Orthogonal proteogenomic analysis identifies the druggable PA2G4-MYC axis in 3q26 AML.

The overexpression of the ecotropic viral integration site-1 gene (EVI1/MECOM) marks the most lethal acute myeloid leukemia (AML) subgroup carrying chromosome 3q26 abnormalities. By taking advantage of the intersectionality of high-throughput cell-based and gene expression screens selective and pan-histone deacetylase inhibitors (HDACis) emerge as potent repressors of EVI1. To understand the mechanism driving on-target anti-leukemia activity of this compound class, here we dissect the expression dynamics of the bone marrow leukemia cells of patients treated with HDACi and reconstitute the EVI1 chromatin-associated co-transcriptional complex merging on the role of proliferation-associated 2G4 (PA2G4) protein. PA2G4 overexpression rescues AML cells from the inhibitory effects of HDACis, while genetic and small molecule inhibition of PA2G4 abrogates EVI1 in 3q26 AML cells, including in patient-derived leukemia xenografts. This study positions PA2G4 at the crosstalk of the EVI1 leukemogenic signal for developing new therapeutics and urges the use of HDACis-based combination therapies in patients with 3q26 AML.

In silico predicted compound targeting the IQGAP1-GRD domain selectively inhibits growth of human acute myeloid leukemia.

Acute myeloid leukemia (AML) is fatal in the majority of adults. Identification of new therapeutic targets and their pharmacologic modulators are needed to improve outcomes. Previous studies had shown that immunization of rabbits with normal peripheral WBCs that had been incubated with fluorodinitrobenzene elicited high titer antibodies that bound to a spectrum of human leukemias. We report that proteomic analyses of immunoaffinity-purified lysates of primary AML cells showed enrichment of scaffolding protein IQGAP1. Immunohistochemistry and gene-expression analyses confirmed IQGAP1 mRNA overexpression in various cytogenetic subtypes of primary human AML compared to normal hematopoietic cells. shRNA knockdown of IQGAP1 blocked proliferation and clonogenicity of human leukemia cell-lines. To develop small molecules targeting IQGAP1 we performed in-silico screening of 212,966 compounds, selected 4 hits targeting the IQGAP1-GRD domain, and conducted SAR of the 'fittest hit' to identify UR778Br, a prototypical agent targeting IQGAP1. UR778Br inhibited proliferation, induced apoptosis, resulted in G2/M arrest, and inhibited colony formation by leukemia cell-lines and primary-AML while sparing normal marrow cells. UR778Br exhibited favorable ADME/T profiles and drug-likeness to treat AML. In summary, AML shows response to IQGAP1 inhibition, and UR778Br, identified through in-silico studies, selectively targeted AML cells while sparing normal marrow.

[Future prospects for the development of novel agents for acute myeloid leukemia].

For nearly 40 years, combination therapy with cytarabine and anthracycline has been the standard of care for acute myeloid leukemia (AML). The cytogenetics and molecular biology of AML are now understood, and the treatment of AML has undergone dramatic changes in Japan with the launch of drugs such as FLT3 inhibitors, Bcl2 inhibitors, and hypomethylating agents since 2018. However, AML remains very difficult to cure, with a high relapse rate. Here, we review novel agents that have not yet been approved in Japan (CPX-351, IDH inhibitors, menin inhibitors, and oral azacitidine) as potential treatments for AML, as well as therapeutic antibodies (BiTEs, DARTs, immune checkpoint inhibitors) currently under investigation in clinical trials or in development. These novel agents are being investigated not only as monotherapy but also as combination therapy with intensive chemotherapy or azacitidine/venetoclax. The new era of AML treatment is expected to support a variety of goals, including leukemic cell elimination, long-term remission, and improved quality of life.

Diversifying the anthracycline class of anti-cancer drugs identifies aclarubicin for superior survival of acute myeloid leukemia patients.

