[Expectations and challenges for clinical application of cancer genome panels in acute myeloid leukemia].

The blood cancer field has played a pioneering role in advancing precision medicine, with milestones such as development of ABL1 inhibitors for chronic myeloid leukemia. The significance of gene mutation information in AML treatment has increased, evident in classifications and guidelines from organizations such as WHO and ELN. This article examines the anticipated roles of cancer genome panels (CGPs) in AML treatment from three perspectives: diagnosis, risk stratification, and treatment selection. Use of CGPs enables more accurate diagnosis and risk stratification. In treatment selection, CGPs not only complements but also substitutes existing companion diagnostics, and is expected to be a crucial information source for future drug adoption and investigation of tumor-agnostic therapies. However, various challenges remain to be addressed, including the purpose and timing of CGPs, the time required for the tests, and how to utilize expert panels.

Reverse Phase Proteomic Array Profiling of Asparagine Synthetase Expression in Newly Diagnosed Acute Myeloid Leukemia.

Asparaginase-based therapy is a cornerstone in acute lymphoblastic leukemia (ALL) treatment, capitalizing on the methylation status of the asparagine synthetase (ASNS) gene, which renders ALL cells reliant on extracellular asparagine. Contrastingly, ASNS expression in acute myeloid leukemia (AML) has not been thoroughly investigated, despite studies suggesting that AML with chromosome 7/7q deletions might have reduced ASNS levels. Here, we leverage reverse phase protein arrays to measure ASNS expression in 810 AML patients and assess its impact on outcomes. We find that AML with inv(16) has the lowest overall ASNS expression. While AML with deletion 7/7q had ASNS levels slightly lower than those of AML without deletion 7/7q, this observation was not significant. Low ASNS expression correlated with improved overall survival (46 versus 54 weeks, respectively, p = 0.011), whereas higher ASNS levels were associated with better response to venetoclax-based therapy. Protein correlation analysis demonstrated association between ASNS and proteins involved in methylation and DNA repair. In conclusion, while ASNS expression was not lower in patients with deletion 7/7q as initially predicted, ASNS levels were highly variable across AML patients. Further studies are needed to assess whether patients with low ASNS expression are susceptible to asparaginase-based therapy due to their inability to augment compensatory ASNS expression upon asparagine depletion.

Recent advances in the reciprocal regulation of m6A modification with non-coding RNAs and its therapeutic application in acute myeloid leukemia.

N6-methyladenosine (m6A) is one of the most common modifications of RNA in eukaryotic cells and is involved in mRNA metabolism, including stability, translation, maturation, splicing, and export. m6A also participates in the modification of multiple types of non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, thereby affecting their metabolism and functions. Increasing evidence has revealed that m6A regulators, such as writers, erasers, and readers, perform m6A-dependent modification of ncRNAs, thus affecting cancer progression. Moreover, ncRNAs modulate m6A regulators to affect cancer development and progression. In this review, we summarize recent advances in understanding m6A modification and ncRNAs and provide insights into the interaction between m6A modification and ncRNAs in cancer. We also discuss the potential clinical applications of the mechanisms underlying the interplay between m6A modifications and ncRNAs in acute myeloid leukemia (AML). Therefore, clarifying the mutual regulation between m6A modifications and ncRNAs is of great significance to identify novel therapeutic targets for AML and has great clinical application prospects.

Unveiling novel insights in acute myeloid leukemia through single-cell RNA sequencing.

