Search

Context: B-cell precursor acute lymphoblastic leukemia (BCP ALL) is a genetically heterogeneous neoplasm with >20 biologic subtypes. Each subtype shows specific genetic traits that determine relapse risk and patients' survival. Objectives: To establish the genetic subtype (primary alteration) of adult BCP ALL patients enrolled in the PETHEMA LAL19 trial (NCT 04179929) and to correlate them with measurable residual disease (MRD) level and survival. Patients and Methods: In the LAL19 trial (NCT04179929), Ph-negative patients (18–65 y) with MRD≥0.01% at day+35 or high-risk genetics receive alloHSCT and MRD

Context: There is a debate regarding the impact of t(1;19) (q23;p13) in adult BCP ALL. While the MD Anderson group suggests it may be a low-risk subtype, the German, English, and French study groups have shown no differential outcome, and Italian and SWOG groups have reported poor outcomes. Objective: To analyze the frequency and clinical impact of t(1;19) in a series of adult BCP ALL patients (pts). Design & Patients: A review of 513 adult BCP ALL pts (15 to 60 years) diagnosed between 2003 and 2017 and treated with MRD-oriented protocols of the PETHEMA Group. Interventions: G-banding and FISH were performed on BM samples. Measurable residual disease (MRD) was centrally assessed by multi-parametric flow cytometry. Main Outcomes Measures: Complete response (CR), overall survival (OS) and cumulative incidence of relapse (CIR), assessed by competing risk analysis. Results: Total of 26 pts with t(1;19)/TCF3-PBX1 (representing 5% of all BCP ALL). 9/23 (39%) cases showed isolated t(1;19) while 14/23 (61%) had additional chromosomal aberrations (ACA). Pts with t(1;19) were more likely to be female (73% vs 45%, p=0.006) and pre-B phenotype (63% vs 17%, p Conclusions: Although showing favorable initial treatment response, pts with t(1;19) experience a higher rate of relapse (especially those with ACA to t(1;19)) than the remaining BCP ALL pts, without differences in OS. A deeper genetic analysis may identify markers of poor outcome enabling a more precise risk stratification of t(1;19) pts.

Background and objective The standardization of treatment of older adults with Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL) is challenging, especially in the age range of 55–65 years. This study aimed to compare intensive, pediatric-inspired therapy with non-intensive therapy in this population of patients. Patients and methods The outcomes of 67 patients prospectively included in two consecutive pediatric-inspired intensive protocols (ALL-HR03 and ALL-HR11) from the Spanish PETHEMA Group were compared with those from 44 patients included in a contemporary semi-intensive protocol (ALL-OLD07). Results Baseline patient and ALL characteristics were similar in both groups, except for a younger median age in the intensive group (medians: 58 vs. 62 years). Patients treated intensively had a higher complete remission rate (85% vs. 64%, p = 0.005), a lower cumulative incidence of relapse (39% [95%CI, 25% to 52%] vs. 60% [95%CI, 38% to 77%], p = .003), a similar cumulative incidence of treatment-related mortality (28% [95% CI, 18%, 40%] vs. 21% [95% CI, 10%, 34%]) and superior event-free survival at 2 years (37% [95%CI, 25%–49%) vs. 21% [8%-34%], p = 0.002). On multivariable analysis the type of protocol was the only variable with independent significance for event-free survival (HR [95% CI]: 2 [1.3, 3], p = .002). Conclusions Compared with less intensive chemotherapy, pediatric-inspired intensive chemotherapy significantly improves the outcome of older adults with Ph-negative ALL in the age range of 55–65 years.

