, which encodes the tumor suppressor p53, is the most frequently mutated gene in human cancer. The selective pressures shaping its mutational spectrum, dominated by missense mutations, are enigmatic, ...and neomorphic gain-of-function (GOF) activities have been implicated. We used CRISPR-Cas9 to generate isogenic human leukemia cell lines of the most common
missense mutations. Functional, DNA-binding, and transcriptional analyses revealed loss of function but no GOF effects. Comprehensive mutational scanning of p53 single-amino acid variants demonstrated that missense variants in the DNA-binding domain exert a dominant-negative effect (DNE). In mice, the DNE of p53 missense variants confers a selective advantage to hematopoietic cells on DNA damage. Analysis of clinical outcomes in patients with acute myeloid leukemia showed no evidence of GOF for
missense mutations. Thus, a DNE is the primary unit of selection for
missense mutations in myeloid malignancies.
The German Research Foundation (DFG) and the Federal Ministry of Education and Research (BMBF) initiated large research programs to foster high quality clinical research in the academic area. These ...investigator initiated trials (IITs) cover important areas of medical research and often go beyond the scope of industry sponsored trials (ISTs). The purpose of this project was to understand to what extent results of randomized controlled IITs and ISTs have an impact on medical practice, measured by their availability for decisions in healthcare and their implementation in clinical practice. We aimed to determine study characteristics influencing a trial's impact such as type of sponsor and place of conduct. In this article, we describe the rationale and design of this project and present the characteristics of the trials included in our study cohort.
The research impact of the following sub-cohorts was compared: German IITs (funded by DFG and BMBF or by other German non-commercial organizations), international IITs (without German contribution), German ISTs, and international ISTs. Trials included were drawn from the DFG-/BMBF-Websites, the German Clinical Trials Register, and from ClinicalTrials.gov . Research impact was measured as follows: 1) proportion of published trials, 2) time to publication, 3) proportion of publications appropriately indexed in biomedical databases, 4) proportion of openly accessible publications, 5) broadness of publication's target group, 6) citation of publications by systematic reviews or meta-analyses, and 7) appearance of publications or citing systematic reviews or meta-analyses in clinical practice guidelines. We also aimed to identify study characteristics associated with the impact of trials.
We included 691 trials: 120 German IITs, 200 International IITs, 171 German ISTs and 200 International ISTs. The median number of participants was 150, 30% were international trials and 70% national trials, 48% drug-trials and 52% non-drug trials. Overall, 72% of the trials had one pre-defined primary endpoint, 28% two or more (max. 36).
The results of this project deepen our understanding of the impact of biomedical research on clinical practice and healthcare policy, add important insights for the efficient allocation of scarce research resources and may facilitate providing accountability to the different stakeholders involved.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In the international randomized phase 3 RATIFY (Randomized AML Trial In FLT3 in patients less than 60 Years old) trial, the multikinase inhibitor midostaurin significantly improved overall and ...event-free survival in patients 18 to 59 years of age with FLT3-mutated acute myeloid leukemia (AML). However, only 59% of patients in the midostaurin arm achieved protocol-specified complete remission (CR), and almost half of patients achieving CR relapsed. To explore underlying mechanisms of resistance, we studied patterns of clonal evolution in patients with FLT3-internal tandem duplications (ITD)-positive AML who were entered in the RATIFY or German-Austrian Acute Myeloid Leukemia Study Group 16-10 trial and received treatment with midostaurin. To this end, paired samples from 54 patients obtained at time of diagnosis and at time of either relapsed or refractory disease were analyzed using conventional Genescan-based testing for FLT3-ITD and whole exome sequencing. At the time of disease resistance or progression, almost half of the patients (46%) became FLT3-ITD negative but acquired mutations in signaling pathways (eg, MAPK), thereby providing a new proliferative advantage. In cases with FLT3-ITD persistence, the selection of resistant ITD clones was found in 11% as potential drivers of disease. In 32% of cases, no FLT3-ITD mutational change was observed, suggesting either resistance mechanisms bypassing FLT3 inhibition or loss of midostaurin inhibitory activity because of inadequate drug levels. In summary, our study provides novel insights into the clonal evolution and resistance mechanisms of FLT3-ITD–mutated AML under treatment with midostaurin in combination with intensive chemotherapy.
•At the time of disease resistance or progression, ∼50% of patients treated with midostaurin become FLT3-ITD negative.•FLT3-ITD persistence can be caused by selection of resistant FLT3 clones, mechanisms bypassing FLT3 inhibition, or insufficient drug activity.
