, and WT1). In AML, patients with high MSI2 expression were more likely to be FLT3-ITD positive (P < .001), NPM1 (P < .001), and DNMT3A (P = .003) mutated. Overall survival (OS) was shorter in AML patients with high MSI2 expression (hazard ratio, 1.48; 95 % confidence interval, 1.13-1.95, P = .005). However, relapse-free survival (RFS, P = .15) and complete remission (CR, P = .39) rates were not influenced by MSI2 expression. In multivariate analysis, MSI2 expression remained an independent prognostic factor for OS (P = .03). NUMB expression had no impact on survival (OS, P = .47; RFS, P = .59) and CR rate (P = .39). MSI2 but not NUMB is associated with shorter OS in AML patients and may indicate a more aggressive form of AML.

ID1 expression associates with other molecular markers and is not an independent prognostic factor in cytogenetically normal acute myeloid leukaemia.

In acute myeloid leukaemia with normal karyotype (CN-AML), gene mutations (e.g. NPM1, FLT3, CEBPA) as well as deregulated gene expression affect outcome. High expression of ID1 was described as a negative prognostic factor. We have shown that CEBPA regulates ID1 expression. Therefore, we analysed the prognostic impact of ID1 expression in 269 patients (aged 16-60 years) with CN-AML in the context of other molecular markers, particularly CEBPA mutations. ID1(high) status was an independent negative prognostic factor for overall survival (OS) in multivariate analysis when analysed together with age, extramedullary disease, platelets, expression of BAALC and WT1, FLT3-internal tandem duplication, NPM1, WT1 single nucleotide polymorphism rs16754 and IDH1. ID1 expression was higher in CEBPA wildtype patients than in patients with monoallelic CEBPA mutations and these patients showed higher ID1 expression compared to patients with biallelic CEBPA mutations. Thus, when CEBPA mutations were considered, ID1 expression lost its prognostic impact. Likewise, the negative impact of ID1(high) status on relapse-free survival (RFS) was lost when CEBPA mutations were included in the analysis. In CEBPA wildtype patients, ID1 expression had no impact on complete remission-rate, OS or RFS. In conclusion, CEBPA mutations seem to deregulate ID1 expression. Therefore, ID1 expression is not an independent prognostic factor in CN-AML.

Prognostic significance of combined MN1, ERG, BAALC, and EVI1 (MEBE) expression in patients with myelodysplastic syndromes.

Overexpression of MN1, ERG, BAALC, and EVI1 (MEBE) genes in cytogenetically normal acute myeloid leukemia (AML) patients is associated with poor prognosis, but their prognostic effect in patients with myelodysplastic syndromes (MDS) has not been studied systematically. Expression data of the four genes from 140 MDS patients were combined in an additive score, which was validated in an independent patient cohort of 110 MDS patients. A high MEBE score, defined as high expression of at least two of the four genes, predicted a significantly shorter overall survival (OS) (HR 2.29, 95 % CI 1.3-4.09, P= .005) and time to AML progression (HR 4.83, 95 % CI 2.01-11.57, P< .001) compared to a low MEBE score in multivariate analysis independent of karyotype, percentage of bone marrow blasts, transfusion dependence, ASXL1, and IDH1 mutation status. In a validation cohort of 110 MDS patients, a high MEBE score predicted shorter OS (HR 1.77; 95 % CI 1.04-3.0, P= .034) and time to AML progression (HR 3.0, 95 % CI 1.17-7.65, P= .022). A high MEBE expression score is an unfavorable prognostic marker in MDS and is associated with an increased risk for progression to AML. Expression of the MEBE genes is regulated by FLI1 and c-MYC, which are potential upstream targets of the MEBE signature.

Rare occurrence of DNMT3A mutations in myelodysplastic syndromes.

