Immunotherapeutic targeting of surfaceome heterogeneity in AML.

Immunotherapy remains underexploited in acute myeloid leukemia (AML) compared to other hematological malignancies. Currently, gemtuzumab ozogamicin is the only therapeutic antibody approved for this disease. Here, to identify potential targets for immunotherapeutic intervention, we analyze the surface proteome of 100 genetically diverse primary human AML specimens for the identification of cell surface proteins and conduct single-cell transcriptome analyses on a subset of these specimens to assess antigen expression at the sub-population level. Through this comprehensive effort, we successfully identify numerous antigens and markers preferentially expressed by primitive AML cells. Many identified antigens are targeted by therapeutic antibodies currently under clinical evaluation for various cancer types, highlighting the potential therapeutic value of the approach. Importantly, this initiative uncovers AML heterogeneity at the surfaceome level, identifies several antigens and potential primitive cell markers characterizing AML subgroups, and positions immunotherapy as a promising approach to target AML subgroup specificities.

Outcomes and adverse events in older acute lymphoblastic Leukemia patients treated with a pediatric-inspired protocol with Pegylated or native Asparaginase.

This retrospective report presents the outcomes and adverse events (AEs) observed in 73 patients aged 60 years or older diagnosed with Philadelphia Chromosome-negative Acute Lymphoblastic Leukemia (Ph-negative ALL) treated with a pediatric-inspired protocol incorporating either Pegylated (PEG-ASP) or Native Asparaginase (EC-ASP). Notably, 61% of patients experienced AEs of Grade III-IV severity. The most prevalent AEs included thrombosis (35.6%), febrile neutropenia (38.4%), and transaminitis (34.2%). AEs did not translate into significant differences concerning overall survival, leukemia-free survival, or early mortality. Furthermore, we observed a reduction in early mortality rates (11% vs. 20%) and an increase in median overall survival (54 vs. 48 months) compared to our previous data. These findings suggest that the utilization of a pediatric-inspired chemotherapy protocol, with ASP, is an effective and well-tolerated therapeutic option for older patients with Ph-negative ALL. However, it emphasizes the importance of diligent monitoring and close follow-up throughout treatment.

Outcomes of intensive and nonintensive blast-reduction strategies in accelerated and blast-phase MPN.

ABSTRACT: Transformation of BCR::ABL1-negative myeloproliferative neoplasms (MPN) to an accelerated or blast phase is associated with poor outcomes. The efficacy of acute myeloid leukemia (AML)-type intensive and nonintensive hypomethylating agent-based regimens is not well studied. We therefore performed a retrospective analysis of patients with MPN-AP/BP (N = 138) treated with intensive (N = 81) and nonintensive (N = 57) blast-reduction strategies. We used clinically relatable response criteria developed at the Princess Margaret Cancer Centre. The overall best response, comprising complete remission (CR), complete remission with incomplete hematologic recovery (CRi), and reversion to chronic phase MPN (cMPN), in the intensive and nonintensive groups was 77% (62 of 81) and 39% (21 of 54), respectively. Similar overall best response rates were observed in patients receiving induction with daunorubicin combined with cytarabine arabinoside (daunorubicin + ara-C) (74% [23 of 31]) or FLAG-IDA/NOVE-HiDAC (78% [39 of 50], P = .78). However, patients receiving daunorubicin + ara-C more often required second inductions (29% [9 of 31] vs 4% [2 of 50], P = .002). Most responses in the entire cohort were reversions to cMPN (55 of 83 [66%]). CR and CRi comprised 30% (25 of 83) and 4% (3 of 83) of responses, respectively. Mutations in TP53 (overall response [OR] 8.2 [95% confidence interval [CI] 2.01, 37.1], P = .004) and RAS pathway (OR 5.1 [95%CI 1.2, 23.7], P = .03) were associated with inferior treatment response for intensively treated patients, and poorer performance status (Eastern Cooperative Oncology Group) was associated with inferior treatment response in both intensively (OR 10.4 [95% CI 2.0, 78.5], P = .009) and nonintensively treated groups (OR 12 [95% CI 2.04, 230.3], P = .02). In patients with paired samples before and after therapy (N = 26), there was a significant residual mutation burden remaining irrespective of response to blast-reduction therapy.

