Cancer-related cognitive impairment in older adults with acute myeloid leukemia treated with hypomethylating agents and venetoclax chemotherapy: a longitudinal descriptive study.

PURPOSE: To explore cancer-related cognitive impairment (CRCI) in older adults with acute myeloid leukemia (AML) receiving venetoclax in combination with hypomethylating agents or low-dose cytarabine chemotherapy. METHODS: This study is a longitudinal, qualitative descriptive study. Participants were recruited using purposive sampling. Semi-structured interviews were conducted among 11 older adults with AML at cycle 2, cycle 4, and cycle 7 of chemotherapy. An early end-of-study interview was conducted for those who changed treatment plans during the study follow-up. RESULTS: A total of 22 transcripts were included for thematic analysis. Four themes emerged: (1) CRCI experiences, (2) impact of CRCI, (3) CRCI coping strategies, and (4) perceived CRCI-related factors. Older adults with AML experienced challenges in memory, language, and attention both intermittently and daily. These cognitive changes impacted their emotion, daily activities, social connection, and their caregivers' responsibilities. Hence, these older adults with AML developed problem-solving and emotional coping strategies to cope with CRCI. Older adults with AML also identified demographic, physiology/clinical, psychological, and other factors that might contribute to CRCI. CONCLUSION: This study offers important insight for clinicians to understand how older adults with AML experience CRCI and how it impacts their daily routines. It indicates that clinicians should ask patients about their experience with cognitive changes at each encounter to provide support or coping strategies as needed to prevent CRCI from further hindering their quality of life.

Novel Vpx virus-like particles to improve cytarabine treatment response against acute myeloid leukemia.

Knowledge of the molecular pathogenesis of acute myeloid leukemia has advanced in recent years. Despite novel treatment options, acute myeloid leukemia remains a survival challenge for elderly patients. We have recently shown that the triphosphohydrolase SAMHD1 is one of the factors determining resistance to Ara-C treatment. Here, we designed and tested novel and simpler virus-like particles incorporating the lentiviral protein Vpx to efficiently and transiently degrade SAMHD1 and increase the efficacy of Ara-C treatment. The addition of minute amounts of lentiviral Rev protein during production enhanced the generation of virus-like particles. In addition, we found that our 2nd generation of virus-like particles efficiently targeted and degraded SAMHD1 in AML cell lines with high levels of SAMHD1, thereby increasing Ara-CTP levels and response to Ara-C treatment. Primary AML blasts were generally less responsive to VLP treatment. In summary, we have been able to generate novel and simpler virus-like particles that can efficiently deliver Vpx to target cells.

The outcome in pediatric acute myeloblastic leukemia; results of the first-line treatment and contribution of hematopoietic stem cell transplantation to survival of relapsed patients.

Background/aim: To analyze the long-term outcome of pediatric patients with acute myeloblastic leukemia. Materials and methods: Data from 69 patients 0-18 years of age diagnosed between December 2001 and October 2019 were analyzed in April 2023. Patients received MRC-AML10 chemotherapy (2ADE+MACE+MidAC). No maintenance chemotherapy or preventive cranial radiotherapy was administered. Twelve patients with Down syndrome and 15 patients with promyelocytic leukemia were in the cohort. Patients with Down syndrome received reduced chemotherapy (cumulative anthracycline 420 mg/m2, cytarabine 3.4 g/m2, etoposide 1400 mg/m2). ATRA was added to chemotherapy in promyelocytic leukemia. Results: Four patients (5.8%) died in the induction (two typhlitis, one intracranial hemorrhage, and one resistant disease). The complete remission rate of 66 patients was 87.8%. There was one death due to cardiotoxicity. Total infection-related deaths were 7.2%. Seven patients with high-risk criteria and one with resistant disease underwent hematopoietic stem cell transplantation (HSCT) following the first-line treatment. All seven patients in remission were alive and disease-free. The relapse rate was 34.4% (n = 21). Four patients developing marrow relapse were disease-free in the second remission after salvage and maintenance chemotherapy. Thirteen patients (18.84%) underwent HSCT in the second remission and 8 are alive and disease-free. The mean follow-up period of patients from diagnosis was 185 ± 13 months. Thirty-four patients (49.2%) were alive and disease-free in the first remission whereas another two patients in the first remission developed secondary malignancy. In good, standard, and poor risk groups, event-free survival (EFS) rates were 68.2%, 52.9%, and 10%, and overall survival (OS) rates were 86.4%, 79.4%, and 20%, respectively. Fifteen years of EFS and OS of the whole cohort were 49.3% and 69.6%, respectively. Conclusion: When compared with national data and multicenter studies of developed countries, survival rates were acceptable.