Acute myeloid leukemia (AML) is a complex and heterogeneous group of aggressive hematopoietic stem cell disease. The presence of diverse and functionally distinct populations of leukemia cells within the same patient's bone marrow or blood poses a significant challenge in diagnosing and treating AML. A substantial proportion of AML patients demonstrate resistance to induction chemotherapy and a grim prognosis upon relapse. The rapid advance in next generation sequencing technologies, such as single-cell RNA-sequencing (scRNA-seq), has revolutionized our understanding of AML pathogenesis by enabling high-resolution interrogation of the cellular heterogeneity in the AML ecosystem, and their transcriptional signatures at a single-cell level. New studies have successfully characterized the inextricably intertwined interactions among AML cells, immune cells and bone marrow microenvironment and their contributions to the AML development, therapeutic resistance and relapse. These findings have deepened and broadened our understanding the complexity and heterogeneity of AML, which are difficult to detect with bulk RNA-seq. This review encapsulates the burgeoning body of knowledge generated through scRNA-seq, providing the novel insights and discoveries it has unveiled in AML biology. Furthermore, we discuss the potential implications of scRNA-seq in therapeutic opportunities, focusing on immunotherapy. Finally, we highlight the current limitations and future direction of scRNA-seq in the field.

A Prospective Study to Evaluate the Effect of Therapeutic Drug Monitoring-Based Posaconazole Prophylaxis on Invasive Fungal Infection Rate During Acute Myeloid Leukemia Induction Therapy.

Invasive fungal infections (IFIs) are a significant cause of morbidity and mortality in de-novo acute myeloid leukemia patients receiving induction chemotherapy. Despite using posaconazole, a broad-spectrum antifungal, for IFI prophylaxis, the breakthrough IFI rate is high in the real-world setting. One of the reasons could be frequent suboptimal plasma posaconazole levels. In the present study, we evaluated if therapeutic drug monitoring (TDM) guided posaconazole prophylaxis can reduce the IFI rates in comparison to a historical cohort. We enrolled 90 patients, > / = 16 years of age, without baseline IFIs, planned for remission induction therapy. All patients were started on posaconazole suspension 200 mg TDS and the dose was increased in a stepwise manner if trough levels were found to be suboptimal (< 350 ng/ml for day 2 or < 700 ng/ml subsequently). The TDM based approach resulted in a significant decline in breakthrough IFI rates (18% versus 52%, P < 0.0001) A total of 69 patients (78%) required dose escalation. Thirty-one patients required change in antifungals due to either suboptimal levels, persistent fever, diarrhoea or vomiting. We could not demonstrate an exposure-response relationship but the difference in IFI rates in patients with a median posaconazole level > / = 700 ng/ml (0%) and < 700 ng/ml (21.6%) was clinically meaningful. Posaconazole levels were found to be significantly lower in patients on antacids and prokinetics. The incidence of posaconazole-related grade 3 toxicity was low (2.3%). Thus TDM-based dosing of posaconazole helps reduce breakthrough IFI rate and should be a part of posaconazole prophylaxis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12288-023-01709-3.

Aberrant ecotropic viral integration site-1 (EVI-1) and myocyte enhancer factor 2 C gene (MEF2C) in adult acute myeloid leukemia are associated with adverse t (9:22) & 11q23 rearrangements.

Acute myeloid leukemia (AML) shows multiple chromosomal translocations & point mutations which can be used to refine risk-adapted therapy in AML patients. Ecotropic viral integration site-1 (EVI-1) & myocyte enhancer factor 2 C gene (MEF2C) are key regulatory transcription factors in hematopoiesis and leukemogenesis & both drive immune escape. This prospective study involved 80 adult de novo AML patients recruited from Oncology Center, Mansoura University, between March 2019 and July 2021. The MEF2C and EVI1 expression were measured using a Taqman probe-based qPCR assay. The results revealed that EVI1 and MEF2C expression were significantly elevated in AML patients as compared to control subjects (p = 0.001. 0.007 respectively). Aberrant expressions of EVI1 and MEF2C showed a significant negative correlation with hemoglobin levels (p = 0.034, 0.025 respectively), & bone marrow blasts (p = 0.007, 0.002 respectively). 11q23 translocation was significantly associated with EVI1 and MEF2C (p = 0.004 and 0.02 respectively). Also, t (9;22) was significantly associated with EVI1 and MEF2C (p = 0.01 and 0.03 respectively), higher expression of EVI1 and MEF2C were significantly associated with inferior outcome after induction therapy (p = 0.001 and 0.018 respectively) and shorter overall survival (p = 0.001, 0.014 respectively). In conclusion, EVI1 & MEF2C were significantly expressed in AML cases. EVI1 & MEF2C overexpression were significantly associated with 11q23 rearrangements and t (9;22) and were indicators for poor outcome in adult AML patients; These results could be a step towards personalized therapy in those patients.

