Upregulation of Insulin-like Growth Factor-I in Response to Chemotherapy in Children with Acute Lymphoblastic Leukemia.

The treatment of childhood cancer is challenged by toxic side effects mainly due to chemotherapy-induced organ damage and infections, which are accompanied by severe systemic inflammation. Insulin-like growth factor I (IGF-I) is a key regulating factor in tissue repair. This study investigated associations between the circulating IGF-I levels and chemotherapy-related toxicity in pediatric acute lymphoblastic leukemia (ALL). In this prospective study, we included 114 patients (age: 1-17 years) with newly diagnosed ALL treated according to The Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol between 2013 and 2018. The patients' plasma levels of IGF-I, and the primary binding protein, IGFBP-3, were measured weekly during the first six weeks of treatment, including the induction therapy. The patients' systemic inflammation was monitored by their C-reactive protein (CRP) and interleukin (IL)-6 levels and their intestinal epithelial damage by their plasma citrulline levels. IGF-I and IGFBP-3 were converted into sex-and age-adjusted standard deviation scores (SDS) using 1621 healthy children as reference. At ALL diagnosis, IGF-I levels were decreased (median (quartiles): -1.2 SDS (-1.9 to -0.5), p = 0.001), but increased significantly following the initiation of chemotherapy, peaking on day 8 (0.0 SDS (from -0.8 to 0.7), p < 0.001). This increase correlated with the levels of CRP (rho = 0.37, p < 0.001) and IL-6 (rho = 0.39, p = 0.03) on day 15, when these markers reached maximum levels. A larger IGF-I increase from day 1 to 15 correlated with a slower recovery rate of the intestinal damage marker citrulline from day 15 to 29 (rho = -0.28, p = 0.01). Likewise, IGFBP-3 was reduced at diagnosis, followed by an increase after treatment initiation, and was highly correlated with same-day IGF-I levels. This study demonstrates a chemotherapy-induced increase in IGF-I, with a response that appears to reflect the severity of tissue damage and systemic inflammation, preceding CRP and IL-6 increases. IGF-I may have potential as an early reactive biomarker for acute toxicity in patients with ALL.

Mitochondria and Acute Leukemia: A Clinician's Perspective.

Acute leukemia is a group of aggressive hematological malignancies, with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) being the most common types. The biology of acute leukemia involves complex genetic and epigenetic alterations that lead to uncontrolled cell proliferation and resistance to apoptosis. Mitochondrial dysfunction is a feature of acute leukemia that results in altered energy production, unregulated cell death pathways, and increased cancer cell survival. Apoptosis, particularly via the mitochondrial pathway, is crucial for cellular homeostasis and cancer prevention. In acute leukemia, disruption of apoptosis is pivotal in disease development and progression, with elevated levels of anti-apoptotic proteins conferring a survival advantage to leukemia cells and promoting resistance to conventional therapies. Targeting mitochondrial apoptosis using BH3 mimetics and anti-apoptotic protein inhibitors is a viable therapeutic strategy. Alterations in the mitochondrial membrane potential, metabolism, and dynamics also contribute to the pathogenesis of acute leukemia. Continued research is vital for developing novel therapies and enhancing survival outcomes in patients with acute leukemia while minimizing the long-term adverse effects of treatment. In this narrative review, we provide a birds-eye view of the available scientific literature on the importance of mitochondria in acute leukemia, and discuss the role of BH3 mimetics in targeting the mitochondrial internal apoptotic machinery.

Language, 6-mercaptopurine adherence, and relapse in children with acute lymphoblastic leukemia.