Hematopoietic stem and progenitor cell membrane-coated vesicles for bone marrow-targeted leukaemia drug delivery.

Leukemia is a kind of hematological malignancy originating from bone marrow, which provides essential signals for initiation, progression, and recurrence of leukemia. However, how to specifically deliver drugs to the bone marrow remains elusive. Here, we develop biomimetic vesicles by infusing hematopoietic stem and progenitor cell (HSPC) membrane with liposomes (HSPC liposomes), which migrate to the bone marrow of leukemic mice via hyaluronic acid-CD44 axis. Moreover, the biomimetic vesicles exhibit superior binding affinity to leukemia cells through intercellular cell adhesion molecule-1 (ICAM-1)/integrin ß2 (ITGB2) interaction. Further experiments validate that the vesicles carrying chemotherapy drug cytarabine (Ara-C@HSPC-Lipo) markedly inhibit proliferation, induce apoptosis and differentiation of leukemia cells, and decrease number of leukemia stem cells. Mechanically, RNA-seq reveals that Ara-C@HSPC-Lipo treatment induces apoptosis and differentiation and inhibits the oncogenic pathways. Finally, we verify that HSPC liposomes are safe in mice. This study provides a method for targeting bone marrow and treating leukemia.

[Efficacy of venetoclax-based induction regimen in newly diagnosed pediatric acute myeloid leukemia].

Objective: To explore the efficacy of venetoclax-based induction regimen for children with newly diagnosed acute myeloid leukemia (AML). Methods: Children with newly diagnosed AML in Beijing Children's Hospital Affiliated to Capital Medical University and Baoding Hospital Affliliated to Capital Medical University from November 2019 and December 2023 were prospectively included. The patients were divided into DAH group (daunorubicin, cytarabine and homoharringtonine) and VAH group (venetoclax, cytarabine and homoharringtonine) according to induction regimen. The clinical data of the children were collected, the clinical characteristics and induced remission rate between the two groups were compared, and multivariate logistic regression was used to analyze the related factors affecting the induced remission rate. Results: A total of 135 patients were enrolled, including 96 cases in the DAH group (54 males and 42 females), aged [M (Q1, Q3)] 6.4 (3.9, 11.6) years and 39 cases in the VAH group (26 males and 13 females), aged 8.0 (6.2, 13.2) years. Among patients initially diagnosed with low-medium risk AML, the morphologic complete remission rates were 94.7% (18/19) in the VAH group and 84.4% (38/45) in the DAH group, respectively, and the negativity conversion rates of minirnal residual disease (MRD) were 57.9% (11/19) and 46.7% (21/45), respectively, with no statistically difference (all P>0.05). Among patients initially diagnoised with high-risk AML, the morphologic complete remission rates in the VAH group was higher than that in the DAH group [95.0% (19/20) vs 70.6% (36/51), P=0.027], and negativity conversion rates of MRD were 45.0% (9/20) and 33.3% (17/51), respectively, with no statistically difference (P=0.359). The induction regimen (venetoclax, cytarabine and homoharringtonin) was beneficial to morphological remission (OR=0.126, 95%CI: 0.025-0.629). FLT3 mutation was not conducive to morphological remission (OR=5.832, 95%CI: 1.778-19.124) and negative MRD (OR=4.166, 95%CI: 1.396-12.433). Conclusion: Venetoclax-based induction regimen is more effective than traditional chemotherapy regimen for newly diagnosed pediatric AML.