Gene mutations and epigenetic changes have been shown to play significant roles in the pathogenesis of myelodysplastic syndromes. Recently, mutations in DNMT3A were identified in 22.1% of patients with acute myeloid leukemia. In this study, we analyzed the frequency and clinical impact of DNMT3A mutations in a cohort of 193 patients with myelodysplastic syndromes. Mutations in DNMT3A were found in 2.6% of patients. The majority of mutations were heterozygous missense mutations affecting codon R882. Patients with DNMT3A mutations were found to have a higher rate of transformation to acute myeloid leukemia. When assessing the global methylation levels in patients with mutated versus unmutated DNMT3A and healthy controls no difference in global DNA methylation levels between the two groups was seen. Our data show that in patients with myelodysplastic syndromes, DNMT3A mutations occur at a low frequency and may be a risk factor for leukemia progression.

Qualitative and quantitative evaluation of bony structures based on DICOM dataset.

PURPOSE: The aim of this study was to investigate bone mass using different cone-beam computed tomographies (CBCTs) combined with image analysis and to determine whether bone quantity or quality was detected. MATERIALS AND METHODS: Different measurements recorded on mandible bones of pigs in the retromolar region were evaluated on ProMax 3D (Planmeca Oy, Finland) and the ILUMA™CT (IMTEC™ Imaging, Ardmore, OK) to calculate a calibration curve. The spatial relationships of pig mandible halves relative to adjacent defined anatomical structures were assessed by means of 3D visualization software. In addition to the screenshot, their bone quality was evaluated in accordance with the Lenkholm and Zarb classification. RESULTS: The CBCT calibration curves based on the measurements taken from the ProMax and ILUMA CT showed linear correlation. Huge Hounsfield units intervals were found between the 2 CBCTs and there was no correlation with the computed tomography. Exact information on the micromorphology of the bone cylinders was not available. A subjective correlation according to Lenkholm and Zarb showed overlapping in all groups. CONCLUSIONS: CBCT is a good choice for analyzing bone mass. However, it does not provide any information on bone quality. To obtain information on the microarchitecture of the spongiosa, it is necessary to use a computed tomography with finite element analysis.

Incidence and prognostic influence of DNMT3A mutations in acute myeloid leukemia.

PURPOSE: To study the incidence and prognostic impact of mutations in DNA methyltransferase 3A (DNMT3A) in patients with acute myeloid leukemia. PATIENTS AND METHODS: A total of 489 patients with AML were examined for mutations in DNMT3A by direct sequencing. The prognostic impact of DNMT3A mutations was evaluated in the context of other clinical prognostic markers and genetic risk factors (cytogenetic risk group; mutations in NPM1, FLT3, CEBPA, IDH1, IDH2, MLL1, NRAS, WT1, and WT1 SNPrs16754; expression levels of BAALC, ERG, EVI1, MLL5, MN1, and WT1). RESULTS: DNMT3A mutations were found in 87 (17.8%) of 489 patients with AML who were younger than 60 years of age. Patients with DNMT3A mutations were older, had higher WBC and platelet counts, more often had a normal karyotype and mutations in NPM1, FLT3, and IDH1 genes, and had higher MLL5 expression levels as compared with patients with wild-type DNMT3A. Mutations in DNMT3A independently predicted a shorter overall survival (OS; hazard ratio [HR], 1.59; 95% CI, 1.15 to 2.21; P = .005) by multivariate analysis, but were not associated with relapse-free survival (RFS) or complete remission (CR) rate when the entire patient cohort was considered. In cytogenetically normal (CN) AML, 27.2% harbored DNMT3A mutations that independently predicted shorter OS (HR = 2.46; 95% CI, 1.58 to 3.83; P < .001) and lower CR rate (OR, 0.42; 95% CI, 0.21 to 0.84; P = .015), but not RFS (P = .32). Within patients with CN-AML, DNMT3A mutations had an unfavorable effect on OS, RFS, and CR rate in NPM1/FLT3-ITD high-risk but not in low-risk patients. CONCLUSION: DNMT3A mutations are frequent in younger patients with AML and are associated with an unfavorable prognosis.

Prognostic significance of ASXL1 mutations in patients with myelodysplastic syndromes.

