Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined. Including the published data from the literature, a total of 107 in-frame KMT2A gene fusions have been identified so far. Further 16 rearrangements were out-of-frame fusions, 18 patients had no partner gene fused to 5'-KMT2A, two patients had a 5'-KMT2A deletion, and one ETV6::RUNX1 patient had an KMT2A insertion at the breakpoint. The seven most frequent TPGs and PTDs account for more than 90% of all recombinations of the KMT2A, 37 occur recurrently and 63 were identified so far only once. This study provides a comprehensive analysis of the KMT2A recombinome in acute leukemia patients. Besides the scientific gain of information, genomic breakpoint sequences of these patients were used to monitor minimal residual disease (MRD). Thus, this work may be directly translated from the bench to the bedside of patients and meet the clinical needs to improve patient survival.

Background: Response to induction chemotherapy assessed by quantification of minimal residual disease (MRD) is the strongest independent prognosticator in B precursor acute lymphoblastic leukemia (BCP-ALL). Molecular underpinnings of MRD poor response are insufficiently understood. Aims: We aimed to identify novel high-risk subtypes in adult BCP-ALL as cell-intrinsic determinants of MRD poor response. Methods: Adult BCP-ALL patients (n=565) were treated according to pediatric inspired protocols of the German Acute Lymphoblastic Leukemia Study group (GMALL) and profiled for integrative analyses by RNA-Seq (n=565), SNP-arrays (n=115), whole exome sequencing (WES; n=84) and whole genome sequencing (WGS; n=3). Results: Concordance between transcriptomic and genomic profiles was used to allocate samples to one of 15 established molecular driver subgroups (Figure A). Unsupervised clustering of gene expression from the remaining samples revealed a distinct cluster (n=12/565, 2.1%) with an in-frame gene fusion between upstream binding transcription factor (UBTF) and ataxin-7-like protein 3 (ATXN7L3) as exclusive event in these patients. Both fusion partners are in direct neighborship at 17q21.31. WGS revealed a 10.08 kb genomic deletion which truncated UBTF at exon 17/21 and comprised most of the intergenic region between both genes (Figure B). UBTF-ATXN7L3 rearranged cases frequently harbored 1q gains (n=5/7). Further genomic profiling showed a remarkable paucity of additional cooperating events compared to other molecular subtypes, supporting a prominent driver function of the newly identified fusion. UBTF and ATXN7L3 are global epigenetic regulators involved in transcriptional control. Both genes were highly expressed across the entire cohort. The gene fusion was associated with a marked increase of Caudal Homeobox 2 (CDX2) expression. Analysis of functional modules related CDX2 to upregulated HOXA9 and MEIS1, described essential co-regulators of KMT2A-driven leukemogenesis. NTRK3 expression was also strongly upregulated, suggesting a possible rationale for specific inhibitors. UBTF-AXTN7L3 rearranged patients were older, more frequently female and presented with normal leukocyte counts, low bone marrow infiltration and pro-B immunophenotypes or common ALL with reduced CD10 expression. Response to induction chemotherapy in evaluable patients (n=11) was poor with only 3 patients achieving MRD negativity after consolidation I compared to n=271/402 (67%; p=0.019) in the remaining cohort. Four patients suffered either cytologic (n=2) or molecular (n=2) relapse. Immunotherapeutic treatment intensification using blinatumomab (n=5) or inotuzumab ozogamizin (n=1) and / or allogenic stem cell transplantation (n=7) in MRD poor responders or relapsed cases resulted in an overall survival probability of 80% (+/- 12%) vs. 73% (+/- 2%; p=0.07) in the remaining cohort. Heterogeneous MRD responses were observed for other molecular subtypes (poor: ZNF384 - 48.2% MRD neg., p=0.056; Ph-like - 54.0% MRD neg., p=0.003; KMT2A - 55.8% MRD neg., p=0.127 / good: High Hyperdiploid - 90.9% MRD neg., p=0.01; TCF3-PBX1 - 94.1% MRD neg., p=0.016) indicating how molecular drivers affect chemo-sensitivity in adult BCP-ALL. Image:Summary/Conclusion: Molecular driver alterations determine sensitivity to induction chemotherapy in adult BCP-ALL. UBTF-ATXN7L3 ALL represents a novel subtype with poor induction chemotherapy response which could be successfully salvaged by MRD-based treatment intensification using immunotherapeutic strategies.