Background No standardized and widely accepted cytogenetic classification with prognostic impact for adult T-ALL has been proposed to date. Methods Patients with abnormal karyotypes (65/139, 47%) were classified according to the number of chromosomal alterations (Chun K. et al., 2009). Cohort 216 adults T-ALL patients/ NCT00853008 - NCT01540812 /PETHEMA cooperative group. Prognostic impact of karyotype on event-free survival (EFS), overall survival (OS), and cumulative incidence of relapse (CIR) were assessed. Additionally, next-generation sequencing (NGS) experiments were done. Results Greater than three cytogenetic abnormalities were associated with lower rates of both complete remission (CR, 77% vs. 94%; p=0.032) and minimal residual disease (MRD) level Conclusions Compared to BCP-ALL, a lower cut-off to define complex karyotypes based on the presence of ≥3 cytogenetic alterations allows the identification of T-ALL patients with poor prognosis. Interestingly, molecular analyses of patients carrying ≥3 cytogenetic alterations revealed a unique molecular profile that could contribute to understanding the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R-directed) that might improve the response to treatment and outcome of adult T-ALL patients. Funding ISCIII (PI19/01828), co-funded by ERDF/ESF, “A way to make Europe”/”Investing in your future”.

[EN]: [Background and objective]: Unlike Burkitt lymphoma, molecular abnormalities other than C-MYC rearrangements have scarcely been studied in patients with mature B acute lymphoblastic leukemia (B-ALL). The aim of this study was to analyze the frequency and prognostic significance of copy number alterations (CNA) in genes involved in lymphoid differentiation, cell cycle and tumor suppression in adult patients with B-ALL. [Patients and methods]: We have analyzed by multiplex ligation-dependent probe amplification the genetic material from bone marrow at diagnosis from 25 adult B-ALL patients treated with rituximab and specific chemotherapy. [Results]: The most frequent CNA were alterations in the 14q32.33 region (11 cases, 44%) followed by alterations in the cell cycle regulator genes CDKN2A/B and RB1 (16%). No correlation between the presence of specific CNA and the clinical-biologic features or the response to therapy was found. [Conclusions]: The high frequency of CNA in the 14q32.33 region, CDKN2A/B and RB1 found in our study could contribute to the aggressiveness and invasiveness of mature B-ALL., [ES]: [Fundamento y objetivo]: A diferencia del linfoma de Burkitt, las alteraciones moleculares distintas a los reordenamientos de C-MYC apenas se han estudiado en pacientes con leucemia linfoblástica aguda B (LLA-B) madura. El objetivo de este estudio fue analizar la frecuencia y el significado pronóstico de las copy number alterations (CNA, «alteraciones del número de copias») en genes clave de la diferenciación de los linfocitos, ciclo celular y supresores de tumores en pacientes adultos. [Pacientes y métodos]: Se analizaron, por amplificación de sondas dependiente de ligamento múltiple, muestras de médula ósea en el momento del diagnóstico de 25 adultos con LLA-B madura tratados con rituximab y quimioterapia específica. [Resultados]: Las CNA más frecuentes fueron las alteraciones en la región 14q32.33 (11 casos, 44%), seguidas de las alteraciones en los genes reguladores del ciclo celular CDKN2A/B y RB1 (16%). No se encontró correlación entre la presencia de estas CNA y las características clínico-biológicas o de respuesta al tratamiento. [Conclusiones]: La alta frecuencia de alteraciones en la región 14q32.33, CDKN2A/B y RB1 encontradas en este estudio podría explicar la agresividad e invasividad de la LLA-B madura.

