Clinical impact of minimal residual disease in blood and bone marrow of children with acute myeloid leukemia.

The prognostic significance of bone marrow minimal residual disease (MRD) in pediatric patients with acute myeloid leukemia (AML) is well characterized, but the impact of blood MRD is not known. We, therefore, used flow cytometric assessment of leukemia-specific immunophenotypes to measure levels of MRD in both the blood and bone marrow of patients treated in the AML08 (NCT00703820) clinical trial. Blood samples were obtained on days 8 and 22 of therapy, whereas bone marrow samples were obtained on day 22.

High frequency of heat shock protein 27 overexpression is a highly effective, high-coverage marker for minimal residual disease detection in children with B-cell acute lymphoblastic leukemia.

Background: Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. Minimal residual disease (MRD) detection is the most powerful prognostic tool for monitoring treatment efficacy and predicting clinical outcomes. We aimed to identify key leukemia-associated markers, the proportions of differential expression in patients, and the most effective marker combination for MRD detection by flow cytometry.

Distinct clinical characteristics of DUX4- and PAX5-altered childhood B-lymphoblastic leukemia.

Among the recently described subtypes in childhood B-lymphoblastic leukemia (B-ALL) were DUX4- and PAX5-altered (PAX5alt). By using whole transcriptome RNA sequencing in 377 children with B-ALL from the Malaysia-Singapore ALL 2003 (MS2003) and Malaysia-Singapore ALL 2010 (MS2010) studies, we found that, after hyperdiploid and ETV6-RUNX1, the third and fourth most common subtypes were DUX4 (n = 51; 14%) and PAX5alt (n = 36; 10%). DUX4 also formed the largest genetic subtype among patients with poor day-33 minimal residual disease (MRD; n = 12 of 44).

Clinical significance of novel subtypes of acute lymphoblastic leukemia in the context of minimal residual disease-directed therapy.

We evaluate clinical significance of recently identified subtypes of acute lymphoblastic leukemia (ALL) in 598 children treated with minimal residual disease (MRD)-directed therapy. Among the 16 B-ALL and 8 T-ALL subtypes identified by next generation sequencing, , high-hyperdiploid and -rearranged B-ALL had the best five-year event-free survival rates (95% to 98.4%); , PAX5alt, T-cell, ETP, iAMP21, and hypodiploid ALL intermediate rates (80.

Reduced-intensity therapy for pediatric lymphoblastic leukemia: impact of residual disease early in remission induction.

Legacy data show that ∼40% of children with acute lymphoblastic leukemia (ALL) were cured with limited antimetabolite-based chemotherapy regimens. However, identifying patients with very-low-risk (VLR) ALL remains imprecise. Patients selected based on a combination of presenting features and a minimal residual disease (MRD) level <0.

Phase I Trial of Expanded, Activated Autologous NK-cell Infusions with Trastuzumab in Patients with HER2-positive Cancers.

Purpose: Natural killer (NK) cells exert antibody-dependent cell cytotoxicity (ADCC). We infused expanded, activated autologous NK cells to potentiate trastuzumab-mediated ADCC in patients with HER2-positive malignancies.

Patients And Methods: In a phase I trial, patients with treatment-refractory HER2-positive solid tumors received trastuzumab, with or without bevacizumab, and autologous NK cells expanded by 10-day coculture with K562-mb15-41BBL cells.

Reduced-dose intensity therapy for pediatric lymphoblastic leukemia: long-term results of the Recife RELLA05 pilot study.

Treatment-related mortality is common among children with acute lymphoblastic leukemia (ALL) treated in poor-resource settings. We applied a simplified flow cytometric assay to identify patients with precursor B-cell ALL (B-ALL) at very low risk (VLR) of relapse and treated them with a reduced-intensity treatment plan (RELLA05). VLR criteria include favorable presenting features (age ≥ 1 and < 10 years), white blood cell count of <50 ×109/L, lack of extramedullary leukemia, and minimal residual disease level of <0.

Improved CNS Control of Childhood Acute Lymphoblastic Leukemia Without Cranial Irradiation: St Jude Total Therapy Study 16.

Purpose: Despite contemporary treatment, up to 10% of children with acute lymphoblastic leukemia still experience relapse. We evaluated whether a higher dosage of PEG-asparaginase and early intensification of triple intrathecal therapy would improve systemic and CNS control.

Patients And Methods: Between 2007 and 2017, 598 consecutive patients age 0 to 18 years received risk-directed chemotherapy without prophylactic cranial irradiation in the St Jude Total Therapy Study 16.

Pathologic Features of Down Syndrome Myelodysplastic Syndrome and Acute Myeloid Leukemia: A Report From the Children's Oncology Group Protocol AAML0431.

Context.—: Detailed diagnostic features of acute myeloid leukemia in Down syndrome are lacking, leading to potential misdiagnoses as standard acute myeloid leukemia occurring in patients with Down syndrome.

Objective.

Clofarabine Can Replace Anthracyclines and Etoposide in Remission Induction Therapy for Childhood Acute Myeloid Leukemia: The AML08 Multicenter, Randomized Phase III Trial.

Purpose: To identify effective and less toxic therapy for children with acute myeloid leukemia, we introduced clofarabine into the first course of remission induction to reduce exposure to daunorubicin and etoposide.

Patients And Methods: From 2008 through 2017, 285 patients were enrolled at eight centers; 262 were randomly assigned to receive clofarabine and cytarabine (Clo+AraC, n = 129) or high-dose cytarabine, daunorubicin, and etoposide (HD-ADE, n = 133) as induction I. Induction II consisted of low-dose ADE given alone or combined with sorafenib or vorinostat.

Reverse-engineering flow-cytometry gating strategies for phenotypic labelling and high-performance cell sorting.

