Dasatinib as first-line treatment for adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Impact of the type of tyrosine kinase inhibitor (imatinib or dasatinib) used before allo-HCT on outcome of patients with Philadelphia-positive acute lymphoblastic leukemia. A study on behalf of the Acute Leukemia Working Party of the EBMT

BACKGROUND

The use of tyrosine kinase inhibitors (TKIs) during induction and consolidation, followed by allogeneic hematopoietic cell transplantation (allo-HCT), is a standard of care for patients with Philadelphia (Ph)-positive acute lymphoblastic leukemia (ALL).

OBJECTIVE

The goal of this study was to compare results of allo-HCT according to the type of TKI used pre-transplant, either imatinib, dasatinib or both.

STUDY DESIGN

This was a retrospective, registry-based analysis including adult patients with Ph-positive ALL treated with allo-HCT between years 2010-2022. The analysis included 606 patients pre-treated with imatinib, 163 with dasatinib and 94 with both imatinib and dasatinib. Allo-HCTs were performed in first complete remission from either unrelated (56%), matched sibling (36%) or haploidentical donors (8%).

RESULTS

Relapse incidence at 2 years was 26% in the imatinib group and 21% in the dasatinib group and 19% in the imatinib + dasatinib group (p=0.06) while non-relapse mortality was 19%, 15% and 23%, respectively (p=0.37). No significant differences were found for leukemia-free survival (55% vs. 63% vs. 58%, p=0.11) and overall survival (72% vs. 76% vs. 65%, p=0.32). The incidence of grade 2-4 acute graft-versus-host disease (GVHD) and chronic GVHD was comparable across study groups, while the incidence of grade 3-4 acute GVHD was significantly increased for patients pre-treated with dasatinib alone (20%) than in the imatinib group (10%) or imatinib + dasatinib group (13%) (p=0.002). On multivariate analysis a chance of GVHD and relapse-free survival (GRFS) was significantly decreased while the risk of grade 3-4 acute GVHD was increased for the dasatinib compared to imatinib group (hazard ratio, HR = 1.27, p = 0.048 and HR = 2.26, p = 0.0009, respectively).

CONCLUSIONS

This study provides no evidence for the advantage of one TKI over another in terms of LFS and OS. However, the use of dasatinib is associated with increased risk of severe acute GVHD and decreased GRFS.

Is intensive chemotherapy and allogeneic stem cell transplantation mandatory for curing Philadelphia chromosome-positive acute lymphoblastic leukemia in young patients in the era of multitarget agents?

INTRODUCTION

The treatment outcomes for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) have improved with various tyrosine kinase inhibitors (TKIs) and bispecific T-cell engagers. Although allogeneic stem cell transplantation (allo-SCT) is the standard treatment for young patients with Ph+ALL, its role remains debatable in the era of TKIs and blinatumomab.

AREAS COVERED

There are some issues regarding Ph+ALL. First, do young patients require intensive chemotherapy (IC) in the era of multitarget agents? Second, which TKI is preferred for frontline therapy? Third, should allo-SCT be performed in patients achieving complete remission with ponatinib and IC? Fourth, can chemo-free treatment lead to a cure without allo-SCT? We searched relevant literature from the last 30 years on PubMed; reviewed the role of chemo-free therapies and combinations of ponatinib and IC; and assessed the necessity of allo-SCT in young patients with Ph+ALL.

EXPERT OPINION

Allo-SCT may not be needed, even in young patients with Ph+ALL treated with ponatinib-based IC or combined ponatinib and blinatumomab as frontline therapy. When adopting a ponatinib-based chemo-minimized regimen for induction, allo-SCT is needed with posttransplant ponatinib maintenance. Continuous exposure to ponatinib at pre- or post-transplant is regarded as one of the most important factor for the success of treatment.

Current status of drugs targeting PDGF/PDGFR

As an important proangiogenic factor, platelet-derived growth factor (PDGF) and its receptor PDGFR are highly expressed in a variety of tumors, fibrosis, cardiovascular and neurodegenerative diseases. Targeting the PDGF/PDGFR pathway is therefore a promising therapeutic strategy. At present, a variety of PDGF/PDGFR targeted drugs with potential therapeutic effects have been developed, mainly including PDGF agonists, inhibitors targeting PDGFR and proteolysis targeting chimera (PROTACs). This review clarifies the structure, biological function and disease correlation of PDGF and PDGFR, and it discusses the current status of PDGFR-targeted drugs, so as to provide a reference for subsequent research.

Association of leukemic molecular profile with efficacy of inotuzumab ozogamicin in adults with relapsed/refractory ALL

ABSTRACT

The phase 3 INO-VATE trial demonstrated higher rates of remission, measurable residual disease negativity, and improved overall survival for patients with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) who received inotuzumab ozogamicin (InO) vs standard-of-care chemotherapy (SC). Here, we examined associations between genomic alterations and the efficacy of InO. Of 326 randomized patients, 91 (InO, n = 43; SC, n = 48) had samples evaluable for genomic analysis. The spectrum of gene fusions and other genomic alterations observed was comparable with prior studies of adult ALL. Responses to InO were observed in all leukemic subtypes, genomic alterations, and risk groups. Significantly higher rates of complete remission (CR)/CR with incomplete count recovery were observed with InO vs SC in patients with BCR::ABL1-like ALL (85.7% [6/7] vs 0% [0/5]; P = .0076), with TP53 alterations (100% [5/5] vs 12.5% [1/8]; P = .0047), and in the high-risk BCR::ABL1- (BCR::ABL1-like, low-hypodiploid, KMT2A-rearranged) group (83.3% [10/12] vs 10.5% [2/19]; P < .0001). This retrospective, exploratory analysis of the INO-VATE trial demonstrated potential for benefit with InO for patients with R/R ALL across leukemic subtypes, including BCR::ABL1-like ALL, and for those bearing diverse genomic alterations. Further confirmation of the efficacy of InO in patients with R/R ALL exhibiting the BCR::ABL1-like subtype or harboring TP53 alterations is warranted. This trial was registered at www.ClinicalTrials.gov as #NCT01564784.

MRD in Philadelphia Chromosome-Positive ALL: Methodologies and Clinical Implications

PURPOSE OF REVIEW

Measurable residual disease (MRD) is integral in the management of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). This review discusses the current methods used to evaluate MRD as well as the interpretation, significance, and incorporation of MRD in current practice.

RECENT FINDINGS

New molecular technologies have allowed the detection of MRD to levels as low as 10- 6. The most used techniques to evaluate MRD are multiparametric flow cytometry (MFC), quantitative reverse transcription polymerase chain reaction (RT-qPCR), and high-throughput next-generation sequencing (NGS). Each method varies in terms of advantages, disadvantages, and MRD sensitivity. MRD negativity after induction treatment and after allogeneic hematopoietic cell transplantation (HCT) is an important prognostic marker that has consistently been shown to be associated with improved outcomes. Blinatumomab, a new targeted therapy for Ph + ALL, demonstrates high efficacy in eradicating MRD and improving patient outcomes. In the relapsed/refractory setting, the use of inotuzumab ozogamicin and tisagenlecleucel has shown promise in eradicating MRD. The presence of MRD has become an important predictive measure in Ph + ALL. Current studies evaluate the use of MRD in treatment decisions, especially in expanding therapeutic options for Ph + ALL, including tyrosine kinase inhibitors, targeted antibody therapies, chimeric antigen receptor cell therapy, and HCT.

