Early T-Cell Precursor Acute Lymphoblastic Leukemia: Diagnosis, Updates in Molecular Pathogenesis, Management, and Novel Therapies

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a distinct subtype of T lymphoblastic leukemia (T-ALL) identified in 2009, due to its unique immunophenotypic and genomic profile. The outcome of patients was poor in earlier studies, and they were prone to have induction failure, with more frequent relapse/refractory disease. Recent advances had been made in discoveries of genetic aberrations and molecular pathogenesis of ETP-ALL. However, the diagnosis and management of ETP-ALL is still challenging. There are limited choices of novel therapies so far. In this review article, it highlighted the diagnostic issue of ETP-ALL, pitfall in diagnosis, and strategy of accurate diagnosis. The review also summarized current understanding of molecular mechanism of leukemogenesis. The emerging role of risk-adapted therapy and allogenic stem cell transplant in optimizing the outcome of patients with ETP-ALL was discussed. Finally, some potential novel therapies were proposed based on the current understanding of molecular pathogenesis.

The Impact of Molecular and Cytogenetic Clonal Evolution on Survival in Relapsed/Refractory AML

Background: Clonal diversity and evolution in acute myeloid leukemia (AML) are consequences of disease progression and play a pivotal role in the development of drug resistance and refractoriness to therapy. Much work has been done with characterizing clonal architecture in bulk tumors samples or single-cell DNA sequencing, but real-world data observing the impact of clonal evolution and responses to therapy remains scarce in the relapsed and refractory settings. Therefore, the purpose of this study was to analyze the impact of observed clonal evolution on survival. Patients & Methods: We retrospectively analyzed 81 patients with AML with relapsed or refractory disease from June 2018 to December 2020. Cytogenetic and molecular data were obtained at the time of diagnosis and the time of primary induction failure or relapse, when available. We identified a total of 24 patients that demonstrated evidence of clonal evolution following induction or salvage therapy. Baseline patient demographics were obtained, including cytogenetic risk and next-generation sequencing molecular profiling at diagnosis and throughout treatment alongside dates and types of induction regimens. We compared the survival of those with evidence of clonal evolution to matched groups without. The groups with and without clonal evolution were compared for baseline statistical differences using an unpaired t-test with Welch's correction and Kaplan-Meier survival analyses were computed and compared with log-rank tests using GraphPad Prism. The event for calculating the overall survival was the date of death with patients otherwise censored at the date of last contact. Results: Of the 24 patients with evidence of clonal evolution, we detected that evolution occurred in four (16.7%) patients at the time of primary induction failure (refractory to first induction), 19 (70.8%) at the time of first relapse, and 3 (12.5%) at the time of second relapse. The median age of patients with clonal evolution was 63 years (range: 23 - 74) with 17 (70.8%) males and 7 (29.2%) females. The most commonly occurring mutations were NPM1 (25.0%), FLT3-ITD (20.8%), and TP53 (20.8%). At the time of initial diagnosis, cytogenetic risk was favorable in one (4.2%), intermediate in 7 (29.2%), and adverse in 16 (66.7%). The majority (79.2%) of patients underwent first induction with 7+3 and 8 (33.3%) patients underwent allogenic SCT. At the time of clonal evolution and ignoring the adverse prognosis associated with relapse, one patient with favorable cytogenetics remained favorable, only one (14.3%) patient with intermediate cytogenetics shifted to adverse, and one (6.3%) patient in the adverse category shifted to intermediate by ELN criteria. Three (12.5%) patients out of 24 acquired FLT3-ITD and three (12.5%) acquired an additional cooperating mutation (NRAS, KRAS, or KIT) for a total of 25.0% acquiring a signaling pathway mutation. Out of 10 patients with either mutated TP53 or MLL, three (27.3%) acquired a cooperating mutation in FLT3 or RAS. We then compared the clonal evolution cohort with the 57 remaining relapsed/refractory patients without evidence of clonal evolution. There was no difference between the groups with respect to baseline characteristics, including age (p = 0.989), ECOG status at diagnosis (p = 0.4689), Charlson Comorbidity Index (CCI) score (p = 0.6454), or prior SCT (p = >0.999). The median overall survival (OS) of the clonal evolution group was 227 days and compared to 382 days in the non-evolution cohort (p = 0.843). Conclusion: We did not detect a significant OS difference between those with clonal evolution and those without. Independent of the adverse prognosis associated with relapsed or refractory disease, cytogenetic risk category appeared to remain the same with clonal evolution. Common trends during clonal evolution included acquisition of one or several cooperating mutations in FLT3 or RAS, both with and without the presence of mutated TP53 and MLL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Intensification of Chemotherapy Using a Modified BFM Backbone for Children, Adolescents and Young Adults with T-Cell Acute Lymphoblastic Leukemia (T-ALL) and T-Cell Lymphoblastic Lymphoma (T-LL) Identifies Highly Chemorefractory Patients Who Benefit from Allogeneic Hematopoietic Stem Cell Transplantation