From Skin to Blood: Ulcerative Pyoderma Gangrenosum Unveiling Acute Myeloid Leukemia.

While Pyoderma gangrenosum (PG) is commonly associated with hematological disorders such as acute myeloid leukemia (AML), it typically presents concurrently with the hemopathy, mostly in its bullous form, among middle-aged individuals. Here, we report the unusual case of a young female patient who presented with PG in its ulcerative form, three weeks before the onset of AML. A 31-year-old female presented with a one-week history of painful perianal papulopustule that evolved into an irregular ulceration with violaceous borders, mucopurulent serosity, and erythematous surrounding skin. Laboratory work-up demonstrated elevated inflammatory markers and hyperleukocytosis, with no cytopenia, and normal peripheral blood smear. Two weeks later, the ulcer growth was noted with a similar ulceration at a venipuncture site. A complete blood count revealed pancytopenia, with 45% blasts on the peripheral blood smear. Skin biopsies showed an aseptic neutrophilic infiltrate in favor of PG. Intravenous methylprednisolone was administered with rapid resolution of the lesions. However, the patient died shortly after. The post-mortem results of bone marrow aspirate revealed AML, with immunohistochemistry of the skin lesions confirming the clonality of neutrophils derived from the leukemic clone.  This case highlights a distinctive clinical presentation, illustrating the manifestation of PG three weeks before the onset of AML in its ulcerative rather than bullous form, in a young female patient.

A Rare Case of Acute Pancreatitis as an Initial Presentation of Acute Myeloid Leukemia.

Acute pancreatitis is a rare manifestation of acute myeloid leukemia which can be a presentation at the initial diagnosis or during or after the onset of the disease. Acute myeloid leukemia occurs due to the abnormal proliferation of undifferentiated hematopoietic stem cells in the bone marrow which alter the normal hematopoiesis. We report the case of a 32-year-old male admitted with a one-month history of fever and backache, followed by 15 days of blackish stool discoloration and two days of abdominal pain and reduced urine output. On clinical examination, he was hypoxic with respiratory distress with epigastric tenderness. Blood investigations and imaging were consistent with acute pancreatitis. A complete blood count with peripheral smear showed severe normocytic normochromic anemia and an increased myeloid series containing 50% myeloblasts and 30% monoblasts. Additionally, some cells displayed cytoplasmic vacuolations, with a reticulocyte count of 2%. These findings were suggestive of acute myeloid leukemia M5. Due to the poor Glasgow Coma Scale (GCS), he was intubated and placed on mechanical ventilation. Unfortunately, he did not improve despite treatment and succumbed to the illness.

A Case of Hypernatremia in a Newly Diagnosed Patient With Acute Myeloid Leukemia: Lessons for Nephrologists.

Arginine vasopressin deficiency (AVP-D), formerly known as central diabetes insipidus, is a disease characterized by polyuria, polydipsia, and hypernatremia. The concomitant diagnosis of acute myeloid leukemia (AML) is an underappreciated event that requires prompt recognition and treatment by practicing nephrologists and hematologists. This report highlights this importance by describing the case of a 39-year-old patient newly diagnosed with AML who developed severe hypernatremia. The role of diagnostic testing through desmopressin (DDAVP) challenge and copeptin testing to confirm the diagnosis of AVP-D in this context and the use of DDVAP for treatment are discussed. Practicing nephrologists and primary care providers taking care of patients with similar symptoms will benefit from understanding the pathophysiology of AVP-D, its relationship with AML, and the prognosis in this patient cohort.

