Acute Leukemia Of Ambiguous Lineage Research Articles

Auer rod-positive acute leukemia with predominantly lymphoid immunophenotype: Report on 11 cases and review of literature.

Auer rods (AuRs) are prominent intracellular structures found almost exclusively in myeloid cell malignancies, such as acute myeloid leukemia (AML), chronic and juvenile myelomonocytic leukemia and myelodysplastic syndrome. Extremely rare AuRs have been reported in patients with acute lymphoblastic leukemia (ALL) or among ambiguous lineage leukemia patients with a dominantly lymphoblastic immunophenotype. We report diagnostic and follow-up data of an international cohort of 11 children suffering from leukemias with AuRs and with significant presence of T and myeloid markers, majority of whom categorized as early T-cell precursor (ETP, n=7); or T-ALL (ETP status unknown, n=2), ALAL (acute leukemia of ambiguous lineage, n=1), and AML reclassified from ALAL (n=1). We described other diagnostic details and treatment types and responses. Moreover, we summarize previously published data. Among the four patients who started and remained on ALL-type therapy, all were in the first complete remission, whereas both patients who started and remained on AML-type therapy relapsed and died. Of the patients who followed either a combined ALL/AML protocol (Interfant 06) or who switched from one of the two types of therapy to the other, one patient died, and the remaining four were in first complete remission at the most recent follow-up. We also searched for similar cases in the literature and found only three additional children with nonmyeloid leukemia and AuRs and 10 adults with this type of leukemia. Briefly, ALL- or combined ALL/AML-type therapy may be effective for treating AuR-positive leukemia patients with a lymphoid immunophenotype.

Clinicopathologic features and outcomes of acute leukemia harboring PICALM::MLLT10 fusion

The PICALM::MLLT10 fusion is a rare but recurrent cytogenetic abnormality in acute leukemia, with limited clinicopathologic and outcome data available. Herein, we analyzed 156 acute leukemia patients with PICALM::MLLT10 fusion, including 12 patients from our institutions and 144 patients from the literature. The PICALM::MLLT10 fusion preferentially manifested in pediatric and young adult patients, with a median age of 24 years. T-lymphoblastic leukemia/lymphoma (T-ALL) constituted 65% of cases, acute myeloid leukemia (AML) 27%, and acute leukemia of ambiguous lineage (ALAL) 8%. About half of T-ALL were classified as an early T-precursor (ETP)-ALL. In our institutions’ cohort, mediastinum was the most common extramedullary site of involvement. Eight of 12 patients were diagnosed with T-ALL exhibiting a pro-/pre-T stage phenotype (CD4/CD8-double negative, CD7-positive), and frequent CD79a expression. NGS revealed pathogenic mutations in 5 of 6 tested cases, including NOTCH1, and genes in RAS and JAK-STAT pathways and epigenetic modifiers. Of 138 cases with follow-up, pediatric patients (<18 years) had 5-year overall survival (OS) of 71%, significantly better than adults at 33%. The 5-year OS for AML patients was 25%, notably shorter than T-ALL patients at 54%; this distinction was observed in both pediatric and adult populations. Furthermore, adult but not pediatric ETP-ALL patients demonstrated inferior survival compared to non-ETP-ALL patients. Neither karyotype complexity nor transplant status had a discernible impact on OS. In conclusion, PICALM::MLLT10 fusion is most commonly seen in T-ALL patients, particularly those with an ETP phenotype. AML and adult ETP-ALL patients had adverse prognosis. PICALM::MLTT10 fusion testing should be considered in T-ALL, AML, and ALAL patients.

Immunophenotypic but Not Genetic Changes Reclassify the Majority of Relapsed/Refractory Pediatric Cases of Early T-Cell Precursor Acute Lymphoblastic Leukemia.

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) develops from very early cells with the potential for both T-cell and myeloid differentiation. The ambiguous nature of leukemic blasts in ETP-ALL may lead to immunophenotypic alterations at relapse. Here, we address immunophenotypic alterations and related classification issues, as well as genetic features of relapsed pediatric ETP-ALL. Between 2017 and 2022, 7518 patients were diagnosed with acute leukemia (AL). In addition to conventional immunophenotyping, karyotyping, and FISH studies, we performed next-generation sequencing of the T-cell receptor clonal repertoire and reverse transcription PCR and RNA sequencing for patients with ETP-ALL at both initial diagnosis and relapse. Among a total of 534 patients diagnosed with T-cell ALL (7.1%), 60 had ETP-ALL (11.2%). Ten patients with ETP-ALL experienced relapse or progression on therapy (16.7%), with a median time to event of 5 months (ranging from two weeks to 5 years). Most relapses were classified as AL of ambiguous lineage (n = 5) and acute myeloid leukemia (AML) (n = 4). Major genetic markers of leukemic cells remained unchanged at relapse. Of the patients with relapse, four had polyclonal leukemic populations and a relapse with AML or bilineal mixed-phenotype AL (MPAL). Three patients had clonal TRD rearrangements and relapse with AML, undifferentiated AL, or retention of the ETP-ALL phenotype. ETP-ALL relapse requires careful clinical and laboratory diagnosis. Treatment decisions should rely mainly on initial examination data, taking into account both immunophenotypic and molecular/genetic characteristics.

PICALM::MLLT10 may indicate a new subgroup of acute leukemias with miscellaneous immunophenotype and poor initial treatment response but showing sensitivity to venetoclax.