DELE1 haploinsufficiency causes resistance to mitochondrial stress-induced apoptosis in monosomy 5/del(5q) AML.

Monosomy 5 and deletions of the chromosome 5q (-5/del(5q)) are recurrent events in de novo adult acute myeloid leukemia (AML), reaching up to 40% of cases in secondary AML. These chromosome anomalies are associated with TP53 mutations and with very poor prognosis. Using the large Leucegene genomic and transcriptomic dataset composed of 48 -5/del(5q) patient specimens and 367 control AML, we identified DELE1 - located in the common deleted region - as the most consistently downregulated gene in these leukemias. DELE1 encodes a mitochondrial protein recently characterized as the relay of mitochondrial stress to the cytosol through a newly defined OMA1-DELE1-HRI pathway which ultimately leads to the activation of ATF4, the master transcription factor of the integrated stress response. Here, we showed that the partial loss of DELE1 expression observed in -5/del(5q) patients was sufficient to significantly reduce the sensitivity to mitochondrial stress in AML cells. Overall, our results suggest that DELE1 haploinsufficiency could represent a new driver mechanism in -5/del(5q) AML.

Characteristics and clinical outcomes of patients with acute myeloid leukemia with inv(3)(q21q26.2) or t(3;3)(q21;q26.2).

Acute myeloid leukemia (AML) with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) has a very poor prognosis. Determinants of clinical outcomes and optimal treatment remain uncertain. We retrospectively reviewed 108 cases of AML with inv(3)/t(3;3) and evaluated clinicopathological characteristics and clinical outcomes: 53 newly diagnosed (ND) AML and 55 relapsed/refractory (R/R) AML. Median age was 55 years. White blood cell (WBC) count ≥20x109/L and platelet count ≥140x109/L was observed in 25% and 32% of ND patients, respectively. Anomalies involving chromosome 7 were identified in 56% of patients. The most frequently mutated genes were SF3B1, PTPN11, NRAS, KRAS and ASXL1. In ND patients, the composite complete remission (CRc) rate was 46% overall; 46% with high-intensity treatments and 47% with lowintensity treatments. The 30-day mortality was 14% and 0%, with high- and low-intensity treatment, respectively. In R/R patients, the CRc rate was 14%. Venetoclax based-regimens were associated with a CRc rate of 33%. The 3-year overall survival (OS) was 8.8% and 7.1% in ND and R/R patients, respectively. The 3-year cumulative incidence of relapse was 81.7% overall. Older age, high WBC, high peripheral blast count, secondary AML and KRAS, ASXL1, DNMT3A mutations were associated with worse OS in univariable analyses. The 5-year OS rates were 44% and 6% with or without hematopoietic stem cell transplantation in CR1, respectively. AML with inv(3)/t(3;3) is associated with low CR rates, very high risk of relapse and dismal long-term survival. Intensive chemotherapy and hy pomethylating agents provide similar rates of remission and patients achieving CR benefit from hematopoietic stem cell transplantation in first CR.

Stem cell architecture drives myelodysplastic syndrome progression and predicts response to venetoclax-based therapy.

