Menin Inhibition With Revumenib for KMT2A-Rearranged Relapsed or Refractory Acute Leukemia (AUGMENT-101).

PURPOSE: Revumenib, an oral, small molecule inhibitor of the menin-lysine methyltransferase 2A (KMT2A) interaction, showed promising efficacy and safety in a phase I study of heavily pretreated patients with KMT2A-rearranged (KMT2Ar) acute leukemia. Here, we evaluated the activity of revumenib in individuals with relapsed/refractory (R/R) KMT2Ar acute leukemia. METHODS: AUGMENT-101 is a phase I/II, open-label, dose-escalation and expansion study of revumenib conducted across 22 clinical sites in five countries (ClinicalTrials.gov identifier: NCT04065399). We report results from the phase II, registration-enabling portion. Individuals age ≥30 days with R/R KMT2Ar acute leukemia or with AML and nucleophosmin 1 (NPM1) mutation were enrolled. Revumenib was administered once every 12 hours, at 163 mg (95 mg/m2 if weight <40 kg) with a strong cytochrome P450 inhibitor, in 28-day cycles. The primary end points were the rate of complete remission (CR) or CR with partial hematologic recovery (CR + CRh) and safety. At a prespecified interim analysis, safety was assessed in all KMT2Ar treated patients; efficacy was assessed in those with centrally confirmed KMT2Ar. The separate NPM1 cohort of the trial is ongoing. RESULTS: From October 1, 2021, to July 24, 2023, N = 94 patients (median [range] age, 37 [1.3-75] years) were treated. Grade ≥3 adverse events included febrile neutropenia (37.2%), differentiation syndrome (16.0%), and QTc prolongation (13.8%). In the efficacy-evaluable patients (n = 57), the CR + CRh rate was 22.8% (95% CI, 12.7 to 35.8), exceeding the null hypothesis of 10% (P = .0036). Overall response rate was 63.2% (95% CI, 49.3 to 75.6), with 15 of 22 patients (68.2%) having no detectable residual disease. CONCLUSION: Revumenib led to high remission rates with a predictable safety profile in R/R KMT2Ar acute leukemia. To our knowledge, this trial represents the largest evaluation of a targeted therapy for these patients.

Antimetabolite Dose Intensity and Adverse Outcomes in Children with Acute Lymphoblastic Leukemia: A COG-AALL03N1 Report.

The association between antimetabolite dose intensity (DI) and adverse events among children receiving maintenance therapy for acute lymphoblastic leukemia (ALL) remains unclear, especially in context of antimetabolite adherence. Using COG-AALL03N1 data, we examined the association between high DI during the first four study months and (i) treatment-related toxicities during the subsequent two study months; and (ii) relapse risk. Patients were classified into a high DI phenotype (either 6-mercaptopurine [6-MP] or methotrexate [MTX] DI ≥110% during the first four study months, or 6-MPDI or MTXDI 100%-110% at study enrollment and ≥25% increase over the four study months) and normal DI phenotype (all others). Only patients with wildtype TPMT and NUDT15 were included. 6-MP adherence data were available for 63.7% of study participants and used to stratify as adherent (median adherence ≥85%) and non-adherent (median adherence <85%) participants. Multivariable analyses were adjusted for sociodemographic and clinical prognosticators. Of the 644 patients, 29.3% were exposed to high DI. High DI was associated with a 2.1-fold greater odds of hematologic toxicity (95%CI=1.4-3.1; reference: normal DI) in the entire cohort and 2.9-fold higher among adherers (95%CI=1.6-5.1); odds were comparable among non-adherers (2.1-fold, 95%CI=0.4-10.1).. While high DI was not associated with relapse in the entire cohort (adjusted hazard ratio [aHR]=1.4, 95%CI=0.8-2.4), it was associated with a greater hazard of relapse among adherent participants (aHR=2.4, 95%CI=1.0-5.5) but not among non-adherent participants (aHR=0.9, 95%CI=0.2-3.8). Dose escalation above protocol doses during maintenance therapy for ALL should be done cautiously after assessing adherence to prescribed therapy.