The efficacy of anthracycline-based chemotherapeutics, which include doxorubicin and its structural relatives daunorubicin and idarubicin, remains almost unmatched in oncology, despite a side effect profile including cumulative dose-dependent cardiotoxicity, therapy-related malignancies and infertility. Detoxifying anthracyclines while preserving their anti-neoplastic effects is arguably a major unmet need in modern oncology, as cardiovascular complications that limit anti-cancer treatment are a leading cause of morbidity and mortality among the 17 million cancer survivors in the U.S. In this study, we examined different clinically relevant anthracycline drugs for a series of features including mode of action (chromatin and DNA damage), bio-distribution, anti-tumor efficacy and cardiotoxicity in pre-clinical models and patients. The different anthracycline drugs have surprisingly individual efficacy and toxicity profiles. In particular, aclarubicin stands out in pre-clinical models and clinical studies, as it potently kills cancer cells, lacks cardiotoxicity, and can be safely administered even after the maximum cumulative dose of either doxorubicin or idarubicin has been reached. Retrospective analysis of aclarubicin used as second-line treatment for relapsed/refractory AML patients showed survival effects similar to its use in first line, leading to a notable 23% increase in 5-year overall survival compared to other intensive chemotherapies. Considering individual anthracyclines as distinct entities unveils new treatment options, such as the identification of aclarubicin, which significantly improves the survival outcomes of AML patients while mitigating the treatment-limiting side-effects. Building upon these findings, an international multicenter Phase III prospective study is prepared, to integrate aclarubicin into the treatment of relapsed/refractory AML patients.

Decitabine as epigenetic priming with CLAG induce improved outcome of relapsed or refractory acute myeloid leukemia in children.

BACKGROUND: Decitabine (DAC), a DNA methyltransferase inhibitor, has shown efficacy combined with chemotherapy for relapsed or refractory (R/R) acute myeloid leukemia (AML) in adults, but less is known about its efficacy in children. Accordingly, we conducted a study which involved a priming regimen consisting of DAC with cladribine, cytarabine, and granulocyte-stimulating factor (DAC-CLAG) and compared the efficacy and safety of this regimen with CLAG alone. METHODS: A total of 39 R/R AML children who received the CLAG or DAC-CLAG regimen in Shanghai Children's Hospital were retrospectively enrolled in this non-randomized study. These regimens were studied sequentially over time. Twenty-two patients received CLAG from 2015, while 17 patients were administered epigenetic priming with DAC before CLAG from 2020. Patients were subsequently bridged to stem cell transplantation (SCT) or consolidation chemotherapy. Complete remission (CR) and adverse effects were analyzed by Fisher's exact test, and survival was analyzed by the Kaplan-Meier method. RESULTS: DAC-CLAG conferred a numerically higher CR compared to CLAG (70.59% vs 63.64%; P = 0.740). High CR rates occurred in patients with good cytogenetics (P = 0.029) and prior induction without cladribine (P = 0.099). The 1-year event-free survival (EFS) was 64.71% ± 11.59% and 63.31% ± 10.35% in the DAC-CLAG and CLAG group (P = 0.595), and 1-year overall survival (OS) was 81.45% ± 9.72% and 77.01% ± 9.04%, respectively (P = 0.265). The 1-year OS and EFS after SCT were higher in the DAC-CLAG than in the CLAG cohort (100% vs 92.31% ± 7.39%, P = 0.072; 92.31% ± 7.39% vs 85.71% ± 9.35%, P = 0.158). Univariate analysis revealed that a good prognosis included good cytogenetics (P = 0.002), non-complex karyotype (P = 0.056), CR on reinduction (P < 0.0001), and bridging to SCT (P = 0.0007). Use of a hypomethylating agent (P = 0.049) and bridging to SCT (P = 0.011) were independent prognostic factors. Grade 3/4 hematologic toxicity and infection were the main adverse events. CONCLUSIONS: DAC prior to the CLAG regimen improved remission in pediatric R/R AML, and was feasible and well tolerated. CLAG ± DAC as a salvage therapy prior to SCT induced improved survival.

Efficacy and safety of venetoclax-based combination therapy for previously untreated acute myeloid leukemia: a meta-analysis.

