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Dieter Hoelzer

Publications and source records attributed to Dieter Hoelzer.

At least 19 recordsLinked to original sources
PubMed2006

Molecular relapse in adult standard-risk ALL patients detected by prospective MRD monitoring during and after maintenance treatment: data from the GMALL 06/99 and 07/03 trials.

Although levels of minimal residual disease (MRD) decrease below the detection limit in most adult patients with standard-risk acute lymphoblastic leukemia (ALL) after consolidation treatment, about 30% of these patients will ultimately relapse. To evaluate the power of MRD monitoring as an indicator of impending relapse, we prospectively analyzed postconsolidation samples of 105 patients enrolled in the German Multicenter ALL (GMALL) trial by real-time quantitative polymerase chain reaction (PCR) of clonal immune gene rearrangements. All patients were in hematologic remission, had completed first-year polychemotherapy, and tested MRD negative prior to study entry. Twenty-eight of 105 patients (27%) converted to MRD positivity thereafter, and 17 of 28 (61%) relapsed so far. Median time from molecular (MRD-positive) to clinical relapse was 9.5 months. In 15 of these patients, MRD within the quantitative range of PCR was measured in hematologic remission, and 13 of these patients (89%) relapsed after a median interval of 4.1 months. Of the 77 continuously MRD-negative patients, only 5 (6%) have relapsed. We conclude that conversion to MRD positivity during the early postconsolidation phase in adult standard-risk ALL patients is highly predictive of subsequent hematologic relapse. As a result of the study, as of spring 2006, salvage treatment in the ongoing GMALL trial is intended to be started at the time of recurrence of quantifiable MRD.

Adolescent↗
PubMed2006

High expression of the ETS transcription factor ERG predicts adverse outcome in acute T-lymphoblastic leukemia in adults.

PURPOSE: In adult T-lymphoblastic leukemia (T-ALL) disease-free survival remains limited to 32% to 46%. The adverse prognosis in T-ALL has not been attributed to cytogenetic or molecular aberrations. We have determined the prognostic impact of the oncogenic transcription factor ERG in T-ALL. PATIENTS AND METHODS: ERG expression was analyzed by real-time polymerase chain reaction (PCR) in 105 adults with newly diagnosed T-ALL treated on the German ALL protocols. Patients were dichotomized at ERG's median expression into low (n = 52) and high (n = 53) expressers. Homeobox (HOX) 11 and HOX11L2 expression was determined by real-time PCR. RESULTS: High ERG expressers compared with low ERG expressers had an inferior overall survival (OS, P = .02; 5-year OS: high ERG 26% v low ERG 58%) and relapse-free survival (RFS, P = .003; 5-year RFS: high ERG 34% v low ERG 72%). On multivariable analysis high ERG expression (P = .005), immunophenotypic subgroups (early v mature v thymic T-ALL; overall P = .04), HOX11L2 positivity (P = .055), and absence of HOX11 (P = .017) were independent adverse risk factors predicting RFS. Patients with high ERG expression had a hazard ratio (HR) for relapse of 3.2. Within the good prognostic subgroup of thymic T-ALL (n = 57), high ERG (HR, 4.1; P = .02) and presence of HOX11L2 (HR, 6.6; P = .008) were independent adverse factors for RFS. CONCLUSION: High expression of ERG is an adverse risk factor in adult T-ALL. Within thymic T-ALL, otherwise classified as standard-risk, high ERG expression-identified patients that were four times more likely to fail long-term RFS. The prognostic impact of ERG may assist treatment stratification and suggest the need of alternative regimens.

Adolescent↗
PubMed2006

NUP214-ABL1 in adult T-ALL: the GMALL study group experience.

The NUP214-ABL1 fusion gene in T-cell acute lymphoblastic leukemia (T-ALL) has recently been identified as a possible target for imatinib and related tyrosine kinase inhibitors, but exact data regarding the prognostic impact and frequency of the several putative NUP214-ABL1 mRNA transcripts are still missing. We investigated 279 adult patients with T-ALL treated within the framework of the GMALL 5/93 and 6/99 therapy trials for NUP214-ABL1 by using a novel multiplex real-time, quantitative polymerase chain reaction (PCR). Eleven (3.9%) patients were NUP214-ABL1 positive, and 5 different transcripts were observed; 8 patients had a thymic immunophenotype, 1 had an early T-cell immunophenotype, and 2 had a mature T-cell immunophenotype. NUP214-ABL1-positive and -negative patients did not differ significantly in their major clinical features. In contrast to previous reports suggesting an adverse clinical course for NUP214-ABL1-positive patients, no significant difference in overall survival was observed. Based on the results, we have established and tested a novel PCR method for simplified detection of the NUP214-ABL1 fusion gene.

