Second malignancies in patients treated for childhood acute lymphoblastic leukemia.

1998 ◽  
Vol 16 (8) ◽  
pp. 2848-2853 ◽  
Author(s):  
V M Kimball Dalton ◽  
R D Gelber ◽  
F Li ◽  
M J Donnelly ◽  
N J Tarbell ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Confidence Interval ◽  
Radiation Field ◽  
Lymphoblastic Leukemia ◽  
Epithelioid Sarcoma ◽  
Late Complications ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Malignant Neoplasms ◽  
Childhood All ◽  
Induction Failure

PURPOSE Second malignant neoplasms (SMN) are devastating late complications of childhood acute lymphoblastic leukemia (ALL) and its treatment. We evaluated the incidence and type of SMN diagnosed before leukemic relapse in a large series of patients with ALL. PATIENTS AND METHODS We reviewed the outcome of all patients treated for childhood ALL between 1972 and 1995 on Dana-Farber Cancer Institute (DFCI) and DFCI ALL Consortium protocols. The follow-up time from diagnosis of ALL to induction failure, relapse, remission death, or SMN, whichever occurred first, ranged from 0 to 24.0 years (median, 7.6 years; mean, 6.7 years). RESULTS Thirteen SMNs were diagnosed among 1,597 patients. Eight tumors occurred in a radiation field (five in the CNS and three in the head and neck), two occurred outside of a radiation field (one adenocarcinoma of the sigmoid colon and one epithelioid sarcoma of the chest wall), and three were hematopoietic malignancies. The median time to occurrence was 6.7 years (range, 1.0 to 17.2 years) and the cumulative incidence of second malignancy before another first event was 2.7% (95% confidence interval, 0.7 to 4.7). The risk of a first event, which included induction failure, relapse, or remission death, was 31.0% (95% confidence interval, 28.5 to 33.5). CONCLUSION We found a more than 10-fold risk of other first events when compared with SMN. Thus, we conclude that SMN before first relapse is a relatively uncommon occurrence among survivors of childhood ALL. Future therapeutic regimens must focus on reducing leukemia relapse and enhancing quality of life, as well as preventing SMNs.

Thiopurine methyltransferase genetics is not a major risk factor for secondary malignant neoplasms after treatment of childhood acute lymphoblastic leukemia on Berlin-Frankfurt-Münster protocols

Blood ◽  
2009 ◽  
Vol 114 (7) ◽  
pp. 1314-1318 ◽  
Author(s):  
Martin Stanulla ◽  
Elke Schaeffeler ◽  
Anja Möricke ◽  
Sally A. Coulthard ◽  
Gunnar Cario ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Malignant Neoplasm ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Tpmt Activity ◽  
Malignant Neoplasms ◽  
Thiopurine Methyltransferase ◽  
Childhood All ◽  
Increased Risk ◽  
Secondary Malignant Neoplasm

AbstractThiopurine methyltransferase (TPMT)is involved in the metabolism of thiopurines such as 6-mercaptopurine and 6-thioguanine. TPMT activity is significantly altered by genetics, and heterozygous and even more homozygous variant people reveal substiantially decreased TPMT activity. Treatment for childhood acute lymphoblastic leukemia (ALL) regularly includes the use of thiopurine drugs. Importantly, childhood ALL patients with low TPMT activity have been considered to be at increased risk of developing therapy-associated acute myeloid leukemia and brain tumors. In the present study, we genotyped 105 of 129 patients who developed a secondary malignant neoplasm after ALL treatment on 7 consecutive German Berlin-Frankfurt-Münster trials for all functionally relevant TPMT variants. Frequencies of TPMT variants were similarly distributed in secondary malignant neoplasm patients and the overall ALL patient population of 814 patients. Thus, TPMT does not play a major role in the etiology of secondary malignant neoplasm after treatment for childhood ALL, according to Berlin-Frankfurt-Münster strategies.

