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46,990 result(s) for "Precursors"
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Thiopurine methyltransferase activity is related to the risk of relapse of childhood acute lymphoblastic leukemia: results from the NOPHO ALL-92 study
Myelotoxicity during thiopurine therapy is enhanced in patients, who because of single nucleotide polymorphisms have decreased activity of the enzyme thiopurine methyltransferase (TPMT) and thus more thiopurine converted into 6-thioguanine nucleotides. Of 601 children with acute lymphoblastic leukemia (ALL) who were treated by the NOPHO ALL-92 protocol, 117 had TPMT genotype determined, whereas for 484 patients only erythrocyte TPMT activity was available. The latter were classified as heterozygous, if TPMT activity was <14 IU/ml, or deficient (<1.0 IU/ml). 526 patients had TPMT wild type, 73 were presumed heterozygous, and two were TPMT deficient. Risk of relapse was higher for the 526 TPMT wild type patients than for the remaining 75 patients (18 vs 7%, P =0.03). In cox multivariate regression analysis, sex (male worse; P =0.06), age (higher age worse, P =0.02), and TPMT activity (wild type worse; P =0.02) were related to risk of relapse. Despite a lower probability of relapse, patients in the low TPMT activity group did not have superior survival ( P =0.82), possibly because of an excess of secondary cancers among these 75 patients ( P =0.07). These data suggest that children with ALL and TPMT wild type might have their cure rate improved, if the pharmacokinetics/-dynamics of TPMT low-activity patients could be mimicked without a concurrent excessive risk of second cancers.
The BACE‐1 inhibitor CNP520 for prevention trials in Alzheimer's disease
The beta‐site amyloid precursor protein cleaving enzyme‐1 (BACE‐1) initiates the generation of amyloid‐β (Aβ), and the amyloid cascade leading to amyloid plaque deposition, neurodegeneration, and dementia in Alzheimer's disease (AD). Clinical failures of anti‐Aβ therapies in dementia stages suggest that treatment has to start in the early, asymptomatic disease states. The BACE‐1 inhibitor CNP520 has a selectivity, pharmacodynamics, and distribution profile suitable for AD prevention studies. CNP520 reduced brain and cerebrospinal fluid (CSF) Aβ in rats and dogs, and Aβ plaque deposition in APP‐transgenic mice. Animal toxicology studies of CNP520 demonstrated sufficient safety margins, with no signs of hair depigmentation, retina degeneration, liver toxicity, or cardiovascular effects. In healthy adults ≥ 60 years old, treatment with CNP520 was safe and well tolerated and resulted in robust and dose‐dependent Aβ reduction in the cerebrospinal fluid. Thus, long‐term, pivotal studies with CNP520 have been initiated in the Generation Program. Synopsis Alzheimer's disease (AD) is a chronic neurodegenerative disorder with increasing incidence in the aging societies, but without any disease‐modifying treatment. Deposition of toxic forms of the protein Aβ in the brain is pathologic. Treatment with a BACE‐1 inhibitor may prevent Aβ deposition. Recent BACE inhibitor clinical trials in patients at early or mild‐to‐moderate disease stage have failed, indicating that treatment needs to start earlier, before the onset of clinical symptoms. BACE inhibitor CNP520 was designed to meet the requirements of prevention treatment. CNP520 in preclinical models showed acute and chronic Aβ reduction, and a favorable safety profile. CNP520 is safe and well tolerated in humans, and dose‐dependently reduced Aβ in cerebrospinal fluid. Prevention studies Generation I and II are underway in patients at enhanced risk to develop symptoms of AD. Graphical Abstract Alzheimer's disease (AD) is a chronic neurodegenerative disorder with increasing incidence in the aging societies, but without any disease‐modifying treatment. Deposition of toxic forms of the protein Aβ in the brain is pathologic. Treatment with a BACE‐1 inhibitor may prevent Aβ deposition.