Adolescent↗
PubMed2006

Nilotinib in imatinib-resistant CML and Philadelphia chromosome-positive ALL.

BACKGROUND: Resistance to imatinib mesylate can occur in chronic myelogenous leukemia (CML). Preclinical in vitro studies have shown that nilotinib (AMN107), a new BCR-ABL tyrosine kinase inhibitor, is more potent than imatinib against CML cells by a factor of 20 to 50. METHODS: In a phase 1 dose-escalation study, we assigned 119 patients with imatinib-resistant CML or acute lymphoblastic leukemia (ALL) to receive nilotinib orally at doses of 50 mg, 100 mg, 200 mg, 400 mg, 600 mg, 800 mg, and 1200 mg once daily and at 400 mg and 600 mg twice daily. RESULTS: Common adverse events were myelosuppression, transient indirect hyperbilirubinemia, and rashes. Of 33 patients with the blastic phase of disease, 13 had a hematologic response and 9 had a cytogenetic response; of 46 patients with the accelerated phase, 33 had a hematologic response and 22 had a cytogenetic response; 11 of 12 patients with the chronic phase had a complete hematologic remission. CONCLUSIONS: Nilotinib has a relatively favorable safety profile and is active in imatinib-resistant CML. (ClinicalTrials.gov number, NCT00109707 [ClinicalTrials.gov].).

Adolescent↗
PubMed2006

[Clinical research within the German competence net "acute and chronic leukemias"].

BACKGROUND: Leukemias are a challenge and a cost factor to society because of their frequency in all age groups. They also serve as a model for a variety of diseases and possess exemplary relevance for basic research and patient care. Leukemia research and therapy have achieved high standards and even a leading position in Germany with regard to clinical trials, standardization of diagnostics and molecular studies of prognostic factors, signal transduction and gene expression. Progress is hampered, however, by fragmentation of leukemia trial groups, diagnostic approaches and treatment research activities. GOALS: A network was therefore created to integrate the leading leukemia trial groups on chronic myeloid leukemia (CML), acute myeloid leukemia (AML), acute lymphatic leukemia (ALL), myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (CMPD) and their interdisciplinary partners (diagnostics, treatment research, biometry) in cooperation with basic research and pharmaceutical industry to foster advancements in leukemiarelated research and health care through clinical trials, promotion of translational research, introduction of standards for diagnostics and therapy, and development of evidence-based guidelines. ACHIEVEMENTS: Achievements include establishment of central information, communication and management structures, creation of an AML intergroup comprising five study groups, formation of an MDS study group and establishment of platforms for diagnostics, genomics and proteomics, and medical informatics. Exchange of scientific progress is mediated by intra- and internet, biannual newsletters, regular project group meetings, and annual network symposia. PERSPECTIVES: On the basis of experience with the Competence Network "Acute and chronic leukemias" with its management, communication and information structures, the "European LeukemiaNet" (ELN) has been established within the 6th Framework Program of the European Union. The ELN integrates 78 leading leukemia trial groups (AML, ALL, CML, CLL, MDS, and CMPD), their 83 interdisciplinary partner groups (diagnostics, treatment research, registry, guidelines), industry and SMEs (small- and medium-sized enterprises) across Europe to form a cooperative network for advancements in leukemia-related research and health care.

Acute Disease↗
PubMed2006

Alternating versus concurrent schedules of imatinib and chemotherapy as front-line therapy for Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL).