Thiopurine methyltransferase Genotype Is Not a Risk Factor for Secondary Malignant Neoplasias after Treatment for Childhood Acute Lymphoblastic Leukemia on Berlin-Frankfurt-Muenster Protocols.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 150-150 ◽  
Author(s):  
Martin Stanulla ◽  
Elke Schaeffeler ◽  
Anja Moericke ◽  
Gunnar Cario ◽  
Michel Eichelbaum ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Brain Tumors ◽  
Patient Population ◽  
Lymphoblastic Leukemia ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Tpmt Activity ◽  
Malignant Neoplasms ◽  
Acute Leukemias ◽  
Childhood All ◽  
Increased Risk

Abstract The thiopurines mercaptopurine and thioguanine are important components of contemporary polychemotherapeutic treatment protocols for acute leukemias. Thiopurines are prodrugs that undergo intestinal and hepatic metabolism. Activation occurs via a multistep pathway to form thioguanine nucleotides, which are thought to be the major cytotoxic compound through triggering cell cycle arrest and apoptosis. This process is in competition with direct inactivation of thiopurines or their metabolites by thiopurine S-methyltransferase (TPMT). TPMT is a cytosolic enzyme that is ubiquitously expressed in the human body and catalyzes the S-methylation of thiopurines. The TPMT locus is subject to genetic polymorphism, with heterozygous individuals (5 to 11% of Caucasians) having intermediate TPMT activity, and homozygous individuals (0.3 to 0.5% of Caucasians) having low TPMT activity. At least 20 variant TPMT alleles (*2 to *18) have been described so far that confer decreased enzyme activities compared to the TPMT*1 wild-type allele. TPMT genotype is highly concordant with TPMT phenotype. With regard to long-term adverse effects, patients who have diminished TPMT activity were shown to be at increased risk of developing chemotherapy-induced acute myeloid leukemia and radiation-induced second brain tumors tumors after exposure towards mercaptopurine during therapy for childhood acute lymphoblastic leukemia (ALL). To investigate if such an association is generalizable to other entities of secondary malignant neoplasms (SMN) and different treatment approaches for ALL, we collected specimens of 72 patients who developed a SMN after ALL treatment on Berlin-Frankfurt-Muenster (BFM) protocols, analyzed their TPMT genotype and compared genotype frequencies to these in the general ALL patient population. The 72 patient cohort consisted of 49 hematological SMN (half of them received cranial irradiation), 12 brain tumors, and 11 other solid SMN. Neither in the entire patient group nor in subgroup analyses, differences in allele frequencies of TPMT variants conferring diminished enzyme activity were detectable when comparing SMN patients to the overall ALL patient population. Thus, low TPMT activity does not seem to play a major role in the etiology of SMN after treatment for childhood ALL according to BFM treatment strategies. Factors potentially helpful for the explanation of the previously described relationsship of TPMT activity with SMN will be presented.

scholarly journals TEL-AML1 Fusion Transcript in Relapsed Childhood Acute Lymphoblastic Leukemia

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1716-1722 ◽  
Author(s):  
Karlheinz Seeger ◽  
Hans-Peter Adams ◽  
Dirk Buchwald ◽  
Birgit Beyermann ◽  
Bernhard Kremens ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Prognostic Significance ◽  
Philadelphia Chromosome ◽  
Fusion Transcript ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Long Term Results ◽  
Childhood All ◽  
Cryptic Translocation

