Frameshift Mutations in Leukemia-Associated Genes Correlate With Superior Outcomes in Patients Undergoing Allogeneic Stem Cell Transplant for De Novo Acute Myeloid Leukemia.

Background: Allogeneic stem cell transplant (allo-SCT) is a mainstay of treatment for acute myeloid leukemia (AML). Its success depends largely on response of donor T lymphocytes against leukemia cells, known as graft-vs-leukemia (GvL) effect. A key potential driver of GvL is immune response to mutation-derived neoantigens. Previous studies in solid tumors have demonstrated enhanced immunogenicity of frameshift (FS)-derived peptides vs. those from non-synonymous single nucleotide variants (SNVs). We therefore hypothesized that AML cases bearing FS mutations in leukemia-associated genes would be more immunogenic than those with only other types of mutations (non-FS), and thus benefit more from allo-SCT via more robust GvL. Methods: We identified AML patients who had undergone allo-SCT between 2010 and 2022 and had next-generation sequencing data available on diagnostic specimens using a 42-gene hot spot panel. We compared the impact of tumor mutations present at diagnosis on overall survival and relapse-free survival based on FS versus non-FS status. Results: Ninety-five AML allo-SCT patients were identified. We observed superior relapse-free survival (P = 0.038, hazard ratio (HR): 0.24) and borderline superior overall survival (P = 0.058, HR: 0.55) post-transplant in de novo AML patients, who had at least one FS mutation (other than NPM1) in one of the 42 assessed genes versus those with only non-FS mutations. Conclusions: Our findings suggest that FS-mutated AML cases may benefit more from allo-SCT than those with only non-FS mutations, possibly due to increased generation of immunogenic neoepitopes. If validated in an expanded study, incorporation of somatic FS mutation status in AML could improve patient selection algorithms for bone marrow transplant and thereby lead to superior outcomes.

Translational insights into the genetics and immunobiology of relapsed/refractory follicular lymphoma.

Although follicular lymphoma (FL) is traditionally classified as an indolent subtype of B cell non-Hodgkin lymphoma, clinical trajectories are often diverse based on unique disease biology, and many patients will eventually experience relapse of their disease. Furthermore, progression of disease within 24 months is associated with increased mortality rates for FL. In the last five years, we have witnessed an upsurge in the commercial availability of targeted therapies for relapsed/refractory (R/R) FL, including chimeric antigen receptor-T (CAR-T) products, bispecific T cell engagers (BiTEs), epigenetic modifier therapies, and next-generation Bruton tyrosine kinase (BTK) inhibitors. Furthermore, clinical trial options have increased tremendously and now include combinatorial strategies that exert synergy against malignant germinal center B cells. Here, we provide a 2024 update of novel therapeutic agents whose development has been informed by recent advances in the genetics and immunobiology of R/R FL. Specifically, we emphasize high-value targeted therapeutics, including anti-CD3 x anti-CD20 BiTEs and adoptive T cell therapies. We discuss prospects on selection and sequencing of BiTEs and CAR-T therapies for patients with R/R FL. We underscore the principles of FL pathobiology that are paving way for future drug discovery and shed insight into therapeutic targeting within nodal basins based on our increasing understanding of the FL microenvironment. Finally, we summarize how a greater knowledge of FL immunobiology can inform risk stratification and therapy selection on a personalized basis for R/R FL in 2025.

Natural history of clonal haematopoiesis seen in real-world haematology settings.

Recursive partitioning of healthy consortia led to the development of the Clonal Hematopoiesis Risk Score (CHRS) for clonal haematopoiesis (CH); however, in the practical setting, most cases of CH are diagnosed after patients present with cytopenias or related symptoms. To address this real-world population, we characterize the clinical trajectories of 94 patients with CH and distinguish CH harbouring canonical DNMT3A/TET2/ASXL1 mutations alone ('sole DTA') versus all other groups ('non-sole DTA'). TET2, rather than DNMT3A, was the most prevalent mutation in the real-world setting. Sole DTA patients did not progress to myeloid neoplasm (MN) in the absence of acquisition of other mutations. Contrastingly, 14 (20.1%) of 67 non-sole DTA patients progressed to MN. CHRS assessment showed a higher frequency of high-risk CH in non-sole DTA (vs. sole DTA) patients and in progressors (vs. non-progressors). RUNX1 mutation conferred the strongest risk for progression to MN (odds ratio [OR] 10.27, 95% CI 2.00-52.69, p = 0.0053). The mean variant allele frequency across all genes was higher in progressors than in non-progressors (36.9% ± 4.62% vs. 24.1% ± 1.67%, p = 0.0064). This analysis in the post-CHRS era underscores the natural history of CH, providing insight into patterns of progression to MN.

Revealing role of epigenetic modifiers and DNA oxidation in cell-autonomous regulation of Cancer stem cells.

BACKGROUND: Breast cancer cells (BCCs) can remain undetected for decades in dormancy. These quiescent cells are similar to cancer stem cells (CSCs); hence their ability to initiate tertiary metastasis. Dormancy can be regulated by components of the tissue microenvironment such as bone marrow mesenchymal stem cells (MSCs) that release exosomes to dedifferentiate BCCs into CSCs. The exosomes cargo includes histone 3, lysine 4 (H3K4) methyltransferases - KMT2B and KMT2D. A less studied mechanism of CSC maintenance is the process of cell-autonomous regulation, leading us to examine the roles for KMT2B and KMT2D in sustaining CSCs, and their potential as drug targets. METHODS: Use of pharmacological inhibitor of H3K4 (WDR5-0103), knockdown (KD) of KMT2B or KMT2D in BCCs, real time PCR, western blot, response to chemotherapy, RNA-seq, and flow cytometry for circulating markers of CSCs and DNA hydroxylases in BC patients. In vivo studies using a dormancy model studied the effects of KMT2B/D to chemotherapy. RESULTS: H3K4 methyltransferases sustain cell autonomous regulation of CSCs, impart chemoresistance, maintain cycling quiescence, and reduce migration and proliferation of BCCs. In vivo studies validated KMT2's role in dormancy and identified these genes as potential drug targets. DNA methylase (DNMT), predicted within a network with KMT2 to regulate CSCs, was determined to sustain circulating CSC-like in the blood of patients. CONCLUSION: H3K4 methyltransferases and DNA methylation mediate cell autonomous regulation to sustain CSC. The findings provide crucial insights into epigenetic regulatory mechanisms underlying BC dormancy with KMT2B and KMT2D as potential therapeutic targets, along with standard care. Stem cell and epigenetic markers in circulating BCCs could monitor treatment response and this could be significant for long BC remission to partly address health disparity.

The heart of VIALE-A: Cardiac complications of hypomethylating agents and venetoclax in acute myeloid leukaemia.

As we commemorate 50 years since the introduction of classical 7 + 3 induction chemotherapy for acute myeloid leukaemia (AML), we also embark upon new territory with the advent of novel targeted therapeutics, including BH3 mimetics. To date, we do not have much large-scale longitudinal data regarding the toxicities of such novel therapies. Johnson et al. perform a comprehensive analysis of cardiac toxicities with hypomethylating agents and venetoclax and offer valuable insight into risk-benefit analysis when considering front-line therapy for AML. Commentary on: Johnson et al. Cardiac events in newly diagnosed acute myeloid leukaemia during treatment with venetoclax + hypomethylating agents. Br J Haematol 2024;204:1232-1237.