Core Binding Factor Research Articles

Limited efficacy of 3 + 7 plus gemtuzumab ozogamycin in newly diagnosed fit intermediate genetic risk acute myeloid leukemia patients.

Gemtuzumab-ozogamycin (GO) is approved in combination with high-dose chemotherapy for treatment-naïve low- and intermediate-risk acute myeloid leukemia (AML). In this retrospective real-life multicenter study, we reported efficacy and safety of GO plus high-dose chemotherapy in newly diagnosed AML patients. A total of 31 fit low- and intermediate-risk AML patients treated with GO-based regimens were retrospectively included in this real-life multicenter study, and results were compared with a control cohort treated with 3 + 7 alone. Complete remission (CR) rate after induction was 77%, and most responders (45%) underwent two GO-based consolidation, and minimal residual disease (MRD) negativity was observed in 17 cases (55%) after the end of consolidation. Low genetic risk was associated with increased CR rate compared with intermediate-risk AML (88% vs. 33%; p < .001), as well as prolonged overall survival (OS; hazard ratio, 0.16; 95% confidential interval, 0.02-0.89; p < .001). GO addition resulted in a survival benefit for low-risk AML (median OS not reached vs. 25 months; p = .19) while not for intermediate-risk subjects (10 vs. 13 months; p = .92), compared with the control group. Moreover, GO-treated patients experienced fever of unknown origin or sepsis in 42% or 36% of cases, respectively, with one death during induction due to septic shock, with similar rates compared with the control group (p = .3480 and p = .5297, respectively). No cases of veno-occlusive disease after allogeneic transplantation were observed. Our real-life multicenter study confirmed GO-based treatment efficacy with high MRD negativity rates in fit newly diagnosed AML patients, especially in those with low genetic risk and core binding factor, while limited benefits were observed in intermediate-risk AML. However, further validation on larger prospective cohorts is required.

Abstract 5589: CBFB::MYH11 expression activates Trp53 in myeloid cells, which inhibits cell growth and sensitizes cells to cytarabine

Abstract CBFB::MYH11 acute myeloid leukemia (AML) is a subset of Core Binding Factor AML initiated by an oncofusion in which Core Binding Factor Beta (CBFB) is fused to the C-terminus of smooth muscle myosin heavy chain 11 (MYH11). CBFB::MYH11 AML has a high cure rate with conventional anthracycline/cytarabine induction and high-dose cytarabine consolidation in patients under the age of 60, and remains chemosensitive after multiple relapses; the mechanisms underlying chemosensitivity are unknown. TP53 is a key regulator of DNA damage response and apoptosis, and TP53-mutated AML is often chemoresistant. Large sequencing studies have revealed only rare co-occurrence of TP53 mutations with CBFB::MYH11. We initially used CBFB::MYH11 as a negative control for an unrelated study of TP53 function and unexpectedly found striking synergy. While expression of CBFB::MYH11 in WT murine hematopoietic stem and progenitor cells (HSPCs) induced a low-penetrance (~20%), long latency (~6 months) myelomonocytic AML, expression of CBFB::MYH11 in Trp53-/- HSPCs induced AML with 100% penetrance and a median latency of 8 weeks. CBFB::MYH11-induced AMLs arising in Trp53-/- cells were similar by morphology and flow cytometry phenotype. We validated these findings in a second model, using a conditional Trp53flox/flox x Vav1-Cre model in which Trp53 is inactivated in HSPCs, with nearly identical results. Trp53-/- cells transduced with Empty Vector did not develop AML, but did develop T cell lymphoma with a median latency of 16 weeks, similar to prior studies. Trp53 deficiency also cooperated with RUNX1::RUNX1T1, the other Core Binding Factor oncofusion, to induce a high-penetrance (100%) and short latency AML (median latency 10 weeks); consistent with prior data, RUNX1::RUNX1T1 expression alone in Trp53 WT cells was insufficient to induce AML. To determine whether Trp53 influences the chemosensitivity of CBFB::MYH11 expressing cells, we performed cytarabine dose-response experiments. While CBFB::MYH11-transduced WT HSPCs were very sensitive to cytarabine (relative to EV), sensitivity was reduced in CBFB::MYH11-transduced Trp53-/- cells, suggesting that CBFB::MYH11-induced chemosensitivity is, at least in part, mediated by the TP53 pathway. To determine whether CBFB::MYH11 expression results in upregulation of key TP53 pathway genes, we transduced WT HSPCs with EV or CBFB::MYH11, transplanted cells into WT mice, harvested bone marrow at 3 months, and performed RNA-Seq. Key TP53 pathway genes were upregulated, including Bbc3/Puma, Bax, Cdkn1a/p21, and Trp53 (all 2.6-4.6-fold, p≤0.05). These data suggest that the chemosensitivity and the favorable prognosis of CBFB::MYH11 AML may be due to the direct activation of the TP53 pathway by CBFB::MYH11. Similar studies are underway with RUNX1::RUNX1T1-transduced cells to determine whether TP53 is relevant for the chemosensitivity of that CBF AML as well. Citation Format: Ryan B. Day, Julia A. Hickman, Casey D. Katerndahl, Sai Mukund Ramakrishnan, Christopher A. Miller, Timothy J. Ley. CBFB::MYH11 expression activates Trp53 in myeloid cells, which inhibits cell growth and sensitizes cells to cytarabine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5589.