Efficacy of Chemotherapy-Free Regimens in the Treatment of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Systematic Review and Meta-Analysis

INTRODUCTION

The historical standard of care for Ph+ ALL is chemotherapy plus a tyrosine kinase inhibitor (TKI). Recently chemotherapy-free regimens have shown promising efficacy. We performed a meta-analysis to compare the efficacy of chemotherapy-free regimens for Ph+ ALL.

METHODS

We searched PubMed and Embase for chemotherapy-free regimens for Ph+ ALL published between January 2000 and October 2023. Of the 5,348 articles screened, 9 nonrandomized clinical trials enrolling 413 patients were included. Two trials (N = 117) included treatment with 3 agents (blinatumomab, TKI, and steroid) and 7 trials (N = 248) included treatment with 2 agents (TKI and steroids). R software was used to conduct the meta-analysis (PROSPERO registration no. CRD42023482439).

RESULTS

The pooled complete molecular response (CMR) rate of patients receiving a TKI, blinatumomab, and steroids was 81% (95%CI, 69%-89%). TKIs plus blinatumomab were nearly 6 times as likely to have CMR (odds ratio [OR], 5.98; 95%CI, 2.99-11.96) and more than 5 times as likely to be alive at 1-year (OR, 5.1; 95%CI, 1.74-14.9) as compared to TKIs alone. Patients receiving ponatinib were about twice as likely as those receiving dasatinib to achieve CMR (OR, 2.51; 95%CI, 0.72-8.72).

CONCLUSION

Adding blinatumomab to TKIs and steroids significantly improved Ph+ ALL patients' response and survival rates. Regimens with ponatinib elicited higher molecular response rates than those with other TKIs. The high response and survival rates achieved with blinatumomab plus TKIs and steroids suggest that further studies are required to assess the need for intensive treatments such as chemotherapy or stem cell transplant in these patients.

Development of combination therapies with BTK inhibitors and dasatinib to treat CNS-infiltrating E2A-PBX1+/preBCR+ ALL

ABSTRACT

The t(1;19) translocation, encoding the oncogenic fusion protein E2A (TCF3)-PBX1, is involved in acute lymphoblastic leukemia (ALL) and associated with a pre-B-cell receptor (preBCR+) phenotype. Relapse in patients with E2A-PBX1+ ALL frequently occurs in the central nervous system (CNS). Therefore, there is a medical need for the identification of CNS active regimens for the treatment of E2A-PBX1+/preBCR+ ALL. Using unbiased short hairpin RNA (shRNA) library screening approaches, we identified Bruton tyrosine kinase (BTK) as a key gene involved in both proliferation and dasatinib sensitivity of E2A-PBX1+/preBCR+ ALL. Depletion of BTK by shRNAs resulted in decreased proliferation of dasatinib-treated E2A-PBX1+/preBCR+ cells compared with control-transduced cells. Moreover, the combination of dasatinib with BTK inhibitors (BTKi; ibrutinib, acalabrutinib, or zanubrutinib) significantly decreased E2A-PBX1+/preBCR+ human and murine cell proliferation, reduced phospholipase C gamma 2 (PLCG2) and BTK phosphorylation and total protein levels and increased disease-free survival of mice in secondary transplantation assays, particularly reducing CNS-leukemic infiltration. Hence, dasatinib with ibrutinib reduced pPLCG2 and pBTK in primary ALL patient samples, including E2A-PBX1+ ALLs. In summary, genetic depletion and pharmacological inhibition of BTK increase dasatinib effects in human and mouse with E2A-PBX1+/preBCR+ ALL across most of performed assays, with the combination of dasatinib and BTKi proving effective in reducing CNS infiltration of E2A-PBX1+/preBCR+ ALL cells in vivo.

Integrated systems biology analysis of acute lymphoblastic leukemia: unveiling molecular signatures and drug repurposing opportunities

Acute lymphoblastic leukemia (ALL) is a hematological malignancy characterized by aberrant proliferation and accumulation of lymphoid precursor cells within the bone marrow. The tyrosine kinase inhibitor (TKI), imatinib mesylate, has played a significant role in the treatment of Philadelphia chromosome-positive ALL (Ph + ALL). However, the achievement of durable and sustained therapeutic success remains a challenge due to the development of TKI resistance during the clinical course.The primary objective of this investigation is to propose a novel and efficacious treatment approach through drug repositioning, targeting ALL and its Ph + subtype by identifying and addressing differentially expressed genes (DEGs). This study involves a comprehensive analysis of transcriptome datasets pertaining to ALL and Ph + ALL in order to identify DEGs associated with the progression of these diseases to identify possible repurposable drugs that target identified hub proteins.The outcomes of this research have unveiled 698 disease-related DEGs for ALL and 100 for Ph + ALL. Furthermore, a subset of drugs, specifically glipizide for Ph + ALL, and maytansine and isoprenaline for ALL, have been identified as potential candidates for therapeutic intervention. Subsequently, cytotoxicity assessments were performed to confirm the in vitro cytotoxic effects of these selected drugs on both ALL and Ph + ALL cell lines.In conclusion, this study offers a promising avenue for the management of ALL and Ph + ALL through drug repurposed drugs. Further investigations are necessary to elucidate the mechanisms underlying cell death, and clinical trials are recommended to validate the promising results obtained through drug repositioning strategies.

Management of ALL in adults: 2024 ELN recommendations from a European expert panel

ABSTRACT

Experts from the European Leukemia Net (ELN) working group for adult acute lymphoblastic leukemia have identified an unmet need for guidance regarding management of adult acute lymphoblastic leukemia (ALL) from diagnosis to aftercare. The group has previously summarized their recommendations regarding diagnostic approaches, prognostic factors, and assessment of ALL. The current recommendation summarizes clinical management. It covers treatment approaches, including the use of new immunotherapies, application of minimal residual disease for treatment decisions, management of specific subgroups, and challenging treatment situations as well as late effects and supportive care. The recommendation provides guidance for physicians caring for adult patients with ALL which has to be complemented by regional expertise preferably provided by national academic study groups.

Synergistic effect of cannabidiol with dasatinib on lung cancer by SRC/PI3K/AKT signal pathway

Dasatinib-related resistance frequently occurs and may lead to the failure of chemotherapy; thus, dose interruptions are necessary. Cannabidiol (CBD) has potential for integration with orthodox cancer care. In this study, we explored the combination effect of CBD and dasatinib on A549 cells. CBD in combination with dasatinib could induce significant synergistic apoptosis in vitro (ZIP > 10) and in vivo. The combination of CBD and low-dose dasatinib exhibited antiproliferative and proapoptotic effects through up-regulation of caspase-3 and Bax, and down-regulation of Bcl-2 in A549 cells. The xenograft mouse model suggested that the combination was more efficient and safer. In short, CBD and low-dose dasatinib exhibited a synergistic effect on anticancer by targeting the SRC/PI3K/AKT signaling pathway, suggesting a potential therapeutic option for the treatment of lung cancer.

Long-Term Results of the Dasatinib-Blinatumomab Protocol for Adult Philadelphia-Positive ALL

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report the long-term results of the frontline trial with dasatinib and blinatumomab in induction/consolidation (GIMEMA LAL2116, D-ALBA) for adult Philadelphia-positive ALL (Ph+ ALL), which enrolled 63 patients of all ages. At a median follow-up of 53 months, disease-free survival, overall survival, and event-free survival are 75.8%, 80.7%, and 74.6%, respectively. No events have occurred among early molecular responders. A significantly worse outcome was recorded for IKZF1plus patients. Twenty-nine patients-93.1% being in molecular response (ie, complete molecular response or positive nonquantifiable) after dasatinib/blinatumomab-never received chemotherapy/transplant and continued with a tyrosine kinase inhibitor only; 28 patients remain in long-term complete hematologic response (CHR). An allogeneic transplant was carried out in first CHR mainly in patients with persistent minimal residual disease; 83.3% of patients are in continuous CHR. The transplant-related mortality was 12.5% for patients transplanted in first CHR and 13.7% overall. Nine relapses and six deaths have occurred. ABL1 mutations were found in seven cases. The final analysis of the D-ALBA study shows that a chemotherapy-free induction/consolidation regimen on the basis of a targeted strategy (dasatinib) and immunotherapy (blinatumomab) is effective in inducing durable long-term hematologic and molecular responses in adult Ph+ ALL, paving the way for a new era in the management of these patients.