The PICALM::MLLT10 fusion gene is a rare but recurrent event in acute leukemia (AL) associated with poor prognosis. It is still confused whether PICALM::MLLT10 can solely correspond to acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) or acute leukemias of ambiguous lineage (ALAL). Here, we reported a series of PICALM::MLLT10 positive AL patients with miscellaneous immunophenotype including T-ALL, ALAL, AML, and B-ALL, complex karyotype, half of extramedullary disease (EMD), frequently concomitant PHF6 mutation, and poor initial treatment response to standard chemotherapy aiming to different immunophenotype, but showing sensitivity to combining chemotherapy especially integrated with venetoclax, suggesting this fusion gene may indicate a new subgroup of AL. Eighteen PICALM::MLLT10 positive patients of 533 AL patients (18/533, 3.4%) were identified by RNA sequencing in our center. We found PICALM::MLLT10 positive AL showing miscellaneous immunophenotype, higher expression of leukemic stemness genes and lower expression of biomarkers of venetoclax resistance, more extramedullary involvement, and especially poor response to conventional induction chemotherapy, but may benefit from venetoclax as well as low-dose Ara-C, granulocyte colony-stimulating factor (G-CSF), and anthracyclines combination chemotherapy. Sequential hematopoietic stem cell transplantation (HSCT) after chemotherapy combined with venetoclax may further improve long-term survival in AL patients with complete remission (CR) even measurable residual disease (MRD) positive.

Immunophenotyping in the diagnosis of acute leukemias of ambiguous lineage. The results of centralized diagnosis and practical guidelines

Immunophenotyping in the diagnosis of acute leukemias of ambiguous lineage. The results of centralized diagnosis and practical guidelines

Acute leukemia of ambiguous lineage with BCL11B rearrangement

Acute leukemia of ambiguous lineage with BCL11B rearrangement

Picalm::MLLT10 can Identify a New Subgroup of Acute Leukemias of Ambiguous Lineage with Unique Extramedullary Disease and Treatment Response

Background: Mixed-phenotype acute leukemias (MPAL), which is included in acute leukemias of ambiguous lineage (ALAL), can be classified as four different subtypes based on recurring genetic alterations including BCR::ABL, KMT2A and ZNF384 gene rearrangement as well as BCL11B activation. The 2022 WHO classification has already mentioned PICALM::MLLT10 fusions are also enriched in MPAL but need more data. In 2022 ELN classification, PICALM::MLLT10 was identified as acute myeloid leukemia (AML) with other rare recurring translocations but not ALAL. In addition, there is no separate classification for PICALM::MLLT10 in the new ICC classification. Therefore, it is still confused whether PICALM::MLLT10 corresponds to AML or acute lymphoblastic leukemia (ALL) or ALAL. Methods: Fourteen PICALM::MLLT10 positive patients of 390 AL patients (14/390, 3.6%) were identified by RNA sequencing (RNA-seq) in our center from 2020-2022, including 8 female and 6 male, with a median age of 33 years (16-50 years). These patients were newly diagnosed AL according to bone marrow morphology and immunology including 5 ALAL, 5 T-ALL [ 4 early T-cell precursor ALL (ETP-ALL), 1 cortical T-ALL], 2 AML, 1 B-ALL with aberrant expression of myeloid antigen, and 1 B/T MPAL. Results: The mean white blood cell counts of these patients was 8.25×10 9/L (2.34-51×10 9/L) and platelet counts was 168.5×10 12/L (39-429×10 12/L) individually. It should be mentioned that extramedullary disease (EMD) was found in 7 cases (7/14), including mediastinum, tonsil, and skin. In terms of immunotyping, CD7 was identified in all patients (14/14) and CD33 in 71.4% (10/14) patients. The major concurrence mutations were PHF6 mutation (8/14), JAK3 mutation (5/14), and SUZ12 mutation (4/14). Characteristic cytogenetic abnormality t(10;11)(p12.3;q14.2) was only found in three cases (3/14) (Table 1). The PICALM breakpoints are mainly concentrated in exon 17 (n=6) and exon 19 (n=8). Exon 4 (n=8), exon 6 (n=2), exon 9 (n=2) and exon 10 (n=2) are the most commonbreakpointsof MLLT10. To our knowledge, this is the first report about the breakpoints and fusion gene forms of PICALM::MLLT10. For initial treatment, these patients individually received standard ALL induction chemotherapy (VDPCP, vincristine, idarubicin, pegaspargase, cyclophosphamide, prednisone) and AML induction chemotherapy (3+7 IA regimen including idarubicin, cytarabine). The initial complete remission (CR) rate was only 35.7% (5/14), and 9 patients showing no remission (NR). These NR patients subsequently received salvage chemotherapy. It is worth mentioning that 6 of them received combined chemotherapy regimen including low doses of cytarabine (LDAC), granulocyte colony-stimulating factor (G-CSF) and anthracyclines such as aclarubicin or idarubicin or homoharringtonine (CAG or IAG or HAG), and 2 of 6 patients also further received combination therapy with venetoclax (CAG or IAG +VEN). Finally, 5 of them dramatically achieved CR (5/6). In the other 3 patients, 1 patient who was failure to initial Hyper-CVAD A/B regimen also dramatically achieved CR after the more Hyper-CVAD A regimen combined with venetoclax, and 1 patient achieved CR while another still NR with both receiving CLAG (cladribine, cytarabine, G-CSF) regimen. Subsequently 11 patients (9 CR, 2 with refractory disease) received allogenic hematopoietic stem cell transplantation (allo-HSCT), and all the CR patients survived well after HSCT (follow up 3-24 months, median 15 months) without relapse, while 2 NR patients died soon after transplantation because of severe complications (Table 2). Conclusions: Our data suggested PICALM::MLLT10 positive AL should be more appropriately recognized as an independent ALAL entity and may benefit from LDAC, G-CSF and anthracyclines combination chemotherapy as well as venetoclax. Sequential HSCT after chemotherapy combined with venetoclax may further improve long-term survival in AL patients with CR even MRD positive.