Abstract The cryptic translocation t(12;21)(p13;q22) has been recently recognized as the most common genetic rearrangement in B-lineage childhood acute lymphoblastic leukemia (ALL). The resulting fusion transcript, termed TEL-AML1, has been associated with an excellent prognosis at initial ALL diagnosis. Hence, we postulated that the incidence of TEL-AML1 fusion should be lower in patients with ALL relapse. To address this assumption and to investigate the prognostic significance of TEL-AML1 expression in relapsed childhood ALL, bone marrow samples of 146 children were analyzed by reverse-transcriptase (RT)-polymerase chain reaction (PCR). All children were treated according to Berlin-Frankfurt-Münster (BFM) ALL relapse trial protocols (ALL-REZ BFM 90-96). Their clinical features and outcome were compared with those of 262 patients who could not be tested due to lack of bone marrow samples. Thirty-two of 146 children with relapsed ALL were TEL-AML1–positive. Four of the negative patients had T-lineage and nine Philadelphia chromosome (Ph1)-positive leukemia. Thus, the incidence ofTEL-AML1 in relapsed Ph1-negative, B-cell precursor ALL is 32 of 133 (24%). The 32 TEL-AML1–positive and 101 negative patients differed significantly with respect to duration of last remission (42.5 v 27 months; P = .0001) and age at initial diagnosis (53.5 v 74 months;P = .0269). At a median follow-up time of 21.5 months, children positive for TEL-AML1 had a significantly (P = .0011) higher probability of event-free survival (EFS; 0.79 v 0.33). The predominant majority of patients had been treated for initial ALL according to German multicenter BFM (108 of 133) or Cooperative ALL study group (CoALL) (19 of 133) frontline protocols. The comparison of tested and not-tested (N = 262) patients showed no significant difference.TEL-AML1 positivity predicted a favorable short-term outcome; long-term results are unknown. Screening for TEL-AML1 should become routine at relapse diagnosis and might be used for therapy stratification in future trials.

scholarly journals TEL/AML-1 dimerizes and is associated with a favorable outcome in childhood acute lymphoblastic leukemia

Blood ◽  
1996 ◽  
Vol 88 (11) ◽  
pp. 4252-4258 ◽  
Author(s):  
TW McLean ◽  
S Ringold ◽  
D Neuberg ◽  
K Stegmaier ◽  
R Tantravahi ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Chromosomal Translocation ◽  
Fusion Transcript ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Childhood All ◽  
Polymerase Chain ◽  
B Lineage

Abstract Polymerase chain reaction-based screening of childhood acute lymphoblastic leukemia (ALL) samples showed that a TEL/AML1 fusion transcript was detected in 27% of all cases, representing the most common known gene rearrangement in childhood cancer. The TEL/AML1 fusion results from a t(12;21)(p13;q22) chromosomal translocation, but was undetectable at the routine cytogenetic level. TEL/AML1-positive patients had exclusively B-lineage ALL, and most patients were between the ages of 2 and 9 years at diagnosis. Only 3/89 (3.4%) adult ALL patients were TEL/AML1-positive. Most importantly, TEL/AML1-positive children had a significantly lower rate of relapse compared with TEL/AML1-negative patients (0/22 v 16/54, P = .004). Co- immunoprecipitation experiments demonstrated that TEL/AML-1 formed homodimers in vitro, and heterodimerized with the normal TEL protein when the two proteins were expressed together. The elucidation of the precise mechanism of transformation by TEL/AML1 and the role of TEL/AML1 testing in the treatment of childhood ALL will require additional studies.

Implication of Genetic Variations of Ikzf1, ARIDB5, and CEBPE Genes In the Risk of Childhood Acute Lymphoblastic Leukemia In Korea

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3235-3235
Author(s):  
Dong Kyun Han ◽  
Hee Nam Kim ◽  
Min Ho Shin ◽  
Minenori Eguchi-Ishimae ◽  
Mariko Eguchi ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Genetic Variations ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Asian Countries ◽  
Childhood All ◽  
Genomic Variations ◽  
Genotype Frequencies ◽  
The Impact

