Study Alliance Leukemia Research Articles

Venetoclax-based salvage therapy as a bridge to transplant is feasible and effective in patients with relapsed/refractory AML

AbstractThe B-cell lymphoma 2 inhibitor venetoclax (VEN) in combination with hypomethylating agents has been approved for first-line treatment of patients with acute myeloid leukemia (AML) ineligible for intensive treatment. Emerging data suggest that VEN-containing treatment strategies may also be effective in relapsed/refractory (R/R) AML; however, comparative studies with conventional treatment strategies for medically fit patients as a bridge-to-transplant strategy are limited. Using propensity score matching (PSM) analysis, we compared 37 patients with R/R AML, who received VEN-based salvage therapy as bridge to allogeneic hematopoietic cell transplantation (allo-HCT), with 90 patients from the German Study Alliance Leukemia AML registry, who were treated with non–VEN-containing salvage therapy according to their treating physician’s choice (TPC), including intensive and nonintensive protocols. The overall response rate (complete remission [CR] + CR with incomplete hematologic recovery) among all VEN patients was significantly higher than the TPC control cohort (62% vs 42%; P = .049). Overall, 73% of VEN-treated patients vs 63% of TPC patients were successfully bridged to allo-HCT (P = .41). After a median follow-up of 34.3 months for the VEN cohort and 21.0 months for the TPC cohort, the median overall survival (OS) were 15.8 months (95% confidence interval [CI], 10.6 to NE) and 10.5 months (95% CI, 6.8-19.6; P = .15), respectively. PSM revealed a trend toward improved OS for VEN patients (HR, 0.70; 95% CI, 0.41-1.22; P = .20). Median event-free survival was significantly longer in the VEN cohort (8.0 months) than the TPC cohort (3.7 months; P = .006). In summary, our data suggest that VEN-based salvage therapy is a safe and effective bridge to allo-HCT for this difficult-to-treat AML patient population.

Single or Double Induction With 7 + 3 Containing Standard or High-Dose Daunorubicin for Newly Diagnosed AML: The Randomized DaunoDouble Trial by the Study Alliance Leukemia.

To determine the optimal daunorubicin dose and number of 7 + 3 induction cycles in newly diagnosed AML, this randomized controlled trial compared a once daily dose of 60 mg/m2 with 90 mg/m2 daunorubicin in the first 7 + 3 induction and one versus two cycles of 7 + 3 induction. Patients age 18-65 years with newly diagnosed AML were randomly assigned to 60 versus 90 mg/m2 daunorubicin once daily plus cytarabine. Patients with marrow blasts below 5% on day 15 after first induction were randomly assigned to receive a second induction cycle or no second induction cycle. Eight hundred and sixty-four patients with a median age of 52 years were randomly assigned. After a preplanned interim analysis showing no significant difference in response between 60 and 90 mg/m2, all consecutive patients received 60 mg/m2 daunorubicin once daily. The proportion of good early responders was 44% versus 48% (P = .983) with a composite complete remission (CRc) rate of 90% versus 89% after induction (P = .691); the 3-year relapse-free survival (RFS) after 60 versus 90 mg/m2 once daily was 54% versus 50% (P = .561), and the 3-year overall survival (OS) was 65% versus 58% (P = .242). Among 389 good responders, CRc rates at the end of induction were 87% after single induction and 85% after double induction. The 3-year RFS was 51% versus 60% (hazard ratio [HR], 1.3; P = .091), and the 3-year OS was 76% versus 75% after single versus double induction (HR, 1.0; P = .937). The use of 90 mg/m2 daunorubicin once daily in the context of classical 7 + 3 induction does not significantly improve early response and does not lead to higher remission rates or longer survival than 60 mg/m2 once daily. In patients with a good early response after first induction, a second induction has only a limited impact on RFS and does not result in an OS benefit.

Time from diagnosis to treatment has no impact on survival in newly diagnosed acute myeloid leukemia treated with venetoclax-based regimens.

In newly diagnosed acute myeloid leukemia (AML), immediate initiation of treatment is standard of care. However, deferral of antileukemic therapy may be indicated to assess comorbidities or pretherapeutic risk factors. We explored the impact of time from diagnosis to treatment on outcomes in newly diagnosed AML undergoing venetoclax-based therapy in two distinct cohorts. By querying the Study Alliance Leukemia database and the global health network TriNetX, we identified 138 and 717 patients respectively with an average age of 76 and 72 years who received venetoclax-based first-line therapy. When comparing patients who started treatment earlier or later than 10 days after initial diagnosis, no significant difference in median overall survival was observed - neither in the SAL cohort (7.7 vs. 9.6 months; P=0.42) nor in the TriNetX cohort (7.5 vs. 7.2 months; P=0.41). Similarly, severe infections, bleeding, and thromboembolic events were equally observed between early and later treatments, both in the overall patient groups and specific subgroups (age ≥75 years or leukocytes ≥20x109/L). This retrospective analysis indicates that delaying the start of venetoclax-based therapy in newly diagnosed AML might be a safe option for selected patients, provided that close clinical monitoring is performed.

Risk Stratification of Patients with RUNX1-mutated Acute Myeloid Leukemia

Mutations in RUNX1 ( RUNX1mut) occur in ~15% of intensively treated AML cases. RUNX1mut have no specific hotspot and various types of alteration are observed. The European LeukemiaNet (ELN) risk stratification assigns adverse prognosis to RUNX1mut if they do not co-occur with favorable-risk genotypes. Considering the biological complexity of RUNX1 it seems implausible that all alterations have similar consequences. Using clinical and genetic variables, we developed a prognostic risk stratification model for ELN adverse-risk RUNX1mut AML patients. We combined data from five groups, totaling 609 patients with intensively treated RUNX1mut AML, to develop the model. Our training set included 448 patients treated on trials of the AML Cooperative Group (AMLCG; Herold et al, Leukemia, 2020; (n=178)), AML Study Group (Gerstung et al, NEJM, 2016; (n=116)) and Study Alliance Leukemia (n=154). Patients from the Munich Leukemia Laboratory (MLL; (n=107)) and of the Alliance group (trials NCT00048958, NCT00899223, NCT00900224; Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org; (n=54)) served as independent validation cohorts. Additionally, 955 patients without RUNX1mut treated on AMLCG trials served as controls. Patients with t(15;17), prior treatment, or RUNX1mut with co-occurring favorable-risk genotypes according to ELN 2017 were excluded. Differences between RUNX1mut patients and controls were investigated using univariate logistic regression. Testing was performed using likelihood ratio tests and adjusted for study group. Univariate analyses were adjusted for multiple testing using the Benjamini-Hochberg procedure. We obtained risk prediction models using multivariate Cox regression. Missing values were imputed using the missForest approach. Model selection was performed using forward selection based on the Bayesian information criterion. Cut-offs were based on the 25 th- 50 th- and 75 th-percentile score values obtained in the training data. Performance was evaluated using Kaplan-Meier curves. For internal validation Harrell's C index was estimated using cross-study validation. For external validation, the final risk prediction models were separately applied to the external datasets. RUNX1mut were more common in older, male patients and sAML (table). White blood cells, lactate dehydrogenase and bone marrow blasts were lower in RUNX1mut patients. Mutations in several myelodysplasia-related genes were enriched in RUNX1mut patients ( ASXL1, BCOR, BCORL1, EZH2, KMT2A, PHF6, and STAG2, SF3B1, SRSF2, and U2AF1), whereas DNMT3A, NPM1 and FLT3 were more frequently altered in controls. A strong association with mutations of the splicing factor complex was identified (49% vs. 13%, p<0.0001). Contradicting previous reports, we found no association with IDH mutations. The risk prediction score we obtained for OS is as follows: 0.03054 x age (y) + 0.74996 x adverse MRC + 0.43779 x FLT3-ITD + 0.00317 x WBC count (10^9/L) - 0.00158 x platelet count (10^9/L) + 0.37401 x NRAS-mutation, where the obtained cut-off values are: <1.592 (low risk); 1.592 to 2.303 (moderate risk) >2.303 (high risk). Binary variables are coded as 0 or 1. Harrell's C index estimated using internal validation was 0.6. Kaplan-Meier curves estimated using the training set suggest strong differences in survival between the risk categories. Median overall survival (OS) was 2.5, 1.0 and 0.6 years for low-, intermediate-, and high-risk. External validation using the Alliance cohort shows similar results (Figure). Results obtained for the MLL cohort show smaller differences. However, we still observe clear separation of risk groups with a significant difference between low- and high-risk groups (adjusted p-value: 0.0266). Scores for relapse-free survival (RFS) as well as for OS and RFS censored for allogeneic transplant show similar results. We analyzed a large collection of intensively treated RUNX1mut AML patients and observed heterogenous outcomes that could be predicted by applying few variables (age, MRC-score, FLT3/NRAS mutation-status, and WBC/platelet count). The OS of RUNX1mut high-risk patients is discouraging, highlighting the unmet need of these patients. In addition, our work demonstrates that ELN risk groups can be further stratified and that integrated approaches using routinely available variables can further advance risk prediction.