The best strategy for incorporating imatinib in front-line treatment of Ph+ acute lymphoblastic leukemia (ALL) has not been established. We enrolled 92 patients with newly diagnosed Ph+ ALL in a prospective, multicenter study to investigate sequentially 2 treatment schedules with imatinib administered concurrent to or alternating with a uniform induction and consolidation regimen. Coadministration of imatinib and induction cycle 2 (INDII) resulted in a complete remission (CR) rate of 95% and polymerase chain reaction (PCR) negativity for BCR-ABL in 52% of patients, compared with 19% in patients in the alternating treatment cohort (P = .01). Remarkably, patients with and without a CR after induction cycle 1 (INDI) had similar hematologic and molecular responses after concurrent imatinib and INDII. In the concurrent cohort, grades III and IV cytopenias and transient hepatotoxicity necessitated interruption of induction in 87% and 53% of patients, respectively; however, duration of induction was not prolonged when compared with patients receiving chemotherapy alone. No imatinib-related severe hematologic or nonhematologic toxicities were noted with the alternating schedule. In each cohort, 77% of patients underwent allogeneic stem cell transplantation (SCT) in first CR (CR1). Both schedules of imatinib have acceptable toxicity and facilitate SCT in CR1 in the majority of patients, but concurrent administration of imatinib and chemotherapy has greater antileukemic efficacy.

Adult↗
PubMed2006

Correction of X-linked chronic granulomatous disease by gene therapy, augmented by insertional activation of MDS1-EVI1, PRDM16 or SETBP1.

Gene transfer into hematopoietic stem cells has been used successfully for correcting lymphoid but not myeloid immunodeficiencies. Here we report on two adults who received gene therapy after nonmyeloablative bone marrow conditioning for the treatment of X-linked chronic granulomatous disease (X-CGD), a primary immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes resulting from mutations in gp91(phox). We detected substantial gene transfer in both individuals' neutrophils that lead to a large number of functionally corrected phagocytes and notable clinical improvement. Large-scale retroviral integration site-distribution analysis showed activating insertions in MDS1-EVI1, PRDM16 or SETBP1 that had influenced regulation of long-term hematopoiesis by expanding gene-corrected myelopoiesis three- to four-fold in both individuals. Although insertional influences have probably reinforced the therapeutic efficacy in this trial, our results suggest that gene therapy in combination with bone marrow conditioning can be successfully used to treat inherited diseases affecting the myeloid compartment such as CGD.

Adult↗
PubMed2006

Inhibition of phosphotyrosine phosphatase 1B causes resistance in BCR-ABL-positive leukemia cells to the ABL kinase inhibitor STI571.

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of BCR-ABL-mediated transformation in vitro and in vivo. To investigate whether PTP1B modulates the biological effects of the abl kinase inhibitor STI571 in BCR-ABL-positive cells, we transfected Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia cell-derived K562 cells with either wild-type PTP1B (K562/PTP1B), a substrate-trapping dominant-negative mutant PTP1B (K562/D181A), or empty vector (K562/mock). Cells were cultured with or without STI571 and analyzed for its effects on proliferation, differentiation, and apoptosis. In both K562/mock and K562/PTP1B cells, 0.25 to 1 mumol/L STI571 induced dose-dependent growth arrest and apoptosis, as measured by a decrease of cell proliferation and an increase of Annexin V-positive cells and/or of cells in the sub-G(1) apoptotic phase. Western blot analysis showed increased protein levels of activated caspase-3 and caspase-8 and induction of poly(ADP-ribose) polymerase cleavage. Low concentrations of STI571 promoted erythroid differentiation of these cells. Conversely, K562/D181A cells displayed significantly lower PTP1B-specific tyrosine phosphatase activity and were significantly less sensitive to STI571-induced growth arrest, apoptosis, and erythroid differentiation. Pharmacologic inhibition of PTP1B activity in wild-type K562 cells, using bis(N,N-dimethylhydroxamido)hydroxooxovanadate, attenuated STI571-induced apoptosis. Lastly, comparison of the STI571-sensitive Ph+ acute lymphoblastic leukemia cell line SupB15 with a STI571-resistant subline revealed significantly decreased PTP1B activity and enhanced BCR-ABL phosphorylation in the STI571-resistant SupB15 cells. In conclusion, functional PTP1B is involved in STI571-induced growth and cell cycle arrest, apoptosis, and differentiation, and attenuation of PTP1B function may contribute to resistance towards STI571.

Antineoplastic Agents↗
PubMed2006

Prostate-apoptosis-response-gene-4 increases sensitivity to TRAIL-induced apoptosis.