PURPOSE: To explore the efficacy and safety of venetoclax-based combination therapy for older patients with newly diagnosed acute myeloid leukemia (AML). METHODS: We performed a systematic review and meta-analysis of clinical trials comparing venetoclax plus hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) with mono-HMAs or LDAC. The random or fixed effects model was applied to the studies based on heterogeneity. Dichotomous data were summarized using the risk ratio (RR) and 95% confidence interval (CI). Continuous variable data were reported as weighted mean differences (WMDs). RESULTS: Nine studies, including a total of 1232 patients, were included in this meta-analysis. Thec complete remission (CR)/complete remission with incomplete hematological recovery (CRi) rate of the venetoclax (Ven) + azacytidine (Aza) group was significantly greater than that of the Aza monotherapy group (RR: 2.42; 95% CI: 1.85-3.15; P < 0.001). Similarly, the CR/CRi rate of the Ven + LDAC group was also significantly greater than that of the LDAC monotherapy group (RR: 2.57; 95% CI: 1.58-4.17; P = 0.00). The same results were observed for OS among these groups. However, the incidence of febrile neutropenia was greater in the Ven + Aza group than in the Ven + Decitabine (Dec) or monotherapy Aza group (RR: 0.69; 95% CI: 0.53-0.90; P = 0.006 and RR: 2.19; 95% CI: 1.58-3.03; P < 0.001, respectively). In addition, the Ven + LDAC group had significantly greater rates of constipation, diarrhea, nausea, and vomiting than the LDAC monotherapy group, with RRs and CIs of 0.61 (95% CI 0.44-0.83, P = 0.002), 1.81 (95% CI 1.22-2.67, P = 0.003), 1.39 (95% CI 1.06-1.82, P = 0.016), and 1.80 (95% CI 1.19-2.72, P = 0.005), respectively. CONCLUSION: Venetoclax combined with azacitidine, decitabine, or LDAC significantly improved the CR/CRi and OS of patients with previously untreated AML. However, venetoclax plus azacitidine or LDAC was more likely to lead to increased febrile neutropenia and gastrointestinal toxicity.

Targeting BMAL1 reverses drug resistance of acute myeloid leukemia cells and promotes ferroptosis through HMGB1-GPX4 signaling pathway.

PURPOSE: Acute myeloid leukemia (AML) is a refractory hematologic malignancy that poses a serious threat to human health. Exploring alternative therapeutic strategies capable of inducing alternative modes of cell death, such as ferroptosis, holds great promise as a viable and effective intervention. METHODS: We analyzed online database data and collected clinical samples to verify the expression and function of BMAL1 in AML. We conducted experiments on AML cell proliferation, cell cycle, ferroptosis, and chemotherapy resistance by overexpressing/knocking down BMAL1 and using assays such as MDA detection and BODIPY 581/591 C11 staining. We validated the transcriptional regulation of HMGB1 by BMAL1 through ChIP assay, luciferase assay, RNA level detection, and western blotting. Finally, we confirmed the results of our cell experiments at the animal level. RESULTS: BMAL1 up-regulation is an observed phenomenon in AML patients. Furthermore, there existed a strong correlation between elevated levels of BMAL1 expression and inferior prognosis in individuals with AML. We found that knocking down BMAL1 inhibited AML cell growth by blocking the cell cycle. Conversely, overexpressing BMAL1 promoted AML cell proliferation. Moreover, our research results revealed that BMAL1 inhibited ferroptosis in AML cells through BMAL1-HMGB1-GPX4 pathway. Finally, knocking down BMAL1 can enhance the efficacy of certain first-line cancer therapeutic drugs, including venetoclax, dasatinib, and sorafenib. CONCLUSION: Our research results suggest that BMAL1 plays a crucial regulatory role in AML cell proliferation, drug resistance, and ferroptosis. BMAL1 could be a potential important therapeutic target for AML.

Glutathione-depleting Liposome Adjuvant for Augmenting the Efficacy of a Glutathione Covalent Inhibitor Oridonin for Acute Myeloid Leukemia Therapy.