Background: The prognosis for patients (pts) with relapsed T-ALL and T-LL is dismal. The primary goal of T-ALL/T-LL treatment is to prevent relapse. In the phase 3 Children's Oncology Group (COG) clinical trial AALL1231 (NCT02112916), children, adolescents and young adults (age 1-30 years) with T-ALL and T-LL were treated with a modified augmented BFM (aBFM) backbone that used dexamethasone as the only corticosteroid and included two (rather than one) doses of pegaspargase during induction and delayed intensification. Pts were stratified as standard (SR), intermediate (IR), or very high risk (VHR), primarily based on disease response: morphology, minimal residual disease (MRD) performed by multiparameter flow cytometry at a central reference laboratory) at end of induction and consolidation (T-ALL), and radiographic response for T-LL. Pts were randomized 1:1 to receive/not receive bortezomib during induction and delayed intensification (1.3mg/m 2 x 4 doses per block). VHR T-ALL pts were defined as having day 29 M3 marrow (>25% blasts) or end of consolidation (EOC) MRD >0.1%. 10-15% of T-ALL pts were predicted to be VHR based on COG AALL0434. Pts with induction failure (M3 marrow by morphology) or EOC MRD >0.1% were expected to have 4-yr event-free survival (EFS) of ~66+/-16%. Following consolidation, VHR pts received 3 BFM-based intensification blocks in lieu of interim maintenance (IM). Detectable MRD following the intensification blocks was considered an event and these pts were removed from protocol therapy. VHR ALL pts who had undetectable MRD continued protocol therapy, received delayed intensification, an IM phase with Capizzi escalating methotrexate plus pegaspargase, and maintenance. A secondary aim of AALL1231 was to compare survival in VHR T-ALL pts with EOC MRD ≥ 0.1% but undetectable MRD after intensification of chemotherapy with those who continued to have detectable MRD and were eligible for other treatment strategies, including hematopoietic stem cell transplant (HSCT). This study also analyzed outcomes for pts with M3 marrow at the end of induction. Results: AALL1231 accrued 847 pts (824 eligible and evaluable) of 1400 anticipated from 2014 until early closure. The 3-year EFS for the bortezomib randomization for the SR and IR groups has been reported previously (Teachey, et. al ASH 2020). Because only 2 of 209 T-LL pts were VHR; this report focuses on the outcomes of the 5.2% (32/615) of T-ALL pts who were VHR. In total, 25 VHR T-ALL pts were EOC MRD >0.1%, and 18 of these had MRD sent at the end of HR intensification. Of the 8 pts who became MRD undetectable and continued protocol therapy, only 2 survived (3-year overall survival [OS] 25+15.3%). In contrast, 10 pts who had detectable MRD were taken off protocol and underwent HSCT. Of these 10, only one relapsed (3-year OS 90+12.7%). The 3-year OS for the 10 pts who were M3 at Day 29 was 60.0±17.0%. As there were not enough pts to assess the impact of EOC MRD on pts who were M3 at Day 29, we assessed the impact of EOC MRD on outcomes in M2 (5-25% blasts at Day 29; n = 24) and M3 pts, which defines induction failure in other cooperative groups. M2+M3 T-ALL who were EOC MRD <0.1% (n = 15) had 3-year OS of 86.7±10.0% vs 45.5±15.0% for those with EOC MRD >0.1% (n = 12) pts. Conclusions: T-ALL pts treated on AALL1231 who are EOC MRD ≥0.1% with undetectable MRD after 3 BFM-based intensification blocks had a very poor outcome when treated with standard cytotoxic chemotherapy. In contrast, while patient numbers are small, those pts that remained MRD-positive after 3 intensification blocks and underwent HSCT had an excellent outcome. These data not only impact the recommended treatment for T-ALL pts who are induction and consolidation failures, but also support the importance of the graft-versus-leukemia (GVL) effect in refractory T-ALL. Disclosures Hayashi: Magenta Therapeutics: Consultancy. August: Jazz: Membership on an entity's Board of Directors or advisory committees. Hermiston: Sobi: Consultancy; Novartis: Consultancy. Bollard: Cabeletta Bio: Membership on an entity's Board of Directors or advisory committees; Catamaran Bio and Mana Therapeutics: Other: member and cofounder; SOBI: Other: DSMB. Loh: MediSix therapeutics: Membership on an entity's Board of Directors or advisory committees. Raetz: Pfizer: Research Funding; Celgene: Other: DSMB member. Teachey: BEAM Therapeutics: Consultancy, Research Funding; NeoImmune Tech: Research Funding; Sobi: Consultancy; Janssen: Consultancy.