Abstract 6471: Trends in chemotherapy utilization in acute myeloid leukemia (AML) in last 15 years

Abstract Introduction: Chemotherapy (Chemo) can relieve symptoms and improve quality of life and survival in AML, including in many older and frail adults. However, in a prior study from the US, almost a quarter of patients (pts) with new diagnoses of AML between years (yrs) 2003 and 2011 did not receive chemo (Bhatt et al., Blood Advances, 2018). Our study examined trends in chemo utilization in the last 15 yrs to test the hypothesis that chemo use has increased in more recent yrs. We also examined any disparities in chemo use. Methods: We utilized the National Cancer Database to identify 78,864 pts diagnosed with AML between 2004 and 2019 and divided them into 2 cohorts based on date of diagnosis, 2004-2010 and 2011-2019. We used logistic regression to estimate effect of demographic and disease characteristics on odds of receiving chemo and evaluate differences in these effects between the constructed patient cohorts. Results: Seventy-seven percent of total pts received chemo. Compared to 73% in 2004, 81% of pts received chemo in 2019. The receipt of chemo declined with increasing age with higher use of chemo in all groups in 2011-2019 compared to 2004-2010: &amp;gt;80 (yrs)= 40 vs 33%, 71-80 yrs= 72 vs 63%, 60-70 yrs= 87 vs 84%, 41-59 yrs= 93 vs 92%, and 18-40 yrs = 95 vs 94%.The receipt of chemo was lowest in white pts overall; in black pts, receipt of chemo increased in 2011-2019 compared to 2004-2010: black= 83 vs 76%, white= 78 vs 75%, and others 83 vs 83%. The receipt of chemo was lowest in therapy-related (t)-AML in 2011-2019 and 2004-2010: t-AML 64 vs 60%, acute promyelocytic leukemia= 88 vs 87%, core binding factor AML 93 vs 88% and other 77 vs 74%. In multivariable analysis, the odds of receiving chemo increased in 2011-2019 compared to 2004-2010 in all pts, particularly in older adults. Compared to white, black pts had similar odds of receiving chemo in 2004-2010, but odds were higher in 2011-2019 (Odds ratio, 1.2, 95% confidence interval, 1.1-1.3. Pts with t-AML were less likely to receive chemo compared to all other subtypes in 2004-2010 and 2011-2019. Female sex, lower income, public insurance, higher comorbidity score, and shorter distance to treatment facility were associated with a lower likelihood of receiving chemo; however, chemo utilization did not differ over the two time periods based on these variables. Conclusion: To our knowledge, this is the largest scale analysis of chemo utilization in AML in real-world practice. Chemo receipt increased significantly over the yrs, particularly among older adults, black pts, core binding factor, and t-AML. These recent trends are encouraging and represent novel findings. Despite these results, healthcare disparity based on sex, socioeconomic, and healthcare system factors continues to persist. In addition to developing safer and more effective chemo regimens, other innovative strategies to tackle these disparities are crucial to improve outcomes. Citation Format: Prajwal Dhakal, Bradley Loeffler, Aditya Ravindra, Avantika Pyakuryal, Vijaya Raj Bhatt. Trends in chemotherapy utilization in acute myeloid leukemia (AML) in last 15 years [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6471.

Survival of adult AML patients treated with chemotherapy in the U.S. population by age, race and ethnicity, sex, calendar-year period, and AML subgroup, 2001–2019

Population-based survival studies of adult acute myeloid leukemia (AML) have not simultaneously evaluated age at diagnosis, race and ethnicity, sex, calendar period or AML subtypes/subgroups among chemotherapy-treated patients. For 28,473 chemotherapy-treated AML patients diagnosed at ages ≥20 years in population-based cancer registry areas of the Surveillance, Epidemiology, and End Results Program (2001-2018, followed through 2019), we evaluated 1-month through 5-year relative survival (RS) and 95% confidence intervals (95% CI) using the actuarial method in the SEER∗Stat Survival Session and overall survival (OS) using multivariable Cox regression to estimate proportional hazard ratios (HR) and 95% CI. RS decreased with increasing age (20-39, 40-59, 60-74, 75-84, ≥85 years) at AML diagnosis. RS declined substantially within the first month and, except for acute promyelocytic leukemia, decreasing patterns continued thereafter for core binding factor AML, AML with antecedent condition/therapy, and all other AML. For all ages, acute promyelocytic leukemia RS stabilized after the first year. For total AML the hazard of death was significantly increased for non-Hispanic (NH)-Black (HR=1.18, 95% CI=1.12-1.24) and NH-Pacific Islander patients (HR=1.31, 95% CI=1.11-1.55) compared with NH-White patients. In contrast, NH-Asian and Hispanic patients had similar OS to NH-White patients across all ages and most AML subgroups. Males had significantly inferior survival to females with some exceptions. Compared to 2001-2006, in 2013-2018 OS improved for all age and AML subgroups. Chemotherapy-treated U.S. adults with AML have notable differences in survival by age, race and ethnicity, sex, calendar-year period, and AML subgroup. Despite survival gains over time, our findings highlight the need for improving early outcomes across all AML subgroups, older ages, and Black and Pacific Islander patients and long-term outcomes among most treated groups. Intramural Research Program of the U.S. National Institutes of Health, National Cancer Institute, Division of Cancer Epidemiology and Genetics, and the U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Surveillance and Epidemiology.