COVID-19 Disease in Children With ALL Receiving Maintenance Therapy: Do Not Discount the Risk.

PURPOSE: Unlike most childhood cancers, therapy for ALL includes a prolonged maintenance phase during which children typically resume regular activities. Physicians need data regarding the persistent impact of COVID-19 in this population to help guide families after the pandemic. METHODS: The Pediatric Oncology COVID-19 Case Report (POCC) collects deidentified data (sociodemographics, clinical data [cancer, COVID-19 course]) on children, adolescents, and young adults with cancer and COVID-19 from 104 US pediatric oncology institutions. The analysis presented here compares children (≤21 years) with ALL in maintenance (ALL-MTN) with all other children with cancer and COVID-19. Multivariable analyses adjust for age, race/ethnicity, insurance, absolute neutrophil count at the time of infection, vaccination, and comorbidities. RESULTS: Compared with other children reported to POCC (n = 1,190), those in ALL-MTN (n = 481) were less often hospitalized (23% v 29%, P = .01) or admitted to the intensive care unit (ICU: 3% v 5%, P = .01); these findings persisted in multivariable analysis (hospitalization: odds ratio [OR], 0.7 [95% CI, 0.6 to 0.9]; ICU: OR, 0.5 [95% CI, 0.2 to 0.8]). However, cancer-directed therapy was changed more often for children in ALL-MTN (50% v 33%, P ≤ .01; OR, 2.0 [95% CI, 1.6 to 2.5[). Vaccination was an independent prognostic factor in our multivariable model, decreasing odds of hospitalization (OR, 0.7 [95% CI, 0.5 to 0.9]). CONCLUSION: Children in ALL-MTN required fewer hospitalizations and ICU admissions but more therapy modifications than other children with cancer. Vaccination against COVID-19 reduced the odds of hospitalization.

Development and Validation of a Ready-to-Talk Measure for Use in Adolescents and Young Adults Living With Advanced Cancer.

BACKGROUND: In the era of evolving and emerging therapies, adolescents and young adults (AYAs) living with advanced cancer experience a high degree of uncertainty, making palliative care and end-of-life (PCEOL) discussions difficult. Clinical conversations determine values/preferences that guide shared decision-making and goals of treatment, including end-of-life care when cancer progresses. Initiating PCEOL conversations is challenging for clinicians. OBJECTIVE: This study describes the development and validation of an instrument that measures AYA readiness to engage in PCEOL clinical conversations. METHODS: A Ready-to-Talk Measure (R-T-M) was developed, guided by the revised conceptual model of readiness across 3 domains (awareness, acceptance, and willingness). Content experts evaluated validity, and 13 AYAs with advanced cancer participated in cognitive interviews. Acceptability (item applicability, clarity, interpretation, sensitivity, missingness) and experiences (benefit, burden) were analyzed. RESULTS: The scale content validity index was ≥0.90 for each domain. Forty-two of the 55 R-T-M items were acceptable without any change. Three items were deleted. Ten items were modified, and 3 were added. Adolescents and young adults wanted more items about friends/siblings and about AYA unique qualities for clinicians to know them better. Adolescents and young adults acknowledged benefit through talking about difficult, relevant topics. CONCLUSION: Ready-to-Talk Measure validity was strengthened by deleting or modifying unclear or misinterpreted items and by adding items. Next steps include psychometric analysis to determine reliability/dimensionality and stakeholder input to make the R-T-M a clinically useful tool. IMPLICATIONS FOR PRACTICE: Ready-to-Talk Measure assessment of readiness to engage in PCEOL conversations while identifying unique preferences of AYAs holds promise for facilitating ongoing discussions.

COVID-19 infection in children, adolescents, and young adults with Down syndrome and hematologic malignancies.