Emerging Therapies in Management of Cholangiocarcinoma

Cholangiocarcinoma is a heterogeneous group of biliary tract cancers that has a poor prognosis and globally increasing incidence and mortality. While surgical resection remains the only curative option for the treatment of cholangiocarcinoma, the majority of cancers are unresectable at the time of diagnosis. Additionally, the prognosis of cholangiocarcinoma remains poor even with the current first-line systemic therapy regimens, highlighting the difficulty of treating locally advanced, metastatic, or unresectable cholangiocarcinoma. Through recent developments, targetable oncogenic driver mutations have been identified in the pathogenesis of cholangiocarcinoma, leading to the utilization of molecular targeted therapeutics. In this review, we comprehensively discuss the latest molecular therapeutics for the treatment of cholangiocarcinoma, including emerging immunotherapies, highlighting promising developments and strategies.

How to Manage Philadelphia-Positive Acute Lymphoblastic Leukemia in Resource-Constrained Settings

Recent studies have indicated that more than half of adult patients newly diagnosed with Ph+ ALL can now achieve a cure. However, determining the most suitable protocol for less-resourced settings can be challenging. In these situations, we must consider the potential for treatment toxicity and limited access to newer agents and alloSCT facilities. Currently, it is advisable to use less intensive induction regimens for Ph+ ALL. These regimens can achieve high rates of complete remission while causing fewer induction deaths. For consolidation therapy, chemotherapy should remain relatively intensive, with careful monitoring of the BCR-ABL1 molecular transcript and minimal residual disease. AlloSCT may be considered, especially for patients who do not achieve complete molecular remission or have high-risk genetic abnormalities, such as IKZF1-plus. If there is a loss of molecular response, it is essential to screen patients for ABL mutations and, ideally, change the TKI therapy. The T315I mutation is the most common mechanism for disease resistance, being targetable to ponatinib. Blinatumomab, a bispecific antibody, has shown significant synergy with TKIs in treating this disease. It serves as an excellent salvage therapy, aside from achieving outstanding results when incorporated into the frontline.

Low-Intensity and Chemo-Free Treatments in Ph+ ALL: Progression-Free Survival Based on Indirect Comparisons

In Philadelphia chromosome-positive B-cell (Ph+) acute lymphoblastic leukemia (LLA), growing evidence has accumulated regarding the efficacy of low-intensity and chemo-free regimens. Our objective was to analyze all recent trials evaluating these treatments and to compare them in terms of efficacy. We applied the Shiny method, an artificial intelligence technique, to analyze Kaplan-Meier curves and reconstruct patient-level data. Reconstructed patient data were then evaluated through standard survival statistics and subjected to indirect head-to-head treatment comparisons. The endpoint was progression-free survival (PFS). Based on 432 reconstructed patients, eight trials were analyzed. The survival data from these trials were pooled into three types of treatments: (i) treatments based on tyrosine kinase inhibitors (TKIs) combined with reduced-intensity chemotherapy (denoted as TKICHE); (ii) TKIs associated with steroids with no chemotherapy (TKISTE); (iii) chemotherapy-free combinations of blinatumomab plus TKIs (TKIBLI). According to the Shiny method, the three PFS curves were reported in a single Kaplan-Meier graph and subjected to survival statistics. In terms of PFS, TKIBLI ranked first, TKICHE second, and TKISTE third; the differences between these three regimens were statistically significant. This multi-treatment Kaplan-Meier graph, generated through the Shiny method, summarized the current evidence on these treatments in both qualitative and quantitative terms.

Case report: Deep molecular remissions post two separate CD19-targeted chimeric antigen receptor T-cell therapies do not prevent disease from relapsing in Philadelphia chromosome-positive acute lymphoblastic leukemia

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is an aggressive B-cell malignancy. The management of a relapsed Ph+ ALL patient is challenging. Currently, either allogeneic stem cell transplant (allo-SCT) or CD19-targeted chimeric antigen receptor T-cell (CAR T-cell) are usually employed as salvage modalities for a relapsed patient. However, there are few reports concerning cases that had both allo-SCT and multiple CAR T-cell therapies, and the optimal management of such patients is unclear. Here, we report a relapsed Ph+ ALL male who was first salvaged with autologous CAR T-cell therapy, followed by allo-SCT. Unfortunately, he had a second relapse even with complete molecular remission (CMR) response after the first CAR T and allo-SCT. This patient was then successfully salvaged by a second CAR T-cell product that is donor-derived. However, even with a CMR response once again following the second CAR T-cell therapy and prophylactic donor lymphocyte infusion, he experienced a molecular relapse; ponatinib was employed as the subsequent salvage treatment. He achieved a CMR response following ponatinib and was still in remission at the last follow-up. No ABL kinase mutation was detected during the whole course of the disease. This case indicated that a repeated CD19-targeted CAR T-cell treatment is feasible and may be effective in a relapsed Ph+ ALL patient that had previous CAR T-cell and allo-SCT, even though both CAR T-cell have the same construction. However, even with a deep response after each CAR T-cell therapy and allo-SCT, there is still a very small amount of undetectable leukemic cells. The optimal management of Ph+ ALL patients who have a deep response after a second CAR T-cell therapy deserves further exploration.

Dasatinib plus prednisone as induction and consolidation for adults with Ph-positive acute lymphoblastic leukaemia: A single-arm, multicentre, phase 2 trial

To reducing chemotherapy-related toxicity, the chemo-free regimens become a new trend of Ph + ALL treatment. Therefore, we conducted a phase 2 trial of dasatinib plus prednisone, as induction (Course I) and early consolidation (Courses II and III) treating newly diagnosed Ph + ALL. The trial was registered at www.chictr.org.cn, ChiCTR2000038053. Forty-one patients were enrolled from 15 hospitals. The complete remission (CR) was 95% (39/41), including two elderly induction deaths. By the end of Course III, 25.6% (10/39) of patients achieved a complete molecular response. With a median follow-up of 15.4 months, 2-year disease-free survival (DFS) were 100% and 33% for patients who receiving haematopoietic stem cell transplantation (HSCT) at CR1 and receiving chemotherapy alone respectively. When censored at time of HSCT, 2-year DFS were 51% and 45% for young and elderly patients (p = 0.987). 2-year overall survival were 45%, 86% and 100% for patients without HSCT, receiving HSCT after relapse and receiving HSCT at CR1 respectively. A total of 12 patients had marrow recurrences and one had CNS relapse, with 38% occurred early (between Courses I and III). IKZF1 gene deletion was shown to be associated with relapse (p = 0.019). This chemo-free induction and early consolidation regimen was efficacious and well-tolerated in de novo Ph + ALL. Allogeneic HSCT conferred definite survival advantage after chemo-free induction.