BACKGROUND: Discrepancies in the utilization of reactive oxygen species (ROS) between cancer cells and their normal counterparts constitute a pivotal juncture for the precise treatment of cancer, delineating a noteworthy trajectory in the field of targeted therapies. This phenomenon is particularly conspicuous in the domain of nano-drug precision treatment. Despite substantial strides in employing nanoparticles to disrupt ROS for cancer therapy, current strategies continue to grapple with challenges pertaining to efficacy and specificity. One of the primary hurdles lies in the elevated levels of intracellular glutathione (GSH). Presently, predominant methods to mitigate intracellular GSH involve inhibiting its synthesis or promoting GSH efflux. However, a conspicuous gap remains in the absence of a strategy capable of directly and efficiently clearing GSH. METHODS: We initially elucidated the chemical mechanism underpinning oridonin, a diminutive pharmacological agent demonstrated to perturb reactive oxygen species, through its covalent interaction with glutathione. Subsequently, we employed the incorporation of maleimide-liposomes, renowned for their capacity to disrupt the ROS delivery system, to ameliorate the drug's water solubility and pharmacokinetics, thereby enhancing its ROS-disruptive efficacy. In a pursuit to further refine the targeting for acute myeloid leukemia (AML), we harnessed the maleic imide and thiol reaction mechanism, facilitating the coupling of Toll-like receptor 2 (TLR2) peptides to the liposomes' surface via maleic imide. This strategic approach offers a novel method for the precise removal of GSH, and its enhancement endeavors are directed towards fortifying the precision and efficacy of the drug's impact on AML targets. RESULTS: We demonstrated that this peptide-liposome-small molecule machinery targets AML and consequently induces cell apoptosis both in vitro and in vivo through three disparate mechanisms: (I) Oridonin, as a Michael acceptor molecule, inhibits GSH function through covalent bonding, triggering an initial imbalance of oxidative stress. (II) Maleimide further induces GSH exhaustion, aggravating redox imbalance as a complementary augment with oridonin. (III) Peptide targets TLR2, enhances the directivity and enrichment of oridonin within AML cells. CONCLUSION: The rationally designed nanocomplex provides a ROS drug enhancement and targeted delivery platform, representing a potential solution by disrupting redox balance for AML therapy.

Valrubicin-loaded immunoliposomes for specific vesicle-mediated cell death in the treatment of hematological cancers.

We created valrubicin-loaded immunoliposomes (Val-ILs) using the antitumor prodrug valrubicin, a hydrophobic analog of daunorubicin. Being lipophilic, valrubicin readily incorporated Val-lLs that were loaded with specific antibodies. Val-ILs injected intravenously rapidly reached the bone marrow and spleen, indicating their potential to effectively target cancer cells in these areas. Following the transplantation of human pediatric B-cell acute lymphoblastic leukemia (B-ALL), T-cell acute lymphoblastic leukemia (T-ALL), or acute myeloid leukemia (AML) in immunodeficient NSG mice, we generated patient-derived xenograft (PDX) models, which were treated with Val-ILs loaded with antibodies to target CD19, CD7 or CD33. Only a small amount of valrubicin incorporated into Val-ILs was needed to induce leukemia cell death in vivo, suggesting that this approach could be used to efficiently treat acute leukemia cells. We also demonstrated that Val-ILs could reduce the risk of contamination of CD34+ hematopoietic stem cells by acute leukemia cells during autologous peripheral blood stem cell transplantation, which is a significant advantage for clinical applications. Using EL4 lymphoma cells on immunocompetent C57BL/6 mice, we also highlighted the potential of Val-ILs to target immunosuppressive cell populations in the spleen, which could be valuable in impairing cancer cell expansion, particularly in lymphoma cases. The most efficient Val-ILs were found to be those loaded with CD11b or CD223 antibodies, which, respectively, target the myeloid-derived suppressor cells (MDSC) or the lymphocyte-activation gene 3 (LAG-3 or CD223) on T4 lymphocytes. This study provides a promising preclinical demonstration of the effectiveness and ease of preparation of Val-ILs as a novel nanoparticle technology. In the context of hematological cancers, Val-ILs have the potential to be used as a precise and effective therapy based on targeted vesicle-mediated cell death.