INTRODUCTION: Children, adolescents, and young adults (CAYAs) with Down syndrome (DS) and hematologic malignancies are particularly vulnerable to infections and related complications. There are limited data regarding COVID-19 infections in this group. We aimed to understand the clinical course of COVID-19 in this population. METHODS: This observational study leverages the de-identified clinical and sociodemographic data captured by the Pediatric Oncology COVID-19 Case Report Registry (POCC) regarding CAYAs with cancer and COVID-19. We evaluated CAYAs (≤21 years at COVID-19 infection) with hematologic malignancies and COVID-19 reported from April 1, 2020 to May 2, 2023, comparing those with and without DS. Using multivariable logistic regression, we examined rates of hospitalization, intensive care unit (ICU) admission, respiratory support, and changes in cancer-directed therapy. RESULTS: Among 1408 CAYAs with hematologic malignancies, 55 had DS (CAYA-DS). CAYA-DS had higher rates of hospitalization, ICU admission, and respiratory support (p < .001) than CAYAs without DS. Similarly, multivariable analyses found higher odds of hospitalization (odds ratio [OR] = 2.8, 95% confidence interval [CI]: 1.5-5.1), ICU admission (OR = 4.2, 95% CI: 1.9-9.1), and need for respiratory support (OR = 4.2, 95% CI: 2.0-8.8) among CAYA-DS. Modifications to cancer-directed therapy were more common among CAYA-DS when related to neutropenia (p = .001), but not when unrelated to neutropenia (p = .88); CAYA-DS did not have higher odds of changes to cancer-directed therapy (OR = 1.20, 95% CI: 0.7-2.1). CONCLUSIONS: We identify CAYA-DS with hematologic malignancies as a vulnerable subpopulation at greater risk for severe COVID-19 infection. This can inform conversations with patients and families regarding therapeutic and preventive measures, as well as the risks and benefits of modifying chemotherapy in the setting of COVID-19.

Adolescents and young adults with cancer: the clinical course of COVID-19 infections.

Adolescents and young adults (ie, individuals aged 15-39 years, known as AYAs) with cancer face unique vulnerabilities yet remain underrepresented in clinical trials, including adult registries of COVID-19 in cancer (AYAs: 8%-12%). We used the Pediatric Oncology COVID-19 Case Report to examine the clinical course of COVID-19 among AYAs with cancer. The Pediatric Oncology COVID-19 Case Report collects deidentified clinical and sociodemographic data regarding individuals aged from birth to 39 years with cancer (37%) and COVID-19 from more than 100 institutions. Between April 1, 2020, and November 28, 2023, 191 older AYAs (individuals 22-39 years of age) and 640 younger AYAs (individuals 15-21 years of age) were captured. Older AYAs were less often hospitalized (P < .001), admitted to the intensive care unit (P = .02), and required respiratory support (P = .057). In multivariable analyses, older AYAs faced 80% lower odds of intensive care unit admission but 2.3-times greater odds of changes to cancer-directed therapy. Unvaccinated patients had 5.4-times higher odds of intensive care unit admission. Among AYAs with cancer, the COVID-19 course varies by age. These findings can inform oncology teams directing COVID-19 management and prevention in AYA patients with cancer.

Role of Transporters and Enzymes in Metabolism and Distribution of 4-Chlorokynurenine (AV-101).

4-Chlorokynurenine (4-Cl-KYN, AV-101) is a prodrug of a NMDA receptor antagonist and is in clinical development for potential CNS indications. We sought to further understand the distribution and metabolism of 4-Cl-KYN, as this information might provide a strategy to enhance the clinical development of this drug. We used excretion studies in rats, in vitro transporter assays, and pharmacogenetic analysis of clinical trial data to determine how 4-Cl-KYN and metabolites are distributed. Our data indicated that a novel acetylated metabolite (N-acetyl-4-Cl-KYN) did not affect the uptake of 4-Cl-KYN across the blood-brain barrier via LAT1. 4-Cl-KYN and its metabolites were found to be renally excreted in rodents. In addition, we found that N-acetyl-4-Cl-KYN inhibited renal and hepatic transporters involved in excretion. Thus, this metabolite has the potential to limit the excretion of a range of compounds. Our pharmacogenetic analysis found that a SNP in N-acetyltransferase 8 (NAT8, rs13538) was linked to levels of N-acetyl-4-Cl-KYN relative to 4-Cl-KYN found in the plasma and that a SNP in SLC7A5 (rs28582913) was associated with the plasma levels of the active metabolite, 7-Cl-KYNA. Thus, we have a pharmacogenetics-based association for plasma drug level that could aid in the drug development of 4-Cl-KYN and have investigated the interaction of a novel metabolite with drug transporters.