Cytarabine prevents neuronal damage by enhancing AMPK to stimulate PINK1 / Parkin-involved mitophagy in Parkinson's disease model.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder, which may be largely due to the mitochondrial dysfunction and impaired mitophagy. Thus, it is of great importance to seek novel therapeutic strategies for PD targeting mitochondrial function and mitophagy. Cytarabine is a marine-derived antimetabolite used in the treatment of acute leukemia, which is also used in the study of the nervous system. In this study, we found that cytarabine pretreatment significantly inhibited the apoptosis and necrosis in the ROT-induced SH-SY5Y cell PD model and reduced the oxidative stress, as evidenced by the reduced MDA levels and the increased levels of SOD, GSH, and total antioxidant capacity. Cytarabine can also enhance mitochondrial vitality, improve mitochondrial respiratory function, and preserve mitochondrial morphology. Cytarabine also enhanced the expression of the mitophagy-related proteins PINK1, Parkin, VDAC1, and DJ-1, and its actions can be reversed by treatment with AMPK inhibitor - Compound C (CC), suggesting that AMPK activation may be involved in cytarabine-enhanced mitophagy. Furthermore, cytarabine can also ameliorate the motor symptoms in the MPTP-induced PD-like mice model, and attenuate the neuropathy in the substantia nigra (SN) of PD mice, while Compound C antagonized cytarabine's beneficial effects. In summary, marine-derived compound cytarabine could resist neurological damage both in vitro and in vivo by activating AMPK to increase PINK1/Parkin-induced mitophagy, serving as a promising disease modulator for treating neurodegenerative disease.

Clinical features, treatment, and outcome of juvenile dogs with meningoencephalitis of unknown etiology.

BACKGROUND: The information relating to the outcome specifically for juvenile dogs with meningoencephalitis of unknown etiology (MUE) is lacking. OBJECTIVES: To describe the clinical presentation, diagnostic findings, treatment, and outcome in a cohort of dogs with MUE <52 weeks old. ANIMALS: Thirty-four client-owned dogs. METHODS: Multicenter retrospective case series. Records from 5 referral centers were searched. Data was extracted from the medical records and referring veterinarians were contacted for survival data if this was not available from the record. RESULTS: The mean age was 31 weeks; the youngest dog was 11 weeks and 3 dogs were <16 weeks old. Altered mentation (71%), ataxia (44%), seizures (29%), and circling (26%) were the most common presenting complaints. Neuroanatomical localization was to the forebrain (38%), multifocal (35%), brainstem (18%), and cerebellum (12%). Corticosteroid monotherapy (n = 15) and corticosteroid plus cytosine arabinoside (n = 15) were used in equal proportions. Outcome data was available for 26 dogs, 8 (31%) were alive at the time of data collection with a follow-up range of 135 to 2944 days. Death or euthanasia was related to MUE in 17/18 dogs that died during the study period. Kaplan-Meier survival analysis demonstrated a median survival time for all-cause death of 84 days. CONCLUSION: The prognosis for MUE in this subset of dogs was considered poor.

Upregulation of HOXA3 by isoform-specific Wilms tumour 1 drives chemotherapy resistance in acute myeloid leukaemia.

Upregulation of the Wilms' tumour 1 (WT1) gene is common in acute myeloid leukaemia (AML) and is associated with poor prognosis. WT1 generates 12 primary transcripts through different translation initiation sites and alternative splicing. The short WT1 transcripts express abundantly in primary leukaemia samples. We observed that overexpression of short WT1 transcripts lacking exon 5 with and without the KTS motif (sWT1+/- and sWT1-/-) led to reduced cell growth. However, only sWT1+/- overexpression resulted in decreased CD71 expression, G1 arrest, and cytarabine resistance. Primary AML patient cells with low CD71 expression exhibit resistance to cytarabine, suggesting that CD71 may serve as a potential biomarker for chemotherapy. RNAseq differential expressed gene analysis identified two transcription factors, HOXA3 and GATA2, that are specifically upregulated in sWT1+/- cells, whereas CDKN1A is upregulated in sWT1-/- cells. Overexpression of either HOXA3 or GATA2 reproduced the effects of sWT1+/-, including decreased cell growth, G1 arrest, reduced CD71 expression and cytarabine resistance. HOXA3 expression correlates with chemotherapy response and overall survival in NPM1 mutation-negative leukaemia specimens. Overexpression of HOXA3 leads to drug resistance against a broad spectrum of chemotherapeutic agents. Our results suggest that WT1 regulates cell proliferation and drug sensitivity in an isoform-specific manner.