Display omitted
The majority of patients with acute myeloid leukemia (AML) are older and exhibit a poor prognosis even after intensive therapy. Inducing differentiation and apoptosis of leukemic blasts by ...DNA-hypomethylating agents, like e.g. azacytidine (AZA) and decitabine (DAC), represent well-tolerated alternative treatment approaches. Both agents show convincing response as single agents in AML. However, there is a lack of knowledge regarding molecular mechanisms and predictive biomarkers for these agents. Areas covered: This review will (i) provide an overview of the current knowledge of molecular mechanisms underlying the action of these drugs, (ii) report promising predictive biomarkers, (iii) elude on new combined treatment options, and (iv) discuss novel approaches to improve outcomes. A literature search was performed using PubMed to find recent major publications, which provide biological and clinical research about epigenetic therapy in AML patients. Expert commentary: Numerous studies have demonstrated that HMA therapy with AZA or DAC may lead to significant response rates, even in pre-treated patients. Nevertheless, there is still an unmet need to further improve outcome in elderly AML patients. Therefore, novel treatment combinations are needed and some of them, such as AZA plus venetoclax, already show promising results.
The role of subclonal
mutations, defined by a variant allele frequency of <20%, has not been addressed in acute myeloid leukemia yet. We, therefore, analyzed their prognostic value in a cohort of ...1,537 patients with newly diagnosed disease, prospectively treated within three trials of the "German-Austrian Acute Myeloid Leukemia Study Group". Mutational analysis was performed by targeted deep sequencing and patients with
mutations were categorized by their variant allele frequency into groups with frequencies >40%, 20%-40% and <20%. A total of 108
mutations were found in 98 patients (6.4%). Among these, 61 patients had variant allele frequencies >40%, 19 had variant allele frequencies between 20%-40% and 18 had frequencies <20%. Compared to specimens with clonal
mutations, those with subclonal ones showed significantly fewer complex karyotypes and chromosomal losses. In either
-mutated group, patients experienced significantly fewer complete responses (
<0.001) and had worse overall and event-free survival rates (
<0.0001). In Cox regression analyses adjusting for age, white blood cell count, cytogenetic risk and type of acute myeloid leukemia, the adverse prognostic effect of
mutations remained significant for all
-mutated subgroups. These data suggest that subclonal
mutations are a novel prognostic parameter in acute myeloid leukemia and emphasize the usefulness of next-generation sequencing technologies for risk stratification in this disorder. The study was registered at ClinicalTrials.gov with number NCT00146120.
Monitoring of measurable residual disease (MRD) provides prognostic information in patients with Nucleophosmin1-mutated (NPM1mut) acute myeloid leukemia (AML) and represents a powerful tool to ...evaluate treatment effects within clinical trials. We determined NPM1mut transcript levels (TLs) by quantitative reverse-transcription polymerase chain reaction and evaluated the prognostic impact of NPM1mut MRD and the effect of gemtuzumab ozogamicin (GO) on NPM1mut TLs and the cumulative incidence of relapse (CIR) in patients with NPM1mut AML enrolled in the randomized phase 3 AMLSG 09-09 trial. A total of 3733 bone marrow (BM) samples and 3793 peripheral blood (PB) samples from 469 patients were analyzed. NPM1mut TL log10 reduction ≥ 3 and achievement of MRD negativity in BM and PB were significantly associated with a lower CIR rate, after 2 treatment cycles and at end of treatment (EOT). In multivariate analyses, MRD positivity was consistently revealed to be a poor prognostic factor in BM and PB. With regard to treatment effect, the median NPM1mut TLs were significantly lower in the GO-Arm across all treatment cycles, resulting in a significantly greater proportion of patients achieving MRD negativity at EOT (56% vs 41%; P = .01). The better reduction in NPM1mut TLs after 2 treatment cycles in MRD positive patients by the addition of GO led to a significantly lower CIR rate (4-year CIR, 29.3% vs 45.7%, P = .009). In conclusion, the addition of GO to intensive chemotherapy in NPM1mut AML resulted in a significantly better reduction in NPM1mut TLs across all treatment cycles, leading to a significantly lower relapse rate.
•Measurable residual disease monitoring is of prognostic relevance in NPM1mut acute myeloid leukemia patients.•Gemtuzumab ozogamicin given to intensive therapy led to better clearance of NPM1mut transcript level, resulting in a lower relapse rate.
Display omitted
We performed serial measurable residual disease (MRD) monitoring in bone marrow (BM) and peripheral blood (PB) samples of 155 intensively treated patients with RUNX1-RUNX1T1+ AML, using a ...qRT-PC–based assay with a sensitivity of up to 10−6. We assessed both reduction of RUNX1-RUNX1T1 transcript levels (TLs) and achievement of MRD negativity (MRD−) for impact on prognosis. Achievement of MR2.5 (>2.5 log reduction) after treatment cycle 1 and achievement of MR3.0 after treatment cycle 2 were significantly associated with a reduced risk of relapse (P = .034 and P = .028, respectively). After completion of therapy, achievement of MRD− in both BM and PB was an independent, favorable prognostic factor in cumulative incidence of relapse (4-year cumulative incidence relapse: BM, 17% vs 36%, P = .021; PB, 23% vs 55%, P = .001) and overall survival (4-year overall survival rate BM, 93% vs 70%, P = .007; PB, 87% vs 47%, P < .0001). Finally, during follow-up, serial qRT-PCR analyses allowed prediction of relapse in 77% of patients exceeding a cutoff value of 150 RUNX1-RUNX1T1 TLs in BM, and in 84% of patients exceeding a value of 50 RUNX1-RUNX1T1 TLs in PB. The KIT mutation was a significant factor predicting a lower CR rate and inferior outcome, but its prognostic impact was outweighed by RUNX1-RUNX1T1 TLs during treatment. Virtually all relapses occurred within 1 year after the end of treatment, with a very short latency from molecular to morphologic relapse, necessitating MRD assessment at short intervals during this time period. Based on our data, we propose a refined practical guideline for MRD assessment in RUNX1-RUNX1T1+ AML.