Characteristics of Health Care Settings Where Adolescents and Young Adults Receive Care for ALL.

PURPOSE: Individuals diagnosed with cancer between 15 and 39 years (adolescent and young adult [AYA]) face unique vulnerability. Detail is lacking about care delivery for these patients, especially those with ALL. We address these knowledge gaps by describing AYA ALL care delivery details at National Cancer Institute Community Oncology Research Program (NCORP) (sub)affiliates by model of care. METHODS: Participating institutions treated at least one AYA with ALL from 2012 to 2016. Study-specific criteria were used to determine the number of unique clinical facilities (CFs) per NCORP and their model of care (adult/internal medicine [IM], pediatric, mixed [both]). Surveys completed by NCORPs for each CF by model of care captured size, resources, services, and communication. RESULTS: Among 84 participating CFs (adult/IM, n=47; pediatric, n=15; mixed, n=24), 34% treated 5-10 AYAs with ALL annually; adult/IM CFs more often treated <5 (adult/IM, 60%; pediatric, 40%; mixed, 29%). Referral decisions were commonly driven by an age/diagnosis combination (58%), with frequent ALL-specific age minimums (87%) or maximums (80%). Medical, navigational, and social work services were similar across models while psychology was available at more pediatric CFs (pediatric, 80%; adult/IM, 40%; mixed, 46%-54%). More pediatric or mixed CFs reported oncologists interacting with pediatric/adult counterparts via tumor boards (pediatric, 93%; adult/IM, 26%; mixed, 96%) or initiating contact (pediatric, 100%; adult/IM, 77%; mixed 96%); more pediatric CFs reported an affiliated counterpart (pediatric, 53%; adult, 19%). Most CFs reported no AYA-specific resources (79%) or meetings (83%-98%). CONCLUSION: System-level aspects of AYA ALL care delivery have not been examined previously. At NCORPs, these characteristics differ by models of care. Additional work is ongoing to investigate the impact of these facility-level factors on guideline-concordant care in this population. Together, these findings can inform a system-level intervention for diverse practice settings.

Intronic Germline DICER1 Variants in Patients With Sertoli-Leydig Cell Tumor.

Germline pathogenic loss-of-function (pLOF) variants in DICER1 are associated with a predisposition for a variety of solid neoplasms, including pleuropulmonary blastoma and Sertoli-Leydig cell tumor (SLCT). The most common DICER1 pLOF variants include small insertions or deletions leading to frameshifts, and base substitutions leading to nonsense codons or altered splice sites. Larger deletions and pathogenic missense variants occur less frequently. Identifying these variants can trigger surveillance algorithms with potential for early detection of DICER1-related cancers and cascade testing of family members. However, some patients with DICER1-associated tumors have no pLOF variants detected by germline or tumor testing. Here, we present two patients with SLCT whose tumor sequencing showed only a somatic missense DICER1 RNase IIIb variant. Conventional exon-directed germline sequencing revealed no pLOF variants. Using a custom capture panel, we discovered novel intronic variants, ENST00000343455.7: c.1752+213A>G and c.1509+16A>G, that appear to interfere with normal splicing. We suggest that when no DICER1 pLOF variants or large deletions are discovered in exonic regions despite strong clinical suspicion, intron sequencing and splicing analysis should be performed.

Clinical Features and Risk Factors Associated With Multisystem Inflammatory Syndrome in Children With Cancer and COVID-19.