[Effect of TLK2 Expression Regulated by MiR-21 on Proliferation and Apoptosis of Acute Myeloid Leukemia Cells].

OBJECTIVE: To investigate the effect of TLK2 expression regulated by miR-21 on proliferation and apoptosis of acute myeloid leukemia cells. METHODS: Seventy patients with AML admitted to our hospital from January 2019 to July 2022 were selected, while 30 patients with iron deficiency anemia were selected as the control group. Bone marrow mononuclear cells (BMMNCs) of the patients were obtained using Ficoll density gradient centrifugation. RT-qPCR was used to determine the expression levels of miR-21 and TLK2 mRNA in BMMNCs. Mimics-miR-21, mimics-NC, inhibitor-miR-21, inhibitor-NC and NC were transfected into HL-60 cells using liposome-mediated transfection technology. CCK-8 method was used to determine the activity of transfected HL-60 cells after treatment with cytarabine. The apoptosis rate of HL-60 transfected cells was determined by TUNEL method. The expression of TLK2 mRNA in HL-60 cells transfected with inhibitor-miR-21 was determined by RT-qPCR. RESULTS: The relative expression levels of miR-21 and TLK2 mRNA in BMMNCs of AML patients were significantly higher than those of controls (both P < 0.05). After HL-60 cells were treated with cytarabine, both the cell activity of inhibitor-miR-21 group and mimics-miR-21 group decreased significantly with the increase of cytarabine concentration (both P < 0.05). However, at each concentration point of cytarabine, the cell activity of inhibitor-miR-21 group was lower than that of control group (P < 0.05), while mimics-miR-21 group was higher than control group (P < 0.05). After HL-60 cells were treated with cytarabine, the apoptosis rate of inhibitor-miR-21 group was significantly increased (P < 0.05), while that of mimics-miR-21 group was significantly decreased (P < 0.05). After HL-60 cells were treated with inhibitor-miR-21, the relative expression of TLK2 mRNA decreased significantly (P < 0.05). CONCLUSION: miR-21 is highly expressed in AML patients, which may promote the apoptosis of AML cells by inhibiting the expression of TLK2.

Retrospective analysis of pediatric patients with Burkitt lymphoma treated in Tanzania following the implementation of the 2016 National Treatment Guidelines: Poor outcomes to current standard-of-care therapy.

BACKGROUND: Despite the excellent outcomes achieved in the treatment of pediatric Burkitt lymphoma (BL) in high-income countries (HICs), outcomes remain poor in low- and middle-income countries (LMICs). Efforts to improve BL outcomes in Tanzania included the creation of National Treatment Guidelines in 2016. However, disease outcomes in Tanzania following the creation of these guidelines have not been reported to date. PROCEDURE: Historical records from 2016 to 2021 for patients 0-18 years of age with a diagnosis of BL and seen at Bugando Medical Centre (BMC), in Mwanza, Tanzania, were curated into an electronic database and analyzed descriptively. Patients in this cohort were treated per the Tanzanian National Treatment Guidelines, which include six cycles of cyclophosphamide, vincristine, and methotrexate (COM) chemotherapy with intrathecal methotrexate and cytarabine. RESULTS: In total, 92 BL patients' records were eligible for analysis. Patients in this cohort were most commonly Murphy stage II (28%) or stage III (34%). Nearly all, 91%, met International Network for Cancer Treatment and Research (INCTR) high-risk criteria at presentation. Forty-two percent of patients did not receive a biopsy and were treated with a presumed diagnosis of BL alone. A 1-year event-free survival of 29.6% (95% confidence interval [CI]: 20.3%-39.5%) and a 1-year overall survival of 38.5% (95% CI: 28%-48.9%) were observed. A high rate of treatment abandonment (34%) was also observed. CONCLUSION: In a historical cohort of pediatric patients with BL treated per the 2016 Tanzanian National Treatment Guidelines, we observed poor outcomes and a high rate of abandonment. These outcomes appear inferior to those achieved in the INCTR clinical trial that informed the guidelines' creation, and highlights the importance of "real-world" outcomes data in LMICs. These data reinforce the idea that continued clinical research and capacity building efforts are necessary to improve BL outcomes in LMICs.