Safety and Efficacy of High-Dose Chemotherapy with TreoMel 200 vs. TreoMel 140 in Acute Myeloid Leukemia Patients Undergoing Autologous Stem Cell Transplantation.

(1) Background: Treosulfan and melphalan (TreoMel)-based high-dose chemotherapy (HDCT) has shown promising safety and efficacy as a conditioning regimen for acute myeloid leukemia (AML) patients undergoing autologous stem cell transplantation (ASCT). However, despite intensive first-line induction treatment and upfront consolidation with HDCT and ASCT, AML relapse rates are still high, and further efforts are needed to improve patient outcomes. The aim of this study was to compare two melphalan dose schedules in regard to the safety of TreoMel HDCT and patient outcomes. (2) Methods: We retrospectively analyzed the safety and efficacy of two melphalan dose schedules combined with standard-dose treosulfan in AML patients undergoing HDCT and ASCT at the University Hospital of Bern, Switzerland, between August 2019 and August 2023. Patients received treosulfan 42 g/m2 combined with either melphalan 140 mg/m2 (TreoMel 140) or melphalan 200 mg/m2 (TreoMel 200). Co-primary endpoints were progression-free survival (PFS), overall survival (OS), as well as safety profile. (3) Results: We included a total of 51 AML patients: 31 (60.8%) received TreoMel 140 and 20 (39.2%) TreoMel 200. The patients' basal characteristics were comparable between both cohorts. No significant differences in the duration of hospitalization or the adverse event profile were identified. There were no statistically significant differences in relapse (0.45 vs. 0.30, p = 0.381) and mortality rates (0.42 vs. 0.15, p = 0.064) between the melphalan 140 mg/m2 and 200 mg/m2 cohorts, nor for PFS (HR: 0.81, 95% CI: 0.29-2.28, p = 0.70) or OS (HR: 0.70, 95% CI: 0.19-2.57, p = 0.59) for the TreoMel 140 vs. TreoMel 200 cohort. (4) Conclusions: A higher dose of melphalan (TreoMel 200) was well tolerated overall. No statistically significant differences for patient outcomes could be observed, possibly due to the relatively small patient cohort and the short follow-up. A longer follow-up and prospective randomized studies would be required to confirm the safety profile and clinical benefit.

Chameleonic Chloroma: A Case of Myeloid Sarcoma Presenting as a Pancreatic Head Mass.

We report a case of pancreatic myeloid sarcoma (MS), an extremely rare manifestation of acute myeloid leukemia (AML), in a 35-year-old male who presented with epigastric pain and watery stools. Initial diagnostic testing was inconclusive; however, following an extensive evaluation, endoscopic biopsies suggested AML, which was confirmed by a bone marrow biopsy. Given that few cases are documented in the literature, pancreatic MS without a preexisting hematologic malignancy poses a significant diagnostic challenge.

Characterization of CD34+ Cells from Patients with Acute Myeloid Leukemia (AML) and Myelodysplastic Syndromes (MDS) Using a t-Distributed Stochastic Neighbor Embedding (t-SNE) Protocol.

Using multi-color flow cytometry analysis, we studied the immunophenotypical differences between leukemic cells from patients with AML/MDS and hematopoietic stem and progenitor cells (HSPCs) from patients in complete remission (CR) following their successful treatment. The panel of markers included CD34, CD38, CD45RA, CD123 as representatives for a hierarchical hematopoietic stem and progenitor cell (HSPC) classification as well as programmed death ligand 1 (PD-L1). Rather than restricting the evaluation on a 2- or 3-dimensional analysis, we applied a t-distributed stochastic neighbor embedding (t-SNE) approach to obtain deeper insight and segregation between leukemic cells and normal HPSCs. For that purpose, we created a t-SNE map, which resulted in the visualization of 27 cell clusters based on their similarity concerning the composition and intensity of antigen expression. Two of these clusters were "leukemia-related" containing a great proportion of CD34+/CD38- hematopoietic stem cells (HSCs) or CD34+ cells with a strong co-expression of CD45RA/CD123, respectively. CD34+ cells within the latter cluster were also highly positive for PD-L1 reflecting their immunosuppressive capacity. Beyond this proof of principle study, the inclusion of additional markers will be helpful to refine the differentiation between normal HSPCs and leukemic cells, particularly in the context of minimal disease detection and antigen-targeted therapeutic interventions. Furthermore, we suggest a protocol for the assignment of new cell ensembles in quantitative terms, via a numerical value, the Pearson coefficient, based on a similarity comparison of the t-SNE pattern with a reference.

