Clonal evolution from B-cell acute lymphoblastic leukemia with BCR::ABL1 multilineage involvement to acute myeloid leukemia after multiple anti-CD19 chimeric antigen receptor T-cell therapy.

Not available.

Genetic and clinical characteristics of acute B-cell lymphoblastic leukemia with MEF2D fusions and report of two novel MEF2D rearrangements.

The MEF2D rearrangement is a recurrent chromosomal abnormality detected in approximately 2.4-5.3% of patients with acute B-cell lymphoblastic leukemia (B-ALL). Currently, MEF2D-rearranged B-ALL is not classified as an independent subtype in the WHO classification. Consequently, the clinical significance of MEF2D rearrangement in B-ALL remains largely unexplored. In this study, we retrospectively screened 260 B-ALL patients with RNA sequencing data collected between November 2018 and December 2022. Among these, 10 patients were identified with MEF2D rearrangements (4 with MEF2D::HNRNPUL1, 3 with MEF2D::BCL9, 1 with MEF2D::ARID1B, 1 with MEF2D::DAZAP1 and 1 with MEF2D::HNRNPM). Notably, HNRNPM and ARID1B are reported as MEF2D fusion partners for the first time. The patient with the MEF2D::HNRNPM fusion was resistant to chemotherapy and chimeric antigen receptor T-cell therapy and relapsed early after allogenic stem cell transplantation. The patient with MEF2D::ARID1B experienced early extramedullary relapse after diagnosis. All 10 patients achieved complete remission after induction chemotherapy. However, 9/10 (90%) of whom experienced relapse. Three of the 9 patients relapsed with aberrant expression of myeloid antigens. The median overall survival of these patients was only 11 months. This small cohort showed a high incidence of early relapse and short survival in patients with MEF2D rearrangements.

Investigations of the prognostic value of RUNX1 mutation in acute myeloid leukemia patients: Data from a real-world study.

RUNX1 is one of the recurrent mutated genes in newly diagnosed acute myeloid leukemia (AML). Although historically recognized as a provisional distinct entity, the AML subtype with RUNX1 mutations (AML-RUNX1mut) was eliminated from the 2022 WHO classification system. To gain more insight into the characteristics of AML-RUNX1mut, we retrospectively analyzed 1065 newly diagnosed adult AML patients from the First Affiliated Hospital of Soochow University between January 2017 and December 2021. RUNX1 mutations were identified in 112 patients (10.5%). The presence of RUNX1 mutation (RUNX1mut) conferred a lower composite complete remission (CRc) rate (40.2% vs. 58.4%, P＜0.001), but no significant difference was observed in the 5-year overall survival (OS) rate (50.2% vs. 53.9%; HR=1.293; P=0.115) and event-free survival (EFS) rate (51.5% vs. 49.4%; HR=1.487, P=0.089), even within the same risk stratification. Multivariate analysis showed that RUNX1mut was not an independent prognostic factor for OS (HR=1.352, P=0.068) or EFS (HR=1.129, P=0.513). When patients were stratified according to induction regimen, RUNX1mut was an unfavorable factor for CRc both on univariate and multivariate analysis in patients receiving conventional chemotherapy, and higher risk stratification predicted worse OS. In those who received venetoclax plus hypomethylating agents, RUNX1mut was not predictive of CRc and comparable OS and EFS were seen between intermediate-risk and adverse-risk groups. The results of this study revealed that the impact of RUNX1mut is limited. Its prognostic value depended more on treatment and co-occurrent abnormalities. VEN-HMA may abrogate the prognostic impact of RUNX1, which merits a larger prospective cohort to illustrate.

Preemptive inotuzumab ozogamicin eradicated measurable residual disease in Ph-negative acute lymphoblastic leukemia relapsed post CD19 CART therapy.

There are no reports of application of inotuzumab ozogamicin (InO) for the treatment of MRD in r/r B-ALL. We firstly report the efficacy of InO for a patient experienced morphological relapse after HSCT and molecular relapse after CART therapy.