Identification of triciribine as a novel myeloid cell differentiation inducer.

Differentiation therapy using all-trans retinoic acid (ATRA) for acute promyelocytic leukemia (APL) is well established. However, because the narrow application and tolerance development of ATRA need to be improved, we searched for another efficient myeloid differentiation inducer. Kinase activation is involved in leukemia biology and differentiation block. To identify novel myeloid differentiation inducers, we used a Kinase Inhibitor Screening Library. Using a nitroblue tetrazolium dye reduction assay and real-time quantitative PCR using NB4 APL cells, we revealed that, PD169316, SB203580, SB202190 (p38 MAPK inhibitor), and triciribine (TCN) (Akt inhibitor) potently increased the expression of CD11b. We focused on TCN because it was reported to be well tolerated by patients with advanced hematological malignancies. Nuclear/cytoplasmic (N/C) ratio was significantly decreased, and myelomonocytic markers (CD11b and CD11c) were potently induced by TCN in both NB4 and acute myeloid leukemia (AML) M2 derived HL-60 cells. Western blot analysis using NB4 cells demonstrated that TCN promoted ERK1/2 phosphorylation, whereas p38 MAPK phosphorylation was not affected, suggesting that activation of the ERK pathway is involved in TCN-induced differentiation. We further examined that whether ATRA may affect phosphorylation of ERK and p38, and found that there was no obvious effect, suggesting that ATRA induced differentiation is different from TCN effect. To reveal the molecular mechanisms involved in TCN-induced differentiation, we performed microarray analysis. Pathway analysis using DAVID software indicated that "hematopoietic cell lineage" and "cytokine-cytokine receptor interaction" pathways were enriched with high significance. Real-time PCR analysis demonstrated that components of these pathways including IL1ß, CD3D, IL5RA, ITGA6, CD44, ITGA2B, CD37, CD9, CSF2RA, and IL3RA, were upregulated by TCN-induced differentiation. Collectively, we identified TCN as a novel myeloid cell differentiation inducer, and trials of TCN for APL and non-APL leukemia are worthy of exploration in the future.

Pharmacogenomics, Race, and Treatment Outcome in Pediatric Acute Myeloid Leukemia.

Importance: Disparities in outcomes exist between Black and White patients with acute myeloid leukemia (AML), with Black patients experiencing poorer prognosis compared with their White counterparts. Objective: To assess whether varying intensity of induction therapy to treat pediatric AML is associated with reduced disparities in treatment outcome by race. Design, Setting, and Participants: A comparative effectiveness analysis was conducted of 86 Black and 359 White patients with newly diagnosed AML who were enrolled in the AML02 trial from 2002 to 2008 or the AML08 trial from 2008 to 2017. Statistical analysis was conducted from July 2023 through January 2024. Interventions: Patients in AML02 were randomly assigned to receive standard low-dose cytarabine-based induction therapy or augmented high-dose cytarabine-based induction therapy, whereas patients in AML08 received high-dose cytarabine-based therapy. Main Outcomes and Measures: Cytarabine pharmacogenomic 10-single-nucleotide variant (ACS10) scores were evaluated for association with outcome according to race and treatment arm. Results: This analysis included 86 Black patients (mean [SD] age, 8.8 [6.5] years; 54 boys [62.8%]; mean [SD] leukocyte count, 52 600 [74 000] cells/µL) and 359 White patients (mean [SD] age, 9.1 [6.2] years; 189 boys [52.6%]; mean [SD] leukocyte count, 54 500 [91 800] cells/µL); 70 individuals with other or unknown racial and ethnic backgrounds were not included. Among all patients without core binding factor AML who received standard induction therapy, Black patients had significantly worse outcomes compared with White patients (5-year event-free survival rate, 25% [95% CI, 9%-67%] compared with 56% [95% CI, 46%-70%]; P = .03). By contrast, among all patients who received augmented induction therapy, there were no differences in outcome according to race (5-year event-free survival rate, Black patients, 50% [95% CI, 38%-67%]; White patients, 48% [95% CI, 42%-55%]; P = .78). Among patients who received standard induction therapy, those with low ACS10 scores had a significantly worse 5-year event-free survival rate compared with those with high scores (42.4% [95% CI, 25.6%-59.3%] and 70.0% [95% CI, 56.6%-83.1%]; P = .004); however, among patients who received augmented induction therapy, there were no differences in 5-year event-free survival rates according to ACS10 score (low score, 60.6% [95% CI, 50.9%-70.2%] and high score, 54.8% [95% CI, 47.1%-62.5%]; P = .43). Conclusions and Relevance: In this comparative effectiveness study of pediatric patients with AML treated in 2 consecutive clinical trials, Black patients had worse outcomes compared with White patients after treatment with standard induction therapy, but this disparity was eliminated by treatment with augmented induction therapy. When accounting for ACS10 scores, no outcome disparities were seen between Black and White patients. Our results suggest that using pharmacogenomics parameters to tailor induction regimens for both Black and White patients may narrow the racial disparity gap in patients with AML.