Abstract Abstract 3235 Background: Recent western studies have showed the implication of the germline genomic variations in IKZF1 gene at 7p12.2, ARIDB5 gene at 10q21.2, and CEBPE gene at 14q11.2 on the risk of childhood acute lymphoblastic leukemia (ALL); the most significant association was observed in the single nucleotide polymorphism (SNP) rs4132601 which located at 3' region of the IKZF1. IKZF1 plays important role in lymphocyte differentiation, proliferation and function, ARIDB5 in embryogenesis and growth regulation, and CEBPE in regulation of myelopoiesis. Genomic variants in these genes are therefore considered to be involved in transcriptional regulation and differentiation of B cell progenitors. However, there have been no reports on the role of germline variations in leukemogenesis of childhood ALL in Asian countries. The aim of this study is to show the impact of these genetic variants on childhood ALL in Korea. Patients and Methods: To examine the association between genetic variations (IKZF1 rs4132601, ARIDB5 rs7089424, and CEBPE rs2239633) and the risk of childhood ALL, we here analyzed 228 children with ALL and 508 healthy individuals in Korea. Results: In ARIDB5 rs7089424, TG and GG genotypes were significantly associated with a risk for ALL (odds ratio [OR], 1.63; 95% confidential interval [CI], 1.07–2.48; P=0.02 for TG genotype, OR, 2.69; 95% CI, 1.42–5.07; P=0.002 for GG genotype). The allele incidence of ARIDB5 rs7089424 was also significantly associated with a risk for ALL (OR, 1.66; 95% CI, 1.24–2.22; P=0.0006). CEBPE rs2239633 TT genotype showed a significant association with a decreased risk for ALL (OR, 0.54; 95% CI, 0.33–0.90; P=0.02 for TT genotype). The allele incidence of CEBPE rs2239633 was also associated with a decreased risk for ALL (OR, 0.77; 95% CI, 0.61–0.97; P=0.02). There was no significant association between IKZF1 rs4132601 polymorphism and a risk for ALL in this study. Conclusion: These results suggest that genomic variations of ARIDB5 and CEBPE may play an important role in the risk for childhood ALL in Korea, compared with findings from western countries showing a significant relation between IKZF1 and childhood ALL. Several factors should be considered to explain a discrepancy between our results and the previous studies, which include different genotype frequencies in polymorphisms and varied susceptibility to ALL in different ethnic groups. Further studies incorporating larger number of cases and analyzing other SNPs or other Asian countries are warranted in childhood ALL. Disclosures: No relevant conflicts of interest to declare.

Genomic Variants Associated with Childhood Acute Lymphoblastic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. SCI-11-SCI-11
Author(s):  
Mary V. Relling
Keyword(s):  
Genetic Variation ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Drug Clearance ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Pharmacokinetic Data ◽  
Clinical Effects ◽  
Childhood All ◽  
Genome Wide ◽  
A Genome

Abstract Abstract SCI-11 Genome-wide interrogations have a role in addressing both the etiology and the responsiveness of childhood acute lymphoblastic leukemia (ALL). Recent work by our own1 and other groups identified common polymorphisms in ARID5B, and to a lesser extent in IKZF1, as predisposing to the development of childhood ALL. Polymorphisms in these two genes can account for ∼ 40% of the population attributable risk of ALL, and differences in the frequency of the minor allele among different ancestral groups can account for a large portion of the differences in the incidence of ALL among different race groups. The association of these inherited polymorphisms with specific ALL subtypes (e.g. ARID5B with risk of hyperdiploid ALL) indicates that germline polymorphisms affect not only risk of ALL but may also affect or confound association analyses between germline variants and the probability of cure of ALL. The biological basis for the prognostic differences that exist among ALL subtypes remain largely unknown, and it is plausible that inherited polymorphisms may affect both susceptibility to subtypes of ALL as well as to drug responsiveness. Genome-wide analyses have also identified polymorphisms associated with eradication of MRD across multiple treatment protocols.2 Polymorphisms in IL15 indicate variants that likely affect the inherent pharmacodynamic responsiveness of ALL to drug-induced apoptosis. Approximately 20% of the polymorphisms associated with MRD were also associated with rapid drug clearance in the host, even though pharmacokinetic data were only available for 2 of the 4–8 medications used during induction. These findings lead us to suggest that perhaps half of the polymorphisms associated with eradication of ALL are related to effects on host drug clearance, and about half have penetrant effects on the inherent responsiveness of the ALL cells themselves. A genome-wide analysis for the determinants of clearance of one such drug, methotrexate, identified a strong effect of polymorphisms in the SLCO1B1 transporter.3 Genome-wide approaches have identified the importance of genes that decades of candidate gene approaches did not reveal, illustrating the utility of an agnostic approach to genotype-phenotype association studies in childhood ALL. 1. Treviño LR, Yang W, French D, et al. Germline genomic variations associated with childhood acute lymphoblastic leukemia. Nat Genet 41:1001–5, 2009. 2. Yang J, Cheng C, Yang W, et al. Genome-wide interrogation of germline genetic variation associated with treatment response in childhood acute lymphoblastic leukemia. JAMA 301:393–403, 2009. 3. Treviño LR, Shimasaki N, Yang W, et al. Germline genetic variation in an organic anion transporter polypeptide associated with methotrexate pharmacokinetics and clinical effects. J Clin Oncol 27:5972–8, 2009. Disclosures: Relling: St. Jude Children's Research Hospital: Employment, Patents & Royalties; Enzon Pharmaceuticals: Research Funding.