Combining Brentuximab Vedotin With Dexamethasone, High-dose Cytarabine, and Cisplatin as Salvage Treatment in Pediatric Relapsed or Refractory Classic Hodgkin Lymphoma: Two Case Reports.

Hodgkin lymphoma (HL) is among the most commonly occurring malignancies in adolescents. For relapsed/refractory disease, many regimens have been proposed. Novel agents are increasingly used, like brentuximab vedotin (BV), an antiCD30 antibody-drug conjugate, used as a single agent or in combination with classic regimens mainly in adults, while limited is the experience in pediatrics. We report here on 2 boys with aggressive and high-risk relapsed HL, successfully treated with the BV plus dexamethasone, high-dose cytarabine, cisplatin regimen as induction salvage treatment. Our experience provides real-world evidence on the use of BV-dexamethasone, high-dose cytarabine, cisplatin as first-line salvage therapy for relapsed/refractory HL and expands the current therapeutic choices.

[A Retrospective Study of R±DHAX Regimen versus R-CHOP Regimen First-Line Treatment of Elderly Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To investigate the clinical efficacy and prognosis of Rituximab combined with DHAX and CHOP regimen in the first-line treatment of elderly patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). METHODS: A total of 36 elderly patients with DLBCL who were admitted and treated with 3 of more courses of treatment from August 2011 to August 2021 were retrospectively analyzed, and they were divided into rituximab±DHAX (R±DHAX) regimen group (18 cases) and rituximab±CHOP (R-CHOP) regimen group (18 cases) according to the treatment plan, and clinical features, efficacy and survival of the patients were observed. RESULTS: Compared with R-CHOP group, patients of the R±DHAX group were older, and had worse performance status and higher IPI score, the differences between two groups in age, ECOG score and IPI score were statistically significant ( P =0.005 P =0.018, P =0.035), but there were no significant differences beween two groups in gender, whether there were B symptoms, whether LDH was elevated, whether there was extranodal involvement, cell origin, bone marrow infiltration, and whether rituximab was combined ( P =0.738, P =1, P =0.315, P =0.305, P =0.413, P =0.177, P =0.711, P =0.229). The efficacy could be evaluated in 36 cases, including CR 14 (38.9%), PR 17 (47.2%), PD 5 (13.9%), and ORR of 86.1% (31/36). There were no statistically significant differences in CRï¼»(27.8%（5/18） vs 50.0%（9/18）; P >0.05ï¼½ and PR ï¼»44.4%（8/18） vs 50.0%（9/18）; P >0.05ï¼½ of R±DHAX group and R-CHOP group, there was statistically significant difference in ORRï¼»72.2%（13/18） vs 100.0%（18/18）; P =0.045ï¼½ between two groups. The 1-year OS of R±DHAX group and R-CHOP group was (38.9±11.5%)% and (94.4±7.4%)%, respectively, 2-year OS was (16.7±8.8)% and (72.2±10.6)%, respectively, and the differences between two groups were statistically significant ( P =0.001, P =0.002). The median survival time in the R±DHAX group was 11 months(95%CI :8.9-13.1), and the median survival time in the R-CHOP group was not reached, and there was a statistically significant difference between the groups (P < 0.001). CONCLUSION: For elderly DLBCL patients, R±DHAX may not be superior to R-CHOP in OS, and ECOG score, IPI score and age may affect the survival of elderly DLBCL patients. However, R±DHAX regimen is safe, tolerable and has a certain efficacy, which can be used as one of the clinical treatment options for elderly DLBCL.

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.

Case report: Rapid resolution of grade IV ICANS after first line intrathecal chemotherapy with methotrexate, cytarabine and dexamethasone.