Acute Leukemias of Ambiguous Lineage Have Durable Response to Hypomethylating Agents Plus Venetoclax in Older Patients

Background: The standard of care for frontline therapy of acute leukemias of ambiguous lineage (ALAL) remains controversial due to their rarity; however, outcomes are generally poor. Intensive chemotherapy (IC) regimens are standard, with evidence suggesting that acute lymphoblastic leukemia regimens are more effective than those used for acute myeloid leukemia (AML). Strategies for treating older or frail patients are limited. Although treatment with a hypomethylating agent plus venetoclax (HMA/Ven) is standard therapy for IC-ineligible AML patients, the role of HMA/Ven in ALAL remains poorly characterized. We performed a retrospective chart review of patients at our institution with Philadelphia-negative ALAL, comparing the outcomes of those treated with HMA/Ven and those who received IC. Method: Patients ≥ 18 years treated at Weill Cornell Medical Center with newly diagnosed, pathologically confirmed acute undifferentiated leukemia (AUL), T/myeloid, or Philadelphia chromosome-negative B- and B/T-myeloid leukemia were included. Frontline HMA/Ven was defined as Ven plus azacytydine, decitabine, or oral decitabine/cedazuridine (one patient had initial HMA monotherapy followed by HMA/Ven). Intensive chemotherapy included patients who received variations of standard ALL or AML IC regimens (hyper- or mini-hyper-CV[A]D, cytarabine plus daunorubicin or idarubicin, or cladribine plus idarubicin and cytarabine) with or without Ven. Tyrosine kinase inhibitors including midostaurin or gilteritinib were added for patients with fms-like tyrosine kinase 3 ( FLT3) mutations. Baseline and disease characteristics were collected as well as disease response, subsequent lines of therapy, whether the patient proceeded to allogeneic hematopoietic cell transplantation (HCT), rate of morphologic complete remission (CR), and overall survival (OS). Results: Of 16 patients, 7 received frontline HMA/Ven. B/myeloid was the most common disease type (n=8), followed by T/myeloid (n=4), AUL (n=3), and 1 patient with B/T/myeloid disease. The median age was 74 years (interquartile range [IQR] 62-80). Patients who received HMA/Ven were older than those who received IC, with median ages of 79 (IQR: 77-82) and 62 (IQR: 56-70; p = 0.01), respectively. Baseline white blood cell, hemoglobin, platelet counts, and lactate dehydrogenase, as well as blast percentages in both peripheral blood and bone marrow were similar between the groups. Although not validated in ALAL, markers of adverse myeloid disease as per the ELN 2022 schema were prevalent in both groups, including mutations in RUNX1, ASXL1, SRSF2, and TP53 (Figure A). One HMA/Ven patient and 3 IC patients underwent HCT. Of evaluable patients, 83% and 88% of HMA/Ven and IC patients achieved CRs, respectively. At 2 years, both groups had 50% overall survival (95% CI 22.5-100 in both). Among HMA/Ven recipients, overall survival ranged from 10-56 months, not including two patients with ongoing follow-up at 3 and 46 months (Figure B). Discussion: The treatment of ALAL remains a challenge, particularly in older patients who may be unfit for intensive treatment strategies. In our study, patients who received HMA/Ven had similarly durable disease control to younger patients who received IC in the frontline setting. Prolonged responses were seen in both AUL and MPAL. Multicenter registry and prospective analyses are needed; however, given the rarity of these diagnoses, our findings suggest that HMA/Ven should be considered as a frontline therapy for unfit patients with ALAL.

Canadian Cancer Trials Group SC.26 - Emotion and Symptom-Focused Engagement (EASE): A Multi-Site Randomized Controlled Trial of an Intervention for Individuals with Acute Leukemia

Background: Despite the rapid onset and life-threatening nature of acute leukemia (AL) and its treatment, there is a lack of research on its psychological and physical consequences and even less on interventions to alleviate them [Bryant 2016]. A longitudinal study of individuals with newly diagnosed or recently relapsed AL showed substantial physical and psychological distress in this population [Rodin 2013; Zimmermann 2013]. Based on these findings, an integrated psychosocial and early palliative care intervention, Emotion And Symptom-focused Engagement (EASE), was developed for patients with AL [Rodin 2015]. A phase II randomized pilot trial of EASE vs. usual care demonstrated feasibility and showed promising positive effects on traumatic stress symptoms (primary outcome) and other secondary outcomes, including depressive symptoms, number and severity of physical symptoms and related distress, pain, quality of life (QOL), satisfaction with care, and attachment security [Rodin 2020]. Study design and methods:The Canadian Cancer Trials Group SC.26 (NCT04224974) randomized phase III trial is underway to test the effectiveness and cost-effectiveness of the EASE intervention in AL. EASE is a novel manualized intervention that combines psychological support with routine symptom screening plus triggered referral to palliative care for symptom control. The goal is to reduce psychological distress and symptom burden, and enhance QOL and satisfaction with care in individuals with newly diagnosed AL undergoing induction therapy. Participants are randomized in a 1:1 unblinded ratio to usual care (UC) or UC and EASE (EASE). EASE consists of two components: the psychotherapy intervention (EASE-psy) and triggered early palliative care (EASE-phys). EASE-psy involves tailored supportive psychotherapy delivered by trained therapists over the initial 8 weeks following hospital admission for treatment of AL. It combines elements of relational support, affect regulation, and trauma-informed cognitive behavioural therapy. All patients randomized to EASE receive weekly symptom screening during the initial inpatient treatment period with triggered referral to early palliative care (EASE-phys). Subjects are stratified by centre, age (≤60 vs. &amp;gt;60) and type of acute leukemia (acute myeloid leukemia vs. acute lymphoblastic leukemia). For patients diagnosed with a mixed phenotype acute leukemia, the dominant sub-type is used for stratification purposes. Patients are ≥18 years, newly diagnosed and recruited within 2 weeks of hospital admission, and receiving or expected to receive induction therapy with curative intent. Current exclusion criteria include major communication difficulties at the time of recruitment; receipt of on-site psychological/psychiatric counselling or palliative care services at the time of recruitment; a diagnosis of acute promyelocytic leukemia or acute leukemia of ambiguous lineage. The two primary outcomes reflect the dual nature of the physical and psychosocial components of the EASE intervention: Mean severity of traumatic stress symptoms at 4 weeks using the 30-item Stanford Acute Stress Reaction Questionnaire (SASRQ) [Cardeña 1996] updated to be DSM-5-concordant [American Psychiatric Association 2013] and mean physical symptom severity at 4 weeks using the Memorial Symptom Assessment Scale (MSAS) [Portenoy 1994]. Hypotheses will be tested using multilevel modeling with maximum likelihood estimation, conducted as intention-to-treat analyses. Economic analysis will be conducted to measure the cost-effectiveness of the EASE intervention. Utilities will be derived from the EQ-5D-5L [Herdman 2011] and FACIT-Sp [Webster 2003] questionnaires. The planned sample size of this study is 266. Since January 2022, 53 patients at 4 Canadian centres have undergone randomization. Conclusion: The information obtained from this study will inform clinicians and decision makers of the value of implementing the EASE intervention in adults with AL.