White blood cell count nadir to zero following intensive chemotherapy as a predictive factor for patients with acute myeloid leukemia.

Predictors for response to intensive therapy in AML have focused on baseline factors: percent leukemic blasts in marrow, cytogenetic/molecular genetic abnormalities, and presence of secondary AML. Non-baseline dynamic factors, occurring after induction but before response, may be useful for decisions related to salvage chemotherapy. We hypothesized white blood cell (WBC) count nadir after induction may be a real time indicator of treatment efficacy. We also examined whether time to stem cell transplant (SCT) or baseline molecular genetic abnormalities are associated with a low nadir. Data showed WBC nadir = 0 was a negative predictor for response to intensive induction and was correlated with reduced overall survival and progression free survival. Patients with WBC nadir = 0 did not have a significantly longer time to SCT, and none of the mutations increased the likelihood of reaching WBC nadir = 0. WBC nadir may be a useful real-time monitor in AML patients receiving intensive induction chemotherapy.

Metformin as an Enhancer for the Treatment of Chemoresistant CD34+ Acute Myeloid Leukemia Cells.

Acute myeloid leukemia is the second most frequent type of leukemia in adults. Due to a high risk of development of chemoresistance to first-line chemotherapy, the survival rate of patients in a 5-year period is below 30%. One of the reasons is that the AML population is heterogeneous, with cell populations partly composed of very primitive CD34+CD38- hematopoietic stem/progenitor cells, which are often resistant to chemotherapy. First-line treatment with cytarabine and idarubicin fails to inhibit the proliferation of CD34+CD38- cells. In this study, we investigated Metformin's effect with or without first-line conventional chemotherapy, or with other drugs like venetoclax and S63845, on primitive and undifferentiated CD34+ AML cells in order to explore the potential of Metformin or S63845 to serve as adjuvant therapy for AML. We found that first-line conventional chemotherapy treatment inhibited the growth of cells and arrested the cells in the S phase of the cell cycle; however, metformin affected the accumulation of cells in the G2/M phase. We observed that CD34+ KG1a cells respond better to lower doses of cytarabine or idarubicin in combination with metformin. Also, we determined that treatment with cytarabine, venetoclax, and S63845 downregulated the strong tendency of CD34+ KG1a cells to form cell aggregates in culture due to the downregulation of leukemic stem cell markers like CD34 and CD44, as well as adhesion markers. Also, we found that idarubicin slightly upregulated myeloid differentiation markers, CD11b and CD14. Treatment with cytarabine, idarubicin, venetoclax, metformin, and S63845 upregulated some cell surface markers like HLA-DR expression, and metformin upregulated CD9, CD31, and CD105 cell surface marker expression. In conclusion, we believe that metformin has the potential to be used as an adjuvant in the treatment of resistant-to-first-line-chemotherapy AML cells. Also, we believe that the results of our study will stimulate further research and the potential use of changes in the expression of cell surface markers in the development of new therapeutic strategies.