International Consensus Classification of acute lymphoblastic leukemia/lymphoma
The updated International Consensus Classification (ICC) of B-acute lymphoblastic leukemia (B-ALL) and T-acute lymphoblastic leukemia (T-ALL) includes both revisions to subtypes previously outlined in the 2016 WHO classification and several newly described entities. The ICC classification incorporates recent clinical, cytogenetic, and molecular data, with a particular emphasis on whole transcriptome analysis and gene expression (GEX) clustering studies. B-ALL classification is modified to further subclassify BCR::ABL1-positive B-ALL and hypodiploid B-ALL. Additionally, nine new categories of B-ALL are defined, including seven that contain distinguishing gene rearrangements, as well as two new categories that are characterized by a specific single gene mutation. Four provisional entities are also included in the updated B-ALL classification, although definitive identification of these subtypes requires GEX studies. T-ALL classification is also updated to incorporate BCL11B-activating rearrangements into early T-precursor (ETP) ALL taxonomy. Additionally, eight new provisional entities are added to the T-ALL subclassification. The clinical implications of the new entities are discussed, as are practical approaches to the use of different technologies in diagnosis. The enhanced specificity of the new classification will allow for improved risk stratification and optimized treatment plans for patients with ALL.
Blinatumomab versus Chemotherapy for Advanced Acute Lymphoblastic Leukemia
Among adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia, treatment with the bispecific anti-CD19 and anti-CD3 monoclonal antibody blinatumomab resulted in longer overall survival and higher remission rates than did chemotherapy. The prognosis for adults with newly diagnosed acute lymphoblastic leukemia (ALL) has improved over the past three decades. With the use of intensive chemotherapy regimens, complete remission rates are 85 to 90% and long-term survival rates are 30 to 50%. 1 – 4 Still, most adults with B-cell precursor ALL will have a relapse and will die from complications of resistant disease or associated treatment. Among adults with relapsed or refractory ALL, remission rates are 18 to 44% with the use of standard salvage chemotherapy, but the duration of remission is typically short. 5 – 10 A major goal in this population is to . . .
η-Secretase processing of APP inhibits neuronal activity in the hippocampus
A new pathway for the processing of β-amyloid precursor protein (APP) is described in which η-secretase activity, in part mediated by the MT5-MMP metalloproteinase, cleaves APP, and further processing by ADAM10 and BACE1 generates proteolytic fragments capable of inhibiting long-term potentiation in the hippocampus. Neuronal inhibition by APP by-products Michael Willem et al . describe a previously unknown pathway for the processing of β-amyloid precursor protein (APP) in which η-secretase cleaves APP to yield a soluble C-terminal fragment termed CTF-η. The soluble fragment, sAPP-η can be further processed by ADAM10 and BACE1 to generate the peptides Aη-α and Aη-β respectively, which are capable of inhibiting long-term potentiation in the hippocampus. The relevant η-secretase activity is largely due to the membrane-bound matrix metalloproteinase, MT5-MMP, whose activity is enriched in dystrophic neurites in a mouse model of Alzheimer's disease and in the brains of Alzheimer's patients. Genetic or pharmacological inhibition of BACE1 results in increased accumulation of both CTF-η and Aη-α. This work suggests that BACE 1-based therapies may result in the generation of another potentially toxic substance (Aη-α) and that therapeutic inhibition of BACE1 activity requires careful titration. Alzheimer disease (AD) is characterized by the accumulation of amyloid plaques, which are predominantly composed of amyloid-β peptide 1 . Two principal physiological pathways either prevent or promote amyloid-β generation from its precursor, β-amyloid precursor protein (APP), in a competitive manner 1 . Although APP processing has been studied in great detail, unknown proteolytic events seem to hinder stoichiometric analyses of APP metabolism in vivo 2 . Here we describe a new physiological APP processing pathway, which generates proteolytic fragments capable of inhibiting neuronal activity within the hippocampus. We identify higher molecular mass carboxy-terminal fragments (CTFs) of APP, termed CTF-η, in addition to the long-known CTF-α and CTF-β fragments generated by the α- and β-secretases ADAM10 (a disintegrin and metalloproteinase 10) and BACE1 (β-site APP cleaving enzyme 1), respectively. CTF-η generation is mediated in part by membrane-bound matrix metalloproteinases such as MT5-MMP, referred to as η-secretase activity. η-Secretase cleavage occurs primarily at amino acids 504–505 of APP 695 , releasing a truncated ectodomain. After shedding of this ectodomain, CTF-η is further processed by ADAM10 and BACE1 to release long and short Aη peptides (termed Aη-α and Aη-β). CTFs produced by η-secretase are enriched in dystrophic neurites in an AD mouse model and in human AD brains. Genetic and pharmacological inhibition of BACE1 activity results in robust accumulation of CTF-η and Aη-α. In mice treated with a potent BACE1 inhibitor, hippocampal long-term potentiation was reduced. Notably, when recombinant or synthetic Aη-α was applied on hippocampal slices ex vivo , long-term potentiation was lowered. Furthermore, in vivo single-cell two-photon calcium imaging showed that hippocampal neuronal activity was attenuated by Aη-α. These findings not only demonstrate a major functionally relevant APP processing pathway, but may also indicate potential translational relevance for therapeutic strategies targeting APP processing.