Therapy-Related Myelodysplastic Syndrome Following Treatment for Childhood Acute Lymphoblastic Leukemia: Outcome of Patients Registered in the EWOG-MDS 98/06 Studies,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4130-4130
Author(s):  
Brigitte Strahm ◽  
Roland Amann ◽  
Barbara De Moerloose ◽  
Michael Dworzak ◽  
Henrik Hasle ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Myelodysplastic Syndrome ◽  
Treatment Failure ◽  
Lymphoblastic Leukemia ◽  
Univariate Analysis ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Intensive Chemotherapy ◽  
Complex Karyotype ◽  
Childhood All ◽  
Preparative Regimen

Abstract Abstract 4130 Objective: Therapy-related myelodysplastic syndrome (tMDS) following treatment of childhood acute lymphoblastic leukemia (ALL) is one of the most frequently observed secondary malignancies in survivors of childhood cancer. Allogeneic stem cell transplantation (SCT) is the only curative treatment. This analysis was performed to asses the outcome of patients with tMDS following treatment for childhood ALL reported to the EWOG-MDS study group. Patients and Transplant Procedure: Forty-three patients (19 male/24 female) were diagnosed with tMDS between August 1989 and August 2009. The median age at diagnosis was 8.9 yrs (3.4–20.5). The median interval from diagnosis of ALL to the diagnosis of tMDS was 3.3 yrs (1.7–7.0). Five patients did not receive SCT and died due to progressive disease at a median of 5.6 mo after diagnosis. Thirty-eight patients were transplanted. One patient was excluded from the analysis due to insufficient data. In the 37 patients karyotype analysis revealed the following results: normal karyotype (5), abnormalities of chromosome 7 +/− additional aberrations (10), random aberrations (9), structurally complex karyotype (9), failed analysis (4). The highest WHO type was refractory cytopenia (RC) in 4 patients, whereas 33 patients had advanced AML like therapy prior to SCT was employed in 11 patients. Donors were matched siblings (13), matched unrelated volunteers (15), or mismatched or insufficiently typed family or unrelated donors (9). Conditioning consisted of busulfan, cyclophosphamide and melphalan (Bu/Cy/Mel) (23), an alternative busulfan based regimen (6), a radiation based regimen (5) or others (3). Results: After a median follow up of 4.1 (0.5 – 9.4) years, 14 patients are alive in first complete remission (CR). Seventeen patients developed relapse after a median time of 266 days (28 days – 3.4 years). Of these, three patients are alive in CR after a second allograft. Six patients died of transplant-related complications after first (4) or second (2) SCT. In summary, SCT for tMDS following ALL resulted in a probability of event-free and overall survival at 5 years of 0.34 and 0.42, respectively. In univariate analysis, the presence of a structurally complex karyotype, SCT from a mismatched donor and a preparative regimen other than Bu/Cy/Mel were factors predicting a decreased probability of event-free survival. The use of intensive chemotherapy prior to SCT resulted in a trend towards better survival due to a reduction in relapse incidence. In multivariate COX-analysis, a conditioning regimen other than BuCyMel remained the only variable associated with a high risk of treatment failure. Conclusion: Allogeneic SCT with a preparative regimen consisting of Bu/Cy/Mel is feasible and effective in patients developing tMDS following treatment for childhood ALL. Relapse is the main cause of treatment failure and intensive chemotherapy prior SCT may possibly contribute to an improved outcome. Disclosures: Hasle: Pfizer: Research Funding.

scholarly journals HLA-DP genetic variation, proxies for early life immune modulation and childhood acute lymphoblastic leukemia risk