Importance: Little is known about the risk of post-COVID-19 multisystem inflammatory syndrome in children (MIS-C) in the setting of childhood cancer. Objective: To evaluate factors associated with MIS-C and describe the clinical course of COVID-19 in the setting of MIS-C. Design, Setting, and Participants: Multisite observational cohort study of a registry representing more than 100 US pediatric oncology sites. All included patients were registered between April 1, 2020, and May 18, 2022. Sites submitted deidentified data surrounding sociodemographics, cancer diagnosis and treatment, and COVID-19 course (symptoms, maximum support required, outcome). Patients with MIS-C (n = 24) were compared with matched controls (n = 96). Children (<21 years) with cancer who developed COVID-19 while receiving cancer treatment or within 1 year of completing treatment were characterized based on their development of MIS-C. Exposures: (1) Clinical and sociodemographic characteristics of children with cancer and COVID-19; and (2) MIS-C. Main Outcomes and Measures: (1) Development of MIS-C among children with cancer and COVID-19; and (2) symptoms and disease severity associated with MIS-C. Results: Among 2035 children with cancer and COVID-19, 24 (1.2%) developed MIS-C. COVID-19 occurred at a median (IQR) age of 12.5 (5.5-17.1) years in those with MIS-C and 11 (6-16) years among matched controls (P = .86). The majority of children with MIS-C had a hematologic cancer (83.3% [n = 20]), were publicly insured (66.7% [n = 16]), and were Hispanic (54.2% [n = 13]). Half (n = 12) had 1 or more noncancer comorbidity. Those with comorbidities were more likely to develop MIS-C than those without (odds ratio [OR], 2.5 [95% CI, 1.1-5.7]). Among children with MIS-C, 100% (n = 24) were admitted to the hospital and 54.2% (n = 13) to the intensive care unit (ICU), while COVID-19 contributed to the death of 20.1% (n = 5); cancer therapy was changed in 62.5% (n = 15). Compared with matched controls, those with MIS-C had higher odds of symptoms classified as systemic (OR, 4.7 [95% CI, 1.4-15.8]) or gastrointestinal (OR, 5.0 [95% CI, 1.7-14.6]) along with higher odds of hospitalization (OR, 42.9 [95% CI, 7.1-258]), ICU admission (OR, 11.4 [95% CI, 3.6-36.4]), and changes to cancer therapy (OR, 24.9 [95% CI, 6.5-94.8]). Conclusions and Relevance: In this cohort study among children with cancer and COVID-19, those with MIS-C had a more severe clinical course than those without MIS-C. The risk of MIS-C and its severity are important to consider as clinicians monitor patients with COVID-19. These findings can inform their conversations with families regarding COVID-19 risks and the benefits of prevention strategies that are pharmacologic (vaccination) and nonpharmacologic (masking), as well as treatment (antivirals, monoclonal antibodies).

Poverty and relapse risk in children with acute lymphoblastic leukemia: a Children's Oncology Group study AALL03N1 report.

The association between individual-level poverty and relapse in children receiving maintenance treatment for acute lymphoblastic leukemia (ALL) remains unclear. In a secondary analysis of COG-AALL03N1, we used data from US Census Bureau to categorize patients living below year-specific federal poverty thresholds, calculated using self-reported annual household income and size of household. Participants with federal poverty thresholds above 120% of their yearly household income were categorized as living in extreme poverty. Hazard of relapse was estimated using multivariable proportional subdistributional hazards regression for patients living in extreme poverty while receiving ALL maintenance therapy after adjusting for relevant predictors. Among 592 patients in this analysis, 12.3% of the patients were living in extreme poverty. After a median follow-up of 7.9 years, the cumulative incidence of relapse at 3 years from study enrollment among those living in extreme poverty was significantly higher (14.3%) than those not living in extreme poverty (7.6%). Multivariable analysis demonstrated that children living in extreme poverty had a 1.95-fold greater hazard of relapse than those not living in extreme poverty; this association was mitigated after the inclusion of race/ethnicity in the model, likely because of collinearity between race/ethnicity and poverty. A greater proportion of children living in extreme poverty were nonadherent to mercaptopurine (57.1% vs 40.9%); however, poor adherence did not completely explain the association between poverty and relapse risk. Future studies need to understand the mechanisms underlying the association between extreme poverty and relapse risk. This trial was registered at www.clinicaltrials.gov as #NCT00268528.

The menin inhibitor revumenib in KMT2A-rearranged or NPM1-mutant leukaemia.