PURPOSE: To study the incidence and prognostic impact of mutations in Additional sex comb-like 1 (ASXL1) in a large cohort of patients with myelodysplastic syndrome (MDS). PATIENTS, MATERIALS, AND METHODS: Overall, 193 patients with MDS and 65 healthy volunteers were examined for ASXL1 mutations by direct sequencing and for expression levels of ASXL1. The prognostic impact of ASXL1 mutation and expression levels was evaluated in the context of other clinical and molecular prognostic markers. RESULTS: Mutations in ASXL1 occurred with a frequency of 20.7% in MDS (n = 40 of 193) with 70% (n = 28) of mutations being frameshift mutations and 30% (n = 12) being heterozygous point mutations leading to translational changes. ASXL1 mutations were correlated with an intermediate-risk karyotype (P = .002) but not with other clinical parameters. The presence of ASXL1 mutations was associated with a shorter overall survival for frameshift and point mutations combined (hazard ratio [HR], 1.744; 95% CI, 1.08 to 2.82; P = .024) and for frameshift mutations only (HR, 2.06; 95% CI, 1.21 to 3.50; P = .008). ASXL1 frameshift mutations were associated with a reduced time to progression of acute myeloid leukemia (AML; HR 2.35; 95% CI, 1.17 to 4.74; P = .017). In multivariate analysis, when considering karyotype, transfusion dependence, and IDH1 mutation status, ASXL1 frameshift mutations remained an independent prognostic marker in MDS (overall survival: HR, 1.85; 95% CI, 1.03 to 3.34; P = .040; time to AML progression: HR, 2.39; 95% CI, 1.12 to 5.09; P = .024). CONCLUSION: These results suggest that ASXL1 mutations are frequent molecular aberrations in MDS that predict an adverse prognostic outcome. Screening of patients for ASXL1 mutations might be useful for clinical risk stratification and treatment decisions in the future.

Integrative prognostic risk score in acute myeloid leukemia with normal karyotype.

To integrate available clinical and molecular information for cytogenetically normal acute myeloid leukemia (CN-AML) patients into one risk score, 275 CN-AML patients from multicenter treatment trials AML SHG Hannover 0199 and 0295 and 131 patients from HOVON/SAKK protocols as external controls were evaluated for mutations/polymorphisms in NPM1, FLT3, CEBPA, MLL, NRAS, IDH1/2, and WT1. Transcript levels were quantified for BAALC, ERG, EVI1, ID1, MN1, PRAME, and WT1. Integrative prognostic risk score (IPRS) was modeled in 181 patients based on age, white blood cell count, mutation status of NPM1, FLT3-ITD, CEBPA, single nucleotide polymorphism rs16754, and expression levels of BAALC, ERG, MN1, and WT1 to represent low, intermediate, and high risk of death. Complete remission (P = .005), relapse-free survival (RFS, P < .001), and overall survival (OS, P < .001) were significantly different for the 3 risk groups. In 2 independent validation cohorts of 94 and 131 patients, the IPRS predicted different OS (P < .001) and RFS (P < .001). High-risk patients with related donors had longer OS (P = .016) and RFS (P = .026) compared with patients without related donors. In contrast, intermediate-risk group patients with related donors had shorter OS (P = .003) and RFS (P = .05). Donor availability had no impact on outcome of patients in the low-risk group. Thus, the IPRS may improve consolidation treatment stratification in CN-AML patients. Study registered at www.clinicaltrials.gov as #NCT00209833.

Prognostic importance of histone methyltransferase MLL5 expression in acute myeloid leukemia.