Explainable End-to-End Supervised Learning Identifies Myelodysplastic Neoplasms in Bone Marrow Smears

Myelodysplastic neoplasms (MDS) encompass clonal myeloid malignancies that are characterized by ineffective hematopoiesis, cytopenia, myelodysplasia, and recurrent genetic events. Apart from genetic abnormalities and the assessment of peripheral blood for cytopenia, cytomorphologic evaluation of bone marrow morphology is key in initial diagnosis and response assessment as well as to detect disease transformation to acute myeloid leukemia (AML). However, the identification of aberrant morphologies in bone marrow cells is challenging and prone to inter-observer variability even for seasoned morphologists resulting in discrepancies between local site and central review. After the introduction of deep learning (DL) models for computer vision tasks, a wide variety of applications in imaging diagnostics has been addressed using convolutional neural networks including the assessment of bone marrow cell types and prediction of hematological malignancies. Bone marrow smear (BMS) images of manually selected regions of interest (ROI) from 483 MDS patients treated at the University Hospital Dresden were captured at 40-fold magnification with a resolution of 2560*1920 pixels and pre-processed. In parallel, BMS images from two control cohorts were taken: (i) 1226 AML patients registered in the German Study Alliance Leukemia (SAL) registry, and (ii) 236 healthy bone marrow donors. In addition, an external validation cohort of 50 MDS patients was obtained from the Munich Leukemia Laboratory (MLL). Image-level labels were provided denoting the corresponding diagnosis: “MDS”, “AML” and “healthy donor”. To balance different sample sizes between the datasets, simple image augmentation techniques such as random sized cropping, color shifting, and linear transformations were used. Training and testing were performed with 5-fold cross-validation, i.e. multiple train-test-splits of 80:20. Importantly, cell-level labels, e.g. specifically annotated cell types or features like distinct dysplastic morphologies were not used to train our model as we intended to abstract visual information exclusively through our neural networks instead of using expert-guided feature engineering. Six different recently introduced convolutional neural network (CNN) architectures were compared (ResNet-34/50/101/152, ResNeXt-50/101, ShuffleNet V2, DenseNet-121/169/201, Wide ResNet-50/101, and SqueezeNet 1.1). To evaluate individual model performance, we used accuracy, recall (=sensitivity), precision (=positive predictive value), and area-under-the-curve (AUC) of both the receiver-operating-characteristic (ROC) and precision-recall-curve (PRC). Binary classification tasks showed high accuracy of 0.956 and 0.981 for distinguishing MDS from healthy donors and AML, respectively (Table I). Results were validated in the external MDS cohort reaching an accuracy of 0.916 for MDS vs. donors and 0.968 for MDS vs. AML (Table I). For explainability, we used occlusion sensitivity mapping which iteratively blocks image areas from being evaluated by the CNNs, measures consecutive drops in prediction performance, and thus identifies image areas of high importance (highlighted in green). By reviewing images, we found the CNNs to target nuclei not only of dysplastic cells but rather of all available cells in a ROI (Figure 1). Using supervised end-to-end deep learning, we developed a software framework to distinguish between MDS, AML, and healthy controls with very high accuracy. Importantly, models do not require laborious feature engineering, i.e. manually drafted, cell-level labels alleviating the need for time-consuming and cost-ineffective manual labeling and thereby bypassing a key bottleneck for current standards of computer vision in microscopy.

Mimicking Clinical Trials with Synthetic Acute Myeloid Leukemia Patients Using Generative Artificial Intelligence

Data sharing is often hindered by concerns of patient privacy, regulatory aspects, and proprietary interests thereby impeding scientific progress and establishing a gatekeeping mechanism in clinical medicine since obtaining large data sets is costly and time-consuming. We employed two different generative artificial intelligence (AI) technologies: CTAB-GAN+ and Normalizing Flows (NFlow) to synthesize clinical trial data based on pooled patient data from four previous multicenter clinical trials of the German Study Alliance Leukemia (AML96, AML2003, AML60+, SORAML) that enrolled adult patients (n=1606) with acute myeloid leukemia (AML) who received intensive induction therapy. As a generative adversarial network (GAN), CTAB-GAN+ consists of two adversarial networks: a generator producing synthetic samples from random noise and a discriminator aiming to distinguish between real and synthetic samples. The model converges as the discriminator can no longer reliably differentiate between real or synthetic data. Contrastingly, NFlow consists of a sequence of invertible transformations (flows) starting from a simple base distribution and gradually adding complexity to better mirror the training data. Both models were trained on tabular data including demographic, laboratory, molecular genetic and cytogenetic patient variables. Detection of molecular alterations in the original cohort was performed via next-generation sequencing (NGS) using the TruSight Myeloid Sequencing Panel (Illumina, San Diego, CA, USA) with a 5% variant-allele frequency (VAF) mutation calling cut-off. For cytogenetics, standard techniques for chromosome banding and fluorescence-in-situ-hybridization (FISH) were used. Hyperparameter tuning of generative models was conducted using the Optuna Framework. For each model, we used a total of 70 optimization trials to optimize a custom score inspired by TabSynDex which assesses both the resemblance of the synthetic data to real training data and its utility. Pairwise analyses were conducted between the original and both synthetic data sets, respectively. All tests were carried out as two-sided tests using a significance level α of 0.05. Table 1 summarizes baseline patient characteristics and outcome for both synthetic cohorts compared to the original cohort. Firstly, we found both models to adequately represent patient features, albeit that some individual variables showed a statistically significant deviation from the original cohort. It is important to note that for such a large sample size (n=1606 for each cohort), even miniscule differences can be rendered statistically significant notwithstanding any meaningful clinical difference. Interestingly, variables that deviated from the original distribution were different for both models indicating model architecture to play a vital role in sample representation: While CTAB-GAN+ showed significant deviations for both age and sex, NFlow showed significant deviations for AML status. Complete remission rate was similar between original (70.7%, odds ratio [OR]: 2.41) and CTAB-GAN+ (73.7%, OR: 2.81, p=0.059) and NFlow (69.1%, OR: 2.24, p=0.356). For event-free survival (EFS), which was not included as a target in hyperparameter tuning, both networks deviated significantly from the original cohort (original: median 7.2 months, HR: 1.36; CTAB-GAN+: median 12.8 months, HR 0.74, p<0.001; NFlow: median 9.0 months, HR: 0.87, p=0.001). Overall survival (OS) was well represented by NFlow compared to the original cohort, while CTAB-GAN+ showed a significant deviation (original: median 17.5 months, HR: 1.14; CTAB-GAN+: median 19.5 months, HR 0.88, p<0.001; NFlow: median 16.2 months, HR: 1.00, p=0.055). Both models showed an adequate graph representation in Kaplan-Meier analysis (Figure 1). Here, we demonstrate using two different generative AI technologies that synthetic data generation provides an attractive solution to circumvent issues in current standards of data collection and sharing. It effectively allows for bypassing logistical, organizational, and financial burdens, as well as regulatory and ethical concerns. Ultimately, this enables explorative research inquiries into previously inaccessible data sets and offers the prospect of fully synthetic control arms in prospective clinical trials.