Blinatumomab for MRD-Negative Acute Lymphoblastic Leukemia in Adults
The addition of blinatumomab to consolidation chemotherapy in adults with B-cell precursor acute lymphoblastic leukemia who had minimal residual disease–negative status after treatment improved overall and relapse-free survival.
Imatinib after induction for treatment of children and adolescents with Philadelphia-chromosome-positive acute lymphoblastic leukaemia (EsPhALL): a randomised, open-label, intergroup study
Trials of imatinib have provided evidence of activity in adults with Philadelphia-chromosome-positive acute lymphoblastic leukaemia (ALL), but the drug's role when given with multidrug chemotherapy to children is unknown. This study assesses the safety and efficacy of oral imatinib in association with a Berlin–Frankfurt–Munster intensive chemotherapy regimen and allogeneic stem-cell transplantation for paediatric patients with Philadelphia-chromosome-positive ALL. Patients aged 1–18 years recruited to national trials of front-line treatment for ALL were eligible if they had t(9;22)(q34;q11). Patients with abnormal renal or hepatic function, or an active systemic infection, were ineligible. Patients were enrolled by ten study groups between 2004 and 2009, and were classified as good risk or poor risk according to early response to induction treatment. Good-risk patients were randomly assigned by a web-based system with permuted blocks (size four) to receive post-induction imatinib with chemotherapy or chemotherapy only in a 1:1 ratio, while all poor-risk patients received post-induction imatinib with chemotherapy. Patients were stratified by study group. The chemotherapy regimen was modelled on a Berlin–Frankfurt–Munster high-risk backbone; all received four post-induction blocks of chemotherapy after which they became eligible for stem-cell transplantation. The primary endpoints were disease-free survival at 4 years in the good-risk group and event-free survival at 4 years in the poor-risk group, analysed by intention to treat and a secondary analysis of patients as treated. The trial is registered with EudraCT (2004-001647-30) and ClinicalTrials.gov, number NCT00287105. Between Jan 1, 2004, and Dec 31, 2009, we screened 229 patients and enrolled 178: 108 were good risk and 70 poor risk. 46 good-risk patients were assigned to receive imatinib and 44 to receive no imatinib. Median follow-up was 3·1 years (IQR 2·0–4·6). 4-year disease-free survival was 72·9% (95% CI 56·1–84·1) in the good-risk, imatinib group versus 61·7% (45·0–74·7) in the good-risk, no imatinib group (p=0·24). The hazard ratio (HR) for failure, adjusted for minimal residual disease, was 0·63 (0·28–1·41; p=0·26). The as-treated analysis showed 4-year disease-free survival was 75·2% (61·0–84·9) for good-risk patients receiving imatinib and 55·9% (36·1–71·7) for those who did not receive imatinib (p=0·06). 4-year event-free survival for poor-risk patients was 53·5% (40·4–65·0). Serious adverse events were much the same in the good-risk groups, with infections caused by myelosuppression the most common. 16 patients in the good-risk imatinib group versus ten in the good-risk, no imatinib group (p=0·64), and 24 in the poor-risk group, had a serious adverse event. Our results suggests that imatinib in conjunction with intensive chemotherapy is well tolerated and might be beneficial for treatment of children with Philadelphia-chromosome-positive ALL. Projet Hospitalier de Recherche Clinique-Cancer (France), Fondazione Tettamanti-De Marchi and Associazione Italiana per la Ricerca sul Cancro (Italy), Novartis Germany, Cancer Research UK, Leukaemia Lymphoma Research, and Central Manchester University Hospitals Foundation Trust.