Hispanic children with acute lymphoblastic leukemia (ALL) have lower 6-mercaptopurine (6MP) adherence and greater hazard of relapse compared with non-Hispanic White children. We examined the association between Spanish language and 6MP adherence, and hazard of relapse. 6MP adherence was measured electronically over a 6-month period. Participants were grouped by the language of demographic questionnaire completion: Non-Hispanic White-English Speaking (ES, n = 159), Hispanic-Spanish Speaking (Hispanic-SS, n = 59), and Hispanic-ES (n = 109). Hispanic-ES had significantly lower fitted median 6MP adherence compared with non-Hispanic White-ES participants (88.3%, 95% CI = 84.7% to 91.2% vs 95.0%, 95% CI = 93.6% to 96.2%, P < .001). There was no difference in fitted median 6MP adherence between Hispanic-ES and Hispanic-SS participants (88.3%, 95% CI = 84.1% to 91.5% vs 88.3%, 95% CI = 84.7% to 91.2%, P = .9) or adjusted hazard of relapse for Hispanic-SS participants (HR = 0.9, 95%CI = 0.3 to 2.4, P = .8). Spanish language use among Hispanic patients with ALL is not associated with lower 6MP adherence or greater relapse risk. Factors related to Hispanic ethnicity, apart from language, appear to influence adherence.

Treatment of persistent coronavirus disease 2019 (COVID-19) in a B cell acute lymphoblastic leukemia patient with using nirmatrelvir/ritonavir extended course: A case report.

Patients with hematological malignancies are at increased risk of persistent coronavirus disease 2019 (COVID-19) infection, a unique clinical condition, for which the optimal treatment is unknown. Here we report a case of persistent COVID-19 in acute lymphoblastic leukemia (ALL) patient who successfully responded to extended course nirmatrelvir/ritonavir.

Distinct FLT3 Pathways Gene Expression Profiles in Pediatric De Novo Acute Lymphoblastic and Myeloid Leukemia with FLT3 Mutations: Implications for Targeted Therapy.

Activating FLT3 mutations plays a crucial role in leukemogenesis, but identifying the optimal candidates for FLT3 inhibitor therapy remains controversial. This study aims to explore the impacts of FLT3 mutations in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) and to compare the mutation profiles between the two types to inspire the targeted application of FLT3 inhibitors. We retrospectively analyzed 243 ALL and 62 AML cases, grouping them into FLT3-mutant and wild-type categories, respectively. We then assessed the associations between FLT3 mutations and the clinical manifestations, genetic characteristics, and prognosis in ALL and AML. Additionally, we compared the distinct features of FLT3 mutations between ALL and AML. In ALL patients, those with FLT3 mutations predominantly exhibited hyperdiploidy (48.6% vs. 14.9%, p < 0.001) and higher FLT3 expression (108.02 [85.11, 142.06] FPKM vs. 23.11 [9.16, 59.14] FPKM, p < 0.001), but lower expression of signaling pathway-related genes such as HRAS, PIK3R3, BAD, MAP2K2, MAPK3, and STAT5A compared to FLT3 wild-type patients. There was no significant difference in prognosis between the two groups. In contrast, AML patients with FLT3 mutations were primarily associated with leucocytosis (82.90 [47.05, 189.76] G/L vs. 20.36 [8.90, 55.39] G/L, p = 0.001), NUP98 rearrangements (30% vs. 4.8%, p = 0.018), elevated FLT3 expression (74.77 [54.31, 109.46] FPKM vs. 34.56 [20.98, 48.28] FPKM, p < 0.001), and upregulated signaling pathway genes including PIK3CB, AKT1, MTOR, BRAF, and MAPK1 relative to FLT3 wild-type, correlating with poor prognosis. Notably, internal tandem duplications were the predominant type of FLT3 mutation in AML (66.7%) with higher inserted base counts, whereas they were almost absent in ALL (6.3%, p < 0.001). In summary, our study demonstrated that the forms and impacts of FLT3 mutations in ALL differed significantly from those in AML. The gene expression profiles of FLT3-related pathways may provide a rationale for using FLT3 inhibitors in AML rather than ALL when FLT3 mutations are present.

Low-Level BCR::ABL1 Transcript at Diagnosis in Childhood Leukemia: A 10-Year Single Institution Study.