Long-Term Outcome of 1296 Patients with Newly Diagnosed with APL: A Harmony Alliance Study

Background: APL, a rare and aggressive subtype of acute myeloid leukemia (AML), is now curable in 75-90% of patients using targeted agents [All-trans retinoic acid (ATRA)/Arsenic Trioxide (ATO) or ATRA combined with chemotherapy (ATRA+Idarubicin, AIDA-based)]. Despite significant advances in survival, most reports are based on low patient numbers, which limit reliability of data. Aims: to study factors associated with outcome in a large patient cohort diagnosed with APL, and treated according to two European trials (UK AML-17 and GIMEMA APL0406), or recorded in national registries from 6 countries, enrolled in the HARMONY database. Methods: The Harmony platform includes to-date 1868 patients with APL, diagnosed between 2007 and 2020. The present analysis was performed on 1296 patients, who met the data quality requirements, by evaluating the list of variables shown in Table 1. Patients were treated according to APL0406 and AML17 clinical trials, or were included in the Study Alliance Leukemia (SAL), Swedish Cooperative Group or AML study Group (AML-SG) registries. After acquisition from the sources, data were harmonized and transformed using an Observational Medical Outcomes Partnership Common Data Model, and registered in the HARMONY Big Data Platform. Results: Of 1296 patients, 562 were treated with ATRA-ATO (median age 51 yrs, range 16-94; M:F ratio 1), and 605 with ATRA-Idarubicin (AIDA, median age 50 yrs, range 17-86; M:F ratio 1) (p for age groups according to treatment=0.3538). According to Sanz risk-score, 250 patients (44.4%) were low-risk (LR), 258 (45.9%) intermediate-risk (IR), and 50 (8.9%) high-risk (HR) in the ATRA-ATO cohort. The AIDA cohort included 191 LR (31.5%), 235 IR (38.8%), and 171 HR (28.3%) patients (p for risk groups according to treatment: < 0.001). Treatment data were not available in 8 patients (1.3%) The 10-year overall survival (OS) was 90% and 77% in ATRA-ATO vs AIDA groups, respectively (p<0.001, figure 1), while event-free survival (EFS) was 86% and 67%, respectively (p<0.001). At a median follow-up of 4.5 yrs (range 0.02 - 10.2), OS and EFS in patients treated with ATRA-ATO was similar in the three Sanz-risk classes (OS: LR: 94.6%, IR: 91%, HR: 85.6%, p=0.233, EFS: LR: 93.1%, IR: 88.7%, HR: 85.7%, p=0.319). The median follow-up of patients treated with AIDA was 6 yrs (range: 0-14.2). OS was 87.8% in LR, 83.5% in IR, and 74.8% in HR (p=0.004), while EFS was 72% in LR, 74.8% in IR, and 67.2% in HR (p=0.102). OS was significantly associated with age (<50 yrs: n=611, 50-69: n=516, >70: n=169), both overall (p<0.001), and within treatment groups (ATRA-ATO: p<0.001, AIDA: p<0.001). EFS also correlated with age subgroups, both overall (p<0.001) and according to treatment (ATRA-ATO: p<0.001, AIDA: p<0.001). No differences in OS were detected in between de-novo and secondary APL (p=0.746) both in ATRA-ATO (p=0.720) and in AIDA (p=0.766) cohorts. Patients treated outside the clinical trial context had inferior outcomes when compared to clinical trials, with a significant higher rate of early deaths (ED, 10% vs 2.8%, p<0.001), and inferior survival with major differences for the AIDA cohort (8-year OS: 73.6% vs 88.2%, p<0.001, EFS: 69.3% vs 71.7%, p=0.291), versus the ATRA-ATO cohort (8-year OS: 88% vs 93.3%, p=0.010, 8-years EFS: 80.6% vs 92.4%, p<0.001). The multivariate analysis for OS showed that age (50-69 vs <50 years, p<0.001, HR 4.2; >70 vs <50 years p<0.001, HR 8.9), Sanz-risk score (High vs Low/Intermediate p<0.001, HR 2), treatment type (AIDA vs ATRA-ATO p=0.001, HR 1.9) and treatment context (clinical trial vs non-clinical trial p=0.005, HR 1.7) were independent predictors of OS. The multivariate analysis for EFS showed an independent correlation with type of treatment (AIDA vs ATRA-ATO, p<0.001 HR 2.6), age (50-69 vs <50 years, p<0.001, HR 2.1; >70 vs <50 years p<0.001, HR 4.8) and Sanz-risk score (High vs Low/Intermediate p=0.005, HR 1.5), but not with treatment context. In multivariate analysis treatment type was the only predictive factor for early deaths (AIDA vs ATRA-ATO, p=0.047 HR 2.04). Summary/Conclusions: The analysis at long-term of the Harmony APL registry confirmed that patients treated with the ATRA-ATO chemo-free regimen present a significant survival advantage vs the AIDA regimen, with reduced ED rates and prolonged OS, independent of Sanz-risk score. Patients enrolled in clinical trials presented improved survival both in AIDA and in ATRA-ATO cohorts.