A Clinically Applicable Gene Expression based Score predicts Resistance to Induction Treatment in Acute Myeloid Leukemia

Prediction of resistant disease at initial diagnosis of acute myeloid leukemia (AML) can be achieved with high accuracy by using cytogenetic data and 29 gene expression markers (PS29MRC). Our aim was to establish PS29MRC as a clinically usable assay by using the widely implemented NanoString platform and further validate the classifier in a more recently treated patient cohort. 351 patients with newly diagnosed AML intensively treated within the AMLCG registry were analyzed. As a continuous variable, PS29MRC performed best in predicting induction failure in comparison to previously published risk models (OR=2.37; p=1.20·10-9). The classifier was strongly associated with overall survival (HR=1.38; p=2.62·10-6). We were able to establish a previously defined cut-off that allows a classifier dichotomization (PS29MRCdic). PS29MRCdic significantly identified induction failure with 59% sensitivity, 77% specificity and 72% overall accuracy (OR=4.81; p=4.15·10-10). PS29MRCdic was able to improve the ELN-2017 risk classification within every category (favorable: OR=5.44; p=0.017; intermediate: OR=4.43; p=0.011; adverse: OR=2.52; p=0.034). Median patients' overall survival with high PS29MRCdic was 1.8 years compared to 4.3 years of low-risk patients. In multivariate analysis including ELN-2017, clinical and genetic markers, only age and PS29MRCdic were independent predictors of refractory disease. In patients aged 60 or older, only PS29MRCdic was left as significant variable. In summary, we confirmed PS29MRC as a valuable classifier that can be calculated and reproduced on a widely available platform to identify high-risk patients in AML. Risk classification can still be refined beyond ELN-2017 and predictive classifiers might facilitate clinical trials focusing on these high-risk AML patients.

NUP-98 Rearrangements Led to the Identification of Candidate Biomarkers for Primary Induction Failure in Pediatric Acute Myeloid Leukemia

Conventional chemotherapy for acute myeloid leukemia regimens generally encompass an intensive induction phase, in order to achieve a morphological remission in terms of bone marrow blasts (<5%). The majority of cases are classified as Primary Induction Response (PIR); unfortunately, 15% of children do not achieve remission and are defined Primary Induction Failure (PIF). This study aims to characterize the gene expression profile of PIF in children with Acute Myeloid Leukemia (AML), in order to detect molecular pathways dysfunctions and identify potential biomarkers. Given that NUP98-rearrangements are enriched in PIF-AML patients, we investigated the association of NUP98-driven genes in primary chemoresistance. Therefore, 85 expression arrays, deposited on GEO database, and 358 RNAseq AML samples, from TARGET program, were analyzed for “Differentially Expressed Genes” (DEGs) between NUP98+ and NUP98-, identifying 110 highly confident NUP98/PIF-associated DEGs. We confirmed, by qRT-PCR, the overexpression of nine DEGs, selected on the bases of the diagnostic accuracy, in a local cohort of PIF patients: SPINK2, TMA7, SPCS2, CDCP1, CAPZA1, FGFR1OP2, MAN1A2, NT5C3A and SRP54. In conclusion, the integrated analysis of NUP98 mutational analysis and transcriptome profiles allowed the identification of novel putative biomarkers for the prediction of PIF in AML.

Immunophenotypic Pattern and Treatment Outcome after Completion of Induction Remission in Children with Acute Lymphoblastic Leukemia

Background: Acute lymphoblastic leukemia (ALL) is presented with different immunophenotypic pattern. Objective: The purpose of the study was to evaluate the immunophenotypic pattern of ALL and also, to recognize the frequency of different ALL subtypes and treatment outcome after induction remission therapy. Methodology: This prospective study was conducted in the Department of Paediatric Hematology and Oncology at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from June 2017 to July 2018 for a period of one year. Newly diagnosed admitted cases of ALL aged 1 to 17.9 years were included. Immunophenotyping from aspirate marrow samples were done in a special hematology laboratory. Patients were monitored during induction remission period with physical examination and required investigations. Result: Among 87 analyzed patients, 81 patients (93.1%) were B-cell ALL and 6 patients (6.9%) were T-cell ALL. After completion of induction remission therapy 61 patients had undergone complete remission and among them B cell ALL were 56(69.1%) and T cell were 5(83.3%) (P=0.464). None of the patient had partial response or induction failure. Complication were developed in 53(60.91%) patients during induction therapy. Most common cause of death was septicemia (22/26). Death was more in patients who had total WBC count >50X109/L (p=0.017) and received regimen B (p=0.031). Conclusion: B cell ALL was more common and most of the patients had undergone complete remission after induction remission therapy. Journal of Current and Advance Medical Research, January 2021;8(1):59-64