INTRODUCTION: Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is a high risk form of ALL associated with dismal outcomes in the pre-tyrosine kinase inhibitor (TKI) era. Addition of a TKI to chemotherapy improves outcomes. Therefore, testing for the presence of the Philadelphia chromosome by at least two methods at the time of diagnosis is critical. Diagnostic testing may include karyotype, fluorescent in situ hybridisation (FISH), and RT-PCR for the BCR::ABL1 transcript. The significance of low-level BCR::ABL1 transcript by RT-PCR in the absence of the Philadelphia chromosome on karyotype or by FISH is unknown. METHODS: This is a retrospective review of children diagnosed with acute leukemia at our institution from 2010 to 2020. Those positive for the BCR::ABL1 transcript by qualitative RT-PCR, and negative for t(9;22) by karyotype or FISH were analyzed for demographics, cytogenetic and molecular features at diagnosis and relapse, treatment and outcomes. The Kaplan-Meier method was used to estimate event-free and overall survival. RESULTS: Forty-seven of 306 (15%) patients with Ph- ALL had low-level BCR::ABL1 detected by RT-PCR. Most (77%) had B-cell ALL. The e1a2 transcript was detected most frequently, in 43 (91%) patients. BCR::ABL1 was quantifiable in 12/43 (28%) patients, with a median of 0.0008% (range 0.0003-0.095%). Seven patients (15%) relapsed. No patient with low-level BCR::ABL1 at diagnosis developed Ph + ALL at relapse. There was no difference in 5-year event-free (77% versus 81%, p = 0.407) or overall survival (86% versus 91%, p = 0.3) between children with low-level BCR::ABL1 (n = 47) and those without (n = 259). CONCLUSION: BCR::ABL1 low-level positivity in children with newly diagnosed Ph- ALL is a relatively common finding and did not adversely affect outcome for patients treated using a contemporary risk-adapted approach.

The combination of a tyrosine kinase inhibitor and blinatumomab in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia or Philadelphia chromosome-like acute lymphoblastic leukemia.

Tyrosine kinase inhibitors (TKIs) have revolutionized Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) treatment. The combination of blinatumomab and a TKI in the frontline setting has shown the safety and efficacy of the chemotherapy-free treatment approach in patients with Ph + ALL. This retrospective analysis included 19 patients with Ph + ALL and Ph-like ALL treated with the combination of blinatumomab and a TKI. Of the 14 newly diagnosed patients, the overall response, complete remission (CR), and molecular response (CMR) rates after one cycle of blinatumomab were 100% (10/10), 90% (9/10), and 57% (8/14), respectively. Of the five relapsed patients, the CR and CMR rates were 50% (2/4) and 40% (2/5). Blinatumomab in combination with TKIs is safe and effective and hence this combination therapy could be a viable therapeutic option in front-line treatment of patients with Ph + ALL.

Evaluation of oral complications in children undergoing chemotherapy: An observational study.

BACKGROUND: Chemotherapy, a cornerstone treatment for childhood cancers, can negatively impact oral health. This study aimed to evaluate the prevalence and evolution of oral complications in these patients. MATERIALS AND METHODS: A prospective observational study enrolled 44 children diagnosed with malignancy undergoing chemotherapy at a tertiary care institute in central India. Oral examinations were performed at baseline, with follow-ups at 3-6 and 9-12 months. Data collected included demographics, medical history, oral hygiene practices, and oral lesions. Blood counts and World Health Organization grading for mucositis were used. Descriptive statistics and appropriate statistical tests analyzed the data (P ≤ 0.05). RESULTS: Acute lymphoblastic leukemia (ALL) was the most prevalent malignancy. Children reported various oral complaints such as ulcers, bleeding gums, and difficulty eating. Mucositis prevalence significantly decreased over follow-up visits (baseline: 56.8% and second follow-up: 13.3%). Gingival inflammation was present, though mean scores decreased over time. Oral hygiene scores varied without significant changes. Caries experience scores increased from baseline to follow-up. CONCLUSION: This study identified a high prevalence of ALL and diverse oral complications in children undergoing chemotherapy. While mucositis severity lessened over time, other issues such as caries persisted. These findings highlight the critical need for preventive oral care strategies to safeguard this vulnerable population's oral health.