Venetoclax Plus High-Dose Cytarabine and Mitoxantrone (HAM-Ven) As Salvage Treatment for Relapsed/Refractory AML: Updated Results of the Phase-I/II SAL Relax Trial

Background Primary refractory disease and relapse remain the main obstacles for cure in AML. In fit patients, several salvage cytostatic options based on higher doses of cytarabine have been published, with complete remission (CR) rates ranging from 40-55%. The BCL2 inhibitor venetoclax has demonstrated impressive antileukemic activity when combined with hypomethylating agents or low-dose cytarabine in newly diagnosed unfit AML patients. In the phase-I part of the RELAX trial of the Study Alliance Leukemia (SAL), we demonstrated the feasibility of combining venetoclax with higher-dose cytarabine plus mitoxantrone (HAM) in relapsed AML, resulting in a CR/CRi rate of 92%. Here, we report the updated results from the phase-I and additional patients from the phase-II dose expansion in relapsed or refractory (r/r) AML patients. Methods Patients with r/r AML fit for intensive salvage treatment were eligible. Based on the safety results from the phase-I part, patients were treated with the recommended phase-II dose combination of 400 mg venetoclax PO QD (d1-14) including a 2-day ramp-up, followed by cytarabine 1000 mg/m 2 IV BID (d3-5) in combination with mitoxantrone 10 mg/m 2 IV QD (d5-7). Concomitant CYP3A inhibitors were allowed with the appropriate dose adjustments, patients did not receive G-CSF. Patients achieving a CR could enter a maintenance phase with 400 mg venetoclax PO QD over twelve 28-day cycles. This research was supported by a grant from AbbVie Inc. The trial is registered under NCT04330820. Results Between April 2020 and June 2023, 12 patients were enrolled in the dose-escalation part and 40 patients in the expansion part, of whom 38 were evaluable for response by the time of writing. Median follow-up was 6.7 months. Among the 12 patients in the dose-escalation part, 3 received 200 mg/m 2 cytarabine QD over seven days, 3 received 500 mg/m 2 BID over three days and 3 received 1000 mg/m 2 BID over three days, each with identical doses of venetoclax (400 mg PO QD d1-14) and mitoxantrone (10 mg/m 2 IV QD d5-7). Of all 38 evaluable patients, 17 (44.7%) had adverse genetic risk according to ELN2022, and 1 (2.6%) had progressed from antecedent MDS. Median age was 56 years (range, 26-74 years). All patients experienced CTCAE grade ≥3 cytopenias. A median number of two non-hematologic grade 3 and 4 adverse events (AEs) in 32 patients with sufficient data were recorded. Grade 3 and 4 AEs occurring in ≥ 10% of patients included febrile neutropenia, pneumonia, sepsis and gastrointestinal disorders. The 30- and 60-day mortality was 2.6% and 5.2%. Remission assessment showed CR/CRi in 31/38 patients (81.6%). Among the seven patients with no CR/CRi, six showed refractory disease and one died in aplasia before response assessment. CR/CRi rate was 100% (8/8), 81,8% (9/11) and 70.6% (12/17) in patients with favorable, intermediate, and adverse risk, respectively. Utilizing LAIP-based DFN MRD approach, 7/32 (21.9%) evaluable patients were classified as MRD negative (CR/CRi MRD-). In 7/25 (28%) CR/CRi MRD+ patients, the MRD burden was below 0.1% CD45 + events. Of all 31 CR/CRi patients, 26 are in ongoing CR/CRi, 16 received allogeneic HCT as postremission treatment. Three patients died in CR from infectious complications after allogeneic HCT or post-remission treatment and two relapsed and succumbed to progressive disease. Six patients commenced maintenance treatment, of whom four are in ongoing remission. Discussion The combination of venetoclax with higher doses of cytarabine and mitoxantrone (HAM-Ven) is a well-tolerated and very efficacious treatment option leading to complete remissions in 81.6% of patients with r/r AML studied in the RELAX trial. Safety and efficacy compare favorably with published results from the FLAG-Ida-Ven regimen, thereby providing a less dose-intense, fludarabin-free approach for the treatment of fit r/r AML patients. Enrollment into the RELAX trial is currently ongoing. Updated results will be presented at the meeting.

Secondary-Type Mutations Do Not Impact the Favorable Outcome of NPM1-Mutated Acute Myeloid Leukemia Patients - Results from a Large Cohort of Intensively Treated Patients

Introduction: In 2022, the ELN risk classification for AML was updated for the second time. One of the major novelties of the ELN2022 is that all secondary-type mutations (STMs, i.e., mutations in the genes SRSF2, SF3B1, U2AF1, ZRSR2, ASXL1, EZH2, BCOR, and STAG2) were now added to the adverse risk characteristics. However, a pertinent question also raised by the ELN expert panel is whether STMs abrogate the positive prognostic value of co-occurring, favorable NPM1 mutations. Aim: The aim of this study was to analyze the prognostic value of STMs in AML patients (pts) who also harbor an NPM1 mutation. Methods: We investigated a pooled cohort of 936 NPM1-mutated AML pts who were treated in previously reported multicenter trials of the Study Alliance Leukemia or the AML Cooperative Group. Eligibility was determined based on diagnosis of non-APL, age ≥ 18 years, NPM1 mutation detected in targeted sequencing, curative treatment intent, and available biomaterial at diagnosis. Standard techniques for chromosome banding and fluorescence-in-situ-hybridization (FISH) were used for karyotyping. Next-generation panel sequencing was performed to detect genetic alterations that are recurrently found in myeloid neoplasms. Results: In our multicenter cohort of 936 NPM1-mutated AML pts, median follow-up for the entire cohort was 8.0 years. We found 125 patients (13.4%) harboring at least one STM ( SRSF2 [n=48; 5.1%], STAG2 [n=32; 3.2%], EZH2 [n=22, 2.4%], BCOR [n=16; 1.7%], SF3B1 [n=13; 1.4%], ASXL1 [n=12; 1.3%], ZRSR2 [n=5; 0.5%], and U2AF1 [n=4; 0,4%]). A comparison of pretreatment clinical and genetic features revealed that pts with a STM were significantly older ( p=.003, median 59 vs. 55 years), had lower white blood cell counts ( p<.001, 22.2*10 9/L vs. 39.7*10 9/L,) and platelet counts ( p<.001, 46.5*10 9/L vs. 65.0 10 9/L). The strongest pair-wise associations between gene mutations were observed between U2AF1 and RUNX1 ( p<.001) as well as SRSF2 and IDH2 ( p<.001). With respect to outcome, complete remission (CR) rate did not differ significantly between NPM1-mutated patients with or without additional STMs ( p=.41, 74.4% vs. 77.7%, OR 0.83 [95%-CI 0.54-1.29]). Median RFS for NPM1-mutated pts with STMs was 32.9 months (95%-CI: 13.0-46.0) while patients without STMs had a median RFS of 24.3 months (95%-CI: 18.7-33.3) corresponding to a HR of 1.04 ( p=0.80, 95%-CI 0.79-1.37; Figure A). Median OS for NPM1-mutated pts with or without STMs was 27.2 months (95%-CI: 14.2-49.0) and 29.1 months (95%-CI: 23.5-41.4), respectively, corresponding to a HR of 1.11 ( p=.37, 95%-CI 0.88-1.41; Figure B). To focus solely on the impact of STMs, we subsequently excluded patients with co-occurring mutations in TP53 or myelodysplasia-related cytogenetics, which all define an ELN adverse risk. Again, we observed no differences in CR rate ( p=.54, 78% vs. 75.4%), RFS ( p=.59, median 33.2 months vs. 26.6 months), or OS ( p=.33, median 27.4 month vs. 32.6 month) between NPM1-mutated patients with or without STMs. Next, we restricted our analysis to pts who are classified favorable risk according to ELN2022. Again, we found no significant outcome differences based on the STM status (unmutated vs. mutated: CR rate, 80% vs. 70.7% [ p=.072]; RFS, median 49.7 months vs. 46.0 months [ p=.702]; OS, median 45.3 months vs. 59.8 months [ p=.092]). Conclusion: NPM1 mutations rank as the second most frequent mutations in AMLand the most common in patients with a normal karyotype and serve as an established favorable prognostic marker. Our data from a large cohort demonstrate that additional STMs have no adverse effect on the clinical outcome of NPM1-mutated patients. As a result, these patients should still be considered ELN favorable risk.