Preferential HDAC6 inhibitors derived from HPOB exhibit synergistic antileukemia activity in combination with decitabine.

Histone deacetylase 6 (HDAC6) is an emerging drug target to treat oncological and non-oncological conditions. Since highly selective HDAC6 inhibitors display limited anticancer activity when used as single agent, they usually require combination therapies with other chemotherapeutics. In this work, we synthesized a mini library of analogues of the preferential HDAC6 inhibitor HPOB in only two steps via an Ugi four-component reaction as the key step. Biochemical HDAC inhibition and cell viability assays led to the identification of 1g (highest antileukemic activity) and 2b (highest HDAC6 inhibition) as hit compounds. In subsequent combination screens, both 1g and especially 2b showed synergy with DNA methyltransferase inhibitor decitabine in acute myeloid leukemia (AML). Our findings highlight the potential of combining HDAC6 inhibitors with DNA methyltransferase inhibitors as a strategy to improve AML treatment outcomes.

Olutasidenib: a novel mutant IDH1 inhibitor for the treatment of relapsed or refractory acute myeloid leukemia.

INTRODUCTION: Recurrent mutations in isocitrate dehydrogenase 1 (mIDH1) occur in about 7% to 14% of all cases of acute myeloid leukemia (AML). The discovery of targetable mutations in AML, including IDH mutations, expanded the therapeutic landscape of AML and led to the development of targeted agents. Despite significant advances in current treatment options, remission and overall survival rates remain suboptimal. The IDH1 inhibitor, olutasidenib, demonstrated encouraging safety and clinical benefits as monotherapy in patients with relapsed or refractory (R/R) mIDH1 AML. AREAS COVERED: This review outlines the olutasidenib drug profile and summarizes key safety and efficacy data, focusing on the 150 mg twice daily dose from the pivotal registrational cohort of the phase 2 trial that formed the basis for the US Food and Drug Administration approval of olutasidenib in patients with R/R AML with a susceptible IDH1 mutation. EXPERT OPINION: Olutasidenib offers patients with R/R mIDH1 AML a new treatment option, with improved complete remission and a longer duration of response than other targeted mIDH1 treatment options. Olutasidenib provided clinical benefit with a manageable safety profile. Additional analyses to further characterize the safety and efficacy of olutasidenib in frontline and R/R settings as monotherapy and as combination therapy are ongoing.

Olutasidenib is an oral prescription medication for patients diagnosed with acute myeloid leukemia (AML) with a specific mutation in the isocitrate dehydrogenase 1 (IDH1) gene. The US FDA approved olutasidenib at a dose of 150 mg twice a day for use as stand-alone (monotherapy) treatment in patients with IDH1-mutated AML whose disease has come back or has not improved after previous treatment(s). Olutasidenib is not traditional chemotherapy; it is a targeted treatment called an IDH1 inhibitor, which blocks IDH1 when it has been altered (mutated). These alterations happen in some patients, and when they do, the products of these alterations can lead to leukemia. By blocking mutated IDH1, the body can resume normal blood cell production and functioning. In studies, response to olutasidenib was measured by the number of people who went into remission. Complete remission (CR) means there is no sign of cancer and laboratory values are normal. Complete remission with partial hematologic recovery (CRh) means there is no sign of cancer, but some lab values do not reach normal levels. Thirty-five percent of people taking olutasidenib achieved CR or CRh and stayed in remission for 25.9 months. About 14% of patients who did not achieve remission also experienced some improvement in symptoms. The most common side effects in studies were nausea, feeling tired, fever, constipation, diarrhea, abnormal liver function tests, and changes in certain blood tests. Serious side effects included liver problems and differentiation syndrome, which is a potentially life-threatening situation that can occur when blood cells mature too quickly. Olutasidenib is also being studied in patients with IDH1 mutated AML who have never been treated before and in combination with a chemotherapy medication called azacitidine.

The potential of triplet combination therapies for patients with FLT3-ITD -mutated acute myeloid leukemia.