Role of RUNX2 in Oral Squamous Cell Carcinoma (OSCC): A Systematic Scoping Review

RUNX2, known as the core-binding factor subunit alpha-1 (Cbfa1), is a protein-coding gene recognized and responsible for its involvement in bone development and osteoblast differentiation. However, its dysregulation and aberrant expression have been linked to the pathogenesis of many diseases, such as oral squamous cell carcinoma (OSCC). This review highlights the significance of the RUNX2 gene in oral squamous cell carcinoma. Objectives. To review the contribution of the RUNX2 gene in oral squamous cell carcinoma and its implication on clinical diagnosis and treatments. Materials and Methods. A systematic scoping review was conducted to elucidate the role of RUNX2 in OSCC. A framework of five stages for scoping reviews outlined by Arksey and O’Malley (2005) was adopted for the current study. Results. The review showed that RUNX2 plays a role in the development and progression of OSCC, a common form of head and neck cancer. Conclusion. RUNX2 is an essential player in the molecular mechanisms underlying the development and progression of oral squamous cell carcinoma, and its dysregulation promotes tumor initiation, progression, and metastasis, making it a potential target therapy for future research aimed at developing novel therapies for oral squamous cell carcinoma. Clinical Relevance. Understanding the precise mechanisms by which RUNX2 contributes to OSCC pathogenesis can lead to target treatment for this challenging form of cancer.

Addition of single dose gemtuzumab ozogamicin to intensive induction chemotherapy in core-binding factor acute myeloid leukemia

In a meta-analysis of 5 trials, the addition of gemtuzumab ozogamicin (GO) to intensive induction chemotherapy led to a survival benefit in patients with core-binding factor (CBF) acute myeloid leukemia (AML). Given the heterogeneous incorporation of GO in clinical trials, the ideal dose and schedule remains unclear. We conducted a single-center retrospective analysis to compare outcomes of patients with CBF-AML treated with intensive induction chemotherapy, with or without a single dose of GO 3 mg/m2, during induction only. We included 87 patients (GO=32, control=55). The composite complete remission (cCR) rate was higher in the control group (93%) compared to the GO group (82%) (p<0.001). The rate of measurable residual disease (MRD) negative cCR, by flow cytometry, was similar between both groups. There were no significant differences between the two groups in terms of toxicity. The 3-year relapse-free survival (RFS) for both groups was similar (71% vs 68%, p=0.5). The 3-year overall survival (OS) for the GO group was 68%, compared to 66% for the control group (p=0.9).In multivariable analysis, age and MRD positive status were risk factors for inferior outcomes. We find that survival of patients with CBF-AML is favorable in the real-world setting. The addition of single-dose GO, during induction, did not lead to a higher remission rate or survival benefit, when compared to intensive chemotherapy without GO. Further investigation into the incorporation of GO in the treatment algorithm for CBF-AML is needed.

Hypomethylating agent monotherapy in core binding factor acute myeloid leukemia: a French multicentric retrospective study

Very few data are available about hypomethylating agent (HMA) efficiency in core binding factor acute myeloid leukemias (CBF-AML). Our main objective was to evaluate the efficacy and safety of HMA in the specific subset of CBF-AML. Here, we report the results of a multicenter retrospective French study about efficacy of HMA monotherapy, used frontline or for R/R CBF-AML. Forty-nine patients were included, and received a median of 5 courses of azacitidine (n = 46) or decitabine (n = 3). ORR was 49% for the whole cohort with a median time to response of 112 days. After a median follow-up of 72.3 months, median OS for the total cohort was 10.6 months. In multivariate analysis, hematological relapse of CBF-AML at HMA initiation was significantly associated with a poorer OS (HR: 2.13; 95%CI: 1.04–4.36; p = 0.038). Responders had a significantly improved OS (1-year OS: 75%) compared to non-responders (1-year OS: 15.3%; p < 0.0001). Hematological improvement occurred for respectively 28%, 33% and 48% for patients who were red blood cell or platelet transfusion-dependent, or who experienced grade 3/4 neutropenia at HMA initiation. Adverse events were consistent with the known safety profile of HMA. Our study highlights that HMA is a well-tolerated therapeutic option with moderate clinical activity for R/R CBF-AML and for patients who cannot handle intensive chemotherapy.

Hematological Neoplasms with Eosinophilia.

Eosinophils in peripheral blood account for 0.3-5% of leukocytes, which is equivalent to 0.05-0.5 × 109/L. A count above 0.5 × 109/L is considered to indicate eosinophilia, while a count equal to or above 1.5 × 109/L is defined as hypereosinophilia. In bone marrow aspirate, eosinophilia is considered when eosinophils make up more than 6% of the total nuclear cells. In daily clinical practice, the most common causes of reactive eosinophilia are non-hematologic, whether they are non-neoplastic (allergic diseases, drugs, infections, or immunological diseases) or neoplastic (solid tumors). Eosinophilia that is associated with a hematological malignancy may be reactive or secondary to the production of eosinophilopoietic cytokines, and this is mainly seen in lymphoid neoplasms (Hodgkin lymphoma, mature T-cell neoplasms, lymphocytic variant of hypereosinophilic syndrome, and B-acute lymphoblastic leukemia/lymphoma). Eosinophilia that is associated with a hematological malignancy may also be neoplastic or primary, derived from the malignant clone, usually in myeloid neoplasms or with its origin in stem cells (myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions, acute myeloid leukemia with core binding factor translocations, mastocytosis, myeloproliferative neoplasms, myelodysplastic/myeloproliferative neoplasms, and myelodysplastic neoplasms). There are no concrete data in standardized cytological and cytometric procedures that could predict whether eosinophilia is reactive or clonal. The verification is usually indirect, based on the categorization of the accompanying hematologic malignancy. This review focuses on the broad differential diagnosis of hematological malignancies with eosinophilia.