Genetic polymorphisms and their association with methotrexate polyglutamates during maintenance treatment in Korean children and young adults with acute lymphoblastic leukemia.

The aim of this study was to investigate the impact of genetic polymorphisms on methotrexate (MTX) metabolism in Korean children and young adults with acute lymphoblastic leukemia, specifically focusing on MTX polyglutamates (MTX-PGs) in erythrocytes, which have been rarely studied. Korean children and young adult patients undergoing maintenance therapy for acute lymphoblastic leukemia, who were receiving weekly oral MTX doses of 20 mg/m²/week, were prospectively included. We investigated erythrocyte MTX-PG (PG1 to PG5) levels, MTX-PG/MTX dose ratios, and 222 genetic polymorphisms spanning 78 genes and three intergenic areas related to MTX transport, folate cycle metabolism, purine/pyrimidine pathways, and non-pathway genes (including TPMT and NUDT15 genotypes) to explore their association with MTX metabolism. MTX-PG levels were associated with MTX dose (p < 0.05), and MTX-PG3 comprised the majority of the total MTX-PGs, with a median of 39.3 %. Various polymorphisms within the same gene demonstrated differing associations with each type of MTX-PG, underscoring the complexity of MTX pharmacogenetics. Among the polymorphisms examined, 14 across 13 genes showed significant associations with MTX-PG2-5 levels, even after adjusting for the false discovery rate (ABCC5, ATG16L1, CEP72, FSTL5, GMPS, HTR3A, IMPDH1, NT5C2, SLC28A3, SLCO1B3, SUCLA2, TPMT, and TYMS). This study enhances our understanding of genetic polymorphisms in MTX metabolism and therapeutic monitoring for MTX maintenance, promoting personalized medicine in acute lymphoblastic leukemia patients.

Prediction of Response to FDA-Approved Targeted Therapy and Immunotherapy in Acute Lymphoblastic Leukemia (ALL).

OPINION STATEMENT: Acute lymphoblastic leukemia (ALL) represents the predominant cancer in pediatric populations, though its occurrence in adults is relatively rare. Pre-treatment risk stratification is crucial for predicting prognosis. Important factors for assessment include patient age, white blood cell (WBC) count at diagnosis, extramedullary involvement, immunophenotype, and cytogenetic aberrations. Minimal residual disease (MRD), primarily assessed by flow cytometry following remission, plays a substantial role in guiding management plans. Over the past decade, significant advancements in ALL outcomes have been witnessed. Conventional chemotherapy has remarkably reduced mortality rates; however, its intensive nature raises safety concerns and has led to the emergence of treatment-resistant cases with recurrence of relapses. Consequently, The U.S. Food and Drug Administration (FDA) has approved several novel treatments for relapsed/refractory ALL due to their demonstrated efficacy, as indicated by improved complete remission and survival rates. These treatments include tyrosine kinase inhibitors (TKIs), the anti-CD19 monoclonal antibody blinatumomab, anti-CD22 inotuzumab ozogamicin, anti-CD20 rituximab, and chimeric antigen receptor (CAR) T-cell therapy. Identifying the variables that influence treatment decisions is a pressing necessity for tailoring therapy based on heterogeneous patient characteristics. Key predictive factors identified in various observational studies and clinical trials include prelymphodepletion disease burden, complex genetic abnormalities, and MRD. Furthermore, the development of serious adverse events following treatment could be anticipated through predictive models, allowing for appropriate prophylactic measures to be considered. The ultimate aim is to incorporate the concept of precision medicine in the field of ALL through valid prediction platform to facilitate the selection of the most suitable treatment approach.

An Optimized Peptide Antagonist of CXCR4 Limits Survival of BCR-ABL1-Transformed Cells in Philadelphia-Chromosome-Positive B-Cell Acute Lymphoblastic Leukemia.

Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is characterized by reciprocal chromosomal translocation between chromosome 9 and 22, leading to the expression of constitutively active oncogenic BCR-ABL1 fusion protein. CXC chemokine receptor 4 (CXCR4) is essential for the survival of BCR-ABL1-transformed mouse pre-B cells, as the deletion of CXCR4 induces death in these cells. To investigate whether CXCR4 inhibition also effectively blocks BCR-ABL1-transformed cell growth in vitro, in this study, we explored an array of peptide-based inhibitors of CXCR4. The inhibitors were optimized derivatives of EPI-X4, an endogenous peptide antagonist of CXCR4. We observed that among all the candidates, EPI-X4 JM#170 (referred to as JM#170) effectively induced cell death in BCR-ABL1-transformed mouse B cells but had little effect on untransformed wild-type B cells. Importantly, AMD3100, a small molecule inhibitor of CXCR4, did not show this effect. Treatment with JM#170 induced transient JNK phosphorylation in BCR-ABL1-transformed cells, which in turn activated the intrinsic apoptotic pathway by inducing cJun, Bim, and Bax gene expressions. Combinatorial treatment of JM#170 with ABL1 kinase inhibitor Imatinib exerted a stronger killing effect on BCR-ABL1-transformed cells even at a lower dose of Imatinib. Surprisingly, JM#170 actively killed Sup-B15 cells, a BCR-ABL1+ human ALL cell line, but had no effect on the BCR-ABL1- 697 cell line. This suggests that the inhibitory effect of JM#170 is specific for BCR-ABL1+ ALL. Taken together, JM#170 emerges as a potent novel drug against Ph+ ALL.

Evaluation of the CCL17/CCL22-CCR4 axis in pediatrics with B-cell acute lymphoblastic leukemia before and after a chemotherapy course.

AIMS: Acute lymphoblastic leukemia (ALL) is the most common type of pediatrics cancer. Chemokines exert different roles in leukemia process through leukocyte recruitment and regulation of disease severity. Due to the prominent roles of chemokine/receptor axes, this study aimed to measure the blood expression levels of CCR4 and their ligands in pediatrics with B-cell ALL (B-ALL). We also evaluated the impact of cytotoxic chemotherapy on this axis. MATERIAL AND METHOD: Thirty children suffering from B-ALL were included in the study and followed up for 30 days after completion of a chemotherapy course. The blood sampling was performed before and after chemotherapy. 30 healthy donors have also entered the study as control subjects. The mRNA expression of CCL17, CCL22 and CCR4 genes was determined by quantitative real-time PCR. The frequency of the peripheral blood mononuclear cells expressing CCR4 (CCR4 + PBMCs) was also evaluated by the flow cytometry method. Moreover, we evaluated the association of the CCL17/CCL22-CCR4 axis with some diagnostic, prognostic and predictive biomarkers in ALL patients. RESULTS: There was overexpression of the CCL17/CCL22-CCR4 axis along with lactate dehydrogenase (LDH) in pediatrics with B-ALL compared to healthy controls. After induction of chemotherapy, the blood expression levels of the CCL17/CCL22-CCR4 axis have reached the levels of healthy controls. The findings for the blood expression levels of CCR4 were also confirmed using flow cytometry. CONCLUSION: The CCL17/CCL22-CCR4 axis can be used as a novel predictive and prognostic biomarker in B-ALL.

Clinical analysis of immune reconstitution after chemotherapy in children with acute lymphoblastic leukemia.