PURPOSE: To assess the prognostic importance of mixed lineage leukemia 5 (MLL5) expression in acute myeloid leukemia (AML). PATIENTS AND METHODS: MLL5 transcript levels from 509 patients with AML who were treated in multicenter trials AML SHG 0199 and AML SHG 0295 and 48 healthy volunteers were analyzed by real-time reverse-transcription polymerase chain reaction in the context of other molecular markers (NPM1, FLT3, CEBPA, IDH1/IDH2, NRAS, KIT, MN1, BAALC, ERG, and WT1). RESULTS: Patients with high (n = 127) compared with low (n = 382) MLL5 expression had a higher complete response rate in multivariate analysis (odds ratio, 1.87; 95% CI, 1.08 to 3.24; P = .026). In multivariate analysis, high MLL5 expression was a favorable prognostic marker for overall survival (OS; hazard ratio [HR], 0.66; 95% CI, 0.49 to 0.89; P = .007) and relapse-free survival (RFS; HR, 0.72; 95% CI, 0.52 to 1.01; P = .057). Patient characteristics, cytogenetic aberrations, and gene mutations were similarly distributed between patients with high and low MLL5 expression except for a higher platelet count in those with high MLL5 expression. MLL5 expression independently predicted prognosis in cytogenetically normal AML patients (n = 268; OS: HR, 0.53; 95% CI, 0.33 to 086; P = .011; RFS: HR, 0.61; 95% CI, 0.38 to 0.99; P = .05) and in patients with core-binding factor leukemias (n = 81; OS: HR, 0.12; 95% CI, 0.02 to 0.91; P = .04; RFS: HR, 0.18; 95% CI, 0.04 to 0.77; P = .02). The prognostic importance of high MLL5 expression was independently validated in 167 patients treated in the AMLSG 07/04 trial (OS: HR, 0.5; 95% CI, 0.27 to 0.92; P = .023; RFS: HR, 0.49; 95% CI, 0.25 to 0.96; P = .033). CONCLUSION: High MLL5 expression levels are associated with a favorable outcome and may improve risk and treatment stratification in AML.

FLT3-internal tandem duplication and age are the major prognostic factors in patients with relapsed acute myeloid leukemia with normal karyotype.

BACKGROUND: Several genetic aberrations with prognostic impact in first-line therapy have been described in patients with acute myeloid leukemia and normal karyotype. However, little is known about the influence of these aberrations on outcome after relapse. This study aimed to identify clinical and molecular risk factors for patients with relapsed acute myeloid leukemia with normal karyotype. DESIGN AND METHODS: We analyzed 94 patients with acute myeloid leukemia and normal karyotype after first relapse for clinical and molecular risk factors for survival. All patients had received first-line treatment and follow-up within two prospective, multicenter trials. Leukemic blasts were analyzed at diagnosis for genetic aberrations in the FLT3, NPM1, CEBPA, WT1, IDH1 and IDH2 genes by polymerase chain reaction and/or direct sequencing. RESULTS: A second complete remission was achieved in 52% of patients who received re-induction therapy. The presence of an FLT3-internal tandem duplication, duration of first complete remission less than 6 months and age above the median of 47 years were associated with a significantly lower rate of second complete remission. The median survival after relapse was 11 months and the 6-year survival rate was 28%. In multivariate analysis, FLT3-internal tandem duplication and age above the median were the only independent negative prognostic factors for survival. The 6-year survival rate of patients with none of these factors was 56%, whereas it was significantly inferior in patients with one or both of these factors (15% and 6%, respectively). This was also true for patients who underwent allogeneic stem cell transplantation after relapse. CONCLUSIONS: FLT3-internal tandem duplication and age are the major prognostic factors in patients with relapsed acute myeloid leukemia with a normal karyotype. Patients with at least one of these risk factors have a dismal outcome and might be considered for investigational treatment approaches after relapse. (ClinicalTrials.gov Identifier: NCT00209833).

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.

Prognostic impact of IDH2 mutations in cytogenetically normal acute myeloid leukemia.