Myelodysplastic syndromes (MDS) are heterogeneous neoplastic disorders of hematopoietic stem cells (HSCs). The current standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, almost 50% of MDS patients fail HMA therapy and progress to acute myeloid leukemia, facing a dismal prognosis due to lack of approved second-line treatment options. As cancer stem cells are the seeds of disease progression, we investigated the biological properties of the MDS HSCs that drive disease evolution, seeking to uncover vulnerabilities that could be therapeutically exploited. Through integrative molecular profiling of HSCs and progenitor cells in large patient cohorts, we found that MDS HSCs in two distinct differentiation states are maintained throughout the clinical course of the disease, and expand at progression, depending on recurrent activation of the anti-apoptotic regulator BCL-2 or nuclear factor-kappa B-mediated survival pathways. Pharmacologically inhibiting these pathways depleted MDS HSCs and reduced tumor burden in experimental systems. Further, patients with MDS who progressed after failure to frontline HMA therapy and whose HSCs upregulated BCL-2 achieved improved clinical responses to venetoclax-based therapy in the clinical setting. Overall, our study uncovers that HSC architectures in MDS are potential predictive biomarkers to guide second-line treatments after HMA failure. These findings warrant further investigation of HSC-specific survival pathways to identify new therapeutic targets of clinical potential in MDS.

Outcomes of acute lymphoblastic leukemia with KMT2A (MLL) rearrangement: the MD Anderson experience.

Acute lymphoblastic leukemia (ALL) with t(4;11)(q21;q23)-KMT2A-AFF1 is associated with a poor prognosis. The impact of KMT2A rearrangements other than t(4;11) is uncertain, and the benefit of allogeneic stem cell transplantation (HSCT) is unclear. We reviewed adult patients with ALL treated at our institution from 1984 to 2019 and identified 50 out of 1102 (5%) with KMT2A rearrangement, including 42 (84%) with t(4;11)/KMT2A-AFF1 and 8 (16%) with other gene partners. The median age was 45 years (range, 18-78 years); median white blood cell count was 109.0 3 109/L (range, 0.5-1573.0). The complete remission (CR) rate was 88%, and the rate of measurable residual disease negativity by flow cytometry at CR was 41% (76% overall during follow-up). At the last follow-up, 14 patients were alive. The 5-year overall survival (OS) rate was 18% (95% confidence interval [CI], 9% to 35%), with no difference between t(4;11) and other KMT2A rearrangements (P 5 .87). In a 4-month landmark analysis, the 5-year OS rate was 32% (95% CI, 14% to 70%) in patients who underwent HSCT vs 11% (95% CI, 3-39) in others (P 5 .10). Our study confirms the poor prognosis of ALL with any KMT2A rearrangement and the role of HSCT in these patients.

Long-term outcome of hyper-CVAD-R for Burkitt leukemia/lymphoma and high-grade B-cell lymphoma: focus on CNS relapse.

Burkitt leukemia/lymphoma (BL) and high-grade B-cell lymphoma (HGBL) have a high incidence of central nervous system (CNS) involvement, which is associated with poor prognosis. The hyper-cyclophosphamide, vincristine, Adriamycin, and dexamethasone plus rituximab (CVAD-R) regimen includes systemic and intrathecal CNS-directed therapy to treat and prevent CNS disease. We report here the long-term safety and efficacy of the hyper-CVAD-R regimen in adults with BL and HGBL, focusing on its efficacy to prevent CNS relapse. Among 79 adults (54 BL, 25 HGBL), the median age was 44 years (25% ≥60 years old), 73% had bone marrow (BM) involvement, and 28% had CNS involvement. The complete response rate was 91% (BL 96%; HGBCL 79%; P = .16). The 5-year relapse-free survival (RFS) and overall survival (OS) rates were 58% and 52%, respectively. The cumulative incidence of relapse (CIR) was 21% (BL 14%; HGBCL 37%, P = .06) and was associated with baseline BM (27% vs 0%; P = .02) and CNS (42% vs 12%; P < .01) involvement. In multivariate analyses, age and CNS involvement were independent predictors for OS and RFS. The 5-year CNS CIR was 6% (BL 4%; HGBL 11%; P = .31); 16% with baseline CNS involvement (P = .03). Our data support the use of hyper-CVAD-R in preventing CNS relapse, especially among high-risk patients with BM or CNS involvement.

