CBFB-MYH11 fusion

P3, N=204, Completed, University of Ulm | Active, not recruiting --> Completed

P=N/A, N=400, Completed, Acute Leukemia French Association | Recruiting --> Completed

Subsequently, the type I CBFB::MYH11 fusion gene was identified through exhaustive exploration using RNA sequencing for fusion gene discovery. This exceptional case highlights the existence of a distinctive subtype of CBFB::MYH11 that may yield false-negative results in conventional chimeric fusion screening, thus emphasizing the indispensable utility of PCR primer modification, FISH, and RNA sequencing in the investigative process.

Paradoxically, CBFB::MYH11 expression was associated with increased RUNX1/2 expression, suggesting the presence of a sensor for reduced functional RUNX1 protein, and a feedback loop that that may attempt to compensate by increasing RUNX1/2 transcription. These findings may have broad implications for AML pathogenesis.

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... 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.

Exon 17 KIT mutations serve as an important predictor of relapse in RUNX1::RUNX1T1 pediatric AML. In addition, a high KIT VAF may predict poor outcomes in these patients. These results emphasize the need to incorporate KIT mutational analysis into risk stratification for pediatric CBF-AML.

Conclusion We have demonstrated that NGS has a high sensitivity for identification of RNA fusion genes, is complementary to conventional cytogenetics testing, and has vast clinical impact in terms of diagnosis, prognostication and clinical management. We advocate for the integration of NGS with DNA and RNA sequencing into routine investigation of suspected myeloid malignancies for a more precise and comprehensive diagnostic approach.

Since then, GO has been incorporated to the intensive regimen [traditional '3+7' or fludarabine-cytarabine and GCSF (FLAG)] and has become the standard approach for CBF-AML. CLAG-GO is highly effective and safe when treating CBF-AML as frontline therapy and seems encouraging treatment. More patients need to be treated and longer follow up is needed to confirm these preliminary results.

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 > 60y...Midostaurin was added in FLT3-mutated pts...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... 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.

In 11/13 patients, the mast cell fraction was positive for the CBF fusion but all other sorted cell fractions tested were negative. In the remaining two specimens, all cell fractions were negative, likely due to FISH sensitivity compared to RT-PCR. Both CBF fusions exhibited the same pattern, with fusions detected only in the mast cell fractions (7 RUNX1::RUNX1T1 and 4 CBFB::MYH11).

This HDPCR prototype assay includes seven relevant AML-MRD biomarkers and shows the sensitivity of <0.1% and specificity required to detect AML relapse in <24 hours. This assay uses the proprietary ChromaCode Cloud software to easily and rapidly report the VAF of relevant AML-MRD variants, making it an optimal solution to meet AML-MRD testing needs.

She had an aggressive clinical course following initiation of cytarabine-based induction chemotherapy. The underlying mutational landscape may significantly influence the biological behaviour of otherwise favourable risk of CBF-AML cases.

To this end, we constructed a risk model for Chinese AML patients, in which the clinical information (age and gender), gene mutations (NPM1, RUNX1, SH2B3, and TP53), and fusions (CBFB::MYH11 and RUNX1::RUNX1T1) were included, and our model could help divide the patients into favorable, intermediate, and adverse groups. These results affirmed the clinical value of both WHO and ELN, but a more suitable prognosis model should be established in Chinese cohorts, such as the models we proposed.

Although CBF-AML is sensitive to high-dose cytarabine, t-CBF-AML has worse overall survival than de novo CBF- AML. The objective of this review is to discuss the available data on the pathogenesis, mutations, and therapeutic options in patients with t-CBF-AML.

For control group, patients received one cycle of induction therapy with idarubicin (12 mg/m² on days 1-3) plus cytarabine (100 mg/m² on days 1-7), followed by one cycle of idarubicin (8 mg/m² on days 1-3) plus cytarabine (2 g/m² q12h on days 1-3) and two cycles of high-dose cytarabine consolidation therapy (2 g/m² q12h on days 1-3). Conclusion Sorafenib combined with chemotherapy significantly increased the CMR after 4 cycles of therapy, however, the incidence of haematological and non-haematological adverse events did not apparently increased. The impact of sorafenib combined with chemotherapy on relapse and survival of CBF-AML need further following-up.

Moreover, there is persistent controversy about the optimal dose intensity of cytarabine consolidation, which complicates interpretation of correlative studies with respect to outcome associations...Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org. Clinicaltrials.gov: NCT00048958(CALGB 8461), NCT00899223(CALGB 9665), NCT00900224(CALGB 20202) *co-senior authors

Mary's Hospital between Jul 2017 and Oct 2021, (b) having available information on chromosome and gene mutation at diagnosis and (c) treated with either intensive chemotherapy (IC), hypomethylating agents (HMA), or HMA plus Venetoclax (HMA/VEN)... This study suggests that genomic clustering by unsupervised ML could identify genomic groups by co-occurrence patterns having different survival outcomes according to each treatment modality, thus potentially guiding treatment selection in older adults with AML.