Deficiency of Cbfβ in articular cartilage leads to osteoarthritis-like phenotype through Hippo/Yap, TGFβ, and Wnt/β-catenin signaling pathways.

Osteoarthritis (OA) is the most prevalent degenerative joint disorder, causing physical impairments among the elderly. Core binding factor subunit β (Cbfβ) has a critical role in bone homeostasis and cartilage development. However, the function and mechanism of Cbfβ in articular cartilage and OA remains unclear. We found that Cbfβf/fAggrecan-CreERT mice with Cbfβ-deficiency in articular cartilage developed a spontaneous osteoarthritis-like phenotype with articular cartilage degradation. Immunofluorescence staining showed that Cbfβf/fAggrecan-CreERT mice exhibited a significant increase in the expression of articular cartilage degradation markers and inflammatory markers in the knee joints. RNA-sequencing analysis demonstrated that Cbfβ orchestrated Hippo/Yap, TGFβ/Smad, and Wnt/β-catenin signaling pathways in articular cartilage, and Cbfβ deficiency resulted in the abnormal expression of downstream genes involved in maintaining articular cartilage homeostasis. Immunofluorescence staining results showed Cbfβ deficiency significantly increased active β-catenin and TCF4 expression while reducing Yap, TGFβ1, and p-Smad 2/3 expression. Western blot and qPCR validated gene expression changes in hip articular cartilage of Cbfβ-deficient mice. Our results demonstrate that deficiency of Cbfβ in articular cartilage leads to an OA-like phenotype via affecting Hippo/Yap, TGFβ, and Wnt/β-catenin signaling pathways, disrupting articular cartilage homeostasis and leading to the pathological process of OA in mice. Our results indicate that targeting Cbfβ may be a potential therapeutic target for the design of novel and effective treatments for OA.

Camrelizumab for Preemptive Treatment of Molecular Recurrence after Allogeneic Hematopoietic Stem Cell Transplantation in Core-Binding Factor Acute Myeloid Leukemia: Two Case Reports

Camrelizumab for Preemptive Treatment of Molecular Recurrence after Allogeneic Hematopoietic Stem Cell Transplantation in Core-Binding Factor Acute Myeloid Leukemia: Two Case Reports

Metabolomic profile of acute myeloid leukaemia parallels of prognosis and response to therapy

The heterogeneity of acute myeloid leukemia (AML), a complex hematological malignancy, is caused by mutations in myeloid cells affecting their differentiation and proliferation. Thus, various cytogenetic alterations in AML cells may be characterized by a unique metabolome and require different treatment approaches. In this study, we performed untargeted metabolomics to assess metabolomics differences between AML patients and healthy controls, AML patients with different treatment outcomes, AML patients in different risk groups based on the 2017 European LeukemiaNet (ELN) recommendations for the diagnosis and management of AML, AML patients with and without FLT3-ITD mutation, and a comparison between patients with FLT3-ITD, CBF-AML (Core binding factor acute myelogenous leukemia), and MLL AML (mixed-lineage leukemia gene) in comparison to control subjects. Analyses were performed in serum samples using liquid chromatography coupled with mass spectrometry (LC–MS). The obtained metabolomics profiles exhibited many alterations in glycerophospholipid and sphingolipid metabolism and allowed us to propose biomarkers based on each of the above assessments as an aid for diagnosis and eventual classification, allowing physicians to choose the best-suited treatment approach. These results highlight the application of LC–MS-based metabolomics of serum samples as an aid in diagnostics and a potential minimally invasive prognostic tool for identifying various cytogenetic and treatment outcomes of AML.

Understanding differential technologies for detection of MRD and how to incorporate into clinical practice.

Patient- and leukemia-specific factors assessed at diagnosis classify patients with acute myeloid leukemia (AML) in risk categories that are prognostic for outcome. The induction phase with intensive chemotherapy in fit patients aims to reach a complete remission (CR) of less than 5% blasts in bone marrow by morphology. To deepen and sustain the response, induction is followed by consolidation treatment. This postremission treatment of patients with AML is graduated in intensity based on this favorable, intermediate, or adverse risk group classification as defined in the European Leukemia Network (ELN) 2022 recommendations. The increment of evidence that measurable residual disease (MRD) after induction can be superimposed on risk group at diagnosis is instrumental in tailoring further treatment accordingly. Several techniques are applied to detect MRD such as multiparameter flow cytometry (MFC), quantitative (digital) polymerase chain reaction (PCR), and next-generation sequencing. The clinical implementation of MRD and the technique used differ among institutes, leading to the accumulation of a wide range of data, and therefore harmonization is warranted. Currently, evidence for MRD guidance is limited to the time point after induction using MFC or quantitative PCR for NPM1 and core binding factor abnormalities in intermediate-risk patients. The role of MRD in targeted or nonintensive therapies needs to be clarified, although some data show improved survival in patients achieving CR-MRD negativity. Potential application of MRD for selection of conditioning before stem cell transplantation, monitoring after consolidation, and use as an intermediate end point in clinical trials need further evaluation.