Clinical characteristics of 34 adult patients with acute leukemias of ambiguous lineage

Clinical characteristics of 34 adult patients with acute leukemias of ambiguous lineage

Preliminary Safety and Efficacy of Venetoclax and Selinexor in Combination with Chemotherapy in Pediatric and Young Adult Patients with Relapsed or Refractory Acute Myeloid Leukemia: Selclax

Background: Survival rates for children and adolescent/young adults (AYAs) with relapsed or refractory acute myeloid leukemia (R/R AML) remain poor. Previous clinical trials have demonstrated that the selective inhibitor of nuclear export selinexor and the BCL2 inhibitor venetoclax are each safe and active when combined with chemotherapy in children with R/R AML (NCT02212561, NCT03194932). However, many patients are refractory to these combinations. Preclinical data indicate that selinexor and venetoclax are synergistic and that selinexor may abrogate resistance to venetoclax. We thus aimed to characterize the toxicity profile and explore preliminary activity of venetoclax and selinexor with chemotherapy in pediatric and AYA patients with R/R AML and report results from the dose escalation phase of the SELCLAX clinical trial (NCT04898894). Methods: SELCLAX is a Phase I and expansion cohort study of selinexor and venetoclax in combination with chemotherapy in pediatric and AYA patients with R/R AML. For the dose escalation phase, eligibility criteria included &amp;lt; 30 years of age, adequate organ function and performance status, primary refractory, early first relapse (&amp;lt; 12 months from initial diagnosis), relapsed and refractory to salvage, post-transplant relapse or second or greater relapse AML or acute leukemia of ambiguous lineage (ALAL). The primary endpoint was determination of the recommended phase 2 dose (RP2D) of venetoclax and selinexor with chemotherapy. In the dose level 1 (DL1) cohort, venetoclax was given at 360 mg/m 2 per dose (max 600 mg) on days 1-21 in combination with selinexor at 40 mg/m 2 on days 1, 8, 15. For dose level 2 (DL2), venetoclax was dosed as in DL1, and selinexor was dosed at 40 mg/m 2 twice weekly on days 1, 3, 8, 10, 15, 17. Chemotherapy (fludarabine 30 mg/m 2, cytarabine 2 g/m 2 ± granulocyte colony stimulating factor 5 mcg/kg [FLA(G)]) was given on days 16-20. Response was evaluated by blast percentage in day 8 and 15 peripheral blood and in day 15 and end-cycle bone marrow. Any patient with a two-log (100-fold) reduction in measurable residual disease (MRD) between baseline and Day 15 was designated an “exceptional responder” (ER). At the discretion of the treating physician, ER patients could continue venetoclax until day 28 with additional selinexor (DL1: day 22; DL2: day 22, 24); FLA(G) could either be omitted or given on days 30-34; omission of FLA(G) deemed a patient non-evaluable (NE) for dose-limiting toxicity (DLT). Evaluable patients were assessed for DLTs, and dosing was escalated according to a rolling-six design. Results: As of July 14, 2023, fifteen patients (aged 3-17 years) with R/R AML (n=14) or ALAL (n=1) were enrolled in the dose escalation phase ( Table 1). Nearly all patients had high-risk cytomolecular features: KMT2A-rearranged (n=5), NUP98-rearranged (n=5), -7/del(7) (n=3), or FUS::ERG (n=1). Seven patients were enrolled on DL1 (one NE, replaced); eight patients were enrolled on DL2 (two NE, replaced). In the DL1 cohort, one DLT was reported of grade 3 anorexia requiring nasogastric feeds; however, this was cofounded by a prior history of anorexia, mucositis, and poor dentition requiring extractions and restorations. At DL2, one patient experienced a hematologic DLT with failure to recover absolute neutrophil count above 500/uL and platelet count above 25,000/uL by day 43 from start of FLA(G). There were no DLTs in the other five evaluable patients in DL2 and no serious adverse events (AEs) reported. The most common Grade 3 or 4 AE was febrile neutropenia (16.7%). Of the evaluable patients, five of twelve (41.7%) achieved complete response (CR) or complete response with incomplete count recovery (CRi). One patient was an ER on Day 15 at DL2 and did not receive FLA(G); thus, this patient was not evaluable for DLT assessment. Six patients proceeded to hematopoietic cell transplant after protocol therapy, five of whom are alive to date. Conclusion: Venetoclax and selinexor with FLA(G) chemotherapy is a tolerable combination in pediatric and AYA patients with R/R AML. Early activity of this combination regimen was observed in some patients, including those with primary refractory or early first-relapsed AML. Enrollment of the dose expansion phase at DL2 is underway in two cohorts: venetoclax-naïve and venetoclax-exposed.

Phase 1/2 First-in-Human Study of the Menin-MLL Inhibitor DSP-5336 in Patients with Relapsed or Refractory Acute Leukemia