Validation, Implementation, and Clinical Impact of the Oncomine Myeloid Targeted-Amplicon DNA and RNA Ion Semiconductor Sequencing Assay.

The identification of clinically significant genes recurrently mutated in myeloid malignancies necessitates expanding diagnostic testing with higher throughput, such as targeted next-generation sequencing. We present validation of the Thermo Fisher Oncomine Myeloid Next-Generation Sequencing Panel (OMP), targeting 40 genes and 29 fusion drivers recurrently mutated in myeloid malignancies. The study includes data from a sample exchange between two Canadian hospitals demonstrating high concordance for detection of DNA and RNA aberrations. Clinical validation demonstrates high accuracy, sensitivity, and specificity of the OMP, with a lower limit of detection of 5% for single-nucleotide variants and 10% for insertions/deletions. Prospective sequencing was performed for 187 samples from 168 unique patients presenting with suspected or confirmed myeloid malignancy and other hematological conditions to assess clinical impact of identifying variants. Of detected variants, 48% facilitated or clarified diagnoses, 29% affected prognoses, and 25% had the potential to influence clinical management. Of note, OMP was essential to identifying patients with premalignant clonal states likely contributing to cytopenias. We also found that the detection of even a single variant by the OMP assay, versus 0 variants, was predictive of overall survival, independent of age, sex, or diagnosis (P = 0.03). This study demonstrates that molecular profiling of myeloid malignancies with the OMP represents a promising strategy to advance molecular diagnostics.

Hyper-CVAD regimen in combination with ofatumumab as frontline therapy for adults with Philadelphia chromosome-negative B-cell acute lymphoblastic leukaemia: a single-arm, phase 2 trial.

BACKGROUND: The addition of rituximab to intensive chemotherapy improves outcomes in patients with B-cell acute lymphoblastic leukaemia. Ofatumumab is an anti-CD20 monoclonal antibody that binds to the small extracellular loop of CD20 and has greater in vitro complement-mediated cytotoxicity than rituximab. In this study, we assessed the activity and safety of ofatumumab in combination with chemotherapy in patients with Philadelphia chromosome (Ph)-negative CD20-positive B-cell acute lymphoblastic leukaemia. METHODS: This was a single-arm, phase 2 trial done at the MD Anderson Cancer Center (Houston, TX, USA). Patients with newly diagnosed, Ph-negative B-cell acute lymphoblastic leukaemia or lymphoblastic lymphoma with CD20 expression of at least 1% were eligible. Patients were treated with up to eight courses of the hyper-CVAD regimen (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) on courses 1, 3, 5, and 7 alternating with high-dose methotrexate and cytarabine on courses 2, 4, 6, and 8. Ofatumumab was administered on days 1 and 11 of courses 1 and 3 and on days 1 and 8 of courses 2 and 4 for a total of eight doses. The first dose of ofatumumab was 300 mg intravenously and all subsequent doses were 2000 mg intravenously. Patients received 30 courses of maintenance therapy with 6-mercaptopurine, vincristine, methotrexate, and prednisone (POMP), with four intensification courses (high-dose methotrexate plus L-asparaginase and hyper-CVAD plus ofatumumab on courses 6-7 and 18-19). The primary endpoints were event-free survival, overall response, and overall survival. All enrolled patients were included in the primary and safety analyses. The trial is registered with ClinicalTrials.gov, NCT01363128. FINDINGS: Between Aug 26, 2011, and May 18, 2017, 69 patients (67 patients had B-cell acute lymphoblastic leukaemia and two had B-cell lymphoblastic lymphoma; median age 41 years [IQR 32-50]) were enrolled and treated, including 33 (48%) aged between 18 and 39 years. Nine (27%) of 33 patients had Ph-like acute lymphoblastic leukaemia. With a median follow-up of 44 months (26-53), 4-year event-free survival was 59% (95% CI 48-73); 69% (54-87) in adolescents and young adults aged 18-39 years. 4-year overall survival was 68% (58-81); 74% (60-91) in adolescents and young adults. The overall response rate was 98% (64 of 65 patients). The most common non-haematological grade 3 or 4 adverse events were infections (35 [54%] of 65 patients during induction and 53 [78%] of 68 patients during consolidation). Ten (14%) of 69 patients died in complete remission from sepsis (two [3%]), cardiac arrest (one [1%]), therapy-related acute myeloid leukaemia (two [3%]), and haematopoietic stem-cell transplantation complications (five [7%]). None of these deaths were considered related to ofatumumab treatment by the study investigators. INTERPRETATION: The combination of hyper-CVAD plus ofatumumab is safe and active in adults with Ph-negative CD20-positive B-cell acute lymphoblastic leukaemia. Modifications of this regimen with the addition of novel monoclonal and bispecific antibody constructs targeting CD19 and CD22 might further improve outcomes and allow reduction in the intensity and duration of chemotherapy. FUNDING: Novartis.