Surviving the Storm: Cardiac Tamponade and Effusive Constrictive Pericarditis Complicated by Pericardial Decompression Syndrome Induced by COVID-19 Infection in the Setting of Newly Diagnosed Acute Myeloid Leukemia (AML).

Coronavirus disease 2019 (COVID-19)-induced pericarditis and pericardial myocarditis are common entities; however, the development of pericardial effusion post-COVID-19 infection has only been reported in about 5% of cases. Rapid and acute progression to pericardial tamponade is uncommon, and progression to effusive constrictive pericarditis (ECP) and pericardial decompression syndrome (PDS) is an even rarer phenomenon. We describe these phenomena in this report to raise awareness and aid clinicians in the early diagnosis and management of these conditions. We report a case of a 45-year-old female with a past medical history of recent COVID-19 infection, uncontrolled diabetes mellitus, and hypertension who presented with severe chest pain, which was determined to be acute pericarditis post-COVID-19 infection. The patient developed a large pericardial effusion leading to cardiac tamponade within one day of initial presentation. Urgent pericardiocentesis was performed but was complicated by rapid decompensation of the patient, which has been assumed to be ECP following pericardiocentesis and PDS.  Close monitoring of acute pericarditis with pericardial effusion is required in these patients for the early detection of cardiac tamponade, which requires urgent pericardiocentesis. Judicious post-pericardiocentesis follow-up is also required for the early diagnosis of conditions such as ECP and PDS. These cases are generally managed symptomatically, but in cases of severe ECP syndrome, pericardial stripping may be required.

Pediatric Myeloid Sarcoma of the Testes Treated With Surgery and Adjuvant Radiation Therapy.

Myeloid sarcoma (MS) is a rare extramedullary tumor of immature granulocytic cells and is most often associated with acute myeloid leukemia (AML). Myeloid sarcomas can occur anywhere in the body but are seldom present in the testicles, especially in the pediatric population. The treatment of MS, especially testicular myeloid sarcoma (TMS) is not well defined in the literature and the role of radiation therapy in the treatment of TMS is even less well defined. In this case report, we discuss the treatment for TMS in a pediatric patient, review the literature, and discuss the role of radiation therapy in the treatment.

Sickle Cell Anomaly Meets Leukemic Challenge: A Case Report.

This case report delves into the rare occurrence of sickle cell disease (SCD) and acute myeloid leukemia (AML) coexisting in a 36-year-old patient. The initial presentation, marked by escalating fatigue, pallor, and recurrent episodes initially attributed to sickle cell disease, unveiled an unexpected discovery of AML upon bone marrow examination. The diagnostic hurdles stemming from overlapping clinical features necessitated a thorough approach incorporating hematological, molecular, and imaging studies. Managing both conditions concurrently entailed navigating complexities addressed by a multidisciplinary team, tailoring chemotherapy regimens, and implementing personalized strategies to tackle complications associated with SCD. This case underscores the significance of tailored and comprehensive approaches in diagnosing and managing patients with overlapping hematological disorders. The insights gleaned from this instance contribute to the evolving comprehension of such intricate interplays, guiding future research endeavors and enhancing the care provided to patients simultaneously grappling with SCD and acute myeloid leukemia (AML). This case study investigates the unusual medical history of a 36-year-old male patient who concurrently has acute myeloid leukemia and sickle cell disease. Since childhood, the patient has endured severe anemia, necessitating frequent red blood cell transfusions or exchange blood therapy. Additionally, the patient was prescribed hydroxyurea (HU) for approximately 26 months.