Corticosteroid therapy is the mainstay of immune effector cell-associated neurotoxicity syndrome (ICANS) management, although its use has been associated with worse overall survival (OS) and progression-free survival (PFS) after chimeric antigen receptor T-cell (CAR-T cell) therapy. Many options are being investigated for prophylaxis and management. Accumulating evidence supports the use of intrathecal (IT) chemotherapy for the management of high-grade ICANS. Here, we describe a case of a patient with stage IV Primary mediastinal B-cell lymphoma (PMBCL) successfully treated with IT methotrexate, cytarabine, and dexamethasone as first-line therapy for CD19 CAR-T cell-associated grade IV ICANS. The stable and rapid resolution of ICANS to grade 0 allowed us to discontinue systemic corticosteroid use, avoiding CAR-T cells ablation and ensuring preservation of CAR-T cell function. The described patient achieved a complete radiologic and clinical response to CD19 CAR-T cell therapy and remains disease-free after 9 months. This case demonstrates a promising example of how IT chemotherapy could be used as first-line treatment for the management of high-grade ICANS.

SOX11 is a novel binding partner and endogenous inhibitor of SAMHD1 ara-CTPase activity in mantle cell lymphoma.

The sterile alpha motif and histidine-aspartate (HD) domain containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate triphosphohydrolase with ara-CTPase activity that confers cytarabine (ara-C) resistance in several haematological malignancies. Targeting SAMHD1's ara-CTPase activity has recently been demonstrated to enhance ara-C efficacy in acute myeloid leukemia. Here, we identify the transcription factor SRY-related HMG-box containing protein 11 (SOX11) as a novel direct binding partner and first known endogenous inhibitor of SAMHD1. SOX11 is aberrantly expressed not only in mantle cell lymphoma (MCL), but also in some Burkitt lymphomas. Co-immunoprecipitation of SOX11 followed by mass spectrometry in MCL cell lines identified SAMHD1 as the top SOX11 interaction partner which was validated by proximity ligation assay. In vitro, SAMHD1 bound to the HMG box of SOX11 with low-micromolar affinity. In situ crosslinking studies further indicated that SOX11-SAMHD1 binding resulted in a reduced tetramerization of SAMHD1. Functionally, expression of SOX11 inhibited SAMHD1 ara-CTPase activity in a dose-dependent manner resulting in ara-C sensitization in cell lines and in a SOX11-inducible mouse model of MCL. In SOX11-negative MCL, SOX11-mediated ara-CTPase inhibition could be mimicked by adding the recently identified SAMHD1 inhibitor hydroxyurea. Taken together, our results identify SOX11 as a novel SAMHD1 interaction partner and its first known endogenous inhibitor with potentially important implications for clinical therapy stratification.

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.

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.

Intensive Reinduction Chemotherapy Followed by Early Allogeneic Hematopoietic Cell Transplantation for Relapsed/Refractory High-Grade Myeloid Neoplasms.

Outcomes for adults with relapsed/refractory (R/R) high-grade myeloid neoplasms remain poor, with allogeneic hematopoietic cell transplantation (HCT) the sole therapy likely to result in cure. We conducted the present study to determine the feasibility of early HCT-within 60 days of beginning reinduction chemotherapy-to see whether getting patients to HCT in an expeditious manner would expand the number of patients being offered this curative option. In this proof-of-principle feasibility study, we included adults age 18 to 75 years with R/R myeloid malignancies with ≥10% blood/marrow blasts at diagnosis who were eligible for a reduced-intensity HCT. Subjects received reinduction chemotherapy with cladribine, cytarabine, mitoxantrone, and filgrastim (CLAG-M) and proceeded to HCT with reduced-intensity conditioning (fludarabine/ melphalan). We enrolled 30 subjects, all of whom received CLAG-M reinduction, although only 9 underwent HCT within 60 days (<15, the predetermined threshold for feasibility "success"), with a median time to HCT of 48 days (range, 42 to 60 days). Eleven additional subjects received HCT beyond the target 60 days (off-study), with a median time to transplantation of 83 days (range, 53 to 367 days). Barriers to early HCT included infection, physician preference, lack of an HLA-matched donor, logistical delays, and disease progression, all of which may limit the real-world uptake of such early-to-transplantation protocols.