Labor-Induced Pregnancy Cases In Dr Soetomo General Hospital: A Descriptive Study

Background: Labor induction is a procedure to stimulate uterine contractions during pregnancy before labor begins on its own to achieve a vaginal birth with medical or mechanical intervention to start the labor. This procedure aims to stimulate more extensive contraction in the uterus. The labor induction can reduce the caesarean rate. Prostaglandin E2 (PGE2) and misoprostol are the commonest medicine used to ripen the cervix in the Dr. Soetomo Hospital. Objective: Our study aim to evaluate the success rate of induction of labor patient. Methods: This study was a descriptive study using the medical record in 2018 in the Dr. Soetomo General Hospital, Surabaya. A total of 183 patient’s medical record data who underwent induced labor were used in this study. Inclusion criteria were the women with indication to deliver and have no cephalo-pelvic disproportion. Women with contraindication labor induction were excluded. Data was described using table and narrative approach. Results: The most range of gestational age was 21-36 weeks (53.01%) followed by 37-42 weeks (42.07%). There were 68 patients (37,1%) primigravida and 115 patients (62,8%) were multipara. The major induced labor was conducted with misoprostol (78.6%), and the most pelvic scores were 2 (58.46%) before underwent induced labor. Vertex delivery was the preferred mode of delivery after the induction of labor with 89 patients (48,62%). The labor induction failure followed with the caesarean operation were 27 patients (14,7%) and one patient (0,54%) with hysterotomy, most of them caused by failure to progress and fetal distress. There were 78 babies (43%) with the weight over 2500 g, 28 babies (31%) were over 2000 g, and the other was below 2000 g. A total of 84.71% with labor induction can be delivered vaginally, and It is a good number to reduce the rate of caesarean operations. Conclusion: This study concludes that misoprostol uses for the induction of labor than the other. Delivery abdominal is less percentage than the additional delivery finds that as a failure of induction of labor. The Labor induction success to delivered vaginally can reduce the rate of caesarean operation.

Case Report: Targeting 2 Antigens as a Promising Strategy in Mixed Phenotype Acute Leukemia: Combination of Blinatumomab With Gemtuzumab Ozogamicin in an Infant With a KMT2A-Rearranged Leukemia

Mixed phenotype acute leukemia (MPAL) accounts for 2-5% of leukemia in children. MPAL are at higher risk of induction failure. Lineage switch (B to M or vice versa) or persistence of only the lymphoid or myeloid clone is frequently observed in biphenotypic/bilineal cases, highlighting their lineage plasticity. The prognosis of MPAL remains bleak, with an event-free survival (EFS) of less than 50% in children. A lymphoid-type therapeutic approach appears to be more effective but failures to achieve complete remission (CR) remain significant. KMT2A fusions account for 75-80% of leukemia in infants under one year of age and remains a major pejorative prognostic factor in the Interfant-06 protocol with a 6 years EFS of only 36%. The search for other therapeutic approaches, in particular immunotherapies that are able to eradicate all MPAL clones, is a major issue. We describe here the feasibility and tolerance of the combination of two targeted immunotherapies, blinatumomab and Gemtuzumab Ozogamicin, in a 4-year-old infant with a primary refractory KTM2A-rearranged MPAL. Our main concern was to determine how to associate these two immunotherapies and we describe how we decided to do it with the parents’ agreement. The good MRD response on the two clones made it possible to continue the curative intent with a hematopoietic stem cell transplant at 9 months of age. Despite a relapse at M11 post-transplant because of the recurrence of a pro-B clone retaining the initial lymphoid phenotype, the child is now 36 months old, in persistent negative MRD CR2 for 12 months after a salvage chemotherapy and an autologous CAR T cells infusion, with no known sequelae to date. This case study can thus lead to the idea of a sequential combination of two immunotherapies targeting two distinct leukemic subclones (or even a single biphenotypic clone), as a potential one to be tested prospectively in children MPAL and even possibly all KMT2A-rearranged infant ALL.