Large case-control study indicates no association of KIR genotype and risk of developing acute myeloid leukemia.

Immunogenetic association studies may give rise to new hypotheses on the immune surveillance of cancer. We hypothesized that certain combinations of killer immunoglobulin-like receptor (KIR) and HLA genotypes may enhance natural killer (NK) cell immunity against nascent acute myeloid leukemia (AML) and, thereby, lead to a skewed genotype distribution among patients. For this purpose, we analyzed KIR and HLA genotypes of 1767 German patients with AML and compared the results with that of the data of 51 890 German volunteers who had registered with German bone marrow donor file (DKMS). Patient samples were retrieved from the Collaborative Biobank and the biorepository of the Study Alliance Leukemia. All samples were genotyped with high-resolution amplicon-based next-generation sequencing. Because of the large number of controls, this study was very sensitive to detect the impact of KIR genotype. Knowledge on KIRs and their cognate HLA ligands allowed for testing of several hypotheses of NK cell-mediated endogenous leukemia surveillance. We did not find significant differences between the 2 cohorts in regard to the presence or absence of single KIR genes. When grouped based on telomeric or centromeric gene content, the major haplotypes A/A, A/B, and B/B were equally distributed among patients and control subjects. Using information on KIRs and their HLA ligands, we further tested receptor-ligand models and summation models without revealing markedly significant differences between patients and controls, albeit we observed a trend pointing at a minor protective effect of a low number of inhibitory KIR/KIR-ligand pairs. The results suggest that the KIR/KIR-ligand genotype has no effect on the susceptibility for the development of de novo AML.

Venetoclax-Based Salvage Therapy Improves Outcome in Relapsed/Refractory AML Patients Eligible for Intensive Treatment: A Propensity Score Matching Analysis

Background: Venetoclax (VEN)-based combination therapy with hypomethylating agents (HMA) has been approved for first-line treatment in AML patients ineligible for intensive treatment. There is evidence for efficacy also in the in relapsed/ refractory setting (R/R) in fit patients pretreated with intensive regimes, but comparative controlled data is lacking. Here, we report our updated data of VEN-based salvage treatment as bridge to allogeneic hematopoietic cell transplantation (allo-HCT) in R/R AML patients and compared it to non-VEN-based intensive treatment according to physician's choice in a propensity score matching analysis using patient data from the German Study Alliance Leukemia (SAL) registry (ClinicalTrials.gov Identifier: NCT03188874). Design/Methods: We analyzed patients with R/R AML after initial intensive induction therapy, who started VEN-based salvage treatment as bridging to allo-HCT at the University Hospital Heidelberg between October 2018 and April 2021. Using propensity score matching, these patients were compared to patients from the registry of the SAL, who received non-VEN-containing salvage treatment based to the decision of the treating physician. Results: A total of 37 patients (median age 62 y, range 23 to 79 y), who received VEN-based salvage treatment were included. All patients had initially received intensive therapy, 25 patients (68 %) had been refractory to an intensive induction therapy regime, 12 patients (32 %) had been diagnosed with morphologic (9 patients) or molecular relapse (3 patients) after intensive first line therapy. According to the 2017 ELN classification, 10 patients (27%) had favorable risk, 10 (27%) intermediate risk and 17 (46%) adverse risk disease. 36 patients received VEN in combination with standard-dose azacytidine and one patient with low-dose cytarabine. VEN was given at a daily dose of 400mg/day in 21 to 28 days cycles after initial ramp up or at a reduced dose of 100mg/day in case of co-medication with strong CYP3A inhibitors. The overall response rate (CR, CRi, MLFS and PR) in VEN-based treated patients was 89% (n=33) with CR/CRi being the best response in 57% (n=21), MLFS in 19% (n=7) and PR in 13% (n=5) of the patients. 30- and 60-day mortality was 3% (n=1). Eventually, allo-HCT was performed in 26 patients (70%). At the time of analysis 17 (65%) of these patients were alive and 16 (62%) were still in CR. For comparison, we identified 88 patients (median age 61 y; range 22- 78 y) within the SAL-registry, who received an intensive non VEN-containing salvage therapy for their R/R AML. The SAL cohort contained more patients with intermediate risk (ELN 2017 classification) than the VEN-treated cohort (56% vs. 27%; p=0.005) but less patients with adverse risk (22% vs. 46%; p=0.009). The distribution of favorable risk was similar (23% vs. 27%; p=0.65). Allo-HCT was performed in 59 patients (67%) and in 31 patients allo-HCT was the first salvage treatment after relapse (n=10) or refractoriness to induction therapy (n=21). The remission status prior to allo-HCT was CR/CRi in 11 (19%), PR in 7 (12%), progressive disease (PD) in 38 (64%) and unknown in 3 patients (5%). After a median follow-up of 18.1 months (95%-confidence interval (CI) 13.0-24.4) for the VEN-treated cohort and 56.2 months (95%-CI 24.3-84.9) for the SAL cohort, the median event-free survival (EFS) and relapse-free survival (RFS) of VEN-treated patients were 8.02 months (95%-CI, 5.06-not reached [NR]) and 7.16 months (95%-CI, 4.37-NR), respectively. In contrast, median EFS and RFS for the SAL cohort were 4.53 months (95%-CI, 3.45-8.51) and 9.66 months (95%-CI, 5.59-20.6), respectively. Median overall-survival (OS) in the VEN-cohort was 15.08 months (95%-CI, 10.55-NR) compared to 9.66 months (95%-CI, 4.99-19.5) in the SAL cohort. Propensity score matching including age, white cell count, sex and ELN-risk and allo-HCT status as matching variables revealed a non-significant (p=0.148) benefit for the VEN-treated cohort with a hazard ratio of 0.65 (95%-CI, 0.36-1.17) compared to the SAL cohort. In patients proceeding to allo-HCT, 18-month survival was 60% (95%-CI, 42-85%) compared to 51% (95%-CI, 40-66%) in the SAL cohort. Conclusion: Our data confirms that VEN-containing therapy is a safe and effective salvage therapy for patients with R/R AML that allows an efficient bridging to allo-HCT in many patients with promising outcome after allo-HCT. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Analysis of Patient-Level Data from 3 Cooperative Group Trials Confirms a Survival Advantage for NPM1m Patients Achieving MRD-Negative CR after Intensive Induction