Moving away from chemotherapy in newly diagnosed Philadelphia chromosome-positive B-cell acute lymphoblastic leukaemia

Chemotherapy-free regimens are reshaping the treatment landscape of Philadelphia chromosome-positive acute lymphoblastic leukaemia. The report by Xie et al. suggests that the combination of dasatinib and prednisone is effective as induction and early consolidation. Survival was improved in patients who subsequently underwent allogeneic stem cell transplantation. Commentary on: Xie et al. Dasatinib plus prednisone as induction and consolidation for adults with Ph-positive acute lymphoblastic leukaemia: A single-arm, multicentre, phase 2 trial. Br J Haematol 2023;202:1119-1126.

Ex vivo Drug Sensitivity Imaging-based Platform for Primary Acute Lymphoblastic Leukemia Cells

Resistance of acute lymphoblastic leukemia (ALL) cells to chemotherapy, whether present at diagnosis or acquired during treatment, is a major cause of treatment failure. Primary ALL cells are accessible for drug sensitivity testing at the time of new diagnosis or at relapse, but there are major limitations with current methods for determining drug sensitivity ex vivo. Here, we describe a functional precision medicine method using a fluorescence imaging platform to test drug sensitivity profiles of primary ALL cells. Leukemia cells are co-cultured with mesenchymal stromal cells and tested with a panel of 40 anti-leukemia drugs to determine individual patterns of drug resistance and sensitivity ("pharmacotype"). This imaging-based pharmacotyping assay addresses the limitations of prior ex vivo drug sensitivity methods by automating data analysis to produce high-throughput data while requiring fewer cells and significantly decreasing the labor-intensive time required to conduct the assay. The integration of drug sensitivity data with genomic profiling provides a basis for rational genomics-guided precision medicine. Key features Analysis of primary acute lymphoblastic leukemia (ALL) blasts obtained at diagnosis from bone marrow aspirate or peripheral blood. Experiments are performed ex vivo with mesenchymal stromal cell co-culture and require four days to complete. This fluorescence imaging-based protocol enhances previous ex vivo drug sensitivity assays and improves efficiency by requiring fewer primary cells while increasing the number of drugs tested to 40. It takes approximately 2-3 h for sample preparation and processing and a 1.5-hour imaging time. Graphical overview.

Prophylactic or pre-emptive therapies to prevent relapse after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation is a potent curative treatment for hematological malignancies, but relapse is still a major problem. Donor lymphocyte infusion (DLI) and maintenance therapies after transplantation are promising strategies to reduce the risk of relapse. DLI augments the graft-versus-tumor effect by directly adding allo-reactive donor lymphocytes, and has been used in relapsed patients. In this Progress in Hematology (PIH), we will focus on prophylactic or pre-emptive DLI, including DLI from a haploidentical donor. On the other hand, specific drugs, which are used in maintenance therapies for each disease, kill tumor cells directly and/or immunologically by stimulating immune cells. Maintenance therapies should be started early after transplantation without severe myelosuppression. Molecularly targeted drugs are therefore suitable for use in maintenance therapies, and are reviewed in this PIH. The optimal application of these strategies has not yet been established. However, important evidence regarding their efficacies, adverse events, and effects on immune systems is accumulating, and could help to improve outcomes in allogeneic transplantation.

Phase II study of dose-adjusted EPOCH as initial therapy for adults with high-risk acute lymphoblastic leukemia

Treatments for adults with newly-diagnosed acute lymphoblastic leukemia (ALL) may be prohibitively toxic and/or resource-intense. To address this, we performed a phase II study of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH). Imatinib or dasatinib was added for Ph + disease; rituximab was added when CD20+. Fifty-three patients were evaluable: 28 with Ph + disease, and 25 with Ph-. All patients had ≥1 high-risk clinical feature. Measurable residual disease-negativity by multiparameter flow cytometry within 4 cycles was achieved in 71% in patients with Ph + ALL and 64% in Ph - ALL. Median overall survival (OS) was 49 months, with a 2-year OS of 71%. Median relapse-free survival (RFS) in the 47 patients that attained morphologic remission was 24 months, with a 2-year RFS of 57%. Early mortality was 2%. In summary, DA-EPOCH yields deep and durable remissions in adults with ALL comparable to some resource-intense strategies but with a low rate of treatment-related death.

Dasatinib/prednisone induction followed by blinatumomab/dasatinib in Ph+ acute lymphoblastic leukemia

Novel treatment strategies are needed for the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in older patients. This trial evaluated the feasibility and outcomes with the anti-CD19 bispecific T-cell-engaging antibody, blinatumomab, in combination with dasatinib and steroids. Patients 65 years of age or older with Ph+ or Ph-like ALL (with dasatinib-sensitive fusions/mutations) were eligible and could be newly diagnosed or relapsed/refractory. Induction therapy consisted of dasatinib/prednisone. Patients not achieving response by day 56 proceeded to blinatumomab reinduction therapy. Patients achieving response with induction or reinduction therapy proceeded to blinatumomab/dasatinib postremission therapy for 3 cycles followed by dasatinib/prednisone maintenance. All patients received central nervous system prophylaxis with intrathecal methotrexate for a total of 8 doses. Response was assessed at days 28, 56, and 84 and at additional time points based on response parameters. Measurable residual disease was assessed centrally by 8-color flow cytometry at day 28. A total of 24 eligible patients with newly diagnosed Ph+ ALL were enrolled with a median age of 73 years (range, 65-87 years). This combination was safe and feasible. With a median of 2.7 years of follow-up, 3-year overall survival and disease-free survival were 87% (95% confidence interval [CI], 64-96) and 77% (95% CI, 54-90), respectively. Although longer follow-up is needed, these results are encouraging, and future trials are building on this backbone regimen. This trial was registered at www.clinicaltrials.gov as #NCT02143414.

Management of Philadelphia chromosome positive acute lymphoblastic leukemia in the current era

Before the advent of tyrosine kinase inhibitors (TKI) the outcome of Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) was dismal. The TKI combination with induction regimens has greatly improved the long-term outcome of Ph+ ALL, specifically ponatinib a most potent TKI in combination with HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) chemotherapy has demonstrated 5 years overall survival up to 75%. Historically, allogeneic hematopoietic stem cell transplantation (allo-HSCT) used to be the only potential curative option, recent data suggest that patients who achieve complete molecular remission within 3 months of TKI based induction therapies can achieve comparable overall survival with or without allo-HSCT. Intensive cytotoxic chemotherapy may not be the desirable treatment option in elderly Ph+ ALL patients due to anticipated tolerance, recently in a phase II study, "chemotherapy free" combinations such as blinatumomab (bispecific anti-CD3 and anti-CD19 monoclonal antibody) with ponatinib in treatment naïve Ph+ ALL patients have shown a complete response rate of 95% and 2 years overall survival of 93%. In this review we have highlighted the evolving treatment landscape of Ph+ ALL and what to look for in future.