Combination of venetoclax with BCR-ABL tyrosine kinase inhibitor as a therapeutic strategy for Philadelphia chromosome-positive leukemias.

OBJECTIVES: Venetoclax has shown synergism with BCR-ABL1 tyrosine kinase inhibitors (TKIs) in preclinical studies for patients with Philadelphia chromosome-positive (Ph+) leukemias. This combination may suggest a novel treatment strategy for Ph + leukemias. METHODS: We conducted a retrospective study to summarize the activity of combining venetoclax and BCR-ABL1 TKI-based therapies in Ph + leukemias. RESULT: A total of 18 patients with Ph + leukemias were enrolled in this study. At the time of venetoclax and TKI-based therapy, 5 patients were initially diagnosed, with Ph + acute myeloid leukemia (AML) (n = 1) and mixed phenotype acute leukemia (MPAL) (n = 4), 7 patients had chronic myeloid leukemia at blastic phase (CML-BP), and the remaining 6 patients had relapsed or refractory to prior therapy. The overall response rate (ORR) was 88.9% (9 CR, 2 CRi, 4 MLFS, 1 PR), and a major molecular response (MMR) (or better) was achieved in 7 (38.8%) of all patients. With a median follow-up of 7.0 months (range, 2.3-15.6), 15 (83.3%) were in continuous CR at the time of this analysis, with a 1-year OS of 85.6%, 1-year LFS of 76.7%, and 1-year CIR of 22.4%. Moreover, 10 of 18 patients were treated with venetoclax, TKI and hypomethylating agent (HMA) regimens, which also associated with a high ORR rate (6 CR, 1 CRi, 3 MLFS), and can be used for induction or salvage therapy. CONCLUSION: Venetoclax and TKI-based combination regimens may be a feasible approach for Ph + leukemias, and prospective studies are needed to properly assess the safety, tolerability and efficacy of this regimen.

Targeted therapy and immunotherapy for T cell acute lymphoblastic leukemia/lymphoma.

T cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is an aggressive malignancy of progenitor T cells. Despite significant improvements in survival of T-ALL/LBL over the past decades, treatment of relapsed and refractory T-ALL (R/R T-ALL/LBL) remains extremely challenging. The prognosis of R/R T-ALL/LBL patients who are intolerant to intensive chemotherapy remains poor. Therefore, innovative approaches are needed to further improve the survival of R/R T-ALL/LBL patients. With the widespread use of next-generation sequencing in T-ALL/LBL, a range of new therapeutic targets such as NOTCH1 inhibitors, JAK-STAT inhibitors, and tyrosine kinase inhibitors have been identified. These findings led to pre-clinical studies and clinical trials of molecular targeted therapy in T-ALL/LBL. Furthermore, immunotherapies such as CD7 CAR T cell therapy and CD5 CAR T cell therapy have shown profound response rate in R/R T-ALL/LBL. Here, we review the progress of targeted therapies and immunotherapies for T-ALL/LBL, and look at the future directions and challenges for the further use of these therapies in T-ALL/LBL.

Mutation spectrum of FLT3 and significance of non-canonical FLT3 mutations in haematological malignancy.

Fms-like tyrosine kinase 3 (FLT3) is frequently mutated in haematological malignancies. Although canonical FLT3 mutations including internal tandem duplications (ITDs) and tyrosine kinase domains (TKDs) have been extensively studied, little is known about the clinical significance of non-canonical FLT3 mutations. Here, we first profiled the spectrum of FLT3 mutations in 869 consecutively newly diagnosed acute myeloid leukaemia (AML), myelodysplastic syndrome and acute lymphoblastic leukaemia patients. Our results showed four types of non-canonical FLT3 mutations depending on the affected protein structure: namely non-canonical point mutations (NCPMs) (19.2%), deletion (0.7%), frameshift (0.8%) and ITD outside the juxtamembrane domain (JMD) and TKD1 regions (0.5%). Furthermore, we found that the survival of patients with high-frequency (>1%) FLT3-NCPM in AML was comparable to those with canonical TKD. In vitro studies using seven representative FLT3-deletion or frameshift mutant constructs showed that the deletion mutants of TKD1 and the FLT3-ITD mutant of TKD2 had significantly higher kinase activity than wild-type FLT3, whereas the deletion mutants of JMD had phosphorylation levels comparable with wild-type FLT3. All tested deletion mutations and ITD were sensitive to AC220 and sorafenib. Collectively, these data enrich our understanding of FLT3 non-canonical mutations in haematological malignancies. Our results may also facilitate prognostic stratification and targeted therapy of AML with FLT3 non-canonical mutations.