OBJECTIVES: The aim of this retrospective study was to investigate the influence of chemotherapy on the immune status of individual patients diagnosed with acute lymphoblastic leukemia (ALL) and to elucidate the clinical characteristics of immune reconstitution in ALL patients following chemotherapy. METHODS: Clinical data of children with ALL were gathered, including information on the number of lymphocyte subsets prior to chemotherapy, at the end of therapy, six months, and one year after the end of the treatment. RESULTS: A total of 146 children with ALL were included, and T cells, B cells, and NK cells all decreased to various degrees prior to treatment. The abnormal CD3 + T cell numbers group experienced a considerably higher mortality (21.9% vs. 6.1%) and recurrence rate (31.3% vs. 11.4%) compared to the normal group (P < 0.05). T cells, B cells, and NK cells were all significantly compromised at the end of therapy compared to the beginning of chemotherapy, with B cells being more severely compromised (P < 0.001). At the end of treatment, levels of B cells, CD4 + T cells, CD4/CD8, IgG and IgM in low risk (LR) group were significantly higher than those in intermediate risk (IR) group (P < 0.01), and levels of NK cells in LR group were evidently lower than those in IR group (P < 0.001). Six months after the end of therapy, all the above indicators recovered (P < 0.001) except CD4/CD8 ratio (P = 0.451). CONCLUSIONS: The immune systems of the ALL patients were severely compromised upon therapy withdrawal, particularly the B cells. At six months after the therapy ended, the B cells were basically restored to normal level, while the T-cell compartment was not. The impaired numbers of CD3 + T cell may contribute to a weakened anti-tumor response, potentially leading to a poorer prognosis.

Long-Term Remission in T315I+ Relapsed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Blinatumomab and Allogeneic Stem Cell Transplantation: Two Case Studies.

BACKGROUND Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in adults has a poor prognosis with conventional chemotherapy. Treatment with tyrosine kinase inhibitors (TKIs) followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) has improved clinical outcomes; however, the relapse rate is still high. Therapeutic options for patients with relapsed/refractory (R/R) Ph+ ALL are scarce, with very few studies focusing on these patients. Blinatumomab is a novel bispecific T-cell engager antibody construct showing promising efficacy in R/R Ph+ ALL. CASE REPORT Here, we present 2 cases of relapsed Ph+ ALL with T315I mutation refractory to multiple TKIs and chemotherapy. Patient 1 was a 48-year-old woman who had increased leukocytes in her peripheral blood cells, with 90% abnormal cells and decreased platelets. Bone marrow (BM) smear showed 95% blasts. Patient 2 was a 20-year-old man who had leukocytosis with thrombocytopenia, while all other parameters were normal. BM aspirate showed 98% immature granulocytes/blasts. The immunophenotypic observations of both the patients on BM were consistent with the presence of ALL. Both patients were effectively treated with a combination of blinatumomab and allo-HSCT and achieved complete remission in 1 month with minimal residual disease negativity and remained in remission for a long period. CONCLUSIONS The findings suggest, that for patients with R/R Ph+ ALL with T315I mutation who respond poorly to TKIs, salvage therapy with blinatumomab is a potentially effective treatment for improving clinical outcomes. The treatment with blinatumomab can further act as a bridge to HSCT in these patients, helping them to attain deeper remission.

Hepatic veno-occlusive disease with asparaginase products: a review of cases reported to the FDA adverse event reporting system and published in the literature.

Multiple asparaginase products have been approved by the United States (US) Food and Drug Administration (FDA) for the treatment of acute lymphoblastic leukemia in pediatric and adult patients. Hepatic veno-occlusive disease (VOD) is a potentially life-threatening disorder resulting from damage to the liver sinusoidal endothelial cells. To evaluate this safety concern with asparaginase (i.e. Asparlas, Oncaspar, Rylaze, and Erwinaze) use, we performed a postmarketing review of hepatic VOD reports retrieved from the FDA Adverse Event Reporting System database and literature with these four products. We identified 55 cases of hepatic VOD following exposure to asparaginase products. The median time to onset of hepatic VOD from the first dose of asparaginase was 18 days (interquartile range 13-24 days). Notably, 80% (44/55) of cases reported grades 3-5 VOD per the Common Terminology Criteria for Adverse Events. Although patients received asparaginase with standard chemotherapeutic agents known to induce VOD, case-level data indicates that asparaginase products may have contributed to hepatic VOD. Asparaginase products are associated with hepatotoxicity and thrombosis, suggesting a plausible mechanism for asparaginase-induced hepatic VOD. Based on the totality of data, including temporality and biologic plausibility, we determined hepatic VOD to be a class effect with asparaginase products. These data contributed to the addition of hepatic VOD to the hepatoxicity warning in the US Prescribing Information for asparaginase class products.