The evolution of acute lymphoblastic leukemia research and therapy at MD Anderson over four decades

Progress in the research and therapy of adult acute lymphoblastic leukemia (ALL) is accelerating. This analysis summarizes the data derived from the clinical trials conducted at MD Anderson between 1985 and 2022 across ALL subtypes. In Philadelphia chromosome-positive ALL, the addition of BCR::ABL1 tyrosine kinase inhibitors (TKIs) to intensive chemotherapy since 2000, improved outcomes. More recently, a chemotherapy-free regimen with blinatumomab and ponatinib resulted in a complete molecular remission rate of 85% and an estimated 3-year survival rate of 90%, potentially reducing the role of, and need for allogeneic stem cell transplantation (SCT) in remission. In younger patients with pre-B Philadelphia chromosome-negative ALL, the integration of blinatumomab and inotuzumab into the frontline therapy has improved the estimated 3-year survival rate to 85% across all risk categories. Our future strategy is to evaluate the early integration of both immunotherapy agents, inotuzumab and blinatumomab, with low-dose chemotherapy (dose-dense mini-Hyper-CVD-inotuzumab-blinatumomab) into the frontline setting followed by CAR T cells consolidation in high-risk patients, without any further maintenance therapy. In older patients, using less intensive chemotherapy (mini-Hyper-CVD) in combination with inotuzumab and blinatumomab has improved the 5-year survival rate to 50%. Among patients ≥ 65-70 years, the mortality in complete remission (CR) is still high and is multifactorial (old age, death in CR with infections, development of myelodysplastic syndrome or acute myeloid leukemia). A chemotherapy-free regimen with inotuzumab and blinatumomab is being investigated. The assessment of measurable residual disease (MRD) by next-generation sequencing (NGS) is superior to conventional assays, with early MRD negativity by NGS being associated with the best survival. We anticipate that the future therapy in B-ALL will involve less intensive and shorter chemotherapy regimens in combination with agents targeting CD19 (blinatumomab), CD20, and CD22 (inotuzumab). The optimal timing and use of CAR T cells therapy may be in the setting of minimal disease, and future trials will assess the role of CAR T cells as a consolidation among high-risk patients to replace allogeneic SCT. In summary, the management of ALL has witnessed significant progress during the past four decades. Novel combination regimens including newer-generation BCR::ABL1 TKIs and novel antibodies are questioning the need and duration of intensive chemotherapy and allogeneic SCT.

Approach to the Treatment of Philadelphia Chromosome-Negative B-cell ALL in Older Adults: Is Age Becoming just a Number?

PURPOSE OF REVIEW

Despite progress in the treatment of pediatric B-cell acute lymphoblastic leukemia (ALL) and PH + ALL, fewer advancements have been for older adults with PH-negative B-cell ALL. Treatment of this population is mired by higher incidence of poor risk biologic features, increased incidence of medical comorbidities, and higher rates of treatment-related mortality (TRM). Here, we review the difficulties in managing elderly patients with PH-negative ALL.

RECENT FINDINGS

The development of novel agents has brought additional tools to the armamentarium of drugs and has changed the landscape of treatment. More recent clinical trials and future clinical trials focus on blinatumomab, inotuzomab ozogamicin (IO), and/or chimeric antigen receptor T-cell (CAR-T) either alone or integrated with dose-reduced chemotherapy regimens. The introduction of novel agents/therapies and incorporation into our current treatment paradigms may finally offer an avenue to improve the dismal outcomes seen in this population.

Frontline combination of ponatinib and hyper-CVAD in Philadelphia chromosome-positive acute lymphoblastic leukemia: 80-months follow-up results

The combination of ponatinib, a third-generation BCR::ABL1 tyrosine kinase inhibitor, with hyper-CVAD chemotherapy resulted in high rates of complete molecular remissions and survival, without the need for stem cell transplantation (SCT) in most patients with Philadelphia chromosome(Ph)-positive acute lymphocytic leukemia (ALL). Confirming these results in a large cohort of patients with longer follow-up would establish this regimen as a new standard of care. Adults with newly diagnosed Ph-positive ALL were treated with the hyper-CVAD regimen. Ponatinib was added as 45 mg daily × 14 during induction, then 45 mg daily continuously (first 37 patients) or 30 mg daily continuously, with dose reduction to 15 mg daily upon achievement of a complete molecular response (CMR; absence of a detectable BCR::ABL1 transcript by quantitative reverse transcription polymerase-chain reaction at a sensitivity of 0.01%). Maintenance therapy consisted of daily ponatinib and vincristine-prednisone monthly for 2 years, followed by daily ponatinib indefinitely. Twelve intrathecal injections of cytarabine alternating with methotrexate were given as central nervous system prophylaxis. The trial is registered on clinicaltrials.gov with the identifier NCT01424982. Eighty-six patients were treated. Their median age was 46 years (range, 21-80). All 68 patients with active disease at the initiation of therapy achieved complete response (CR) The cumulative CMR rate was 86%. Twenty- patients (23%) underwent allogeneic SCT. With a median follow-up of 80 months (range, 16-129 months), the estimated 6-year event-free survival rate was 65% and the overall survival rate was 75%. There was no difference in outcome by performance of allogeneic SCT in first CR. Common grade 3-5 adverse events included infection (n = 80, 93%), increased liver transaminases (n = 26, 31%) and total bilirubin (n = 13, 15%), hypertension (n = 15, 17%), pancreatitis (n = 13, 15%), hemorrhage (n = 12, 13%), and skin rash (n = 9, 10%). Two ponatinib-related deaths from myocardial infarction (3%; at months 2.6 and 4.3, respectively; both in CR) in the first 37 patients treated led to the ponatinib dose-modifications mentioned earlier, with no further ponatinib-related deaths observed. The long-term results of ponatinib and hyper-CVAD continue to demonstrate excellent outcome results and acceptable safety data, indicating that this strategy is another standard of care approach in frontline Ph-positive ALL.

Optimal Use of Novel Immunotherapeutics in B-Cell Precursor ALL

Novel immune therapies are currently being used for patients with R/R ALL based on their ability to induce not only hematologic but also molecular remission. Despite promising results, specific clinical conditions, such as high tumor burden or extra medullary relapse, are still associated with a remarkably poor clinical outcome. Therefore, how to optimize the choice and the timing of such new treatments within different clinical settings remains a matter of debate. In addition, with the aim of increasing the rate and depth of molecular remission, clinical studies are currently evaluating the combination of these immunotherapies with chemotherapy in the contest of frontline treatment. The preliminary data suggest that this approach may increase the cure rate and perhaps reduce the use of allogeneic stem cell transplantation (alloHSCT) in first remission. In Ph-positive ALL, reproducible results are showing that frontline treatment programs, based on the combination of tyrosine kinase inhibitors and immunotherapy, can achieve unprecedented rates of hematologic and molecular remission as well as a long-term cure, even in the absence of chemotherapy and alloHSCT. The results from these studies have led to the development of potentially curative treatment modalities, even for older ALL patients who cannot be treated with conventional intensive chemotherapy. The present review examined the evidence for an appropriate use of the new immunotherapies in ALL patients and provided some appraisal of the current and future possible uses of these drugs for achieving further therapeutic improvement in the treatment of this disease.

Treatment de-escalation in Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia: the emerging role of chemotherapy-free regimens

The management of Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) has witnessed major progress over the past two decades. Initially, the incorporation of the first-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) imatinib into intensive chemotherapy regimens improved outcomes compared with chemotherapy alone. The combinations of chemotherapy with second- or third-generation TKIs further improved outcomes, with higher rates of complete molecular remission (CMR) and superior survival. The combination of ponatinib plus chemotherapy resulted in durable remissions and prolonged long-term survival, even in patients who did not receive allogeneic stem cell transplantation (SCT). The promising results seen with later-generation TKIs have caused many to re-evaluate the role of allogeneic SCT for patients who achieve CMR with potent TKI regimens. Recently, the chemotherapy-free combinations of blinatumomab plus TKIs were shown to be safe and effective in newly diagnosed Ph-positive ALL, sparing patients the toxicities associated with intensive chemotherapy. In particular, encouraging early results have been seen with the combination of blinatumomab plus ponatinib, suggesting that this regimen may represent a chemotherapy-free and SCT-sparing strategy for patients with Ph-positive ALL. Herein, we discuss the current evidence for frontline therapies of Ph-positive ALL, the treatment de-escalation strategies over time, and the role of allogeneic SCT in view of the emergence of newer chemotherapy-free regimens using potent TKIs.