High IL2RA/CD25 expression is a prognostic stem cell biomarker for pediatric acute myeloid leukemia without a core-binding factor.

CD25 is an aberrant marker expressed on the leukemic stem cell (LSC) surface and an immunotherapy target in acute myeloid leukemia (AML). However, the clinical prevalence and significance of CD25 expression in pediatric AML are unknown. High IL2RA/CD25 expression in pediatric AML showed a stem cell-like phenotype, and elevated CD25 expression was associated with lower overall survival (p<.001) and event-free survival (p<.001) in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 study. This finding was reproduced in AML without a core-binding factor in the Children's Oncology Group study cohort. High CD25 expression has prognostic significance in pediatric AML.

Clinical characteristics and prognostic factors analysis of core binding factor acute myeloid leukemia in real world.

Chromosomal translocations involving core binding factor (CBF) genes account for 15% of adult acute myeloid leukemia (AML) cases in China. Despite being classified as favorable-risk by European Leukemia Net (ELN), CBF-AML patients have a 40% relapse rate. This study aims to analyze clinical characteristics and prognosis of CBF-AML, compare its subtypes (inv(16) and t(8;21)), and validate prognostic factors. Retrospective analysis of 149 AML patients (75 CBF-AML, 74 non-CBF) at Peking University First Hospital (March 2012-March 2022). CBF-AML patients have significantly lower disease-free survival (DFS) (p = 0.005) and higher non-relapse mortality (NRM) (p = 0.028) compared to non-CBF AML. inv (16) and t(8;21) show distinct co-occurring gene mutation patterns, with inv(16) being prone to central nervous system (CNS) leukemia. Multivariate analysis identifies age as a risk factor for overall survival (OS) and disease free survival (DFS), kinase mutation as a risk factor for DFS and Recurrence, while WT1 mutation as a risk factor for OS and non relapse mortality (NRM) risk in t(8;21) AML. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) improves prognosis in low-risk t(8;21). Prognosis of CBF-AML is poorer than ELN guidelines suggest. inv(16) and (8;21) are separate entities with relatively poor prognoses, requiring rational risk stratification strategies. Allo-HSCT may benefit low-risk t(8;21), but further research is needed for conclusive evidence.

Prevalence and Prognosis of Secondary Genetic Aberrations Among Patients With Core Binding Factor Acute Myeloid Leukemia: A Mitelman Database Analysis.

Core binding factor acute myeloid leukemia (CBF-AML) comprises t(8;21) and inv(16) and usually has a favorable prognosis. However, a wide spectrum of secondary genetic aberrations has been shown to be associated with worse outcomes with respect to overall survival (OS) and relapse. We aimed to identify secondary molecular and chromosomal aberrations within each group of CBF-AML, i.e., t(8;21) and inv(16), and to evaluate their prognosis with OS. Using the Mitelman Database of Chromosome Aberrations and Gene Fusions in Cancer, we analyzed 193 cases of CBF-AML reported between 2011 and 2021. We conducted a survival analysis to determine the 5-year OS, and we conducted univariate and multivariate Cox regression to identify independent genetic factors related to OS. Among the 193 cases with CBF-AML, structural and numerical chromosome rearrangements were 25.9% and 40.9%, respectively, and secondary genetic mutations were 54.9%. The 5-year OS for the presence of del(7) and trisomy 22 was significantly worse. NRAS mutations had a worse 5-year OS in the t(8;21) group in the univariate analysis but showed no significant difference in the multivariate analysis. CBF-AML has heterogeneous cytogenetic characteristics but no difference in the 5-year OS between the inv(16) and t(8;21) groups. Finally, the presence of del(7), trisomy 22 and NRAS mutations showed a potential prognostic impact in CBF-AML patients. Secondary genetic findings may need to be identified to determine its association to a worse prognosis, and in the future develop better targeted therapies in patients with CBF-AML.

Abstract A145: CBFβ supports global protein translation in osteosarcoma and may provide a new therapeutic target