Introduction: Menin inhibitors are an exciting new class of agents in development for patients (pts) with acute leukemia who overexpress HOXA9 and MEIS1 genes. Although there is a growing list of fusion genes in acute leukemia that appear to be dependent on homeobox-related gene activity, menin inhibition has been shown to be particularly active in pts with NPM1 mutations (NPM1c) and KMT2A rearrangements (MLLr). DSP-5336 is an investigational, oral small molecule designed to inhibit the menin and MLL protein interaction. Methods: A Phase 1/2 study of DSP-5336 is being conducted in pts with relapsed or refractory (R/R) acute leukemia. The dose escalation portion of the study consists of two parallel arms (Arm A: without concomitant anti-fungal azole therapy; Arm B: with concomitant azole therapy). Pts were eligible with R/R AML, ALL or acute leukemia of ambiguous lineage without a limit on number of prior therapies, with a focus on those with MLLr and NPM1c. Results: Accrual is ongoing with 24 pts enrolled as of April 2023; 14 pts in Arm A at doses of 40 mg BID (n=2), 80 mg BID (n=4), 100 mg BID (n=2) and 120 mg BID (n=6), and 10 pts in Arm B at doses of 40 mg BID (n=4) and 60 mg BID (n=6). The median age was 67.0 years (range 20 - 85) and 62.5% were male. All pts had AML except for 1 pt with acute leukemia of ambiguous lineage. Pts had received a median of 3 (range 1 to 9) prior treatments, and 6 (25%) had received prior alloSCT. MLLr or NPM1c were present in 6 (25%) and 4 (17%) patients, respectively. No dose-limiting toxicities have been observed thus far. Most treatment-emergent adverse events (TEAEs) were grade 1/2. TEAEs assessed as related to DSP-5336 in ≥ 3 pts were nausea (Grade 1 or 2, n = 3 pts) and vomiting (Grade 1 or 2, n = 4 pts). Grade &amp;gt;3 TEAEs occurring in ≥ 3 pts included anemia (6 pts), pneumonia (5 pts), sepsis (3 pts) and hypokalemia (3 pts), all unrelated to study drug. A possible Grade 4 differentiation syndrome (DS) was observed in 1 pt with a TP53 mutation in Arm A receiving 80 mg BID although concurrent pneumonia and sepsis made a clear attribution difficult. No other DS events of any grade have been reported to date. No cardiac toxicities, and no QTc prolongation of any grade related to DSP-5336 have been observed. Out of the 6 pts enrolled with MLLr, 4 were treated at dose levels projected to be active based on preclinical modeling (≥ 60 mg BID with azoles, or ≥ 120 mg BID without azoles). Of these 4 pts, all had received prior intensive induction chemotherapy as well as a venetoclax-based regimen, and 3 had received prior allo-transplant. Of these 4 pts, 1 achieved CRi with a duration of therapy of 5.1 months, 1 achieved MLFS with a duration of therapy of 6.2 months (ongoing), and 1 achieved SD with clearance of peripheral blasts, recovery of peripheral counts, resolution of leukemic gingival infiltration, and reduction in bone marrow (BM) blasts from 85% to 31%. Of the 4 enrolled pts with NPM1c, 2 were treated at doses projected to be effective. Stable disease with complete clearance of peripheral blasts were observed in both pts, and BM blasts were reduced by 66% and 83% respectively. Preliminary pharmacokinetic (PK) analysis has demonstrated generally higher mean exposures at higher dose levels. Across all the dose levels, plasma t 1/2 ranged from 2-6 hours in Arm A and from 2-10 hours in Arm B, with T max reached within 2 hours. Little to no drug accumulation was observed with repeat dosing in both arms. Data to date suggests that azoles may not have a significant effect on DSP-5336 exposure, but enrollment and comparative analyses are ongoing. Target pharmacodynamic changes have been achieved in pts who have MLLr or NPM1m, including rapid decreases in HOXA9, MEIS1, and PBX3 with treatment and, conversely, increases in CD11b compared to pretreatment. Conclusion: DSP-5336 has been well tolerated with no DLTs to date in heavily pretreated R/R AML patients with NPM1c and MLLr AML. Importantly, no cardiac signals (including no QTcF prolongation) have been observed. PK studies have not identified a significant drug-drug interaction with azoles. Although there are early signs of clinical activity and pharmacodynamic changes during administration of DSP-5336, the study is ongoing to determine a recommended Phase 2 dose for single-agent expansion and potential combination regimens. Updated safety and efficacy data will be presented at the meeting.

Idarubicin Versus Daunorubicin Versus Mitoxantrone for Induction Chemotherapy in Acute Myeloid Leukemia: Patient Registration Study of Turkish Society of Hematology-Acute Myeloid Leukemia Working Group

Introduction: Standard induction chemotherapy in newly diagnosed acute myeloid leukemia (AML) includes a combination of standard-dose cytarabine and an anthracycline (idarubicin [IDA], daunorubicin [DNR], or mitoxantrone [MXR]). Anthracycline selection is still not standardized, and the impact of anthracycline selection on survival and response in patients with adverse genetic risk is of interest. The study aimed to retrospectively compare the effectiveness of induction regimens with respect to anthracycline preference. Methods: The study population was recruited from the Turkish AML Registry project database based on documentation of newly diagnosed AML and induction chemotherapy with IDA, DAU, or MXR in combination with cytarabine. Patients diagnosed before 31 August 2022 were received typical “7 + 3” induction chemotherapy containing 3 days of IDA, DAU, or MXR. Results: The study included 317 newly diagnosed AML patients (median age 51; range, 18 - 79; 55.2% male). Of the patients, IDA was administered in 266 (83.9%), DNR in 42 (13.2%), and MXR in 9 (2.8%). The three anthracycline treatment groups were similar between age, gender, type of AML by the World Health Organization (WHO), and risk classification by 2017 European LeukemiaNet (ELN) when evaluated according to the baseline disease characteristics. At the time of diagnosis, although the median white blood cell levels were 19 x 10 9/L (0.4 - 355) in the IDA, 7.8 x 10 9/L (0.7 - 357.2) in the DAU, and 5.5 x 10 9/L (0.6 - 34) in the MXR therapy group (p = 0.019); the hemoglobin and platelet levels and bone marrow blast percentage were similar between the treatment groups. FMS-like tyrosine kinase-3 internal tandem duplication ( FLT3-ITD) (p = 0.561) and Nucleophosmin 1 gene ( NPM1) (p = 0.430) mutation frequencies were also similar between treatment groups. Morphological complete remission (CR) was documented in 65% of all evaluable patients. Among the patient groups, CR was 67.7% for IDA, 50% for DNR, and 55.6% for MXR (p = 0.081). In univariate analysis (Table 1), significant predictors of overall survival (OS) were age ≥60 years (p &amp;lt;0.001), acute leukemias of ambiguous lineage (p &amp;lt;0.001), presence of disseminated intravascular coagulation (DIC) (p = 0.012), and FLT3-ITD mutation (p = 0.018); no significant interaction was noted between NPM1 mutation and OS (p = 0.059). Additionally, when idarubicin was taken as a reference, there was no meaningful relationship between anthracycline type and OS (p values for daunorubicin and mitoxantrone were 0.145 and 0.356, respectively). In multivariate analysis (Table 1), age ≥60 years (p = 0.001), acute leukemias of ambiguous lineage (p = 0.007), and the presence of DIC (p = 0.040) remained significant. After a median follow-up of 29.8 months, 32.5% relapse cases were documented and similarly distributed among IDA (33.1%), DNR (31%), and MXR (22.2%) therapy groups (p = 0.771). During the same period, allogeneic hematopoietic stem cell transplantation (AHSCT) was documented in 10.9% and 26.2% of patients treated for IDA and DNR, respectively. No patient progressed to AHSCT in the MXR arm (p &amp;lt;0.001). In the study, 142 (44.8%) deaths were reported, and there was a 48.5%, 26.2%, and 22.2% mortality rate between the IDA, DNR, and MXR treatment groups, respectively. There was no significant difference in OS by anthracycline type in both the study cohort and age group &amp;lt;60 years (Figures 1A and 1B). There was also no significant difference in OS in patients with the adverse genetic risk group and &amp;lt;60 years age group with adverse genetic risk, according to 2017ELN (Figures 1C and 1D). The results may have been influenced by the number of patients in the treatment groups of the retrospective study and by differences in fitness levels that needed to be measured systematically. Conclusions: We are encouraged that our findings mostly agree with previously published studies and that IDA, DNR, and MXR offer comparable survival values in the research and the younger patient groups. In the future, the ever-changing treatment environment in patient groups with targetable mutations makes choosing the optimal anthracycline for induction chemotherapy in AML much more difficult.