Inotuzumab ozogamicin in combination with low-intensity chemotherapy for older patients with Philadelphia chromosome-negative acute lymphoblastic leukaemia: a single-arm, phase 2 study
Inotuzumab ozogamicin, an anti-CD22 monoclonal antibody bound to a toxin, calicheamicin, has shown single-agent activity in relapsed or refractory acute lymphoblastic leukaemia. We aimed to assess the activity and safety of inotuzumab ozogamicin in combination with low-intensity chemotherapy in older patients with acute lymphoblastic leukaemia. We did a single-arm, phase 2 study at the MD Anderson Cancer Center (Houston, TX, USA). Eligible patients were aged 60 years or older and had newly diagnosed, Philadelphia chromosome-negative, acute lymphoblastic leukaemia, and an Eastern Cooperative Oncology Group performance status of 3 or lower. The induction chemotherapy regimen used was mini-hyper-CVD (a lower intensity version of the conventional hyper-CVAD). Odd-numbered cycles (1,3, 5, and 7) comprised intravenous cyclophosphamide (150 mg/m2 every 12 h on days 1–3) and oral or intravenous dexamethasone (20 mg per day on days 1–4 and days 11–14); no anthracycline was administered. Intravenous vincristine (2 mg flat dose) was given on days 1 and 8. Even-numbered cycles comprised intravenous methotrexate (250 mg/m2 on day 1) and intravenous cytarabine (0·5 g/m2 given every 12 h on days 2 and 3). Intravenous inotuzumab ozogamicin was given on day 3 of the first four cycles at the dose of 1·3–1·8 mg/m2 at cycle 1, followed by 1·0 −1·3 mg/m2 in subsequent cycles. Maintenance therapy with dose-reduced POMP (purinethol [6-mercaptopurine], oncovin [vincristine sulfate], methotrexate, and prednisone) was given for 3 years. The primary endpoint of this study was progression-free survival at 2 years. Analyses were by intention to treat. The study is ongoing, recruiting patients for an approved expansion phase with a modified treatment plan by protocol amendment. The trial is registered with ClinicalTrials.gov, number NCT01371630. Between Nov 12, 2011, and April 22, 2017, 52 patients with a median age of 68 years (IQR 64–72) were enrolled. With a median follow-up of 29 months (IQR 13–48), 2-year progression-free survival was 59% (95% CI 43–72). The most frequent grade 3–4 adverse events were prolonged thrombocytopenia (42 [81%] patients), infections during induction (27 [52%]) and consolidation chemotherapy (36 [69%]), hyperglycaemia (28 [54%]), hypokalaemia (16 [31%]), increased aminotransferases (ten [19%]), hyperbilirubinaemia (nine [17%]), and haemorrhage (seven [15%]). Veno-occlusive disease occurred in four (8%) patients. Six (12%) patients died from adverse events that were deemed treatment related (five [10%] from sepsis and one [2%] from veno-occlusive disease). Inotuzumab ozogamicin plus mini-hyper-CVD chemotherapy is a safe and active first-line therapy option in older patients with newly diagnosed acute lymphoblastic leukaemia and could represent a new therapy for this population. Randomised, phase 3 trials to evaluate the efficacy of this combination compared with the current standard of care in this setting, combination chemotherapy without inotuzumab ozogamicin, are warranted. MD Anderson Cancer Center.
Treatment reduction for children and young adults with low-risk acute lymphoblastic leukaemia defined by minimal residual disease (UKALL 2003): a randomised controlled trial
Minimal residual disease (MRD) is the most sensitive and specific predictor of relapse risk in children with acute lymphoblastic leukaemia (ALL) during remission. We assessed whether treatment intensity could be adjusted for children and young adults according to MRD risk stratification. Between Oct 1, 2003 and June 30, 2011, consecutive children and young adults (aged 1–24 years) with ALL from the UK and Ireland were recruited. Eligible patients were categorised into clinical standard, intermediate, and high risk groups on the basis of a combination of National Cancer Institute (NCI) criteria, cytogenetics, and early response to induction therapy, which was assessed by bone marrow blast counts taken at days 8 (NCI high-risk patients) and 15 (NCI standard-risk patients) after induction began. Clinical standard-risk and intermediate-risk patients were assessed for MRD. Those classified as MRD low risk (undetectable MRD at the end of induction [day 29] or detectable MRD [less than 0·01%] at day 29 that became undetectable by week 11) were randomly assigned to receive one or two delayed intensification courses. Patients