Context IKZF1 (Ikaros) deletion has been proposed as a poor prognostic factor in B-cell precursor acute lymphoblastic leukemia (BCP ALL) in children and adults. Objective To analyze the frequency and prognostic impact of IKZF1 deletions in adult BCP ALL patients. To identify the IKZF1 gene expression signature to find patients with different deletion isoforms and therapeutic opportunities. Patients and methods MLPA or SNP array samples of 151 (109 Ph-negative and 42 Ph+) adult BCP ALL patients treated with MRD-oriented protocols from the PETHEMA Group. RNAseq was performed in 48 of them (27 Ph-negative and 21 Ph+). Results Median age was 40 [15–72] years. Ph+ patients showed older age (52 [20;72] vs. 36 [15;68] years, p 1.5 in RNAseq data analysis, we identified a robust IKZF1 deletion gene expression profile. This resulted in 119 significantly upregulated genes after multi-comparison adjustment (i.e. CCND1, LAMA3, SLC2A9, SNAI1, LDHC, CD34, ID3, CDH2, MAF) and 39 downregulated genes (i.e. ROBO1, HES6, KREMEN1, DHCR24, ABHD15). Downregulated genes were involved in Slit/Robo/EMT, Notch, Wnt/beta-catenin, and glucose and fatty acid metabolism pathways, while upregulated genes were involved in focal adhesion, ROS homeostasis, histone modification, anaerobic metabolism, stem cell quiescence, and IL-6/STAT pathways. A significant number of dysregulated gene targets of chemotherapeutic agents (retinoic acid, doxorubicin, cisplatin, gemcitabine) and targeted therapies, such as FAKi, ERKi, BCL2i, mTORi, JAKi, BRKi, EGFRi and CDKi, were identified. Conclusions Adult BCP ALL patients with IKZF1 partial gene deletions showed poor prognosis. Gene expression analysis enables the identification of potentially targetable lesions. Funding Supported in part by a grant from the Instituto de Salud Carlos III, Ministerio de Economia y Competividad, Spain (PI14/01971); 2017 SGR288 (GRC) Generalitat de Catalunya; and support from CERCA Programme/Generalitat de Catalunya, Fundacio Internacional Josep Carreras. The research leading to this invention has received funding from “la Caixa” Foundation.

Resumen La leucemia aguda linfoblastica (LAL) es la neoplasia mas frecuente en ninos y la principal causa de morbilidad entre las alteraciones hematicas infantiles. Existen 2 subtipos, segun el progenitor linfoide afectado: LAL-B y LAL-T. La LAL-T es menos frecuente e historicamente se asociaba a mal pronostico tanto en adultos como en ninos, aunque en la actualidad los resultados del tratamiento no difieren significativamente entre ambos tipos de LAL. La LAL-T es el subtipo mas complejo y heterogeneo a nivel genetico y el que menos alternativas terapeuticas nuevas presenta en el momento actual. Esta tendencia esta cambiando merced a los progresos notables que se estan efectuando en el conocimiento de su biologia. En esta revision se resumen los hallazgos biologicos mas importantes en la LAL-T efectuados en los ultimos anos y sus posibles implicaciones terapeuticas.