The results of therapy with venetoclax, daratumumab and plerixafor as part of the conditioning regimen in chemotherapy-refractory acute leukemia in children

The main outcomes of allogeneic hematopoietic stem cell transplantation (HSCT) in chemotherapy-refractory acute leukemia remain suboptimal due to a high relapse rate. The incorporation of targeted anti-leukemia agents into the conditioning regimens is a potential approach to improve the efficacy of HSCT. We assessed the safety and potential efficacy of the addition of venetoclax, daratumumab, and plerixafor to the conditioning regimens in children with chemotherapy-refractory acute leukemias who received allogeneic TCRab/CD19-depleted HSCT. We used data from a pilot study, as well as the data of patients from a retrospective cohort who received similar therapy according to the individual indications. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. All 43 patients (33 acute myeloid leukemias (AML), 8 T-cell acute lymphoblastic leukemias (T-ALL) and 2 acute leukemias of ambiguous lineage) had active disease status at the time of transplantation. The preparative regimen included myeloablative conditioning based on either total body irradiation or treosulfan or melphalan. A haploidentical related donor was used as a graft source in 38 cases, while a fully matched related or unrelated donor was used in 5 cases. The engraftment was observed in 93% of cases, no excessive toxicity was noted. MRD-negative complete remission was achieved in 37 patients (86%). The cumulative incidence of grade II–IV acute graft-versus-host disease (GvHD) was 10%, and the cumulative incidence of chronic GvHD was 5%. At 2 years, transplant-related mortality was 7%, relapse incidence was 52%, event-free survival was 41%, and overall survival was 51%. The overall survival rate for the AML group was 58% and 25% for the T-ALL group. Our data show that the addition of targeted agents to the conditioning regimens is safe, however, does not significantly improve the results of HSCT in the study cohort of patients.

The International Consensus Classification of acute leukemias of ambiguous lineage

The International Consensus Classification of acute leukemias of ambiguous lineage

A Pilot Study of Azacitidine As Epigenetic Priming for Chemotherapy in Infants Less Than 1 Year of Age with KMT2A-Rearranged Acute Lymphoblastic Leukemia (ALL); Results from the Children's Oncology Group (COG) Trial AALL15P1