had received induction, consolidation, and interim maintenance therapy before they began delayed intensification. Delayed intensification consisted of pegylated asparaginase on day 4; vincristine, dexamethasone (alternate weeks), and doxorubicin for 3 weeks; and 4 weeks of cyclophosphamide and cytarabine. Computer randomisation was done with stratification by MRD result and balancing for sex, age, and white blood cell count at diagnosis by method of minimisation. Patients, clinicians, and data analysts were not masked to treatment allocation. The primary outcome was event-free survival (EFS), which was defined as time to relapse, secondary tumour, or death. Our aim was to rule out a 7% reduction in EFS in the group given one delayed intensification course relative to that given two delayed intensification courses. Analyses were by intention to treat. This trial is registered, number ISRCTN07355119. Of 3207 patients registered in the trial overall, 521 MRD low-risk patients were randomly assigned to receive one (n=260) or two (n=261) delayed intensification courses. Median follow-up of these patients was 57 months (IQR 42–72). We recorded no significant difference in EFS between the group given one delayed intensification (94·4% at 5 years, 95% CI 91·1–97·7) and that given two delayed intensifications (95·5%, 92·8–98·2; unadjusted odds ratio 1·00, 95% CI 0·43–2·31; two-sided p=0·99). The difference in 5-year EFS between the two groups was 1·1% (95% CI −5·6 to 2·5). 11 patients (actuarial relapse at 5 years 5·6%, 95% CI 2·3–8·9) given one delayed intensification and six (2·4%, 0·2–4·6) given two delayed intensifications relapsed (p=0·23). Three patients (1·2%, 0–2·6) given two delayed intensifications died of treatment-related causes compared with none in the group given one delayed intensification (p=0·08). We recorded no significant difference between groups for serious adverse events and grade 3 or 4 toxic effects; however, the second delayed intensification course was associated with one (<1%) treatment-related death, and 74 episodes of grade 3 or 4 toxic effects in 45 patients (17%). Treatment reduction is feasible for children and young adults with ALL who are predicted to have a low risk of relapse on the basis of rapid clearance of MRD by the end of induction therapy. Medical Research Council and Leukaemia and Lymphoma Research.
Pharmacogenomics of intracellular methotrexate polyglutamates in patients’ leukemia cells in vivo
BACKGROUNDInterpatient differences in the accumulation of methotrexate's active polyglutamylated metabolites (MTXPGs) in leukemia cells influence its antileukemic effects.METHODSTo identify genomic and epigenomic and patient variables determining the intracellular accumulation of MTXPGs, we measured intracellular MTXPG levels in acute lymphoblastic leukemia (ALL) cells from 388 newly diagnosed patients after in vivo high-dose methotrexate (HDMTX) (1 g/m2) treatment, defined ALL subtypes, and assessed genomic and epigenomic variants influencing folate pathway genes (mRNA, miRNA, copy number alterations [CNAs], SNPs, single nucleotide variants [SNVs], CpG methylation).RESULTSWe documented greater than 100-fold differences in MTXPG levels, which influenced its antileukemic effects (P = 4 × 10-5). Three ALL subtypes had lower MTXPG levels (T cell ALL [T-ALL] and B cell ALL [B-ALL] with the TCF3-PBX1 or ETV6-RUNX1 fusions), and 2 subtypes had higher MTXPG levels (hyperdiploid and BCR-ABL like). The folate pathway genes SLC19A1, ABCC1, ABCC4, FPGS, and MTHFD1 significantly influenced intracellular MTXPG levels (P = 2.9 × 10-3 to 3.7 × 10-8). A multivariable model including the ALL subtype (P = 1.1 × 10-14), the SLC19A1/(ABCC1 + ABCC4) transporter ratio (P = 3.6 × 10-4), the MTX infusion time (P = 1.5 × 10-3), FPGS mRNA expression (P = 2.1 × 10-3), and MTX systemic clearance (P = 4.4 × 10-2) explained 42% of the variation in MTXPG accumulation (P = 1.1 × 10-38). Model simulations indicated that a longer infusion time (24 h vs. 4 h) was superior in achieving higher intracellular MTXPG levels across all subtypes if ALL.CONCLUSIONSThese findings provide insights into mechanisms underlying interpatient differences in intracellular accumulation of MTXPG in leukemia cells and its antileukemic effectsFUNDINGTHE National Cancer Institute (NCI) and the Institute of General Medical Sciences of the NIH, the Basque Government Programa Posdoctoral de Perfeccionamiento de Personal Investigador doctor, and the American Lebanese Syrian Associated Charities (ALSAC).