P2, N=61, Completed, National Cancer Institute (NCI) | Active, not recruiting --> Completed

The mutation profiles t(8;21) AMLpatients showed evident differences from those inv(16)/t(16;16) AML. We provide a comprehensive overview on the mutational landscape of CBF-AML.

All 5 patients died, with a short mean overall survival of 5.8 months. Our series suggests that the presence of high risk abnormalities confers distinct biological features and poor prognosis to inv(16) AML.

This is the first study to unravel clinical significance of CDK6 body methylation in AML, and it may serve as an independent prognostic marker. Given that azacitidine and decitabine are widely used, our findings may have implications for combination therapy of CDK4/6 inhibitors with hypomethylating agents in AML. Prospective studies are warranted.

Our study shows that detection of 3'CBFB is not equivalent to unbalanced CBFB rearrangement, and therefore, an alternative confirmatory test is warranted. AML with 3'CBFB/CBFBr often shows similar pathological features to AML with inv(16), but appears to have different mutation profiles and a higher risk of relapse requiring hematopoietic stem cell transplant.

P=N/A, N=200, Recruiting, Acute Leukemia French Association

Three samples in which CD11b increased in response to ATRA had an inversion of chromosome 16 as well as the CBFB-MYH11 fusion gene, and the fourth sample was from a patient with KMT2A-rearranged, therapy-related AML. In conclusion, we identified a subgroup of non-APL AML patients with inv(16) and CBFB-MYH11 as the most sensitive to ATRA-mediated differentiation in vitro, and our results can help identify patients who may benefit from ATRA treatment.

Additionally, we provide insights into the transcriptional landscapes that differentiate these distinct CBFB-MYH11 AML subtypes. Children's Oncology Group trials include CCG-2961 (registered at www.clinicaltrials.gov as NCT00002798), AAML03P1 (NCT00070174), AAML0531 (NCT00372593), and AAML1031 (NCT01371981).

We demonstrate that RUNX1 directly interacts with DNMT3A and that CBFB-MYH11 fusion protein sequesters RUNX1 in the cytoplasm, thereby preventing RUNX1 from interacting with and recruiting DNMT3A to its target genes. Our results identify a novel regulation of DNA methylation and provide a molecular basis how CBFB-MYH11 fusion contributes to leukemogenesis.

In subgroup analysis, pretransplant MRD status significantly affected relapse and LFS only in patients with t(8;21) undergoing allogeneic HCT during CR2. In conclusion, our data demonstrate the different prognostic values of pretransplant MRD for CBF-AML, highlighting the need to develop effective therapeutic strategies for such MRD-positive patients.

P3, N=203, Active, not recruiting, University of Ulm | Recruiting --> Active, not recruiting | Trial primary completion date: Feb 2021 --> Feb 2024

Even in biological subgroups of AML expected to have sensitive disease, induction failure is not rare. Fortunately, the CBM could identify causes of failure and suggest alternative therapies based on co-occurring genomic abnormalities to mitigate the ineffectiveness of standard induction regimens in patients with resistant disease despite their favorable biology. The identification of patient-specific resistance mechanisms characterizes a new therapeutic imperative founded on deep molecular diagnosis that promises to enhance disease outcomes, inform treatment planning, avoid adverse events from ineffective therapies, and reduce costs.

Characterized a first comprehensive genomic landscape of Chinese pediatric AML, our results reveal a distinct mutation profile as compared to the Western cohort, in terms of both mutation frequency and patterns of mutation co-occurrence. These findings further reveal the complexity of pediatric AML and highlight the importance of tailored risk stratification for Chinese patients in clinical management.

In addition, with chromatin immunocleavage sequencing (ChIC-seq) assay, we observed a significant enrichment of RUNX1/CBFβ-SMMHC target genes in Runx1f/fMx1-CreCbfb+/56M cells, especially among down-regulated genes, suggesting that RUNX1 and CBFβ-SMMHC mainly function together as activators of gene expression through direct target gene binding. These data indicate that Runx1 is indispensable for Cbfb-MYH11 induced leukemogenesis by working together with CBFβ-SMMHC to regulate critical genes associated with the generation of a functional AMP population.

We provide proof of principle for immunologically targeting AML-initiating fusions and demonstrate that targeting neoantigens has clinical relevance even in low-mutational frequency cancers like fusion-driven AML. This work also represents a first critical step toward the development of TCR T cell immunotherapy targeting fusion gene-driven AML.