Introduction In the last years genome wide profilings have identified recurrent Copy Number Alterations (CNA) in genes potentially involved in the pathogenesis of Acute Lymphoblastic Leukemia (ALL). These studies have identified deletions in B-cell development genes (IKZF1, EBF1, PAX5, TCF3, etc.), cell cycle regulation genes (CDKN2A/B, RB1, TP53, etc.), glucocorticoid resistance genes (BTG1, CREBBP) and growth factor receptors genes (CRLF2, CSF2RA, IL3RA) among others. Some of these CNA (i.e. IKZF1, CDKN2A, CRLF2) have been reported to have prognostic significance in several pediatric series but there are very few data regarding their impact in B-lineage adult ALL. Our aim was to analyze the frequency and prognostic significance of CNA in a series of 125 B-lineage adult ALL patients treated according to risk-adapted protocols from the Spanish PETHEMA Group. Methods Bone marrow or peripheral blood (with significant blast burden) samples from 125 B-lineage adult ALL patients enrolled in risk-adapted protocols from the PETHEMA Group were analyzed at diagnosis. MLPA assays (MRC-Holland) were performed for the following genes: IKZF1, IKZF2, IKZF3, EBF1, CDKN2A/B, PAX5, ETV6, BTG1, RB1, hsa-miR-31, X/Y PAR1 region genes (CRLF2, CSF2RA, IL3RA) and 14q32.33 region genes (IGH D, MTA1, KIAA0284). Fragment analysis was made by Genescan in an ABI-3130 sequencer (Applied Biosystems). Data normalization provided a value indicative of the presence or absence of CNA: 0-0.20 homozygous deletion, 0.21-0.70 heterozygous deletion, 0.71-1.30 normal, 1.31-1.70 heterozygous duplication and 1.71-2.20 homozygous duplication. Results The median age [range] was 40 [15-74] years, 71 (57%) males, median WBC count 12.11 x109/L [0.4-388]. Immunophenotype: pro-B 14 (11%), common 71 (58%), pre-B 26 (21%), mature-B 10 (8%), unavailable 2 (2%). Cytogenetics: normal 16 (13%), hyperdiploid 6 (5%), hypodiploid 2 (2%), t(9:22) 20 (16%), t(1;19) 8 (6%), 11q23/MLL 11 (9%), 8q24/C-MYC 7 (5%), complex 1 (1%), iAMP21 2 (2%), other translocations or deletions 31 (25%), no growth 20 (16%). CNA frequencies of the 125 patients are shown in the table. IKZF1 deletions were significantly associated with EBF1 deletions, high WBC count and Philadelphia (Ph) chromosome. In the IKZF1 deleted cohort whole gene deletions were as frequent as Ik6 isoforms (28% each). A high codeletion rate was detected in genes located in 9p (CDKN2A/B with PAX5, CDKN2A/B with hsa-miR-31 and PAX5 with hsa-miR-31). CDKN2A/B also showed concomitant deletions with ETV6 while PAX5 showed codeletions with BTG1. CDKN2A/B and PAX5 deleted patients had higher WBC counts than non-deleted individuals. Clinical follow-up data was available for 123 patients of the whole series and for the 105 patients of the Ph-negative cohort. Multivariate analysis showed that advanced age, BTG1 deletions and EBF1 deletions were negative prognostic factors for achieving Complete Remission (CR) and WBC count and IKZF1 deletions significantly reduced CR duration in both cohorts. Interestingly, there were significant differences in relapse rates between whole and partial gene IKZF1 deletions. IKZF1 haploinsufficient patients had a probability of CR duration at 3 years of 83% ± 30% vs. 6% ± 12% of partial gene deletion carriers. Advanced age and IKZF1 deletions were predictors for overall survival in the Ph-negative cohort and age>30 years, IKZF1 deletions and hsa-miR-31 deletions were associated with poor prognosis in the whole series. Conclusions In B-lineage adult ALL, deletions of IKZF1, EBF1, BTG1 or hsa-miR-31 are markers with prognostic significance in addition to age and WBC count. Patients with partial IKZF1 gene deletions have a significantly higher probability of relapse than those with whole gene loss. These genetic abnormalities could help to better define prognostic subgroups in adult patients with B-lineage ALL. Supported by the grants PI10/01417 and RD12-0036-0029 from Instituto Carlos III and a grant from the Spanish Society of Hematology and Hemotherapy (2012). Disclosures: No relevant conflicts of interest to declare.

S174 EBF1 and PAX5 deletions. In the IKZF1 deleted cohort, 13 patients (28%) showed whole gene deletions and Ik6 was the most recurrent short isoform (26%). Multivariate analysis showed that advanced age andEBF1 deletions were negative prognostic factors for achieving Complete Remission (CR) andWBC count and IKZF1 deletions significantly reduced CR duration in both the total series and in the Ph negative subgroup. Interestingly, there were significant differences in relapse rates between whole and partial IKZF1 deletions. IKZF1 haploinsufficient patients had a probability of CR duration at 6 years of 70% 36% vs. 14% 17% of partial gene deletion carriers (p1⁄40.013). Advanced age and CDKN2A/B deletions were predictors for overall survival in the whole series but also in the Ph negative subgroup. Conclusions: IKZF1, EBF1 and CDKN2A/B genetic abnormalities could help to better define prognostic subgroups in adult patients with B-ALL. Deletion Duplication IKZF1 46 (34%) 1 (1%) EBF1 15 (11%) 10 (7%)