Characteristics and outcomes of patients with therapy-related acute myeloid leukemia with normal karyotype.

Normal karyotype in therapy-related acute myeloid leukemia (t-AML) is rare and the relative contribution of prior exposure to chemotherapy or radiotherapy to outcomes in these patients remains uncertain. We performed a retrospective study of 742 patients with newly diagnosed AML and normal karyotype (t-AML, n = 61, and non-t-AML, n = 681). Patients with t-AML were older but had a similar mutational profile compared to those with non-t-AML. Overall survival (OS) and relapse-free survival (RFS) were significantly worse for patients with t-AML (P < 0.01 and P = 0.02, respectively). Patients with t-AML had a higher cumulative incidence of death in remission (51% versus 16%, P < 0.01), but not higher cumulative incidence of relapse (42% versus 56%, respectively, P = 0.21). Both intensive induction and allogeneic hematopoietic stem cell transplantation in first remission were associated with improved OS and RFS in non-t-AML but not in t-AML. Overall, although disease biology appears similar between t-AML and non-t-AML with normal karyotype as indicated by similar risks of relapse, death in remission is the main driver of inferior outcome in t-AML. Careful therapeutic decisions are required to mitigate potential treatment-related toxicity in this rare subgroup of patients with t-AML and normal karyotype.

Clinical Experience With Venetoclax Combined With Chemotherapy for Relapsed or Refractory T-Cell Acute Lymphoblastic Leukemia.

BACKGROUND: Patients with relapsed or refractory (R/R) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) have dismal outcomes. Preclinical studies have suggested that T-ALL cells are sensitive to BCL2 inhibition. The clinical activity of venetoclax, a selective BCL2 inhibitor, in T-ALL is unknown. PATIENT AND METHODS: We retrospectively reviewed the efficacy and safety of venetoclax combined with chemotherapy for patients with R/R T-ALL treated at our institution. RESULTS: Thirteen patients with R/R T-ALL with a median age of 46 years (range, 20-75 years) were treated with venetoclax plus chemotherapy. Five patients (38%) had early T-cell precursor ALL. The patients had received a median of 2 previous lines of therapy (range, 1-11). Venetoclax at a median dose of 200 mg/d for 21 days, generally with a concomitant azole antifungal, was combined with various agents, including hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone), asparaginase, nelarabine, decitabine, or other intensive chemotherapy. Of the 10 patients evaluable for bone marrow response, 6 (60%) achieved a remission with bone marrow blasts < 5%, including 3 with complete hematologic recovery. The median overall survival and relapse-free survival were 7.7 and 4.0 months, respectively. No early death or clinically significant tumor lysis syndrome were reported. The median interval to neutrophil recovery and platelet recovery were 15 days and 44 days, respectively, with prolonged cytopenias observed with venetoclax 400 mg/d or when given for > 14 days per cycle. CONCLUSION: Combination therapy with venetoclax showed promising clinical efficacy in R/R T-ALL. Further studies are warranted to evaluate the clinical benefit of BCL2 inhibitors in T-ALL.