Intensity of induction regimen and outcomes among adults with Ph+ALL undergoing allogeneic hematopoietic stem cell transplantation

Tyrosine kinase inhibitors (TKIs) are essential for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and have allowed for effective, low intensity induction regimens including no or minimal chemotherapy. Whether the use of low intensity induction regimens impacts outcomes after allogeneic hematopoietic stem cell transplant (alloHCT) is less understood. We identified consecutive adult patients with Ph+ ALL undergoing alloHCT in first complete remission (CR1) at our center from 2010 to 2021 and examined the impact of pre-transplant induction intensity on outcomes. Among the 87 identified patients, 44 (51%) received low intensity induction and 43 (49%) received induction with high intensity chemotherapy. Patients receiving low intensity induction were older (median age 60 vs. 47 years, p < 0.01). Following induction, measurable residual disease (MRD) negativity by BCR::ABL1 RT-PCR was similar in the low and high intensity induction cohorts (54% and 52% respectively). Receipt of reduced intensity transplant conditioning was not associated with intensity of induction regimen (39% vs. 19% in low vs. high, respectively, p = 0.06). At a median follow-up of 21 months from transplant, there was no difference between low and high intensity induction with respect to 2-year disease-free survival (58% vs. 56%), 2-year overall survival (62% vs. 63%), 2-year cumulative incidence of relapse (9% vs. 17%), and 2-year non-relapse mortality (33% vs. 29%). We also found no difference in outcomes when patients were segmented by both induction and conditioning regimen intensities. Our retrospective analysis suggests that induction intensity does not impact post-transplant outcomes among patients with Ph+ ALL transplanted in CR1.

How I treat with maintenance therapy after allogeneic HCT

Disease relapse is the leading cause of failure for patients receiving allogeneic hematopoietic cell transplantation (allo-HCT). Maintenance therapy administered after allo-HCT is a promising strategy to reduce the incidence of relapse and enhance the curative potential of allo-HCT. Research investigations and clinical applications of this approach have greatly increased in recent years, with an expanding number of available therapeutic agents to introduce in the posttransplant setting. However, many questions and challenges remain regarding the feasibility and clinical impact of maintenance. In this article, we present four common case scenarios addressing select available therapeutic agents as a framework to review published data and ongoing studies and describe our current standard practice in the rapidly evolving field of maintenance therapy after allo-HCT.

Creation of Philadelphia chromosome by CRISPR/Cas9-mediated double cleavages on BCR and ABL1 genes as a model for initial event in leukemogenesis

The Philadelphia (Ph) chromosome was the first translocation identified in leukemia. It is supposed to be generated by aberrant ligation between two DNA double-strand breaks (DSBs) at the BCR gene located on chromosome 9q34 and the ABL1 gene located on chromosome 22q11. Thus, mimicking the initiation process of translocation, we induced CRISPR/Cas9-mediated DSBs simultaneously at the breakpoints of the BCR and ABL1 genes in a granulocyte-macrophage colony-stimulating factor (GM-CSF) dependent human leukemia cell line. After transfection of two single guide RNAs (sgRNAs) targeting intron 13 of the BCR gene and intron 1 of the ABL1 gene, a factor-independent subline was obtained. In the subline, p210 BCR::ABL1 and its reciprocal ABL1::BCR fusions were generated as a result of balanced translocation corresponding to the Ph chromosome. Another set of sgRNAs targeting intron 1 of the BCR gene and intron 1 of the ABL1 gene induced a factor-independent subline expressing p190 BCR::ABL1. Both p210 and p190 BCR::ABL1 induced factor-independent growth by constitutively activating intracellular signaling pathways for transcriptional regulation of cell cycle progression and cell survival that are usually regulated by GM-CSF. These observations suggested that simultaneous DSBs at the BCR and ABL1 gene breakpoints are initiation events for oncogenesis in Ph+ leukemia. (200/200 words).

Ph+ ALL in 2022: is there an optimal approach?

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) carried a very poor prognosis prior to the advent of tyrosine kinase inhibitors (TKIs) that block the activity of the BCR-ABL1 oncoprotein. With improvements in TKI efficacy and allogeneic hematopoietic cell transplantation (HCT), survival has improved over the past 3 decades, and the role of chemotherapy and allogeneic HCT is now changing. Better risk stratification, the application of the third-generation TKI ponatinib, and the use of immunotherapy with the CD19-CD3 bifunctional T-cell engaging antibody blinatumomab in place of chemotherapy has made therapy for Ph+ ALL more tolerable and arguably more efficacious, especially for older patients who comprise most patients with Ph+ ALL.

Evidence-Based Minireview: What is the optimal tyrosine kinase inhibitor for adults with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia?

The incorporation of BCR::ABL1 tyrosine kinase inhibitors (TKIs) to intensive chemotherapy significantly improved the outcomes of patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). This was first shown with the addition of the first-generation TKI imatinib, which allowed more patients to be bridged to an allogeneic stem cell transplant (SCT) and led to superior long-term outcomes compared with chemotherapy alone. The use of second-generation TKIs (eg, dasatinib and nilotinib) has led to further improvement in outcomes of patients with Ph- positive ALL, with a long-term survival of 40% to 60% in several studies. Ponatinib is a third-generation, more potent TKI that results in high rates of molecular response and promising long-term survival even when allogeneic SCT is not routinely performed. While randomized data to support the TKI selection in Ph-positive ALL are lacking, data from single-arm studies suggest deeper molecular responses and superior survival outcomes with each successive generation of TKI. More recently, chemotherapy-free regimens with blinatumomab and TKIs have shown excellent results in the frontline setting and may represent an emerging paradigm shift in the treatment of Ph-positive ALL.

ERBB1/EGFR and JAK3 Tyrosine Kinases as Potential Therapeutic Targets in High-Risk Multiple Myeloma

Our main objective was to identify abundantly expressed tyrosine kinases in multiple myeloma (MM) as potential therapeutic targets. We first compared the transcriptomes of malignant plasma cells from newly diagnosed MM patients who were risk-categorized based on the patient-specific EMC-92/SKY-92 gene expression signature values vs. normal plasma cells from healthy volunteers using archived datasets from the HOVON65/GMMG-HD4 randomized Phase 3 study evaluating the clinical efficacy of bortezomib induction/maintenance versus classic cytotoxic drugs and thalidomide maintenance. In particular, ERBB1/EGFR was significantly overexpressed in MM cells in comparison to normal control plasma cells, and it was differentially overexpressed in MM cells from high-risk patients. Amplified expression of EGFR/ERBB1 mRNA in MM cells was positively correlated with increased expression levels of mRNAs for several DNA binding proteins and transcription factors with known upregulating activity on EGFR/ERBB1 gene expression. MM patients with the highest ERBB1/EGFR expression level had significantly shorter PFS and OS times than patients with the lowest ERBB1/EGFR expression level. High expression levels of EGFR/ERBB1 were associated with significantly increased hazard ratios for unfavorable PFS and OS outcomes in both univariate and multivariate Cox proportional hazards models. The impact of high EGFR/ERBB1 expression on the PFS and OS outcomes remained significant even after accounting for the prognostic effects of other covariates. These results regarding the prognostic effect of EGFR/ERBB1 expression were validated using the MMRF-CoMMpass RNAseq dataset generated in patients treated with more recently applied drug combinations included in contemporary induction regimens. Our findings provide new insights regarding the molecular mechanism and potential clinical significance of upregulated EGFR/ERBB1 expression in MM.