Introduction Acute lymphoblastic leukemia (ALL) with KMT2A-rearrangement (KMT2A-r) in infants <1 year is a high-risk childhood ALL subtype, with consistently poor event-free survival (EFS) of approximately 35% when treated with intensive chemotherapy with or without hematopoietic stem cell transplant. Infant ALL blasts are characterized by DNA hypermethylation, which is hypothesized to contribute to chemoresistance by altering transcriptional regulation of gene expression. In preclinical studies of KMT2A-r blasts, epigenetic priming with DNA methyltransferase inhibitors improved the in vitro cytotoxicity of chemotherapy. Azacitidine, a pyrimidine nucleoside analog of cytidine and hypomethylating agent, has been used in combination with chemotherapy in children with leukemia. We previously reported that azacitidine was safe and well tolerated in AALL15P1 (ASPHO 2021) and herein we report survival outcomes. Methods The Children's Oncology Group (COG) trial AALL15P1 (NCT02828358) was a single arm, open label, groupwide pilot trial. The primary aim of the trial was to evaluate the tolerability of azacitidine in addition to Interfant-06 standard chemotherapy in infants with newly diagnosed KMT2A-r ALL. Estimation of 5-year EFS was an exploratory aim, given the small sample size. Eligibility criteria included B-ALL or acute leukemia of ambiguous lineage with ≥50% B-lymphoblasts, <366 days of age at diagnosis, and >36 weeks gestational age at enrollment. Exclusions included Down syndrome, secondary ALL, and prior cytotoxic therapy (except intrathecal chemotherapy or corticosteroids). Following an Interfant-based induction, infants with KMT2A-r received 4 courses of azacitidine, 2.5 mg/kg/dose intravenously over 10-40 minutes daily for 5 consecutive days in each course, immediately preceding the start of a chemotherapy course on day 6. Infants without KMT2A-r were removed from protocol following induction and did not receive azacitidine. Treatment failure was defined as failure to achieve M1 marrow status (<5% blasts by morphology) with resolution of extramedullary leukemia by the end of consolidation. EFS and overall survival (OS) were measured from the time of enrollment. Results The study accrued from March 2017 to December 2019 and all protocol-directed treatment concluded in December 2021. Of the 78 infants enrolled, 56 had KMT2A-r (72%), and 53 completed induction therapy and received at least 1 course of azacitidine. No patients were ineligible. Diagnostic clinical characteristics of infants with KMT2A-r included four infants age <7 days (7%), 13 age <90 days (23%), 18 with white blood cell count ≥300,000/µL (32%), 32 CNS2 (57%), and four CNS3 (7%). As of the data cutoff (06/30/2022), the median follow-up is 3.8 years, and the 3-year EFS (SE) and OS (SE) rates are 34.2% (+/- 0.08) and 63.8% (+/-0.08), respectively, for infants with KMT2A-r. Six infants experienced treatment failure. Minimal residual disease (MRD) levels of marrow blasts by flow cytometry in COG-approved laboratories were submitted for 49 KMT2A-r patients at the end of induction. Of those, 32 were MRD negative <0.01% (65%), eight MRD positive 0.01%-<1% (16%) and nine MRD positive ≥1% (18%). Event-free survival was significantly associated with MRD; the 3-year EFS of patients with any positive MRD was 20.6% (+/-0.13) vs. 40.1% (+/-0.09) (p=0.0185) for those without MRD. As previously reported, at no time did the trial meet or exceed the pre-determined dose limiting toxicity boundaries, and the rates and types of toxicities observed were within the expected range for infants receiving standard chemotherapy alone. Conclusions Epigenetic priming with azacitidine prior to standard chemotherapy was well tolerated in infants with KMT2A-r ALL, but the EFS was consistent with the poor survival of historical outcomes. Positive flow MRD at the end of induction predicted a higher risk of treatment failure, relapse, or death, in comparison to negative MRD, but EFS was still unacceptably low for MRD-negative patients. There remains an urgent need for improved therapies for infants with KMT2A-r ALL. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Antigen Directed Therapy Pre-Transplant Confers Superior Post-Transplant Survival Outcome Compared to Conventional Chemotherapy in Pediatric Patients with Relapsed and Refractory B-ALL

Background: Hematopoietic stem cell transplant (HCT) represents the most effective mean to achieve cure for children, adolescents and young adults with relapsed or refractory (R/R) B-ALL. Among the several disease-specific and transplant-specific characteristics evaluated so far, achievement of minimal residual disease (MRD) negative complete remission (CR) prior to HCT is the strongest independent prognostic factor of post-HCT outcome. Antigen directed therapies (ADT) such as blinatumomab, inotuzumab ozogamicin and chimeric antigen receptor (CAR) T-cell are very effective at inducing MRD-negative remission and offer an alternative approach for disease control in patients with chemo-resistant disease. We hypothesized that ADT may provide a more durable disease control and lesser morbidity than conventional chemotherapy (CT) and therefore we sought to explore whether the type of treatment (ADT or CT) adopted to achieve MRD negative CR prior to HCT, impacts post-HCT outcomes. Patients and methods: This is a retrospective, multi-institutional cohort study of patients (pts) with R/R B-ALL who received an allogeneic HCT in MRD negative CR between 2010-2021. Patients were eligible if they were ≤30 years at time of diagnosis of R/R B-ALL, had received either CT or ADT (blinatumomab, CAR T-cell, inotuzumab ozogamicin with or without preceding chemotherapy) for the treatment of R/R B-ALL and had achieved MRD negative CR (<0.01% blasts by flow cytometry) prior to HCT. Patients with isolated extramedullary relapse or acute leukemia of ambiguous lineage or history of prior HCT were excluded. Patients were categorized as being in the "CT" or "ADT" group based on whether they received conventional CT or ADT as last cycle that led to MRD negativity prior to HCT. The primary objective of the study was to compare the EFS, OS and treatment related mortality (TRM) from time of transplant according to the therapy (ADT vs. CT) received pre-HCT. Kaplan-Meier or Aalen-Johansen estimates were used to estimate survival rates and curves were compared using logrank or Gray's tests. Results: Seventy-six pts from 7 centers met eligibility criteria; 38 pts (50.0%) received ADT and 38 pts (50.0%) received chemotherapy as last cycle prior to HCT. Demographic, disease and treatment characteristics are summarized in Table 1; notably, more pts in the ADT group had refractory leukemia and more pts had received ≥4 cycles of therapy before achieving MRD negative remission in the ADT group than in the CT group. The 5-yr. EFS and OS for the entire cohort were 53% and 67%, respectively. EFS was superior in the ADT group compared to the CT group (5-yr. EFS 64% vs. 42%, p=0.04; Figure 1). OS was also superior in the ADT group (85% vs. 47%, p=0.0008; Figure 1). In a univariable and multivariable prognostic model for OS that included age, race, having relapsed or refractory disease and CT or ADT as pre-HCT therapy, pre-HCT therapy was the only significant prognostic factor (p<0.001); in a similar model for EFS, pre-HCT therapy was the only significant prognostic factor in the univariable analysis (p=0.04) but not in the multivariable analysis. There was no difference in the incidence of acute GVHD, rate of immune reconstitution at day 100, time to engraftment and cumulative incidence of relapse between the two groups. However, the CT group appeared to have a higher rate of both TRM (33.0% vs. 8%, p=0.01) and relapse related mortality, although not significant for the latter (19% vs. 7% p=0.12). Conclusion: This multicenter study shows that having received ADT prior to HCT may be beneficial when compared to conventional chemotherapy for patients with R/R B-ALL who receive a HCT in MRD negative CR. Patients who received ADT experienced a superior EFS and OS primarily due to a significantly lower TRM, despite having received more cycles of therapy prior to proceeding to HCT. There was no difference in the relapse rate among the two groups further supporting the notion that MRD negative CR is the single most important predictor of post-HCT relapse. Further analysis is ongoing to identify specific factors that could explain the difference in post-HCT mortality among the 2 groups. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Acute Leukemias of Ambiguous Lineage presenting in Extramedullary Location – Unusual and Challenging Diagnoses: A Report of Two Cases