FLT3 and IRAK4 Inhibitor Emavusertib in Combination with BH3-Mimetics in the Treatment of Acute Myeloid Leukemia.

Targeting the FLT3 receptor and the IL-1R associated kinase 4 as well as the anti-apoptotic proteins MCL1 and BCL2 may be a promising novel approach in the treatment of acute myeloid leukemia (AML). The FLT3 and IRAK4 inhibitor emavusertib (CA4948), the MCL1 inhibitor S63845, the BCL2 inhibitor venetoclax, and the HSP90 inhibitor PU-H71 were assessed as single agents and in combination for their ability to induce apoptosis and cell death in leukemic cells in vitro. AML cells represented all major morphologic and molecular subtypes, including FLT3-ITD and NPM1 mutant AML cell lines and a variety of patient-derived AML cells. Emavusertib in combination with MCL1 inhibitor S63845 or BCL2 inhibitor venetoclax induced cell cycle arrest and apoptosis in MOLM-13 cells. In primary AML cells, the response to emavusertib was associated with the presence of the FLT3 gene mutation with an allelic ratio >0.5 and the presence of NPM1 gene mutations. S63845 was effective in all tested AML cell lines and primary AML samples. Blast cell percentage was positively associated with the response to CA4948, S63845, and venetoclax, with elevated susceptibility of primary AML with blast cell fraction >80%. Biomarkers of the response to venetoclax included the blast cell percentage and bone marrow infiltration rate, as well as the expression levels of CD11b, CD64, and CD117. Elevated susceptibility to CA4948 combination treatments with S63845 or PU-H71 was associated with FLT3-mutated AML and CD34 < 30%. The combination of CA4948 and BH3-mimetics may be effective in the treatment in FLT3-mutated AML with differential target specificity for MCL1 and BCL2 inhibitors. Moreover, the combination of CA4948 and PU-H71 may be a candidate combination treatment in FLT3-mutated AML.

Targeting hematologic malignancies by inhibiting E-selectin: A sweet spot for AML therapy?

E-selectin, a cytoadhesive glycoprotein, is expressed on venular endothelial cells and mediates leukocyte localization to inflamed endothelium, the first step in inflammatory cell extravasation into tissue. Constitutive marrow endothelial E-selectin expression also supports bone marrow hematopoiesis via NF-κB-mediated signaling. Correspondingly, E-selectin interaction with E-selectin ligand (sialyl Lewisx) on acute myeloid leukemia (AML) cells leads to chemotherapy resistance in vivo. Uproleselan (GMI-1271) is a carbohydrate analog of sialyl Lewisx that blocks E-selectin binding. A Phase 2 trial of MEC chemotherapy combined with uproleselan for relapsed/refractory AML showed a median overall survival of 8.8 months and low (2%) rates of severe oral mucositis. Clinical trials seek to confirm activity in AML and mitigation of neutrophil-mediated adverse events (mucositis and diarrhea) after intensive chemotherapy. In this review we summarize E-selectin biology and the rationale for uproleselan in combination with other therapies for hematologic malignancies. We also describe uproleselan pharmacology and ongoing clinical trials.

Acute Myeloid Leukemia Presenting as Common Colds: An Uncommon Consideration.

Acute myeloid leukemia is the most common form of leukemia and can present with a wide variety of signs and symptoms. This article presents a case of a middle-aged male who presented with ongoing upper respiratory cold-like symptoms and was then found to be severely pancytopenic. A diagnosis of acute myeloid leukemia was made after a bone marrow biopsy, and the patient underwent induction chemotherapy. This article brings to light the uncommon diagnosis of acute myeloid leukemia, from a common presentation, a common cold. Additionally, it discusses the initial workup and diagnostic process of acute myeloid leukemia, risk stratification, and a basic treatment algorithm.