Blood ◽  
2012 ◽  
Vol 120 (15) ◽  
pp. 3039-3047 ◽  
Author(s):  
Kevin Y. Urayama ◽  
Anand P. Chokkalingam ◽  
Catherine Metayer ◽  
Xiaomei Ma ◽  
Steve Selvin ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Acute Lymphoblastic Leukemia ◽  
Immune Modulation ◽  
Lymphoblastic Leukemia ◽  
Human Leukocyte ◽  
Potential Interaction ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Childhood All ◽  
Increased Risk ◽  
Ear Infections

Abstract The human leukocyte antigen (HLA) genes are candidate genetic susceptibility loci for childhood acute lymphoblastic leukemia (ALL). We examined the effect of HLA-DP genetic variation on risk and evaluated its potential interaction with 4 proxies for early immune modulation, including measures of infectious exposures in infancy (presence of older siblings, daycare attendance, ear infections) and breastfeeding. A total of 585 ALL cases and 848 controls were genotyped at the HLA-DPA1 and DPB1 loci. Because of potential heterogeneity in effect by race/ethnicity, we included only non-Hispanic white (47%) and Hispanic (53%) children and considered these 2 groups separately in the analysis. Logistic regression analyses showed an increased risk of ALL associated with HLA-DPB1*01:01 (odds ratio [OR] = 1.43, 95% CI, 1.01-2.04) with no heterogeneity by Hispanic ethnicity (P = .969). Analyses of DPB1 supertypes showed a marked childhood ALL association with DP1, particularly for high-hyperdiploid ALL (OR = 1.83; 95% CI, 1.20-2.78). Evidence of interaction was found between DP1 and older sibling (P = .036), and between DP1 and breastfeeding (P = .094), with both showing statistically significant DP1 associations within the lower exposure categories only. These findings support an immune mechanism in the etiology of childhood ALL involving the HLA-DPB1 gene in the context of an insufficiently modulated immune system.

FLT3 inhibition selectively kills childhood acute lymphoblastic leukemia cells with high levels of FLT3 expression

Blood ◽  
2005 ◽  
Vol 105 (2) ◽  
pp. 812-820 ◽  
Author(s):  
Patrick Brown ◽  
Mark Levis ◽  
Sheila Shurtleff ◽  
Dario Campana ◽  
James Downing ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cell ◽  
Childhood Acute Lymphoblastic Leukemia ◽  
Gene Rearrangements ◽  
Childhood All ◽  
Activating Mutations ◽  
Mll Gene ◽  
Flt3 Inhibitor ◽  
Targeted Agent

AbstractFMS-like tyrosine kinase 3 (FLT3) is almost universally expressed in B-precursor childhood acute lymphoblastic leukemia (ALL). Cases of ALL with MLL gene rearrangements and those with high hyperdiploidy (> 50 chromosomes) express the highest levels of FLT3, and activating mutations of FLT3 occur in 18% of MLL-rearranged and 28% of hyperdiploid ALL cases. We determined the antileukemic activity of CEP-701, a potent and selective FLT3 inhibitor, in 8 ALL cell lines and 39 bone marrow samples obtained at diagnosis from infants and children with various subtypes of ALL. CEP-701 induced pronounced apoptotic responses in a higher percentage of samples that expressed high levels of FLT3 (74%, n = 23) compared with samples with low levels of expression (8%, n = 13; P = .0003). Sensitivity to FLT3 inhibition was particularly high in samples with MLL gene rearrangements (82%, n = 11; P = .0005), high hyperdiploidy (100%, n = 5; P = .0007), and/or FLT3 mutations (100%, n = 4; P = .0021). Seven of 7 sensitive samples examined by immunoblotting demonstrated constitutively phosphorylated FLT3 that was potently inhibited by CEP-701, whereas 0 of 6 resistant samples expressed constitutively phosphorylated FLT3. We conclude that the FLT3 inhibitor CEP-701 effectively suppresses FLT3-driven leukemic cell survival. Clinical testing of CEP-701 as a novel molecularly targeted agent for the treatment of childhood ALL is warranted.

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