•MRD assessment in t(8;21) AML allows identification of patients at high relapse risk at defined time points during treatment and follow-up.•MRD after treatment is the most favorable factor for relapse risk and survival, and serial MRD analyses define cutoffs predicting relapse.
Display omitted
Mutations in the nucleophosmin 1 (NPM1) gene are considered founder mutations in the pathogenesis of acute myeloid leukemia (AML). To characterize the genetic composition of NPM1 mutated (NPM1
) AML, ...we assess mutation status of five recurrently mutated oncogenes in 129 paired NPM1
samples obtained at diagnosis and relapse. We find a substantial shift in the genetic pattern from diagnosis to relapse including NPM1
loss (n = 11). To better understand these NPM1
loss cases, we perform whole exome sequencing (WES) and RNA-Seq. At the time of relapse, NPM1
loss patients (pts) feature distinct mutational patterns that share almost no somatic mutation with the corresponding diagnosis sample and impact different signaling pathways. In contrast, profiles of pts with persistent NPM1
are reflected by a high overlap of mutations between diagnosis and relapse. Our findings confirm that relapse often originates from persistent leukemic clones, though NPM1
loss cases suggest a second "de novo" or treatment-associated AML (tAML) as alternative cause of relapse.
Mutations in the nucleophosmin 1 (NPM1) gene are considered a founder event in the pathogenesis of acute myeloid leukemia (AML). To address the role of clonal evolution in relapsed NPM1-mutated ...(NPM1mut) AML, we applied high-resolution, genome-wide, single-nucleotide polymorphism array profiling to detect copy number alterations (CNAs) and uniparental disomies (UPDs) and performed comprehensive gene mutation screening in 53 paired bone marrow/peripheral blood samples obtained at diagnosis and relapse. At diagnosis, 15 aberrations (CNAs, n = 10; UPDs, n = 5) were identified in 13 patients (25%), whereas at relapse, 56 genomic alterations (CNAs, n = 46; UPDs, n = 10) were detected in 29 patients (55%) indicating an increase in genomic complexity. Recurrent aberrations acquired at relapse included deletions affecting tumor suppressor genes (ETV6 n = 3, TP53 n = 2, NF1 n = 2, WT1 n = 3, FHIT n = 2) and homozygous FLT3 mutations acquired via UPD13q (n = 7). DNMT3A mutations (DNMT3Amut) showed the highest stability (97%). Persistence of DNMT3Amut in 5 patients who lost NPM1mut at relapse suggests that DNMT3Amut may precede NPM1mut in AML pathogenesis. Of note, all relapse samples shared at least 1 genetic aberration with the matched primary AML sample, implying common ancestral clones. In conclusion, our study reveals novel insights into clonal evolution in NPM1mut AML.
• Relapsed AML with NPM1 mutation is genetically related to the primary leukemia and characterized by an increase in high-risk aberrations.• DNMT3A mutations show the highest stability and thus may precede NPM1 mutations.
Aberrant expression of
Ecotropic Viral Integration Site 1 (EVI1)
is a hallmark of acute myeloid leukemia (AML) with inv(3) or t(3;3), which is a disease subtype with especially poor outcome. In ...studying transcriptomes from AML patients with chromosome 3q rearrangements, we identified a significant upregulation of the
Nuclear Receptor Interacting Protein 1 (NRIP1)
as well as its adjacent non-coding RNA
LOC101927745
. Utilizing transcriptomic and epigenomic data from over 900 primary samples from patients as well as genetic and transcriptional engineering approaches, we have identified several mechanisms that can lead to upregulation of
NRIP1
in AML. We hypothesize that the
LOC101927745
transcription start site harbors a context-dependent enhancer that is bound by EVI1, causing upregulation of
NRIP1
in AML with chromosome 3 abnormalities. Furthermore, we showed that
NRIP1
knockdown negatively affects the proliferation and survival of 3q-rearranged AML cells and increases their sensitivity to all
-trans
retinoic acid, suggesting that
NRIP1
is relevant for the pathogenesis of inv(3)/t(3;3) AML and could serve as a novel therapeutic target in myeloid malignancies with 3q abnormalities.
PDF