Background:NPM1 mutations (NPM1m), predominantly tetra-nucleotide insertions in exon 12, are clonal driver events in acute myeloid leukemia (AML) and are found exclusively in leukemic cells, making them ideal for sensitive detection of measurable residual disease (MRD) using quantitative polymerase chain reaction (qPCR)- or next generation sequencing (NGS)-based methods. Over 50 peer-reviewed publications across multiple cooperative group trials have shown that NPM1m AML patients in complete remission (CR), CR with incomplete count recovery (CRi), or CR with partial hematologic recovery (CRh) have significantly better survival if they are MRD negative compared to MRD positive. Based on this body of evidence, the European LeukemiaNet recommends monitoring molecular MRD in NPM1m AML patients during treatment to help guide treatment decisions. Purpose: To provide further evidence for the value of NPM1 MRD as a surrogate endpoint for prospective, randomized trials in patients receiving novel agents in combination with intensive chemotherapy by evaluating the relationship between MRD negativity in patients with CR after 2 cycles of chemotherapy and event-free survival (EFS) and overall survival (OS) in a pooled analysis of patient-level data from 3 large cooperative group trials. MRD in all 3 studies was assessed using reverse transcriptase-mediated qPCR (RT-qPCR) of NPM1m transcripts normalized to ABL transcripts. Methods: Deidentified patient data for a total of 1,128 patients who achieved CR, CRi, or CRh, and who had MRD data after 2 cycles of chemotherapy, were provided by the UK National Cancer Research Institute AML Study Group (SG) for the AML17 (N = 539), the AMLSG for the AMLSG 09-09 (N = 497), and the Study Alliance Leukemia (SAL) for the AML2003 (N = 105) trials and standardized using Standard Data Tabulation Models. Data included demographic information, disease history, induction and consolidation treatment received, morphologic response, MRD data after 2 cycles of treatment, relapse, and survival. Cutoffs for MRD negativity were defined according to the definitions used in the individual studies (Ivey A, et al. N Engl J Med. 2016; Kapp-Schwoerer S, et al. Blood. 2020; Shayegi N, et al. Blood. 2013). In addition, sensitivity analyses were conducted using a range of cutoff values. CR was defined as <5% blasts in the bone marrow (BM) with count recovery, occurring within 42 days of the start of the last induction cycle; only these patients were included in the MRD analysis. EFS and OS were estimated using the Kaplan-Meier method and defined according to FDA criteria. Briefly, EFS was measured from day 1 of randomization to the date of treatment failure, hematologic relapse from CR or death from any cause; treatment failure was defined as not achieving CR after two cycles of chemotherapy. OS was measured from day 1 to the date of death from any cause. The absolute risk difference among MRD response status groups in EFS/OS at the 2-month, 1-year, 2-year, 3-year, and 5-year landmarks and their corresponding 95% confidence intervals (CI) were calculated using complementary log-log transformation. Hazard ratios (HR) were fitted using a Cox regression model with EFS/OS as the dependent variable and with MRD-response status and study as independent variables. Results: Among the 515 patients who achieved a CR within 42 days at the start of chemotherapy Cycle 2, MRD negativity confers a substantial survival advantage with EFS HR (95% CI) = 1.6 (1.1-2.3) when measured in BM and 1.8 (1.4-2.4) in peripheral blood (PB) using the study-defined cutoffs for positive and negative. This advantage is also observed using cutoff definitions of MRD negativity ranging from <10 to <1,000 NPM1m/104ABL transcripts. A survival advantage for OS was also observed with HR (95% CI) = 1.5 (1.0-2.4) and 1.7 (1.2-2.3) in BM and PB, respectively. Analysis of the predictive value of MRD negativity in the 613 patients who achieved CRi/CRh within 42 days of the start of Cycle 2 is underway. Conclusions: Analysis of pooled patient-level data confirms the survival advantage of achieving MRD-negative CR as previously reported in 3 independent, cooperative group trials using different induction regimens. The prognostic value of MRD negativity in NPM1m AML is consistent across a broad range of cutoff definitions in both BM and PB providing further evidence for the value of NPM1 MRD as a surrogate endpoint for clinical trials.

Prevalence, Clinical and Molecular Features, and Prognostic Value of Tetraploidy/Near-Tetraploidy in Patients with Acute Myeloid Leukemia

In patients with acute myeloid leukemia (AML), more common aneuploid alterations, such as complex- or monosomal karyotype (CK and MK, respectively) have been intensively studied and are known to confer an adverse prognosis. In contrast, little is known about the prognosis of clonal tetraploidy/near-tetraploidy (T/NT), another rare aneuploidy, defined by presence of 92 chromosomes in tetraploid, and 81-103 chromosomes in near-tetraploid cases. Therefore, we aimed to evaluate prevalence, clinical as well as molecular characteristics and prognostic impact of T/NT in a large cohort of AML patients. We retrospectively assessed 4259 AML patients treated within Study Alliance Leukemia (SAL) trials and/or registered in the SAL AML registry and for whom valid cytogenetic data were available from 1996 until 2020 (the cohort was subsequently enriched by 5 T/NT cases from the AML cooperative group (AMLCG) AML registry). T/NT was defined by presence of ≥ 81 chromosomes in ≥ 10% of metaphases in G-banded karyograms and/or ≥ 4% T/NT cells in interphase fluorescence in-situ hybridization (iFISH). Bone marrow mononuclear cell (BMMC) nuclear area was assessed in patients with available bone marrow smears. In 22 patients with available BMMCs were available, panel next generation sequencing (NGS) and/or whole genome sequencing (WGS) was performed. Student's t test and Kaplan-Meier estimation were used for statistical analyses. We identified 35 patients with T/NT (prevalence 0.82%). Median age was 60.1 years, 34.2% were female. Most patients were diagnosed with de-novo AML (77.2%); secondary AML and therapy-related AML was seen in 20.0% and 2.8%, respectively. Median WBC was 2.9 ×109/L, platelet count was 59 ×109/L and hemoglobin was 6.2 mmol/L; median bone marrow blast count was 64%. As per standard of care molecular studies, there was no evidence of biallelic CEBPA or NPM1 mutations, only one patient harbored an FLT3-ITD mutation; a complex karyotype was observed in 22.9%. In 24 patients considered fit/eligible for intensive chemotherapy (IC) the CR rate was 54.2%, allogeneic hematopoietic cell transplantation (HCT) was performed in 34.2% of patients. As compared to AML patients with diploid karyotype, median BMMC nuclear area was increased (209 µm2 vs. 129 µm2, p = .02). NGS/WGS revealed an accumulation of RUNX1 (15 variants in 11/22 patients), TET2 (15 alterations in 7/22 patients) and SRSF2 (7 variants in 7/22 patients) mutations. Moreover, frequent chromosome 14 aberrations, e.g. del(14q) were observed (5/22 patients). In contrast, only two patients harbored FLT3 mutations and no variants in CEBPA or NPM1 were seen; also, CBF fusions and KMT2A rearrangements were absent (Figure 1A). Median overall survival (OS) of the entire cohort was 9.6 months. Of note, when evaluating patients with sole T/NT vs. patients with T/NT and additional adverse aberrations, median OS in T/NT patients without additional adverse alterations was 26.1 months vs. 5.5 months in patients with T/NT and adverse risk (Figure 1B). Thus, T/NT per se do not seem to confer an adverse prognosis. In summary, we report the first comprehensive evaluation of AML patients with T/NT. T/NT was associated with distinct clinical (male predominance, large BMMC nuclear area) and molecular features (mutations in RUNX1, TET2, SRSF2; del(14)). Most importantly, isolated T/NT was not associated with a poor prognosis; accordingly, we suggest assigning AML patients with T/NT without additional adverse-risk alterations to the intermediate-risk category. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Tandem Duplications of the UBTF gene in Adult AML: A Rare but Recurrent Alteration Associated with Myelodysplasia and Poor Outcome