Case Report: Blinatumomab therapy for the treatment of B-cell acute lymphoblastic leukemia patients with central nervous system infiltration.

The treatment of B-cell acute lymphoblastic leukemia (B-ALL) with central nervous system (CNS) involvement poses a significant clinical challenge because most chemotherapeutic agents exhibit weak permeability to the blood-brain barrier (BBB). In addition, current anti-CNS leukemia treatments often bring short or long-term complications. Immunotherapy including chimeric antigen T-cell therapy and bispecific antibody have shown profound treatment responses in relapsed/refractory B-ALL. However, there is a lack of data on the efficacy of bispecific antibody in treating B-ALL with CNS involvement. Here, we report two ALL patients with CNS leukemia who received blinatumomab. Case 1 was diagnosed with chronic myeloid leukemia in lymphoid blast phase. The patient developed CNS leukemia and bone marrow relapse during the treatment with dasatinib. Case 2 was diagnosed with B-ALL and suffered early hematologic relapse and cerebral parenchyma involvement. After treatment with one cycle of blinatumomab, both patients achieved complete remission in the bone marrow and CNS. Furthermore, this is the first report on the efficacy of blinatumomab in treating CNS leukemia with both of the cerebral spinal fluid and the cerebral parenchymal involvement. Our results suggest that blinatumomab might be a potential option for the treatment of CNS leukemia.

Metagenomic next-generation sequencing performed on blood samples for the early recognition of severe Pneumocystis pneumonia in critical hematological patients.

Severe Pneumocystis pneumonia (PCP) has a poor prognosis, and its early and precise diagnosis is difficult in immunocompromised individuals. Therefore, this study explored the diagnostic value of metagenomic next-generation sequencing (mNGS) of peripheral blood in diagnosing severe PCP in patients with hematological diseases. This prospective study analyzed the clinical manifestations, mNGS results (from the peripheral blood), traditional pathogen detection results, laboratory test results, chest computed tomography (CT) images, treatments, and outcomes of severe PCP in hematological patients who were hospitalized in the 2 centers of the Affiliated Hospital of Soochow University between September 2019 and October 2021. A total of 31 cases of hematological diseases complicated with pulmonary infections, including 7 cases of severe PCP diagnosed by mNGS performed on peripheral blood samples, were analyzed. Traditional pathogen detection methods for PCP cannot be used. In contrast, the laboratory readings for Pneumocystis jirovecii (Pj) detected within 48 hours of symptom onset by mNGS on the 7 blood samples ranged from 12 to 5873, with a median value of 43. Under the guidance of the mNGS results, preemptive antimicrobial therapy with trimethoprim/sulfamethoxazole alone or in combination with caspofungin was administered to treat Pj. After treatment, 4 patients recovered, and 3 patients died of acute respiratory failure and acute respiratory distress syndrome (ARDS). MNGS performed on peripheral blood samples is optional but can provide early recognition of severe PCP and help guide empirical treatment in critical hematological patients.

Rapid molecular response to dasatinib in Ph-like acute lymphoblastic leukemia patients with ABL1 rearrangements: case series and literature review.