Tyrosine kinase inhibitors and reduced-dose chemotherapy for adult Philadelphia chromosome-positive acute lymphoblastic leukemia

Objectives: To compare the outcomes of tyrosine kinase inhibitors (TKIs) in combination with reduced-dose chemotherapy with those of standard induction chemotherapy, as well as the outcomes between chemotherapy and transplantation, in adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL).Methods: We retrospectively reviewed cases of Ph+ ALL treated with TKIs and combination chemotherapy. The patients were allocated to either the TKIs with reduced-dose chemotherapy group or the TKIs with standard chemotherapy group. In additions, patients were further stratified into either the transplant group or the non-transplant group.Results: The complete remission rate (88.7% vs. 83.9%, p = 0.372), major molecular response (58.9% vs. 56.0%, p = 0.750), molecular complete response (20.5% vs. 22.0%, p = 0.891), and early mortality rate (3.2% vs. 3.5%, p = 0.922) were similar between the TKIs with reduced-dose chemotherapy group and the TKIs with standard chemotherapy group. The proportions of lung infections, bloodstream infections, patients with >21 days of hospitalization, the total costs, transfusion costs, and antimicrobial costs were higher in the standard chemotherapy group than in the TKIs with reduced-dose chemotherapy group. The 3-year overall survival rates (59.0% [95% CI, 46.6-74.7%] vs. 38.4% [95% CI, 29.9-49.4%]) and disease-free survival rates (48.6% [95% CI, 34.2-69.1%] vs. 32.0% [95% CI, 23.5-43.7%]) were significantly better in the transplant group than in the non-transplant group.Conclusion: An induction regimen combining TKIs with reduced-dose chemotherapy and transplantation during the first complete remission remains a suitable and effective option for patients with Ph+ ALL.

Advancements on the Multifaceted Roles of Sphingolipids in Hematological Malignancies

Dysregulation of sphingolipid metabolism plays a complex role in hematological malignancies, beginning with the first historical link between sphingolipids and apoptosis discovered in HL-60 leukemic cells. Numerous manuscripts have reviewed the field including the early discoveries that jumpstarted the studies. Many studies discussed here support a role for sphingolipids, such as ceramide, in combinatorial therapeutic regimens to enhance anti-leukemic effects and reduce resistance to standard therapies. Additionally, inhibitors of specific nodes of the sphingolipid pathway, such as sphingosine kinase inhibitors, significantly reduce leukemic cell survival in various types of leukemias. Acid ceramidase inhibitors have also shown promising results in acute myeloid leukemia. As the field moves rapidly, here we aim to expand the body of literature discussed in previously published reviews by focusing on advances reported in the latter part of the last decade.

Tyrosine kinases in KMT2A/MLL-rearranged acute leukemias as potential therapeutic targets to overcome cancer drug resistance

Aim: The main goal of this study was to elucidate at the transcript level the tyrosine kinase expression profiles of primary leukemia cells from mixed lineage leukemia 1 gene rearranged (KMT2A/MLL-R⁺) acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients. Methods: We evaluated protein tyrosine kinase (PTK) gene expression profiles of primary leukemic cells in KMT2A/MLL-R⁺ AML and ALL patients using publicly available archived datasets. Results: Our studies provided unprecedented evidence that the genetic signatures of KMT2A/MLL-R⁺ AML and ALL cells are characterized by transcript-level overexpression of specific PTK. In infants, children and adults with KMT2A/MLL-R⁺ ALL, as well as pediatric patients with KMT2A/MLL-R⁺ AML, the gene expression levels for FLT3, BTK, SYK, JAK2/JAK3, as well as several SRC family PTK were differentially amplified. In adults with KMT2A/MLL-R⁺ AML, the gene expression levels for SYK, JAK family kinase TYK2, and the SRC family kinases FGR and HCK were differentially amplified. Conclusion: These results provide new insights regarding the clinical potential of small molecule inhibitors of these PTK, many of which are already FDA/EMA-approved for other indications, as components of innovative multi-modality treatment platforms against KMT2A/MLL-R⁺ acute leukemias.

Combined inhibition of BCR-ABL1 and the proteasome as a potential novel therapeutic approach in BCR-ABL positive acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a disease of lymphoid progenitor cells with an often aggressive course and is commonly caused by the BCR-ABL fusion gene t(9;22) in adults. This fusion gene encodes a constitutively active tyrosine kinase that can be effectively inhibited by tyrosine kinase inhibitors (TKIs), with imatinib being the paradigmatic agent of this class. However, BCR-ABL+ ALL cells rapidly develop mutations against many of the available TKIs, and consecutive disease relapse still results in an overall unfavorable prognosis for patients with this disease. To date, allogeneic stem cell transplantation is the only known curative therapeutic option for the mostly elderly patients with BCR-ABL+ ALL. The discrepancy between the limited therapeutic armamentarium and the growing therapeutic need in an aging population is therefore a reason to test drug combinations against BCR-ABL+ ALL. In this study, we demonstrate that the combination of TKIs with proteasome inhibitors efficiently and under certain conditions synergistically exerts cytotoxic effects in BCR-ABL+ ALL cells in vitro with respect to the induction of apoptosis. Both sole and combined treatment of BCR-ABL+ ALL with the proteasome inhibitors bortezomib and ixazomib, respectively, and TKI causes a significantly greater reduction in cell viability than TKI treatment alone in both BCR-ABL+ cell lines TOM-1 and BV-173. In BV-173 cells, we observed a significant reduction in cell viability to only 1.26%±0.46% with bortezomib treatment and 1.57±0.7% with combination treatment, whereas cells treated with dasatinib alone still had a viable percentage of 40.58±2.6%. Similar results were obtained when ixazomib was applied to both cell lines, and apoptosis was induced in both cases (93.36%±2.7% apoptotic BV-173 cells when treated with ixazomib and TKI). The combination of TKI and proteasome inhibitor is efficient in vitro, potentially expanding the spectrum of therapeutic options for patients with BCR-ABL+ ALL.

Cost-Effectiveness Analysis of Transplantation-Ineligible Elderly Patients With Acute Leukemia Harboring a Molecular Target: Ph-Positive Acute Leukemia and FLT3-Mutated Acute Myeloid Leukemia

BACKGROUND

Tyrosine kinase inhibitors (TKIs) and FMS-like tyrosine kinase 3 (FLT3) inhibitors are promising agents for Ph-positive acute leukemia (Ph+ AL) and FLT3 mutated acute myeloid leukemia (FLT3-AML), respectively.

METHODS

We examined the cost-effectiveness ratio (CER) of dasatinib and ponatinib for Ph+ AL and the cost-effectiveness of gilteritinib and quizartinib for FLT3-AML in elderly patients. Molecular therapy can fit the elderly population better than chemotherapy (CT).

RESULTS

The daily drug cost of dasatinib, ponatinib, gilteritinib, and quizartinib was $240, $170, $524, and $479 in terms of treatment maintenance dose, respectively. Treatment of Ph+ AL with stem cell transplantation (SCT), CT, dasatinib, and ponatinib yielded CERs of $322,375, $34,928, $61,104, and $46,234, respectively. The CERs for FLT3-AML treated with SCT, CT, gilteritinib, and quizartinib were $355,270, $42,717, $94,987, and $90,080, respectively. Treatment of elderly patients with TKIs and FLT3 inhibitors remained expensive and inferior to conventional CT.

CONCLUSION

Although TKIs and FLT3 inhibitors have an inferior CER than does conventional CT, their promising survival benefit with better QOL can offer a profound advantage. TKI or FLT3 inhibitor monotherapy is recommended as an alternative treatment option for unfit (vulnerable) elderly patients with Ph+ AL or FLT3-AML.