The upstream binding transcription factor (UBTF) is a nucleolar protein that regulates the transcription of ribosomal genes as a component of the RNA Pol I pre-initiation complex. Recently, tandem duplication mutations of the UBTF gene (UBTF-TDs) were identified as recurrent alterations in pediatric AML (Umeda et al., 2022), potentially representing a new subtype-defining lesion. UBTF-TDs were found to be associated with normal karyotype (NK) or trisomy 8 (+8), FLT3-ITD and WT1 mutations as well as poor prognosis. Data on the role of UBTF-TD in adult AML are limited. In the present study, we therefore analyzed the prevalence and prognostic significance of UBTF-TDs in a large cohort of adult AML patients (pts). Methods: Pts included were registered and treated in clinical protocols of the Study Alliance Leukemia (SAL) (AML96, AML2003, AML60+, SORAML) or the SAL-registry. Screening for UBTF-TDs was done by PCR covering exon 13 of the UBTF gene with 6-FAM labelled primers followed by high-resolution fragment analysis using genomic DNA isolated at diagnosis. Mutations were confirmed by Sanger sequencing. All UBTF mutant samples were further analyzed by targeted next generation sequencing (Archer Myeloid Panel) for the presence of co-occurring alterations. Results: Somatic mutations in UBTF were identified in 52 (1.2%) of 4247 pts. Mutations varied in size (3 to 309 bps), all yielding in-frame insertions, duplications or deletions in exon 13 of the UBTF gene. UBTF-TD AMLs frequently presented with a normal karyotype (46%) or +8 (36.5%). Similar to findings in pediatric pts, the co-mutation profile showed significant differences between UBTF-mut and UBTF-wt pts, i.e. UBTF-TDs were significantly associated with FLT3-ITD (48%, p<.001) or WT1 mutations (52%, p<.001), while DTA co-mutations were exceedingly rare (DNMT3A 1.9%; TET2 3.8%; ASXL1 3.8%) (Fig. 1A). Furthermore, UBTF-TDs and several class-defining lesions, i.e. reciprocal translocations such as RUNX1::RUNX1T1,DEK::NUP214 or mutations in CEBPA or NPM1 were mutually exclusive. The prevalence of UBTF-TDs showed a strong negative correlation with increasing age, ranging from 10% in patients <20 years (yrs) to 0.05% in patients >70 yrs, respectively. Accordingly, pts with UBTF-TDs were significantly younger (median age 41 yrs; range 17-77 yrs) than wt pts (med. 57 yrs; range 15-90 yrs, p<.001). Association with clinical parameters revealed significantly lower hemoglobin levels and platelet counts at diagnosis for UBTF-mut pts compared to UBTF-wt pts (median Hb 8.7 vs. 9.2 g/dL; p=.02; median PLT 31.5 vs 53 x 109/L; p=.003). Although UBTF-TDs mainly affected younger pts, cytomorphologic assessment revealed a clear association with myelodysplastic changes in about 60% of patients. Univariate analysis showed a significantly higher rate of complete remissions (CR) in UBTF-mut pts (92.3%) compared to UBTF-wt pts (70.8%) (p<.001). However, UBTF-mut pts had shorter overall (OS) and event-free survival (EFS). This effect was particularly pronounced in the subgroup of pts under 60 years of age (median OS 20.4 months in UBTF-mut pts vs. 45.3 months in UBTF-wt pts, p=.079; median EFS 6.7 months in UBTF-mut pts vs. 11 months in UBTF-wt pts, p<.001) (Fig.1B), who represented the majority (45/52, 87%) of UBTF-TD patients, and in patients with co-mutations of the WT1 gene (data not shown). AlloSCT performed in CR1 in 11 pts (21%) did not improve outcome. In multivariable analyses, the presence of UBTF-TD was associated with a trend for shorter OS (HR: 1.39; 95% CI 0.98-2, p=.06) and significantly worse EFS (HR: 1.68; 95% CI 1.24-2.3; p<.001). Conclusions: This analysis of a large cohort of adult patients with newly diagnosed AML revealed that UBTFmutations can be found in about 1% of all patients with AML, but are considerably more common in young adults. As in pediatric patients, they are associated with a specific cytogenetic and molecular profile, i.e. high rate of +8, FLT3-ITD and WT1 mutations. As a novel finding, adult UBTF-TD patients frequently showed signs of myelodysplasia. The distinct molecular genotype and the fact that UBTF-TDs were associated with a dismal outcome, even in patients treated with alloSCT in CR1, support the classification of this group as a new disease entity and indicate that novel treatment strategies are needed in this subgroup of patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Impaired Overall Survival in Young Patients With Acute Myeloid Leukemia and Variants in Genes Predisposing for Myeloid Malignancies.

Impaired Overall Survival in Young Patients With Acute Myeloid Leukemia and Variants in Genes Predisposing for Myeloid Malignancies.

Point Mutations in the FLT3-ITD Region Are Rare but Recurrent Alterations in Adult AML and Associated With Concomitant KMT2A-PTD.

FLT3-ITD mutations are common druggable alterations in patients with acute myeloid leukemia (AML) and associated with poor prognosis. Beside typical ITD mutations, point mutations and deletions in the juxtamembrane domain (JMD) have been observed. However, due to the low frequency of these alterations, there is only limited information on molecular and clinical associations. To evaluate the prognostic impact of non-ITD mutations in the FLT3 JMD region, we analyzed a large cohort of 1,539 adult AML patients treated in different protocols of the Study Alliance Leukemia, using next-generation sequencing. Non-ITD point mutations and deletions within the FLT3 JMD were identified with a prevalence of ~1.23% (n = 19). Both FLT3-ITD and non-ITD mutations were associated with a higher rate of NPM1 (42%–61%; p < 0.001) and DNMT3A mutations (37%–43%; p < 0.001), as well as an increased percentage of peripheral blood (54%–65%) and bone marrow blast cells (74%; p < 0.001), compared to FLT3-wild-type patients. Most significantly, AML patients with FLT3 non-ITD mutations had a higher rate of concomitant KMT2A-PTD mutations (37.5%; p < 0.001) as compared to FLT3-ITD (7%) or FLT3-wild-type cases (4.5%). In a multivariable analysis, FLT3 non-ITD mutations were not an independent prognostic factor. However, patients with dual FLT3 non-ITD and KMT2A-PTD mutations showed a trend for inferior outcome, which points at a functional interaction in this subset of AML.