Targeting critical epigenetic regulators reverses aberrant transcription in cancer, thereby restoring normal tissue function1-3. The interaction of menin with lysine methyltransferase 2A (KMT2A), an epigenetic regulator, is a dependence in acute leukaemia caused by either rearrangement of KMT2A or mutation of the nucleophosmin 1 gene (NPM1)4-6. KMT2A rearrangements occur in up to 10% of acute leukaemias and have an adverse prognosis, whereas NPM1 mutations occur in up to 30%, forming the most common genetic alteration in acute myeloid leukaemia7,8. Here, we describe the results of the first-in-human phase 1 clinical trial investigating revumenib (SNDX-5613), a potent and selective oral inhibitor of the menin-KMT2A interaction, in patients with relapsed or refractory acute leukaemia (ClinicalTrials.gov, NCT04065399). We show that therapy with revumenib was associated with a low frequency of grade 3 or higher treatment-related adverse events and a 30% rate of complete remission or complete remission with partial haematologic recovery (CR/CRh) in the efficacy analysis population. Asymptomatic prolongation of the QT interval on electrocardiography was identified as the only dose-limiting toxicity. Remissions occurred in leukaemias refractory to multiple previous lines of therapy. We demonstrate clearance of residual disease using sensitive clinical assays and identify hallmarks of differentiation into normal haematopoietic cells, including differentiation syndrome. These data establish menin inhibition as a therapeutic strategy for susceptible acute leukaemia subtypes.

Evaluation of the Association Between Congenital Cytomegalovirus Infection and Pediatric Acute Lymphoblastic Leukemia.

Importance: Acute lymphoblastic leukemia (ALL) is the most common form of pediatric cancer, and a leading cause of death in children. Understanding the causes of pediatric ALL is necessary to enable early detection and prevention; congenital cytomegalovirus (cCMV) has recently been identified as a potential moderate-to-strong factor associated with risk for ALL. Objective: To compare the prevalence of cCMV infection between ALL cases and matched controls. Design, Setting, and Participants: In this population-based case-control study of ALL cases and matched controls, cases consisted of children aged 0 to 14 years between 1987 and 2014 with an ALL diagnosis identified through the Michigan Cancer Surveillance Program and born in Michigan on or after October 1, 1987. Cancer-free controls were identified by the Michigan BioTrust for Health and matched on age, sex, and mother's race and ethnicity. Data were analyzed from November to May 2022. Exposures: cCMV infection measured by quantitative polymerase chain reaction in newborn dried blood spots. Main Outcomes and Measures: ALL diagnosed in children aged 0 to 14 years. Results: A total of 1189 ALL cases and 4756 matched controls were included in the study. Bloodspots were collected from participants at birth, and 3425 (57.6%) participants were male. cCMV was detected in 6 ALL cases (0.5%) and 21 controls (0.4%). There was no difference in the odds of cCMV infection comparing ALL cases with controls (odds ratio, 1.30; 95% CI, 0.52-3.24). Immunophenotype was available for 536 cases (45.1%) and cytogenetic data for 127 (27%). When stratified by subtype characteristics, hyperdiploid ALL (74 cases) was associated with 6.26 times greater odds of cCMV infection compared with unmatched controls (95% CI, 1.44-27.19). Conclusions and Relevance: In this case-control study of cCMV and pediatric ALL, cCMV was associated with increased risk of hyperdiploid ALL. These findings encourage continued research.

Body mass index during maintenance therapy and relapse risk in children with acute lymphoblastic leukemia: A Children's Oncology Group report.