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk subtype with a poor prognosis under conventional chemotherapy. Ph-like ALL has a similar gene expression profile to Philadelphia chromosome-positive (Ph+) ALL, but is highly heterogeneous in terms of genomic alterations. Approximately 10-20% of patients with Ph-like ALL harbor ABL class (e.g. ABL1, ABL2, PDGFRB, and CSF1R) rearrangements. Additional genes that form fusion genes with ABL class genes are still being researched. These aberrations result from rearrangements including chromosome translocations or deletions and may be targets of tyrosine kinase inhibitors (TKIs). However, due to the heterogeneity and rarity of each fusion gene in clinical practice, there is limited data on the efficacy of tyrosine kinase inhibitors. Here, we report three cases of Ph-like B-ALL with ABL1 rearrangements treated with the dasatinib backbone for the CNTRL::ABL1, LSM14A::ABL1, and FOXP1::ABL1 fusion genes. All three patients achieved rapid and profound remission with no significant adverse events. Our findings suggest that dasatinib is a potent TKI for the treatment of ABL1-rearranged Ph-like ALL and can be used as a first-line treatment option for such patients.

Anti-CD19 CAR T-cell consolidation therapy combined with CD19+ feeding T cells and TKI for Ph+ acute lymphoblastic leukemia.

We conducted a single-arm, open-label, single-center phase 1 study to assess the safety and efficacy of multicycle-sequential anti-CD19 chimeric antigen receptor (CAR) T-cell therapy in combination with autologous CD19+ feeding T cells (FTCs) and tyrosine kinase inhibitor (TKI) as consolidation therapy in patients under the age of 65 years with de novo Ph-positive CD19+ B-cell acute lymphoblastic leukemia. Participants were given induction chemotherapy as well as systemic chemotherapy with TKI. Afterward, they received a single cycle of CD19 CAR T-cell infusion and another 3 cycles of CD19 CAR T-cell and CD19+ FTC infusions, followed by TKI as consolidation therapy. CD19+ FTCs were given at 3 different doses. The phase 1 results of the first 15 patients, including 2 withdrawals, are presented. The most common adverse events were cytopenia (13/13) and hypogammaglobinemia (12/13). There was no incidence of cytokine release syndrome above grade 2 or immune effector cell-associated neurotoxicity syndrome or grade 4 nonhematological toxicities. All 13 patients achieved complete remission, including 12 patients with a complete molecular response (CMR) at the data cutoff. The relapse-free survival was 84%, and the overall survival was 83% with a median follow-up of 27 months. The total number of CD19-expressing cells decreased with an increasing CMR rate. CD19 CAR T cells survived for up to 40 months, whereas CD19+ FTCs vanished in 8 patients 3 months after the last infusion. These findings could form the basis for the development of an allo-HSCT-free consolidation paradigm. This trial was registered at www.clinicaltrials.gov as #NCT03984968.

Flumatinib plus venetoclax as an effective therapy for Philadelphia chromosome-positive acute myeloid leukemia: A case report.

Philadelphia chromosome-positive acute myeloid leukemia (Ph + AML) is a rare type of AML with a low survival rate and poor prognosis. We first report a Ph + AML patient who remained in long-term remission after the combination of flumatinib and venetoclax, which could provide corresponding treatment ideas for clinical practice.

Chidamide: Targeting epigenetic regulation in the treatment of hematological malignancy.

Epigenetic alterations frequently participate in the onset of hematological malignancies. Histone deacetylases (HDACs) are essential for regulating gene transcription and various signaling pathways. Targeting HDACs has become a novel treatment option for hematological malignancies. Chidamide is the first oral selective HDAC inhibitor for HDAC1, HDAC2, HDAC3, and HDAC10 and was first approved for the treatment of R/R peripheral T-cell lymphoma by the China Food and Drug Administration in 2014. Chidamide was also approved under the name Hiyasta (HBI-8000) in Japan in 2021. In vitro studies revealed that chidamide could inhibit proliferation and induce apoptosis via cell cycle arrest and the regulation of apoptotic proteins. In clinical studies, chidamide was also efficacious in multiple myeloma, acute leukemia and myelodysplastic syndrome. This review includes reported experimental and clinical data on chidamide monotherapy or chidamide treatment in combination with chemotherapy for various hematological malignancies, offering a rationale for the renewed exploration of this drug.

Comparing the efficacy of salvage regimens for relapsed/refractory B-cell acute lymphoblastic leukaemia: a systematic review and network meta-analysis.