Background:Alterations of the tumor suppressor gene TP53 are observed in 15–20% of patients with acute lymphoid leukemia (ALL) and are associated with resistance to standard treatment regimens and inferior survival. TP53 mutations (TP53mt) have been reported as an early leukemogenic event in patients with acute myeloid leukemia. In ALL however, only limited data are available.Aims:Study the pre‐leukemic mutation pattern of TP53 gene in ALL patients. Therefore, we analyzed the kinetics of the TP53mt in bone marrow and peripheral blood in the group of 43 adult ALL patients harboring TP53mt at the diagnosis (Dx) and compared it to the kinetics of standard EuroMRD IG/TR minimal residual disease (MRD). Moreover, TP53mt were assessed in the distinct hematopoietic populations.Methods:Patients received induction/consolidation treatment according to the GMALL 07/03 and GMALL register protocol. For each patient, TP53‐mutations were analyzed in at least one Dx/MRD‐positive (n = 54) and one MRD‐negative sample, if available (n = 41). The presence of TP53mt was validated by Sanger sequencing and quantified using UMI‐based next generation amplicon sequencing (sensitivity: 5x10−3). In 5 patients, selected based on TP53mt‐status and on the availability of viable cells, distinct hematopoietic populations were sorted using FACS Aria sorter in an MRD‐negative follow‐up sample and analyzed for the presence of the TP53mt using allele‐specific digital droplet PCR (ddPCR, sensitivity: 1,5x10−3‐1x10−2). MRD was monitored using real‐time quantitative PCR of clonal immune gene rearrangements (sensitivity 1x10−5) and multiparameter flow cytometry.Results:In our series of 43 TP53mt ALL patients (B‐ALL 90.7%, T‐ALL 9.3%) MRD analysis revealed quantifiable IG/TR MRD persistence in 7 patients (16.3%), complete MRD remission in 30 patients (69.8%), and MRD persistence at not quantifiable levels in 6 patients (14.0%). In 9 of the MRD‐negative patients (20.9%) the TP53‐mutation was detected at levels between 2.0 and 17.4% (median 8.1%), pointing to the presence of TP53mt in a pre‐leukemic compartment. In 5 of 7 MRD‐persisters also TP53 mutations were detected. In the 2 remaining patients MRD‐level was below the TP53‐assay sensitivity. ddPCR analysis of the sorted, progenitor and mature hematopoietic populations revealed the presence of TP53mt in early hematopoietic cells including multipotent progenitors (MPP: CD19‐34+38−), common myeloid/lymphoid progenitors (CD19‐34+38+13/33−) and early myeloid progenitors (CD34+19‐38+13/33+) but also in differentiated cells as granulocytes (SSChighCD13/33dim) and monocytes (CD19‐34‐3‐13/33high). TP53mt was generally absent in the mature T cells but present in the B‐cell precursors defined as CD19+10+20‐34+ cells (Figure 1); altogether this data point to the pre‐leukemic origin of TP53mt. Interestingly, one patient who relapsed after two years with a fully unrelated IG/TR rearrangement still harbored the TP53mt from Dx sample, pointing to the involvement of the TP53mt in the ALL reoccurrence. The detailed analysis of other relapse‐associated mutations is currently ongoing. The correlation analysis of clinical outcome with the observed TP53 mutation pattern will also be performed.Summary/Conclusion:Hereby, we have shown that in a considerable number of adult ALL patients a TP53 mutation is present in pre‐leukemic cells, causing clonal expansions in different hematopoietic compartments, and thus persisting in MRD negative follow‐up samples. Considering TP53 somatic mutations as an MRD‐marker requires careful interpretation.image