Abstract Background: Core binding factor beta (CBFβ) is a binding partner to the RUNX family of DNA binding transcription factors (RUNX1-3) and acts as a transcriptional co-activator by allosterically increasing their affinity for DNA. RUNX2 is the master regulator of bone growth and differentiation, and its binding to CBFβ is of particular interest to osteosarcoma (OS) research. Notably, increased expression of each is correlated with poor disease-free and overall survival in numerous sarcomas. CBFβ’s transcriptional role is well-understood but recent research in breast cancer cells proposes a non-canonical role in the regulation of protein translation, influencing translation of hundreds of mRNA transcripts via binding with heterogenous nuclear ribonucleoprotein K (hnRNPK). The binding of CBFβ to hnRNPK or RUNX1 is reportedly mutually exclusive, suggesting possible interplay between the two roles. We hypothesize that CBFβ regulates protein translation in OS, participating in the translation of RUNX2 and other oncoproteins, promoting a malignant phenotype. Furthermore, we propose that disrupting its translational role may result in an antitumor effect. While CBFβ’s transcriptional activities are well-characterized, we endeavored to isolate its translational role and investigate its contribution to OS. Methods: CRISPR/Cas9 was used to generate a CBFβ knockout (KO) U2OS cell line, while site-directed mutagenesis of CBFβ and lentiviral transduction of U2OS CBFβ KO cells was used to generate cell lines expressing FLAG-tagged wild type (WT) mutant CBFβ. Western Blotting (WB) was used to assess changes in protein expression and subcellular localization while RUNX2 mRNA expression was measured via qPCR and RNAseq. CBFβ’s interacting partners were identified by Immunoprecipitation Mass Spectrometry (IP-MS). Cellular electro-thermal shift assay was used to evaluate influences of CBFβ mutations on RUNX2 and hnRNPK binding. The Click-IT system followed by WB and IP-MS were used to assess global protein translation and synthesis rates of specific proteins, respectively. Results: CBFβ and hnRNPK interact in U2OS cells and loss of CBFβ leads to a decrease in global protein translation. This results in decreased RUNX2 protein, but not mRNA, expression. Re-introduction of WT CBFβ caused RUNX2 protein levels to recover while expression of CBFβ with key mutations in the binding interface abrogated this effect. Importantly, we observed this was not due to direct protection of RUNX2 from proteasomal degradation by WT CBFβ. We identified a cohort of proteins that appear to be translationally regulated by CBFβ and investigated the impact of CBFβ mutations on its translational activities and RUNX2 binding. We also identified a list of putative CBFβ protein-protein interactions in human OS cells that are altered by these mutations. Conclusions: CBFβ appears to participate in protein translation in OS, regulating the expression of numerous oncoproteins including RUNX2. Key mutations in CBFβ designed to interrupt RUNX2 binding also affect this non-canonical activity of CBFβ. Citation Format: Nicholas A Oldberg, Dayn R Godinez, Luke A Wittenburg. CBFβ supports global protein translation in osteosarcoma and may provide a new therapeutic target [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A145.

Acute myeloid leukemia with t(16;21)(q24;q22), CBFA2T3::RUNX1, in post-treatment setting, a case report

Abstract Introduction/Objective Acute myeloid leukemia (AML) with t(16;21)(q24;q22), CBFA2T3::RUNX1 is an uncommon entity that has been reported in both pediatric and adult patients as de novo AML or secondary to prior chemo/radiation therapy. CBFA2T3::RUNX1 AMLs share similar clinico-pathological features and gene expression profile with RUNX1::RUNX1T1 AML. Methods/Case Report We report a case of AML with CBFA2T3::RUNX1 in a 52 year old female who had history of small cell cervical cancer treated with chemotherapy (4 cycles of cisplatin and etoposide) and pelvic radiation therapy. About 17 months after completion of therapy, she presented with anemia and thrombocytopenia, normal WBC/neutrophil count, eosinophilia and increased blasts (up to 10%) in blood. Bone marrow biopsy shows AML with maturation (FAB-M2), erythropoiesis is present, whereas megakaryocytes are decreased. Flow cytometry analysis shows myeloblasts with aberrant CD19 and CD56 expression; in addition, increased CD117/tryptase positive cells are noted, mostly interstitial and more concentrated around bone trabeculae. By immunohistochemical stains, these cells are at least partially positive for CD25, negative CD2, CD30. Karyotype studies demonstrate t(16;21)(q24;q22) and trisomy 8 in all metaphases. FoundationOne heme NGS studies confirmed CBFA2T3::RUNX1 fusion, and no additional mutations were identified. Patient received induction chemotherapy with Idarubicin/Cytarabine plus GO (Gemtuzumab ozogamicin); day 14 bone marrow showed chemotherapeutic effect and she is now in morphologic remission 5 months after diagnosis. Results (if a Case Study enter NA) NA Conclusion Our case adds to the limited knowledge of CBFA2T3::RUNX1 AMLs. Our case shows morphological and immunophenotypic features similar to AML with RUNX1::RUNX1T1, with unusual presentation of peripheral eosinophilia, and increased CD117/tryptase positive cells in bone marrow, the latter has been reported occasionally in core binding factor AMLs. We emphasize the importance of comprehensive genetic studies in AML patients, lack of adverse genetic abnormalities in our patient indicates favorable risk category regardless of the post-treatment clinical setting.

Influence of Pre-Treatment Features and Therapy Choice By Physicians on Overall Survival in Older Adults with Acute Myeloid Leukemia: A Report from the Beat AML Master Trial