The complete remission (CR) rate and overall survival (OS) of relapsed/refractory (R/R) B-cell acute lymphoblastic leukaemia (B-ALL) are not satisfactory. The available salvage regimens include standard chemotherapy, inotuzumab ozogamicin, blinatumomab and cluster of differentiation (CD)19 chimeric antigen receptor T cells (CAR T), and the NCCN guidelines recommend all of these therapies with no preference. Dual CD19/CD22 CAR T-cells have emerged as new treatments and have shown some efficacy, with high CR rates and preventing CD19-negative relapse. However, direct comparisons of the CR rate and long-term survival among the different salvage therapies are lacking. Databases including PubMed, Embase, Web of Science and Cochrane were searched from inception to January 31, 2022, for relevant studies. The outcomes of interest were complete remission/complete remission with incomplete haematologic recovery (CR/CRi) rates and 1-year overall survival (OS) rates. Odds ratios (ORs) were generated for binary outcomes, and the mean difference (MD) was generated for consecutive outcomes by network meta-analysis. CD19 CAR T-cells demonstrated a significantly better effect in improving the CR/CRi rate than blinatumomab (OR = 8.32, 95% CI: 1.18 to 58.44) and chemotherapy (OR = 16.4, 95% CI: 2.76 to 97.45). In terms of OS, CD19 CAR T-cells and dual CD19/CD22 CAR T-cells both had a higher 1-year OS rate than blinatumomab, inotuzumab ozogamicin and chemotherapy. There was no significant difference between CD19 CAR T-cells and dual CD19/CD22 CAR T-cells in terms of 1-year OS and CR/CRi rates. CD19 CAR T-cells are effective in inducing CR, and CD19 CAR T-cells and dual CD19/CD22 CAR T-cells show benefits for overall survival. More high-quality randomized controlled trials and longer follow-ups are needed to confirm and update the results of this analysis in the future.

Lisaftoclax in Combination with Alrizomadlin Overcomes Venetoclax Resistance in Acute Myeloid Leukemia and Acute Lymphoblastic Leukemia: Preclinical Studies.

PURPOSE: Despite approval of B-cell lymphoma (BCL)-2 inhibitor venetoclax for certain hematologic malignancies, its broader clinical benefit is curtailed by resistance. Our study aimed to determine if treatment with novel anticancer agents targeting BCL-2 and mouse double minute 2 (MDM2) could overcome venetoclax resistance in preclinical models. EXPERIMENTAL DESIGN: Venetoclax-sensitive and venetoclax-resistant acute myeloid leukemia (AML) and acute lymphoblastic leukemia cells and xenograft models were used to evaluate antitumor effects and underlying mechanisms associated with combined BCL-2 inhibitor lisaftoclax (APG-2575) and MDM2 inhibitor alrizomadlin (APG-115). RESULTS: The combination exhibited synergistic antiproliferative and apoptogenic activities in TP53 wild-type AML cell lines in vitro. This synergy was further exemplified by deep antitumor responses and prolonged survival in AML cell line-derived and patient-derived xenograft models. Interestingly, the combination treatment resensitized (to apoptosis) venetoclax-resistant cellular and mouse models established via chronic drug exposure or genetically engineered with clinically relevant BCL-2 gene mutations. Synergistic effects in reducing cellular viability and proliferation were also demonstrated in primary samples of patients with venetoclax-resistant AML treated with lisaftoclax and alrizomadlin ex vivo. Mechanistically, alrizomadlin likely primes cancer cells to BCL-2 inhibition-induced cellular apoptosis by downregulating expression of antiapoptotic proteins myeloid cell leukemia-1 and BCL-extra-large and upregulating pro-death BCL-2-associated X protein. CONCLUSIONS: Lisaftoclax in combination with alrizomadlin overcomes venetoclax resistance mediated by various mechanisms, including BCL-2 mutations. In addition, we posit further, putative molecular mechanisms. Our data rationalize clinical development of this treatment combination in patients with diseases that are insensitive or resistant to venetoclax.