lenalidomide (LEN) vs placebo (PBO) in 650 patients responding to R‐ CHOP, resulting in significantly improved PFS in patients treated with 2 years of LEN maintenance (P = .01). Methods: Relative risks (RR [95% CI]) were calculated on ITT patients to identify treatment effect and pre‐treatment variables that have an impact on patient's respective PD/relapse, death with relapse, or death without relapse. Mean change in HRQoL was assessed per the EORTC QLQ‐C30 v3.0 questionnaire at randomization (≤3 months post induction), cycles 6, 12, 21, end of maintenance (EOM), and 1‐year follow‐ up. The null hypothesis was to observe no difference in Global Health Status (GHS) between treatments and 1‐year follow‐up (Qs 29‐30; primary PRO endpoint). A minimal important difference (MID) of 10 defined the proportion of patients reporting a meaningful difference in QoL. Results: For the ITT population (N = 650), the RR of PD/relapse from DLBCL was lower in the LEN vs PBO arm (RR = 0.67). Irrespective of treatment arm, the risk of death after PD/relapse was associated with elevated aaIPI (RR = 1.80), and in patients who died without PD/ relapse, increased age ≥ 70 (RR = 5.17). HRQoL evaluable patients (n = 136 LEN, n = 127 PBO) had similar questionnaire completion rates at baseline: 59% LEN vs 56% PBO. Subscale scores at baseline were generally similar for LEN vs PBO, respectively: 68 vs 72 for GHS, 80 vs 85 for physical functioning and 32 vs 26 for fatigue. There was no change in MID ± 10 from baseline during maintenance in either group (Figure 1). No significant difference was shown in GHS (improvement, stable, worsening) between LEN and PBO. There was no change in MID ± 10 from baseline at any post‐randomization maintenance visit for secondary endpoints of physical functioning or fatigue subscales, nor in a subset of patients experiencing grade 3/4 treatment‐emergent neutropenia. Conclusions: Competing risk analysis confirmed that lenalidomide in maintenance prevents lymphoma progression without increasing toxic death risks. This analysis suggests that patient‐reported HRQoL in elderly patients with DLBCL receiving 2 years of maintenance LEN following R‐CHOP is not different from patients receiving PBO. HRQoL was maintained despite the higher incidence of grade 3/4 AEs, such as cytopenia, reported in the LEN arm.

Hintergrund: In der Behandlung des schweren Lungenemphysems stellt die endoskopische Lungenvolumenreduktion mittels Coil-Implantation eine erfolgversprechende Option dar. Zur Beurteilung der Effektivität und Sicherheit des Verfahrens werteten wir die in drei norddeutschen Zentren behandelten Patienten retrospektiv aus.

Grundlage: Die bronchoskopische Lungenvolumenreduktion mit Coils (LVRC) ist in multiplen Studien erfolgreich eigesetzt worden mit Verbesserung der Lungenfunktionswerte, der körperlichen Belastbarkeit sowie der Lebensqualität bei bilateral behandelten Patienten.

Follicular lymphoma (FL) with a t(14;18) is a B-cell neoplasm clinically characterized by multiple recurrencies. In order to investigate the clonal evolution of this lymphoma, we studied paired primary and relapse tumor samples from 33 patients with recurrent non-transformed t(14;18)-positive FL. We reconstructed phylogenetic trees of the evolution by taking advantage of the activation-induced cytidine deaminase (AID)-mediated somatic hypermutation (SHM) active in the germinal center reaction using sequences of the clonal V H D H J H rearrangements of the immunoglobulin heavy chain ( IGH ) locus. Mutational analysis of the IGH locus showed evidence for ongoing somatic mutation and for counter-selection of mutations affecting the BCR conformation during tumor evolution. We further followed evolutionary divergence by targeted sequencing of gene loci affected by aberrant SHM as well as of known driver genes of lymphomagenesis, and by array-based genome-wide chromosomal imbalance and DNA methylation analysis. We observed a wide spectrum of evolutionary patterns ranging from almost no evolution to divergent evolution within recurrent non-transformed t(14;18) FL. Remarkably, we observed a correlation of the magnitude of evolutionary divergence across all genetic and epigenetic levels suggesting co-evolution. The distribution of coding mutations in driver genes and the correlation with SHM suggest CREBBP and AID to be potential modifiers of genetic and epigenetic co-evolution in FL.