Venetoclax-Azacitidine As Salvage Therapy and Bridge to Allogeneic Cell Transplantation in Relapsed/Refractory AML Compared to Historical Data of the SAL Registry Study

Venetoclax-Azacitidine As Salvage Therapy and Bridge to Allogeneic Cell Transplantation in Relapsed/Refractory AML Compared to Historical Data of the SAL Registry Study

Real-World Experience of CPX-351 As First-Line Treatment in 188 Patients with Acute Myeloid Leukemia

Real-World Experience of CPX-351 As First-Line Treatment in 188 Patients with Acute Myeloid Leukemia

CEBPA mutations in 4708 patients with acute myeloid leukemia: differential impact of bZIP and TAD mutations on outcome

AbstractBiallelic mutations of the CEBPA gene (CEBPAbi) define a distinct entity associated with favorable prognosis; however, the role of monoallelic mutations (CEBPAsm) is poorly understood. We retrospectively analyzed 4708 adults with acute myeloid leukemia (AML) who had been recruited into the Study Alliance Leukemia trials, to investigate the prognostic impact of CEBPAsm. CEBPA mutations were identified in 240 patients (5.1%): 131 CEBPAbi and 109 CEBPAsm (60 affecting the N-terminal transactivation domains [CEBPAsmTAD] and 49 the C-terminal DNA-binding or basic leucine zipper region [CEBPAsmbZIP]). Interestingly, patients carrying CEBPAbi or CEBPAsmbZIP shared several clinical factors: they were significantly younger (median, 46 and 50 years, respectively) and had higher white blood cell (WBC) counts at diagnosis (median, 23.7 × 109/L and 35.7 × 109/L) than patients with CEBPAsmTAD (median age, 63 years, median WBC 13.1 × 109/L; P < .001). Co-mutations were similar in both groups: GATA2 mutations (35.1% CEBPAbi; 36.7% CEBPAsmbZIP vs 6.7% CEBPAsmTAD; P < .001) or NPM1 mutations (3.1% CEBPAbi; 8.2% CEBPAsmbZIP vs 38.3% CEBPAsmTAD; P < .001). CEBPAbi and CEBPAsmbZIP, but not CEBPAsmTAD were associated with significantly improved overall (OS; median 103 and 63 vs 13 months) and event-free survival (EFS; median, 20.7 and 17.1 months vs 5.7 months), in univariate and multivariable analyses. Additional analyses revealed that the clinical and molecular features as well as the favorable survival were confined to patients with in-frame mutations in bZIP (CEBPAbZIP-inf). When patients were classified according to CEBPAbZIP-inf and CEBPAother (including CEBPAsmTAD and non-CEBPAbZIP-inf), only patients bearing CEBPAbZIP-inf showed superior complete remission rates and the longest median OS and EFS, arguing for a previously undefined prognostic role of this type of mutation.

Minimal-Residual Disease Guided Treatment with Azacitidine in MDS/AML Patients at Imminent Risk of Relapse: Results of the Prospective RELAZA2 Trial

Background: Although many patients (pts) with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) can achieve a complete remission (CR) by intensive chemotherapy, the majority will eventually relapse even after subsequent allogeneic hematopoietic stem cell transplantation (HSCT). Monitoring of minimal residual disease (MRD) in morphological CR has been shown to allow for predicting subsequent hematological relapse, thus opening a window for pre-emptive therapeutic interventions. We report on the results of the RELAZA2 trial (ClinicalTrials.gov NCT01462578) by the Study Alliance Leukemia (SAL) group evaluating azacitidine (AZA) as treatment of MRD to prevent relapse in patients with MDS or AML in CR after completion of standard treatment.Methods: From 2011 to 2015, 205 patients with either advanced MDS (n=27) or AML (n=178) in CR after either conventional chemotherapy only (n=58) or consecutive allogeneic HSCT (n=147) have been prospectively studied in 11 centers in Germany. MRD was centrally monitored in bone marrow or peripheral blood by starting on day 56 after completion of the last therapy followed by monthly intervals for a period of 2 years. Markers used for MRD detection confessed either the quantification of NPM1 mutation level (n=77), leukemia-specific fusion genes (DEK-NUP214 n = 1, t(8;21) n = 9, inv16 n = 10) or by a sensitive donor chimerism analysis of CD34(+) peripheral blood cells (n=108) in patients undergoing allogeneic HSCT. Patients with measurable MRD above a threshold defining imminent relapse but still being in CR preemptively received 6 cycles of AZA (75mg/m2, s.c. days 1-7). This was followed by an MRD risk-adapted AZA-based therapy for up to 18 additional months. Patients developing a hematological relapse went off study. The primary endpoint of the trial was the rate of hematological relapse after 6 cycles of AZA. We report the confirmatory analysis of the primary endpoint of those 53 patients who entered the treatment phase of the study.Results: At a median of 100 days (range 3-601) after start of screening, 53 out of 205 (26%) prospectively screened patients became MRD positive as defined by either a decrease of CD34(+) donor chimerism to <80% (n=19) or a detectable mutation level >1% (NPM1 n=31, t(8,21) n=3) while being still in hematological CR. All of these patients started AZA-based preemptive treatment. Six months after start of MRD-guided therapy, 31 out of 53 patients were still in CR (58%, 95%-CI 44-72%, p<0.001, one-sided binomial test for H0: pexp≤0.3) while a total of 22 patients (42%) relapsed after median of 3 AZA cycles. In fact, 21 patients (40%) responded with either a decline of MRD below a predefined threshold (increasing CD34(+) donor chimerism to ≥80% or mutation level <1%), while a stabilization in the absence of relapse was achieved in 10 patients (19%). Overall response rate was different between patients with (71%) or without (48%) antecedent allogeneic HSCT (p=0.007). After 6 months, 24 patients (45%) continued to receive a median of 9 (range 1-15) subsequent AZA cycles. Eventually, hematologic relapse occurred in 8 of those patients (33%), but was delayed until a median of 397 days (range 196-584 days) after initial MRD detection. Treatment was well tolerated with infections (n=4) and pneumonia (n=3) being the main severe side effects during the first 6 cycles. With a median follow-up of 13 months after start of MRD-guided preemptive treatment the actual overall and progression free survival rate is 76% and 42%, respectively.Conclusion: Pre-emptive MRD-guided therapy with AZA can prevent or substantially delay hematologic relapse in patients with MDS and AML at high-risk of relapse. Success of AZA-based MRD therapy seems to be context-dependent emphasizing the potential immunomodulatory effect of hypomethylating agents. [Display omitted] DisclosuresPlatzbecker:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Research Funding; Acceleron: Consultancy, Honoraria, Research Funding. Hänel:Roche: Honoraria; Novartis: Honoraria. Bug:Celgene: Honoraria, Other: Travel funding; Novartis: Honoraria, Research Funding; Astellas: Other: Travel Funding; Janssen: Other: Travel Funding; Jazz Pharmaceuticals: Other: Travel Funding; Amgen: Honoraria. Götze:Celgene: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Abbvie: Honoraria; BMS: Honoraria. Subklewe:Amgen Research (Munich): Research Funding; Amgen, Inc.: Research Funding. Schetelig:Sanofi Aventis: Consultancy, Research Funding; Roche: Honoraria; Abbvie: Honoraria; Janssen: Consultancy, Honoraria. Rollig:Janssen: Research Funding; Bayer: Research Funding. Thiede:Novartis: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Roche: Consultancy; Agendix: Employment.