The capacity of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) to preferentially induce apoptosis in malignant cells while sparing normal tissues renders it an attractive therapeutic agent. Nevertheless, the molecular determinants governing sensitivity towards TRAIL remain to be defined. Acknowledging the previously demonstrated deregulation of prostate-apoptosis-response-gene-4 (par-4) in ex vivo cells of patients suffering from acute and chronic lymphatic leukemia, we here tested the hypothesis that expression of par-4 influences sensitivity to TRAIL. Evaluating this hypothesis we show, that par-4-transfected T-lymphoblastic Jurkat cells exhibit a considerably increased rate of apoptosis upon incubation with an agonistic TRAIL-antibody as compared to their mock-transfected counterparts. Defining the underlying molecular mechanisms we provide evidence, that par-4 enhances sensitivity towards TRAIL by employing crucial members of the extrinsic pathway. Thus, par-4-overexpressing Jurkat clones show an enforced cleavage of c-Flip(L) together with an increased activation of the initiator caspases-8 and -10. In addition, expression of par-4 enables cells to down-regulate the inhibitor-of-apoptosis proteins cIAP-1, cIAP-2, XIAP and survivin with a concomitantly enhanced activation of the executioner caspases-6 and -7. Supporting the crucial role of caspase-8 in par-4-promoted apoptosis we demonstrate that inhibition of caspase-8 considerably reduces TRAIL-induced apoptosis in par-4 and mock-transfected Jurkat clones and reverses the described molecular changes. In conclusion, we here provide first evidence that expression of par-4 in neoplastic lymphocytes augments sensitivity to TRAIL-induced cell death and outline the responsible molecular mechanisms, in particular the crucial role of caspase-8 activation.

Apoptosis↗
PubMed2006

Novel antibody-based therapy for acute lymphoblastic leukaemia.

In recent decades rapid improvements in the results of treatment of adult acute lymphoblastic leukaemia (ALL) have been achieved. This progress has been based mainly on intensification and optimization of chemotherapy, risk-adapted use of stem-cell transplantation, and improved supportive care. However, results in adult patients are still considerably inferior to those in paediatric ALL, and a barrier to further intensification of chemotherapy appears to have been reached regarding toxicity. More recently, the most significant progress has therefore been achieved by individualized and targeted therapy - for example, treatment with monoclonal antibodies (MoAbs). ALL blast cells express a variety of specific antigens which may serve as targets: e.g. CD19, CD20, CD22, CD33, and CD52. Most experience is available for anti-CD20 (rituximab). In ALL, rituximab is combined with chemotherapy mainly in mature B-ALL and Burkitt's lymphoma, and interim results are very promising. Recently studies with rituximab have also been initiated in B-precursor ALL. Other antibodies would be of interest due to a high rate of antigen (e.g. CD19) expression in ALL, but these are not yet generally available. Clinical application in smaller studies or case reports was reported for anti-CD52 and anti-CD33. Overall it can be stated that MoAb therapy in ALL is a promising treatment approach. Monotherapy with MoAbs in relapsed ALL has also occasionally achieved responses, but greater effects can be expected from combination with chemotherapy and treatment in the state of minimal residual disease. Details of these regimens - required level of antigen expression, timing, schedule, dosage and stage of disease - remain to be defined.

Antibodies, Monoclonal↗
PubMed2006

AIDS-associated Burkitt or Burkitt-like lymphoma: short intensive polychemotherapy is feasible and effective.

The objective was to evaluate the feasibility and efficacy of a short-term, multi-agent and dose intensive regimen in AIDS patients with Burkitt or Burkitt-like lymphoma (BL/BLL) and to compare its efficacy with that of a conventional regimen. This was a retrospective, multi-center cohort study of all HIV-1-infected patients diagnosed with BL/BLL between 1990 - 2004. Patients were assigned to two different chemotherapy approaches. Group A received a protocol which was adapted from the German multi-center study group for adult acute lymphoblastic leukemia (GMALL). Group B received a conventional CHOP-based chemotherapy. Fifty-one patients were included in the analysis. In group A (n = 20), significantly more patients achieved complete remission (75% vs 40%, P = 0.02) than in group B (n = 31). One-year survival in group A was 65% compared to 44% in group B (P = 0.17). In a multi-variable Cox regression analysis, treatment according to the GMALL protocol was significantly associated with prolonged survival with a relative hazard rate of 0.13 (95% CI 0.03 - 0.63, P = 0.01). In conclusion, the short and intensive GMALL protocol for B-ALL/NHL is feasible in patients with AIDS-BL/BLL. Outcome may be improved compared to patients treated with CHOP-based regimens. In the era of HAART, more intensive chemotherapy regimens should be considered in patients with highly aggressive lymphomas.