Motivation: Recent flow and mass cytometers generate datasets of dimensions 20 to 40 and a million single cells. From these, many tools facilitate the discovery of new cell populations associated with diseases or physiology. These new cell populations require the identification of new gating strategies, but gating strategies become exponentially more difficult to optimize when dimensionality increases.

Universal monitoring of minimal residual disease in acute myeloid leukemia.

Background: Optimal management of acute myeloid leukemia (AML) requires monitoring of treatment response, but minimal residual disease (MRD) may escape detection. We sought to identify distinctive features of AML cells for universal MRD monitoring.

Methods: We compared genome-wide gene expression of AML cells from 157 patients with that of normal myeloblasts.

Blockade of CD7 expression in T cells for effective chimeric antigen receptor targeting of T-cell malignancies.

Effective immunotherapies for T-cell malignancies are lacking. We devised a novel approach based on chimeric antigen receptor (CAR)-redirected T lymphocytes. We selected CD7 as a target because of its consistent expression in T-cell acute lymphoblastic leukemia (T-ALL), including the most aggressive subtype, early T-cell precursor (ETP)-ALL.

Improved outcomes for myeloid leukemia of Down syndrome: a report from the Children's Oncology Group AAML0431 trial.

Patients with myeloid leukemia of Down syndrome (ML-DS) have favorable event-free survival (EFS), but experience significant treatment-related morbidity and mortality. ML-DS blast cells ex vivo have increased sensitivity to cytarabine (araC) and daunorubicin, suggesting that optimizing drug dosing may improve outcomes while reducing toxicity. The Children's Oncology Group (COG) AAML0431 trial consisted of 4 cycles of induction and 2 cycles of intensification therapy based on the treatment schema of the previous COG A2971 trial with several modifications.

Concordance of two approaches in monitoring of minimal residual disease in B-precursor acute lymphoblastic leukemia: Fusion transcripts and leukemia-associated immunophenotypes.

Background/purpose: Real-time quantitative polymerase chain reaction (RQ-PCR) for fusion transcripts and flow cytometry for leukemia-specific markers are widely used for minimal residual disease (MRD) detection in acute lymphoblastic leukemia, but the relation between the results of either method is unclear.

Methods: Mononucleated cells from 108 bone marrow samples collected from 55 B-precursor acute lymphoblastic leukemia patients (30 with t(12;21)/ETV6-RUNX1, 16 with t(9;22)/BCR-ABL1 and nine with t(1;19)/TCF3-PBX1) were examined in tandem by RQ-PCR and six-color flow cytometry.

Results: MRD results were concordant in 91 of the 108 paired samples (84.

Clinical impact of minimal residual disease in children with different subtypes of acute lymphoblastic leukemia treated with Response-Adapted therapy.

To determine the clinical significance of minimal residual disease (MRD) in patients with prognostically relevant subtypes of childhood acute lymphoblastic leukemia (ALL), we analyzed data from 488 patients treated in St Jude Total Therapy Study XV with treatment intensity based mainly on MRD levels measured during remission induction. MRD levels on day 19 predicted treatment outcome for patients with hyperdiploid >50 ALL, National Cancer Institute (NCI) standard-risk B-ALL or T-cell ALL, while MRD levels on day 46 were prognostic for patients with NCI standard-risk or high-risk B-ALL. Patients with t(12;21)/(ETV6-RUNX1) or hyperdiploidy >50 ALL had the best prognosis; those with a negative MRD on day 19 had a particularly low risk of relapse: 1.

Expanded and armed natural killer cells for cancer treatment.

The capacity of natural killer (NK) cells to recognize and kill transformed cells suggests that their infusion could be used to treat cancer. It is difficult to obtain large numbers of NK cells ex vivo by exposure to cytokines alone but the addition of stimulatory cells to the cultures can induce NK cell proliferation and long-term expansion. Some of these methods have been validated for clinical-grade application and support clinical trials testing feasibility and safety of NK cell administration.

Clinical utility of sequential minimal residual disease measurements in the context of risk-based therapy in childhood acute lymphoblastic leukaemia: a prospective study.

Background: The level of minimal residual disease during remission induction is the most important prognostic indicator in patients with acute lymphoblastic leukaemia (ALL). We aimed to establish the clinical significance of minimal residual disease in a prospective trial that used sequential minimal residual disease measurements to guide treatment decisions.

Methods: Between June 7, 2000, and Oct 24, 2007, 498 assessable patients with newly diagnosed ALL were enrolled in a clinical trial at St Jude Children's Research Hospital.

Prognostic factors in children with acute myeloid leukaemia and excellent response to remission induction therapy.

Minimal residual disease (MRD) is a strong prognostic factor in children and adolescents with acute myeloid leukaemia (AML) but nearly one-quarter of patients who achieve MRD-negative status still relapse. The adverse prognostic factors among MRD-negative patients remain unknown. We analysed the AML02 study cohort to identify demographic and genetic prognostic factors.

Outcomes of children with BCR-ABL1–like acute lymphoblastic leukemia treated with risk-directed therapy based on the levels of minimal residual disease.

Purpose: BCR-ABL1–like acute lymphoblastic leukemia (ALL) is a recently identified B-cell ALL (B-ALL)subtype with poor outcome that exhibits a gene expression profile similar to BCR-ABL1-positive ALL but lacks the BCR-ABL1 fusion protein. We examined the outcome of children with BCR-ABL1–like ALL treated with risk-directed therapy based on minimal residual disease (MRD) levels during remission induction.

Patients And Methods: Among 422 patients with B-ALL enrolled onto the Total Therapy XV study between 2000 and 2007, 344 had adequate samples for gene expression profiling.