Abstract Introduction/Objective Acute leukemias of ambiguous lineage are uncommon, accounting for &amp;lt;1% of all leukemias, and extramedullary presentations of these leukemias are rare. Methods/Case Report We report two cases of acute leukemia of ambiguous lineage presenting in extramedullary sites. Case 1 is a 41-year-old female who presented with right cervical lymphadenopathy and fatigue. Laboratory and imaging studies showed leukopenia, anemia, and abnormal cervical, supraclavicular, axillary, mediastinal, and abdominal pelvic lymphadenopathy. Biopsy of the axillary lymph node revealed sheets of morphologic blasts. Flow cytometry showed the blasts were of mixed phenotype, with T-cell differentiation supported by CD3 and TdT, and myeloid subpopulation supported by myeloperoxidase and lysozyme. Both these populations were negative for CD10, CD20, CD4, CD8, CD34, CD138, CD1a, CD79a. The morphology and immunophenote establish the diagnosis of T/myeloid mixed-phenotype acute leukemia, not otherwise specified. Case 2 is a 65-year-old female who presented with bilateral lower extremity weakness. Multiple lytic lesions involving the thoracic and cervical spine were detected by imaging. Biopsy of a T12 vertebral lesion revealed sheets of large malignant cells. Extensive immunohistochemical workup revealed positivity for CD45 (weak), CD4, and CD43, supporting a diagnosis of hematopoietic neoplasm of likely hematopoietic origin. Subsequent evaluation eventually led to discovery of chronic myeloid leukemia in blast phase with undifferentiated blasts, BCR-ABL1 positive, originally presenting as extramedullary acute leukemia with undifferentiated blasts. Results (if a Case Study enter NA) NA. Conclusion These cases highlight the challenges of diagnosing peripheral solid tumors of unknown origin. Extramedullary presentation of acute leukemia of ambiguous lineage are particularly challenging and, although rare, include phenotypes ranging from mixed phenotype to undifferentiated types.

Genomic Landscape of Mixed-Phenotype Acute Leukemia.

Mixed-phenotype leukemia (MPAL) is a type of acute leukemia in which the blast population shows mixed features of myeloid, T-lymphoid, and/or B-lymphoid differentiation. MPALs are rare and carry a poor prognosis, thus, often pose both a diagnostic and therapeutic challenge. Conventionally, the diagnosis of MPAL requires either a single blast population with a lineage-defining phenotypic expression of multiple lineages (myeloid, B-cell and/or T-cell) (biphenotypic) or two distinct blast populations that each independently satisfy criteria for designation as AML, B-ALL, and/or T-ALL (bilineage). Given the rarity of MPAL, minimal studies have been performed to describe the genomic landscape of these neoplasms. IRB approval was obtained. Central MCC database was searched for any patient with a diagnosis of acute undifferentiated leukemia (AUL), acute leukemia of ambiguous lineage (ALAL), and MPAL. All patient diagnoses were manually reviewed by a hematopathologist to confirm the diagnosis of MPAL. Genomic and molecular data were collated from the EMR and bioinformatically from MCC genomics repositories. Twenty-eight patients with MPAL were identified. Thirteen were female and 15 were male. Average age was 56 years old (range = 28–81). Ten cases were biclonal and 18 were biphenotypic. Diagnoses were as follows: B/myeloid (n = 18), T/myeloid (n = 9), and T/B (n = 1). Cytogenetic analysis (Karyotype +/− FISH) was available for 27 patients. The most frequent recurrent abnormalities were complex karyotype (n = 8), BCR/ABL1 translocation (n = 6), Del 5q/−5 (n = 4), Polysomy 21 (n = 4). Mutational analysis was available for 18 patients wherein mutations were detected in 45 unique genes. The most frequently mutated genes were TP53 (7), RUNX1 (6), WT1 (4), MLL2 (3), FLT3 (3), CBL (2), ASXL1 (2), TET2 (2), MAP3K6 (2), MLL (2), and MAP3K1 (2). Targetable or potentially targetable biomarkers were found in 56% of cases. Overall survival was 19.5 months (range = 0–70 m). Ten patients were treated with an allogeneic stem cell transplant and had superior outcome (p = 0.0013). In one the largest series of MPAL cases to date, we corroborate previous findings with enriched detection of RUNX1 and FLT3–ITD mutations along with discovery of unreported mutations (MAP3K) that may be amenable to therapeutic manipulation. We also report the frequent occurrence of AML with MDS-related changes (AML-MRC)-defining cytogenetic abnormalities (26%). Finally, we show that those patients that received stem cell transplant had a better overall survival. Our findings support the need to genomically profile MPAL cases to exploit opportunities for targeted therapies in this orphan disease with dismal prognosis.

How I Diagnose Acute Leukemia of Ambiguous Lineage.

Classification of acute leukemia involves assigning lineage by resemblance to normal progenitor cells. This approach provides descriptive information about the blast cells that is useful for disease monitoring, provides clues to pathogenesis, and can help clinicians select effective chemotherapeutic regimens. Acute leukemias of ambiguous lineage (ALALs) are those leukemias that either fail to show evidence of myeloid, B-, or T-lymphoid lineage commitment or show evidence of commitment to more than 1 lineage. The different treatment regimens for acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) make ALAL a challenge both diagnostically and therapeutically. Current classification criteria have reduced the reported incidence of mixed-lineage leukemias by emphasizing fewer markers and categorizing some biphenotypic leukemias with recurrent cytogenetic abnormalities as other entities. Several recent studies have explored the genomic and epigenetic landscape of mixed-phenotype acute leukemia (MPAL) and have suggested a further refinement of the World Health Organization classification to emphasize the genomic heterogeneity of MPAL. Genomic and expression profile data for MPAL reveal mutations commonly seen in both AML and ALL, with T-/myeloid MPAL showing overlapping features with early T-cell precursor lymphoblastic leukemia. Our review aimed to discuss the diagnostic challenges, recent genomic studies, and therapeutic strategies in this poorly understood disease.