BACKGROUND: Obesity at diagnosis of childhood acute lymphoblastic leukemia (ALL) is associated with greater risk of relapse; whether this association extends to obesity during maintenance is unstudied. METHODS: This study used data from AALL03N1 to calculate median body mass index (BMI) for 676 children over 6 consecutive months during maintenance therapy; BMI percentile (BMI%ile) were operationalized as normal/underweight (<85%ile), overweight/obese (85%-98%ile), and extreme obesity (≥99%ile). Hazard of relapse was estimated using multivariable proportional subdistributional hazards regression after adjusting for all relevant demographic and clinical predictors. RESULTS: Median age at study enrollment was 6 years and median length of follow-up was 7.9 years. Overall, 43.3% of the cohort was underweight/normal weight, 44.8% was overweight/obese, and 11.8% had extreme obesity. Cumulative incidence of relapse at 4 years from study enrollment was higher among those with extreme obesity (13.6% ± 4.5%) compared to those with underweight/normal weight (9.0% ± 2.1%). Multivariable analysis revealed that children with extreme obesity had a 2.4-fold (95% confidence interval [CI], 1.1-5.0; p = .01) greater hazard of relapse compared to those who were underweight/normal weight. Overweight/obese patients were at comparable risk to those who were underweight/normal weight (hazard ratio, 0.8; 95% CI, 0.4-1.6). Erythrocyte thioguanine nucleotide (TGN) levels were significantly lower among children with extreme obesity compared to those with underweight/normal weight (141.6 vs. 168.8 pmol/8 × 108 erythrocytes; p = .0002), however, the difference in TGN levels did not explain the greater hazard of relapse among those with extreme obesity. CONCLUSIONS: Extreme obesity during maintenance therapy is associated with greater hazard of relapse in children with ALL. Underlying mechanisms of this association needs further investigation. LAY SUMMARY: Findings from this study demonstrate that extreme obesity during maintenance therapy is associated with a greater hazard of relapse among children with acute lymphoblastic leukemia. We show that children with obesity have lower levels of erythrocyte thioguanine nucleotides even after adjusting for adherence to oral chemotherapy. However, these lower levels do not explain the greater hazard of relapse, paving the way for future studies to explore this association.

Initial clinical applications treating pediatric and adolescent patients using MR-guided radiotherapy.

Purpose: To demonstrate the clinical applications and feasibility of online adaptive magnetic resonance image guided radiotherapy (MRgRT) in the pediatric, adolescent and young adult (AYA) population. Methods: This is a retrospective case series of patients enrolled onto a prospective study. All pediatric (age < 18) and AYA patients (age< 30), treated on the Elekta Unity MR linear accelerator (MRL) from 2019 to 2021 were enrolled onto a prospective registry. Rationale for MRgRT included improved visualization of and alignment to the primary tumor, re-irradiation in a critical area, ability to use smaller margins, and need for daily adaptive replanning to minimize dose to adjacent critical structures. Step-and-shoot intensity-modulated radiation treatment (IMRT) plans were generated for all Unity patients with a dose grid of 3 mm and a statistical uncertainty of < 1% per plan. Results: A total of 15 pediatric and AYA patients have been treated with median age of 13 years (range: 6 mos - 27 yrs). Seven patients were <10 yo. The clinical applications of MRgRT included Wilms tumor with unresectable IVC thrombus (n=1), Ewing sarcoma (primary and metastatic, n=3), recurrent diffuse intrinsic pontine glioma (DIPG, n=2), nasopharyngeal carcinoma (n=1), clival chordoma (n=1), primitive neuroectodermal tumor of the pancreas (n=1), recurrent gluteo-sacral germ cell tumor (n=1), C-spine ependymoma (n=1), and posterior fossa ependymoma (n=1). Two children required general anesthesia. One AYA patient could not complete the MRgRT course due to tumor-related pain exacerbated by longer treatment times. Two AYA patients experienced anxiety related to treatment on the MRL, one of which required daily Ativan. No patient experienced treatment interruptions or unexpected toxicity. Conclusion: MRgRT was well-tolerated by pediatric and AYA patients. There was no increased use of anesthesia outside of our usual practice. Dosimetric advantages were seen for patients with tumors in critical locations such as adjacent to or involving optic structures, stomach, kidney, bowel, and heart.

AV-101, a Pro-Drug Antagonist at the NMDA Receptor Glycine Site, Reduces L-Dopa Induced Dyskinesias in MPTP Monkeys.