An MDM2 degrader shows potent cytotoxicity to MDM2-overexpressing acute lymphoblastic leukemia cells with minimal toxicity to normal cells/tissues.

The MDM2 oncogene is amplified and/or overexpressed in various human cancers and elevated expression of MDM2 protein acts as a survival factor promoting cancer progression through both p53-dependent and -independent pathways. Here, we report a novel small-molecule chemical compound (MX69-102) that we identified to induce MDM2 protein degradation, resulting in reactivation of p53, inhibition of XIAP, and potent cell growth inhibition and apoptosis in MDM2-overexpressing acute lymphoblastic leukemia (ALL) in vitro and in vivo. We have previously identified a compound (MX69) that binds to the MDM2 C-terminal RING domain and induces MDM2 protein degradation. In the present study, we performed structural modifications of MX69 and selected analog MX69-102, showing increased MDM2-targeting activity. MX69-102 exhibited significantly enhanced inhibitory and apoptotic effects on a group of MDM2-overexpressing ALL cell lines in vitro with IC50 values of about 0.2 µM, representing an approximately 38-fold increase in activity compared to MX69. MX69-102 also showed effective inhibition on xenografted human MDM2-overexpressing ALL in SCID mice. Importantly, MX69-102 had minimal or no inhibitory effect on normal human hematopoiesis in vitro and was very well tolerated in vivo in animal models. Based on the strong inhibitory and apoptotic activity against MDM2-overexpressing ALL, along with minimal or no toxicity to normal cells/tissues, MX69-102 is a candidate for further development as a novel MDM2-targeted therapeutic drug for refractory/MDM2-overexpressing ALL.

Fluoroquinolone Prophylaxis in Children With Cancer: A Pro/Con Discussion.

There are conflicting recommendations on whether to use or not to use fluoroquinolone prophylaxis in pediatric oncology patients. An international pediatric clinical practice guideline (CPG) recommends administering levofloxacin prophylaxis in patients with acute myeloblastic leukemia and relapsed acute lymphoblastic leukemia receiving intensive chemotherapy as this practice has been found to reduce episodes of fever and bacteremia. A separate European CPG does not recommend levofloxacin prophylaxis because of concerns for adverse effects, including potentiation of fluoroquinolone resistance and possible increased resistance to other classes of antibiotics. The nuance of the decision to give or not give prophylaxis is discussed in the context of published evidence defining the risks and benefits of levofloxacin prophylaxis for pediatric leukemia patients at high risk for bacterial infection. Knowledge gaps are also identified to guide further investigations to optimize the use of fluoroquinolone prophylaxis in pediatric patients receiving chemotherapy for cancer or undergoing a hematopoietic cell transplantation.

Systematic review: genetic polymorphisms in the pharmacokinetics of high-dose methotrexate in pediatric acute lymphoblastic leukemia patients.

Variations in pharmacokinetic responses to high-dose methotrexate are essential for the prognosis and management of toxicity in the treatment of pediatric acute lymphoblastic leukemia (ALL) patients. This systematic review aimed to identify and evaluate genetic polymorphisms that are significantly associated with the pharmacokinetic parameters of methotrexate during the consolidation phase of pediatric ALL treatment. Using the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, we systematically reviewed the literature from 2013 to 2023. The databases used were PubMed and Scopus. The outcomes of interest are the study design, patient characteristics, sample size, chemotherapy protocol utilized, pharmacokinetic parameters identified, and genetic polymorphisms implicated. We included 31 articles in the qualitative synthesis and found that the SLCO1B1, ABCB1, ABCC2, and MTHFR genes appear to play significant roles in MTX metabolism and clearance. Among these, variations in SLCO1B1 have the most significant and consistent impact on methotrexate clearance. These implicated variants may contribute to the precision and tailoring of HD-MTX treatment in pediatric ALL patients.