Improved Treatment Outcomes With Modified Induction Therapy in Acute Myeloid Leukemia (AML): A Retrospective Observational Study From a Regional Cancer Center.

BACKGROUND: The aggressive, genetically diverse group of malignant illnesses known as acute myeloid leukemia (AML) is characterized by clonally related myeloblast invasion of the bone marrow, blood, and other organs. The treatment regimen plays a crucial role in the management of AML, and it is associated with poor overall survival and enhanced risk of relapse. Induction therapy with a 7+3 DA regimen (daunorubicin + ara-C) has been the treatment of choice for young and fit patients. OBJECTIVE: To evaluate the effect of dose modification in young and fit patients for a modified treatment regimen. METHODS: This was a retrospective, observational study of AML patients to analyze the outcomes of modified induction therapy in AML patients enrolled at Dr. B. Borooah Cancer Institute, Guwahati, Assam, India, from October 2021 to March 2022. The outcomes of modified induction therapy with intensive chemotherapy (modified 7+3 DA) and low-intensity chemotherapy decitabine (10 days) and venetoclax + azacytidine (seven days) were considered after the first two cycles or 60 days, whichever was earlier. RESULTS: Data from 31 patients with de-novo AML was analyzed; the median age of the patients was 41 years (range: 2-71 years), and the male-to-female ratio was 1.8. There were seven patients in the pediatric age group (2-13 years), and 19%, 65%, and 13% of patients belonged to favorable, intermediate, and high-risk groups, respectively. With regards to modified induction therapy (n=31), 20 (65%) patients received modified "7+3 DA", nine (29%) received hypomethylating agents (HMA, decitabine only), and two patients received HMA (azacitidnie) + venetoclax. Additionally, 23/31 patients completed at least two cycles of induction therapy. Overall, 60 day-induction mortality was 13%, and the complete remission (CR) and partial remission (PR) rates were 48% and 26%, respectively. In patients who received modified "7+3 DA", the CR rate was 55%. CONCLUSIONS: The notable reduction in deaths due to infections observed in our study suggests that centers with limited resources for preventing neutropenic complications during induction therapies in AML patients could consider adopting this modified regimen.

Preclinical Characterization of the Anti-Leukemia Activity of the CD33/CD16a/NKG2D Immune-Modulating TriNKET® CC-96191.

Increasing efforts are focusing on natural killer (NK) cell immunotherapies for AML. Here, we characterized CC-96191, a novel CD33/CD16a/NKG2D immune-modulating TriNKET®. CC-96191 simultaneously binds CD33, NKG2D, and CD16a, with NKG2D and CD16a co-engagement increasing the avidity for, and activation of, NK cells. CC-96191 was broadly active against human leukemia cells in a strictly CD33-dependent manner, with maximal efficacy requiring the co-engagement of CD16a and NKG2D. A frequent CD33 single nucleotide polymorphism, R69G, reduced CC-96191 potency but not maximal activity, likely because of reduced CD33 binding. Similarly, the potency, but not the maximal activity, of CC-96191 was reduced by high concentrations of soluble CD33; in contrast, the soluble form of the NKG2D ligand MICA did not impact activity. In the presence of CD33+ AML cells, CC-96191 activated NK cells but not T cells; while maximum anti-AML efficacy was similar, soluble cytokine levels were 10- to >100-fold lower than with a CD33/CD3 bispecific antibody. While CC-96191-mediated cytolysis was not affected by ABC transporter proteins, it was reduced by anti-apoptotic BCL-2 family proteins. Finally, in patient marrow specimens, CC-96191 eliminated AML cells but not normal monocytes, suggesting selectivity of TriNKET-induced cytotoxicity toward neoplastic cells. Together, these findings support the clinical exploration of CC-96191 as in NCT04789655.