N-methyl-D-aspartate (NMDA) receptors have been implicated in L-Dopa-induced dyskinesias (LID) in Parkinson's disease patients, but the use of antagonists that directly inhibit this receptor is associated with severe side effects. L-4-chlorokynurenine (4-Cl-KYN or AV-101) is a pro-drug of 7-chlorokynurenic acid (7-Cl-KYNA), a potent and specific antagonist of the glycine (GlyB) co-agonist site of NMDA receptors. The 7-Cl-KYNA has limited ability to cross the blood-brain barrier, whereas AV-101 readily accesses the brain. We investigated if AV-101 reduces LID in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys while maintaining the antiparkinsonian activity of L-Dopa. A first pilot study using three dyskinetic MPTP monkeys showed that acute AV-101 treatment (250 and 450 mg/kg) reduced LID and maintained the antiparkinsonian activity of L-Dopa. The main study using six additional dyskinetic MPTP monkeys showed that repeated AV-101 treatment (250 mg/kg, b.i.d. for 4 consecutive days) maintained their L-Dopa antiparkinsonian response. We measured significantly less LID when AV-101 was combined with L-Dopa treatment. AV-101 alone or with L-Dopa had no non-motor adverse effects in MPTP monkeys. Our study showed antidyskinetic activity of AV-101 in MPTP monkeys was comparable to amantadine tested previously in our laboratory in this model. We observed no adverse effects with AV-101, which is an improvement over amantadine, with its known side effects.

Evaluation for Bleeding Disorders in Suspected Child Abuse.

Bruising or bleeding in a child can raise the concern for child abuse. Assessing whether the findings are the result of trauma and/or whether the child has a bleeding disorder is critical. Many bleeding disorders are rare, and not every child with bruising/bleeding that may raise a concern for abuse requires an evaluation for bleeding disorders. However, in some instances, bleeding disorders can present in a manner similar to child abuse. Bleeding disorders cannot be ruled out solely on the basis of patient and family history, no matter how extensive. The history and clinical evaluation can be used to determine the necessity of an evaluation for a possible bleeding disorder, and prevalence and known clinical presentations of individual bleeding disorders can be used to guide the extent of laboratory testing. This clinical report provides guidance to pediatricians and other clinicians regarding the evaluation for bleeding disorders when child abuse is suspected.

LAT1, a novel pharmacological target for the treatment of glioblastoma.

The L-Type Amino Acid transporter, LAT1 (SLC7A5), has a crucial role in mediating amino acid uptake into the cells, thus modulating cell growth and proliferation as well as other intracellular functions. Different studies have reported a central role of LAT1 in glioblastoma development and progression, suggesting that the modulation of its activity could be a novel therapeutic strategy. LAT1 also has an important role in the peripheral immune system, by regulating the activation status of several immune cells through modulation of the mechanistic target of rapamycin kinase. In glioblastoma (GBM), the blood-brain barrier is disrupted, which allows the recruitment of peripheral immune cells to the tumour site. These cells, together with resident microglia, contribute to cancer growth and progression. Currently, little is known about the function of LAT1 in the reprogramming of the immune component of the tumour microenvironment in the context of GBM. In this article, we review the available data on the role of LAT1 in the regulation of GBM biology, including its potential role in the tumour microenvironment, particularly in infiltrating-peripheral immune cells and resident microglial cells. In addition, we review the available data on the main pharmacological inhibitors of LAT1, aiming to evaluate their possible role as novel therapeutics for GBM.

Choice architecture for young adult blood donor recruitment - a feasibility study.

Blood shortages remain an ongoing challenge, ameliorable by increasing blood donations. Choice architecture is an emerging concept in psychology dealing with the targeted presentation of options to encourage a desired decision. A pilot study was designed to test the feasibility of implementing six choice architecture strategies on a Midwest high-school blood drive. These include framing, conformity, mere measurement, availability heuristic, loss aversion and status quo bias. A pre-post interrupted time-series evaluation was performed to evaluate for an immediate impact on blood donations. All six of the intended choice architecture strategies were successfully implemented. The pre-intervention 5-year average number of blood donations per blood drive was 15 (4.3% of age eligible donors) whereas post intervention, the number of blood donors rose to 25 (7.1% of age eligible donors; p-value = .0013). The application of choice architecture to blood donor recruitment strategies is feasible and has the potential to reduce the burden of blood shortages.