Unique case of ANCA-negative pauci-immune necrotizing glomerulonephritis with diffuse alveolar hemorrhage, potentially associated with midostaurin.

We present a 61-year-old male with FLT3-mutated acute myeloid leukemia treated with midostaurin who developed acute kidney injury requiring hemodialysis and pulmonary renal syndrome. Antibodies to proteinase-3, myeloperoxidase, and glomerular basement membrane were negative. Renal biopsy confirmed acute pauci-immune focal necrotizing glomerulonephritis (GN) with fibrin crescents indicating rapidly progressing glomerulonephritis. He improved with pulse methylprednisolone, intravenous cyclophosphamide, and plasma exchange with resolution of hemoptysis. This case highlights the importance of prompt renal biopsy to guide early initiation of life-saving therapies. To our knowledge, this is the first reported case of ANCA-negative pauci-immune necrotizing GN likely secondary to midostaurin.

Transcriptomic analysis implicates necroptosis in disease progression and prognosis in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis and cytopenias due to uncontrolled programmed cell death. The presence of pro-inflammatory cytokines and constitutive activation of innate immunity signals in MDS cells suggest inflammatory cell death, such as necroptosis, may be responsible for disease phenotype. We evaluated 64 bone marrow samples from 55 patients with MDS or chronic myelomonocytic leukemia (CMML) obtained prior to (n = 46) or after (n = 18) therapy with hypomethylating agents (HMAs). RNA from sorted bone marrow CD34+ cells was isolated and subject to amplification and RNA-Seq. Compared with healthy controls, expression levels of MLKL (CMML: 2.09 log2FC, p = 0.0013; MDS: 1.89 log2FC, p = 0.003), but not RIPK1 or RIPK3, were significantly upregulated. Higher expression levels of MLKL were associated with lower hemoglobin levels at diagnosis (-0.19 log2FC per 1 g/dL increase of Hgb, p = 0.03). Significant reduction in MLKL levels was observed after HMA therapy (-1.06 log2FC, p = 0.05) particularly among nonresponders (-2.89 log2FC, p = 0.06). Higher RIPK1 expression was associated with shorter survival (HR 1.92, 95% CI 1.00-3.67, p = 0.049 by Cox proportional hazards). This data provides further support for a role of necroptosis in MDS, and potentially response to HMAs and prognosis. This data also indicate that RIPK1/RIPK3/MLKL are potential therapeutic targets in MDS.

Single-agent and combination biologics in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous malignancy characterized by recurrent genetic, epigenetic, and metabolic abnormalities. As a result of our increasing knowledge of the underlying biology of AML leading to rational drug development, several new targeted agents have been recently added to our therapeutic arsenal. The BCL2 inhibitor venetoclax in combination with low-dose cytarabine (LDAC) or hypomethylating agents (HMAs) is safe and effective in older patients with newly diagnosed AML ineligible for intensive chemotherapy. Glasdegib, a hedgehog pathway inhibitor, may be used in combination with LDAC for the same indication and improves survival compared with LDAC alone. In newly diagnosed, fit, older patients with therapy-related AML or AML with myelodysplasia-related changes, the liposome-encapsulated combination of daunorubicin and cytarabine (CPX-351) has shown superiority over the 7 + 3 regimen. The presence of an IDH1 or IDH2 mutation can be effectively targeted by ivosidenib or enasidenib, respectively. Gemtuzumab ozogamicin improves event-free survival in CD33+ patients with favorable or intermediate-risk cytogenetics. With new targeted agents available, comprehensive genomic characterization of AML at diagnosis and relapse is increasingly necessary to select optimal treatment. Herein, we review the new single-agent and combination biologics (omitting FLT3 inhibitors, which are discussed separately) and provide recommendations on how to best use and manage patients on these regimens in clinical practice.