Background: Acute myeloid leukemia (AML) therapy in older patients (age ≥ 60) has undergone a transformation with the introduction of multiple targeted therapies, which has allowed more patients to receive therapy than before. The most successful has been the combination of venetoclax + azacitidine (VA) which generated higher overall complete response rates in phase 2 studies than would be expected with azacitidine alone, leading to accelerated FDA approval on 21Nov2018. The VIALE-A phase 3 study confirmed the improved overall survival (OS, median 14.7 versus 9.6 months) of VA, leading to full FDA approval for marketing. This retrospective analysis provides real world data on the impact of baseline clinical and genomic markers of individuals receiving intensive chemotherapy versus VA. Methods: The precision medicine Beat AML Master Trial (NCT03013998) assigns patients to biomarker specific sub-study treatments based on targeted DNA sequencing and cytogenetics. However, a large subset of patients did not enroll on a sub-study, but were followed for off-study treatment and OS. From this subset, patients enrolled onward from 21Nov2018, when VA received accelerated approval, were examined for differences in clinical/genetic characteristics and OS in those receiving venetoclax + hypomethylating agent (V/HMA), any form of intensive chemotherapy (IC), alternative non-intensive therapy (NIT), or no therapy. The genetic mutations identified in this study are characterized by a variant allele frequency of 20%+, as defined in the trial for determining the dominant clone. The method of Kaplan-Meier was used to estimate OS, and the Cox model was fit to associate patient characteristics with OS. Results: From 21Nov2018, a total of 468 AML patients consented to the Beat AML trial and did not enroll to a sub-study. Treatment was chosen by the investigator based upon available clinical and genomic data. Of these 468 patients, 62 did not receive treatment, 2 had treatment data missing, 226 were treated with V/HMA, 112 with IC, and 66 with NIT. Demographics for all patients include median age 71 (60-90), 40% female, performance status (PS) (0-20%; 1-55%; 2-22%; 3-3%), median white blood cell (WBC) 4.1 (range 0.3-298.6), complex karyotype (CK) 20.6%, core binding factor (CBF) 7.8%, KMT2A-rearranged 3.6%, NPM1-mutated (m) 15.6%, IDH2m 14.6%, TP53m 13.2%, FLT3-ITD/TKD 12.9%, and NRASm/ PTPN11m/ KRASm/ NF1m/ CBLm 23.6%. Demographics that were significantly different (p&amp;lt;0.01) among the three groups (V/HMA, IC, and NIT) include age (younger in IC), PS (worse in NIT), AST/ALT (worse in NIT), CBF (more in IC), CK and TP53m (less in IC). Of the 404 patients who underwent treatment with V/HMA, IC, or NIT, 208 have died with those surviving having a median follow-up of 22.3 months. Figure 1 summarizes the OS of each treatment group. The median OS (95% CI) from time of initiating therapy is 13.6 (10.9-16.8) for V/HMA, 33.8 (20.7-not reached) for IC, and 11.6 (5.2-21.3) months for NIT. Univariable analysis for OS was significant at p&amp;lt;0.05 for increased age, WBC, PS, hemoglobin, CBF, CK, NPM1m, TP53m, TET2m and IC versus V/HMA. Multivariable analysis was significant at p&amp;lt;0.05 (hazard ratio) for increased age (1.14), PS (1.83), WBC (1.08), hemoglobin (0.91), and select genomic aberrations including CBF (0.37), NPM1m (0.35), and TP53m (2.1). Conclusions: These results from a large cohort of older AML patients treated with V/HMA, IC, or NIT show that their outcome is best defined by pre-treatment clinical features previously identified including age, performance status, WBC and hemoglobin along with limited genomic characteristics including CBF, NPM1m, and TP53m. While univariate analysis of OS favored IC over V/HMA and NIT, multivariable analysis supports that this advantage was most likely due to the favorable clinical and genomic features. The OS of V/HMA patients in this cohort is similar to that in the VIALE-A registration study of VA, providing further justification for this treatment for older AML patients deemed ineligible for intensive chemotherapy. Additionally, this data supports use of the patient cohort in this study for ongoing work in understanding and/or validating biomarkers associated with survival with V/HMA.

Multiparametric Flow Cytometry-MRD Assay: Lesson from Phase II Trail REL AML 001

Background: Core-binding factor (CBF) AML with RUNX1/RUNX1T1 (AML1/ETO) and CBFB/MYH11 fusion genes is known as a heterogenous group, accounting for about 10% to 15% of AML. In the Phase II Trial REL AML 001 (EudraCT Number 2017-002094-18; ClinicalTrials ID: NCT 03686345) adult CBF leukemia patients treated with a continuation therapy with Midostaurin were included, and the measurable residual disease (MRD) was performed by molecular MRD assessment (qPCR) and multiparametric flow cytometric-MRD (MCF-MRD) assay. The findings of MCF-MRD assay were compared to qPCR. Methods: 31 patients with AML1/ETO (n=15) and CBFB/MYH11 (n=16) were evaluated between December 2018 to July 2022 with both techniques. A total of 145 determinations (n. AML1/ETO = 56 and n. CBFB/MYH11= 89) were performed. MCF panel included 2 10-color tubes: CD15 FITC/ CD56 PE/ CD34 PerCP-cy5.5/ CD117 PE-cy7/ CD7 APC/ CD13 APC-R700/ CD19 APC H7/ HLADR V450/ CD45 V500C/ CD33 BV630, specific for RUNX1/RUNX1T1 cases and CD64 FITC/ CD2 PE/ CD34 PerCP-cy5.5/ CD117 PE-cy7/ CD200 APC/ CD13 APC-R700/ CD14 APC H7/ HLADR V450/ CD45 V500C/ CD33 BV630, specific for CBFB/MYH11 cases. A mean of 1,733,240 CD45 positive events were acquired, with a mean lower limit of detection (LLOD) of 0.001% (ranging 0.01-0.0003%). In 10 cases (6 RUNX1 and 4 CBFB/MYH11) the molecular and phenotypical features at onset were not available. MCF analyses were performed by InfinicytTM software and reference image tool was used wherever possible. Results: We found a concordance of 76% between MCF cases and RUNX1/RUNX1T1 qPCR, and a concordance of 83% between MCF cases and CBFB/MYH11 qPCR (Tables 1a and 1b). In relapsed cases we observed a dynamic and continuous increase of abnormal MCF events, that was not found in cases without clinical relapse although with positive qPCR (Table 2). The HLADR expression evaluated as the geo mean intensity at presentation and/or at relapse resulted higher in RUNX1/RUNX1T1 patients than in CBFB/MYH11 cases (29845 vs 8979, respectively, p=0.0039 Figure 1). Interestingly, we found in a single case with atypical CBFB/MYH11 fusion gene a high value of HLADR geo mean (44522). The down-regulated expression of HLADR in CBFB/MYH11 blasts may be a useful clue to distinguish AML blasts from the scarcely represented normal CD2 positive myeloid precursors, and from the strongly HLADR positive elements that are found in a regenerating bone marrow background. Conclusion: Although MCF-MRD assay showed lower sensitivity than CBF qPCR, MCF offered interesting informations about the dynamics of the abnormal clone size with time, evaluated as the increasing number of MRD clustering events, which may predict an impending relapse.