Adult↗
PubMed2006

Treatment of adult acute lymphoblastic leukemia.

In the early 1980s, adult acute lymphoblastic leukemia (ALL) was a rarely curable disease with overall survival < 10%. After adapting combinations employed by pediatric groups, the outcome improved to 30-40%. A period of stagnation followed with improvement only in distinct subgroups. In the past 5 years, however, striking new developments have been noticeable. Progress has been made in molecular diagnostics of ALL. Improvements to standard therapy including stem cell transplantation (SCT) have occurred and a variety of new drugs for ALL are under evaluation. Rapid diagnosis and classification of ALL is increasingly important to identify prognostic factors and molecular genetic subsets that will be the focus of "targeted" therapies as we enter the era of subset specific treatment. In the following review we will discuss treatment of adult ALL (excluding elderly patients,(1) adolescents(2) and patients with Ph/BCR-ABL positive ALL(3)).

Adult↗
PubMed2006

The molecular biology of TRAIL-mediated signaling and its potential therapeutic exploitation in hematopoietic malignancies.

Tumor necrosis factor apoptosis ligand (TRAIL) is a type II membrane-bound ligand displaying expression in a broad range of tissues and exhibiting a high grade of homology with the cytotoxic Fas ligand. Interest in TRAIL grew after evidence emerged, that induction of TRAIL-mediated signaling destroyed malignant cells while sparing normal cells. Employing the extrinsic pathway of apoptosis, TRAIL-stimulation is characterized by initial adaptor recruitment and the subsequent activation of caspases. Besides promoting apoptosis, stimulation of the TRAIL receptors may also activate survival signals via the transcription factor NF-kappaB. Moreover, evaluation of the physiological roles of TRAIL-mediated signaling pathways provides evidence for a regulatory function within the immune system. Thus a complex picture of TRAIL-mediated signaling evolves, underscoring the necessity to define its modes of action while assessing its therapeutic potential. This review outlines the current knowledge on the physiological role of TRAIL and discusses its therapeutic potential with particular focus on malignancies of the hematopoietic system.

Animals↗
PubMed2006

Novel agents aiming at specific molecular targets increase chemosensitivity and overcome chemoresistance in hematopoietic malignancies.

In hematologic neoplasias primary or secondary resistance of malignant cells towards the applied treatment presents the major clinical obstacle in the induction of remission and definite cure. Evaluation of the underlying molecular mechanisms determining response or resistance not only enables the clinician to define prognostic markers, but moreover facilitates the design of molecularly targeted agents potentially reversing the causative lesion. Deregulation of apoptosis is considered to contribute to the emergence and propagation of the malignant clone, and several molecular alterations hindering programmed cell death and thus leading to chemoresistance have been defined. While reviewing these molecular alterations this article moreover focuses on the impact of new therapeutic agents, which specifically exploit the knowledge of the molecular characteristics of malignant hematopoetic cells.

Animals↗
PubMed2005

Clinical trial of valproic acid and all-trans retinoic acid in patients with poor-risk acute myeloid leukemia.

BACKGROUND: Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, induced in vitro differentiation of primary acute myeloid leukemia (AML) blasts, an effect enhanced by all-trans retinoic acid (ATRA). Clinical responses to VPA were recently observed in patients with myelodysplastic syndrome (MDS). Herein, the authors have described results of a clinical trial with VPA plus ATRA in 26 patients with poor-risk AML. METHODS: VPA (5-10 mg/kg starting dose) and ATRA (45 mg/m(2)) were administered orally. Low-dose AraC or hydroxyurea were permitted to control leukocytosis. Biologic activity of VPA was confirmed by serial analysis of HDAC2 protein levels in peripheral blood (PB) mononuclear cells. RESULTS: Nineteen of 26 patients completed at least 4 weeks of VPA/ATRA treatment; 7 patients were withdrawn prematurely because of rapidly progressive disease (n = 3) or unacceptable neurologic and cardiovascular toxicity (n = 4). Additional cytoreductive treatment was required in 58% of patients enrolled. Median treatment duration was 3 months. No patient achieved complete remission, one with de novo AML had a minor response, and two patients with secondary AML arising from myeloproliferative disorder (MPD) achieved a partial remission and clearance of PB blasts, respectively. The latter responses were accompanied by profound granulocytosis and erythrocytosis in both patients, reminiscent of the response pattern known from ATRA treatment of acute promyelocytic leukemia. However, cytogenetic analysis of isolated CD34(+) cells and granulocytes did not reveal terminal differentiation of leukemic blasts. CONCLUSIONS: Treatment with VPA/ATRA results in transient disease control in a subset of patients with AML that has evolved from a myeloproliferative disorder but not in patients with a primary or MDS-related AML.