INTRODUCTION: Acute myeloid leukemia (AML) encompasses a heterogeneous group of aggressive myeloid malignancies, where FMS-like tyrosine kinase 3 (FLT3) mutations are prevalent, accounting for approximately 25-30% of adult patients. The presence of this mutation is related to a dismal prognosis and high relapse rates. In the lasts years many FLT3 inhibitors have been developed. AREAS COVERED: This review provides a comprehensive overview of FLT3mut AML, summarizing the state of art of current treatment and available data about combination strategies including an FLT3 inhibitor. EXPERT OPINION: In addition, the review discusses the emergence of drug resistance and the need for a nuanced approaches in treating patients who are ineligible for or resistant to intensive chemotherapy. Specifically, it explores the historical context of FLT3 inhibitors (FLT3Is) and their impact on treatment outcomes, emphasizing the pivotal role of midostaurin, as well as gilteritinib and quizartinib, and providing detailed insights into ongoing trials exploring the safety and efficacy of novel triplet combinations involving FLT3Is in different AML settings.

A systematic review of second-generation FLT3 inhibitors for treatment of patients with relapsed/refractory acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a complex disease with diverse mutations, including prevalent mutations in the FMS-like receptor tyrosine kinase 3 (FLT3) gene that lead to poor prognosis. Recent advancements have introduced FLT3 inhibitors that have improved outcomes for FLT3-mutated AML patients, however, questions remain on their application in complex conditions such as relapsed/refractory (R/R) disease. Therefore, we aimed to evaluate the clinical effectiveness of second-generation FLT3 inhibitors in treating patients with R/R AML. METHODS: A systematic literature search of PubMed, MEDLINE, SCOPUS and Google Scholar databases was made to identify relevant studies up to January 30, 2024. This study was conducted following the guidelines of the PRISMA. RESULTS: The ADMIRAL trial revealed significantly improved overall survival and complete remission rates with gilteritinib compared to salvage chemotherapy, with manageable adverse effects. Ongoing research explores its potential in combination therapies, showing synergistic effects with venetoclax and promising outcomes in various clinical trials. The QuANTUM-R trial suggested longer overall survival with quizartinib compared to standard chemotherapy, although concerns were raised regarding trial design and cardiotoxicity. Ongoing research explores combination therapies involving quizartinib, such as doublet or triplet regimens with venetoclax, showing promising outcomes in FLT3-mutated AML patients. CONCLUSION: These targeted therapies offer promise for managing this subgroup of AML patients, but further research is needed to optimize their use. This study underscores the importance of personalized treatment based on genetic mutations in AML, paving the way for more effective and tailored approaches to combat the disease.

miR-133a and miR-135a Regulate All-Trans Retinoic Acid-Mediated Differentiation in Pediatric Acute Myeloid Leukemia by Inhibiting CDX2 Translation and Serve as Prognostic Biomarkers.

Background: Acute myeloid leukemia (AML) is a type of blood cancer characterized by excessive growth of immature myeloid cells. Unfortunately, the prognosis of pediatric AML remains unfavorable. It is imperative to further our understanding of the mechanisms underlying leukemogenesis and explore innovative therapeutic approaches to enhance overall disease outcomes for patients with this condition. Methods: Quantitative reverse-transcription PCR was used to quantify the expression levels of microRNA (miR)-133a and miR-135a in 68 samples from 59 pediatric patients with AML. Dual-luciferase reporter transfection assay, Cell Counting Kit-8 assay, and western blot analysis were used to investigate the functions of miR-133a and miR-135a. Results: Our study found that all-trans-retinoic acid (ATRA) promoted the expression of miR-133a and miR-135a in AML cells, inhibited caudal type homeobox 2 (CDX2) expression, and subsequently inhibited the proliferation of AML cells. Additionally, miR-133a and miR-135a were highly expressed in patients with complete remission and those with better survival. Conclusions: miR-133a and miR-135a may play an antioncogenic role in pediatric AML through the ATRA-miRNA133a/135a-CDX2 pathway. They hold promise as potentially favorable prognostic indicators and novel therapeutic targets for pediatric AML.