Venetoclax and Azacitidine for Molecular Relapse during First Line Intensive Chemotherapy in Patients with NPM1 Mutated or Core Binding Factor (CBF) AML. a Study from the Dataml Registry

Introduction: Molecular follow-up (FU) for AML patients (pts) with NPM1 mutation, RUNX1::RUNX1T1 or CBFB::MYH11 fusion transcripts has been established over the last ten years. Real-time quantitative PCR (qPCR) is the gold standard for the evaluation of measurable residual disease (MRD) in pts undergoing intensive chemotherapy (IC). Failure to achieve a deep molecular response is a strong predictive factor of relapse and survival and may guide post remission therapy (Ivey A, NEJM 2016). Moreover, the ELN MRD working party recommended a schedule for molecular FU and recently established a definition of molecular relapse (Heuser M, Blood 2021). However, there is no therapeutic consensus for pts with molecular relapse before overt clinical relapse. Frontline allogeneic hematopoietic cell transplantation (alloHCT), salvage IC or even waiting for morphological relapse in order to screen molecular characteristics of the relapsing disease or propose a clinical trial, may be discussed with pts. Venetoclax with azacitidine (VEN/AZA) was recently approved in unfit AML pts and demonstrated a particular efficacy in NPM1-mutated AML. In this study, we thought to describe the safety and efficacy of VEN/AZA in pts with NPM1 mutated or CBF AML in molecular relapse after first line IC. Methods: Pts of the DATAML registry with the following criteria were included in this study : AML with NPM1 mutation, RUNX1::RUNX1T1 or CBFB::MYH11 transcripts, first line IC, morphological complete remission (CR), no alloHCT in first line, regular monitoring of MRD by qPCR in bone marrow (BM) and/or blood, molecular relapse defined according to ELN2021 guidelines on two successive samples, at least one cycle of VEN/AZA. Pts with molecular relapse followed by morphological relapse before VEN/AZA or those who relapsed after alloHCT were not included. Treatment: First line IC was cytarabine 200 mg/m² d1-7 with idarubicin 9mg/m²/d1-5 or daunorubicin 90mg/m²/d1-3 in pts 18-60y or cytarabine 100 mg/m² d1-7 with idarubicin 8mg/m²/d1-5 and lomustine 200 mg/m²/d1 in pts &amp;gt; 60y. Post remission therapy was intermediate or high dose cytarabine or mini-consolidations according to age and performance status. Midostaurin was added in FLT3-mutated pts. At time of molecular relapse, pts received off label venetoclax 400 mg/d (d1-14, d1-21 or d1-28 according to centers) with no ramp-up and azacitidine 75 mg/m²/d subcutaneously (d1-5, d8-9). Antifungal/antibiotic prophylaxis and G-CSF use were not systematically recommended. Results: Twenty-two pts treated with VEN/AZAfrom 21/09/2020 to30/03/2023 were included. Their characteristics at diagnosis were: female (n= 14), median age 55y (range 27-71), de novo AML (n=21), median WBC (68 giga/L, range 2.32-339.7), NPM1 mutation (n=20), CBFB::MYH11 (n=2), FLT3 mutation (n=13). All pts achieved first CR after one cycle of induction chemotherapy. Pts received a median of three consolidation cycles. All but three pts had negative MRD or low level MRD (LL-MRD) in blood and/or BM at the end of consolidation. The median time between CR1 and molecular relapse was 9.5 months (range, 1-50). The median time between molecular relapse and first VEN/AZA cycle was 51 days. During first cycle of VEN/AZA, 12, 5 and 5 pts received 14, 21 or 28 days venetoclax, respectively; 19 were treated as out-pts, 4 received posaconazole and GCSF was used in 11 pts. 12 and 3 pts had grade 3-4 neutropenia or febrile neutropenia (FN), respectively. Only 3 pts (14%) were hospitalized for FN. The median number of VEN/AZA cycles was 2 (range 1-12). After C1+/-C2, 10 (45%) and 11 pts (55%) had undetectable or LL MRD in blood, respectively (Fig1). 20 pts were bridged to alloHCT in morphological CR after a median of 2 cycles (range, 1-4). Only one pt had a molecular progression before transplantation after 2 cycles. Two pts died, one had a molecular relapse after 7 cycles and progress rapidly to frank relapse, the other one died of post-transplant complication while in CR with undetectable MRD. All other pts remained in CR at date of last news. With a median FU from D1C1 of 13.5 months, median OS wat not reached and 1y-OS was 86% (Fig2). Conclusion: In the setting of molecular relapse, VEN/AZA is safe, prevent overt relapse, and induce a high rate of molecular response before alloHCT. Molecular relapse becomes a major therapeutic challenge. Clinical trial endpoints should include the treatment of molecular relapse as an event for RFS and EFS estimation.