Administration, Oral↗
PubMed2005

In vivo drug-response in patients with leukemic non-Hodgkin's lymphomas is associated with in vitro chemosensitivity and gene expression profiling.

Only a few approaches are available to address the mechanisms of cell death in vivo which are induced by anticancer treatment in patients with malignancies. In this study in vitro chemosensitivity testing of primary peripheral blood leukemic cells of five patients suffering from different leukemic non-Hodgkin's lymphomas was combined with the analysis of the in vivo rate of apoptosis by flow-cytometry (Annexin V and depolarisation of mitochondrial membrane potential (MMP) by JC-1). Furthermore, changes in expression patterns of apoptosis related proteins during chemotherapeutic treatment were detected by Western Blot. Gene expression profiling (HG-U133A, Affymetrix, Santa Clara, CA) was employed to identify common marker genes of in vivo drug response. In vitro chemosensitivity was tested using the cytotoxic agents which the patients were scheduled to receive and was strongly correlated with effective reduction of leukemic lymphoma cells in patients resulting in complete remissions in all five cases. Due to the rapid clearance of apoptotic tumor cells in vivo neither the analysis of the in vivo rate of apoptosis and depolarisation of MMP nor the assessment of expression of regulators of apoptosis showed concordant results concerning the drug response. However, assessment of gene expression during therapy could identify a set of 30 genes to significantly discriminate between samples from patients before treatment compared to samples from the same patients after receiving cytotoxic therapy. Among these 30 genes we found a high proportion of genes associated with apoptotic cell death, cell proliferation and cell cycle signalling including complement lysis inhibitor (clusterin/CLU), beta-catenin interacting protein (ICAT), peroxisome proliferator activated receptor alpha (PPARalpha), TNF alpha converting enzyme (ADAM17/TACE), homeo box A3 (HOX1), inositol polyphosphatase 5-phosphatase type IV (PPI5PIV) and inhibitor of p53 induced apoptosis alpha (IPIA-Alpha/NM23-H6). These results indicate that in vitro chemosensitivity testing and gene expression profiling can successfully be utilised to analyse in vivo drug response in patients with leukemic NHL's and can be used to explore new pathway models of drug-induced cell death in vivo which are independent of different lymphoma subtypes and different treatment regimens.

Adenosine↗
PubMed2005

Clinical significance of minimal residual disease quantification in adult patients with standard-risk acute lymphoblastic leukemia.

Adult patients with acute lymphoblastic leukemia (ALL) who are stratified into the standard-risk (SR) group due to the absence of adverse prognostic factors relapse in 40% to 55% of the cases. To identify complementary markers suitable for further treatment stratification in SR ALL, we evaluated the predictive value of minimal residual disease (MRD) and prospectively monitored MRD in 196 strictly defined SR ALL patients at up to 9 time points in the first year of treatment by quantitative polymerase chain reaction (PCR). Frequency of MRD positivity decreased from 88% during early induction to 13% at week 52. MRD was predictive for relapse at various follow-up time points. Combined MRD information from different time points allowed definition of 3 risk groups (P < .001): 10% of patients with a rapid MRD decline to lower than 10(-4) or below detection limit at day 11 and day 24 were classified as low risk and had a 3-year relapse rate (RR) of 0%. A subset of 23% with an MRD of 10(-4) or higher until week 16 formed the high-risk group, with a 3-year RR of 94% (95% confidence interval [CI] 83%-100%). The remaining patients whose RR was 47% (31%-63%) represented the intermediate-risk group. Thus, MRD quantification during treatment identified prognostic subgroups within the otherwise homogeneous SR ALL population who may benefit from individualized treatment.

Adolescent↗