Mutations in the nicotinamide adenine dinucleotide phosphate(+)-dependent isocitrate dehydrogenase gene 2 (IDH2) have recently been found in patients with acute myeloid leukemia (AML) as well as in patients with leukemic transformation of myeloproliferative neoplasms. We analyzed 272 adult patients with cytogenetically normal AML (CN-AML) for the presence of IDH2 mutations in codons R140 and R172. IDH2 mutations of amino acid 140 or 172 could be identified in 12.1% of CN-AML patients, with the majority of mutations (90%) occurring at position R140. The incidence of IDH2 mutations in AML patients with aberrant karyotypes (n = 130) was significantly lower (3.8%, P = .006). IDH2 mutations were mutually exclusive with mutations in IDH1. IDH2 mutation status alone or in combination with IDH1 mutations had no impact on response to therapy, overall survival, and relapse-free survival in patients with CN-AML. In conclusion, IDH2 mutations are frequently found in CN-AML, but in our analysis these mutations did not influence treatment outcome. This study was registered at www.clinicaltrials.gov as #NCT00209833.

Impact of IDH1 R132 mutations and an IDH1 single nucleotide polymorphism in cytogenetically normal acute myeloid leukemia: SNP rs11554137 is an adverse prognostic factor.

PURPOSE: We assessed the prognostic impact of IDH1 R132 mutations and a known single nucleotide polymorphism (SNP) located in the same exon of the IDH1 gene in patients with cytogenetically normal acute myeloid leukemia (CN-AML) in the context of other prognostic markers. PATIENTS AND METHODS: IDH1 exon four was directly sequenced in 275 CN-AML patients from two subsequent AML multicenter treatment trials and 120 healthy volunteers. Moreover, mutations in NPM1, FLT3, CEBPA, and WT1 were analyzed, and mRNA expression of IDH1 was quantified. RESULTS: IDH1 R132 mutations were found in 10.9% of CN-AML patients. IDH1 SNP rs11554137 was found in 12% of CN-AML patients and 11.7% of healthy volunteers. IDH1 R132 mutations had no impact on prognosis. In contrast, IDH1 SNP rs11554137 was an adverse prognostic factor for overall survival in univariate and multivariate analysis. Other significant factors were age, NPM1/FLT3 mutational status, WT1 SNP rs16754, and platelet count. The impact of IDH1 SNP rs11554137 was most pronounced in the NPM1/FLT3 high-risk patients (either NPM1 wild-type or FLT3-internal tandem duplication positive). Patients with IDH1 SNP rs11554137 had a higher expression of IDH1 mRNA than patients with two wild-type alleles. CONCLUSION: IDH1 SNP rs11554137 but not IDH1 R132 mutations are associated with an inferior outcome in CN-AML.

Prognostic factors in adult patients up to 60 years old with acute myeloid leukemia and translocations of chromosome band 11q23: individual patient data-based meta-analysis of the German Acute Myeloid Leukemia Intergroup.

PURPOSE: To identify risk factors for induction success and overall survival (OS) and relapse-free survival (RFS) and to evaluate the impact of allogeneic stem-cell transplantation (alloSCT) in adult patients up to 60 years old with acute myeloid leukemia (AML) and reciprocal translocations involving chromosome band 11q23 [t(11q23)]. PATIENTS AND METHODS: An individual patient data-based meta-analysis was performed on 180 adult patients with AML and t(11q23). These patients were identified by cytogenetics and/or molecular techniques and treated within eight prospective multicenter trials of the German AML Intergroup. The median follow-up time was 53 months. RESULTS: Complete remission rate was 71%. Favorable factors for induction success were the presence of a t(9;11), t(11q23) as a sole aberration, and de novo leukemia. OS rate at 4 years was 29%. Translocations other than t(9;11), platelets less than the median, secondary leukemia, and peripheral blasts greater than the median were adverse risk factors for OS. RFS rate at 4 years was 29%. The presence of a t(6;11) and peripheral blasts greater than the median had a negative impact on RFS. Three risk groups for OS and RFS could be defined by the combination of these factors with 4-year OS rates of 50%, 28%, and 5% and 4-year RFS rates of 37%, 26%, and 5%. An alloSCT from matched related or unrelated donors in first complete remission was beneficial, especially in t(6;11)-negative patients. CONCLUSION: Risk stratification of AML patients with reciprocal translocations of chromosome band 11q23 is feasible based on the translocation partner and clinical parameters.