Modern Management Options for Ph+ ALL

Simple Summary

The use of tyrosine kinase inhibitors has represented a major step forward in the therapy of Philadelphia chromosome positive acute lymphoblastic leukemia. Recent improvements in the therapy are focused on early use of third generation tyrosine kinase inhibitors, their combination with immunotherapy, the refined indication of allogeneic hematopoietic stem cell transplantation, the optimal use and duration of maintenance therapy, and the management of patients with molecular or hematological relapse with combination of targeted therapies and immunotherapy, including cellular therapies. Improvements in the assessment of measurable residual disease and in the detection of mutations in the ABL1 domain are contributing to the better selection of the therapy for newly diagnosed as well as for relapsed or refractory patients.

Abstract

Impressive advances have been achieved in the management of patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) since the initial concurrent use of imatinib and standard chemotherapy. The attenuation of chemotherapy has proven to be equally effective and less toxic, the use of third generation TKI upfront has improved the frequency of complete molecular response and the survival rate, and the combination of tyrosine kinase inhibitors with immunotherapy has further increased the rate of molecular response to 70–80% after consolidation, which has been translated into a survival rate of 75–90% in recent trials. As a result of these improvements, the role of allogeneic hematopoietic stem cell transplantation is being redefined. The methodology of measurable residual disease assessment and the detection of ABL1 mutations are also improving and will contribute to a more precise selection of the treatment for newly diagnosed and relapsed or refractory (R/R) patients. Finally, new compounds combined with immunotherapeutic approaches, including cellular therapy, are being used as rescue therapy and will hopefully be included in first line therapy in the near future. This article will review and update the modern management of patients with Ph+ ALL.

Molecular Diagnostic Testing for Hematopoietic Neoplasms: Linking Pathogenic Drivers to Personalized Diagnosis

Molecular diagnostics inhabit an increasingly central role in characterizing hematopoietic malignancies. This brief review summarizes the genomic targets important for many major categories of hematopoietic neoplasia by focusing on disease pathogenesis. In myeloid disease, recurrent mutations in key functional classes drive clonal hematopoiesis, on which additional variants can specify clinical presentation and accelerate progression. Lymphoblastic leukemias are frequently initiated by oncogenic fusions that block lymphoid maturation while, in concert with additional mutations, driving proliferation. The links between genetic aberrations and lymphoma patient outcomes have been clarified substantially through the clustering of genomic profiles. Finally, the addition of next-generation sequencing strategies to cytogenetics is refining risk stratification for plasma cell myeloma. In all categories, molecular diagnostics shed light on the unique mechanistic underpinnings of each individual malignancy, thereby empowering more rational, personalized care for these patients.

High-Throughput CRISPR Screening in Hematological Neoplasms

CRISPR is becoming an indispensable tool in biological research, revolutionizing diverse fields of medical research and biotechnology. In the last few years, several CRISPR-based genome-targeting tools have been translated for the study of hematological neoplasms. However, there is a lack of reviews focused on the wide uses of this technology in hematology. Therefore, in this review, we summarize the main CRISPR-based approaches of high throughput screenings applied to this field. Here we explain several libraries and algorithms for analysis of CRISPR screens used in hematology, accompanied by the most relevant databases. Moreover, we focus on (1) the identification of novel modulator genes of drug resistance and efficacy, which could anticipate relapses in patients and (2) new therapeutic targets and synthetic lethal interactions. We also discuss the approaches to uncover novel biomarkers of malignant transformations and immune evasion mechanisms. We explain the current literature in the most common lymphoid and myeloid neoplasms using this tool. Then, we conclude with future directions, highlighting the importance of further gene candidate validation and the integration and harmonization of the data from CRISPR screening approaches.

Treatment of Adults With Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia-From Intensive Chemotherapy Combinations to Chemotherapy-Free Regimens: A Review

Importance

With the advent of potent BCR::ABL1 tyrosine kinase inhibitors (TKIs), Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) is now a relatively favorable-risk acute leukemia. In this review, we discuss the current evidence for frontline therapies of Ph-positive ALL, the major principles that guide therapy, and the progress with chemotherapy-free regimens.

Observations

Incorporating TKIs into the chemotherapy regimens of patients with newly diagnosed Ph-positive ALL has led to improved remission rates, higher probability of reaching allogeneic stem cell transplantation (SCT), and longer survival compared with chemotherapy alone. Early achievement of a complete molecular remission (CMR) is an important end point in Ph-positive ALL and identifies patients who have excellent long-term survival and may not need allogeneic SCT. Second-generation TKIs combined with intensive or low-intensity chemotherapy resulted in higher CMR rates compared with imatinib-based regimens. This translated into better outcomes, with less reliance on allogeneic SCT. To further improve the outcomes, the potent third-generation TKI ponatinib was added to chemotherapy. The combination of hyper-CVAD and ponatinib resulted in an overall CMR rate of 84% and a 5-year survival rate of 73% and 86% among patients who did and did not undergo allogeneic SCT, respectively, suggesting that allogeneic SCT may not be needed with this regimen. The recent chemotherapy-free combination of dasatinib and blinatumomab was safe and effective in patients with newly diagnosed Ph-positive ALL and resulted in an estimated 3-year OS rate of 80%; 50% of patients underwent allogeneic SCT. The chemotherapy-free regimen of ponatinib and blinatumomab resulted in a CMR rate of 86% and a 2-year survival rate of 93%, with no relapses or leukemia-related deaths, and with only 1 patient proceeding to allogeneic SCT.

Conclusions and Relevance

The promising results obtained with the chemotherapy-free regimens of blinatumomab plus TKIs question the role of allogeneic SCT in first remission. Patients with Ph-positive ALL who achieve early and deep molecular responses have excellent long-term outcomes and may not benefit from allogeneic SCT.

Mesenchymal Stromal Cells (MSCs): An Ally of B-Cell Acute Lymphoblastic Leukemia (B-ALL) Cells in Disease Maintenance and Progression within the Bone Marrow Hematopoietic Niche

Simple Summary

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer. Even though the cure rate actually exceeds 85%, the prognosis of relapsed/refractory patients is dismal. Recent literature data indicate that the bone marrow (BM) microenvironment could play a crucial role in the onset, maintenance and progression of the disease. In particular, mesenchymal stromal cells (MSCs), which are key components of the BM niche, actively crosstalk with leukemic cells providing crucial signals for their survival and resistance to therapy. We hereby review the main mechanisms exploited by MSCs to nurture and protect B-ALL cells that could become appealing targets for innovative microenvironment remodeling therapies to be coupled with classical leukemia-directed strategies.

Abstract

Mesenchymal stromal cells (MSCs) are structural components of the bone marrow (BM) niche, where they functionally interact with hematopoietic stem cells and more differentiated progenitors, contributing to hematopoiesis regulation. A growing body of evidence is nowadays pointing to a further crucial contribution of MSCs to malignant hematopoiesis. In the context of B-cell acute lymphoblastic leukemia (B-ALL), MSCs can play a pivotal role in the definition of a leukemia-supportive microenvironment, impacting on disease pathogenesis at different steps including onset, maintenance and progression. B-ALL cells hijack the BM microenvironment, including MSCs residing in the BM niche, which in turn shelter leukemic cells and protect them from chemotherapeutic agents through different mechanisms. Evidence is now arising that altered MSCs can become precious allies to leukemic cells by providing nutrients, cytokines, pro-survivals signals and exchanging organelles, as hereafter reviewed. The study of the mechanisms exploited by MSCs to nurture and protect B-ALL blasts can be instrumental in finding new druggable candidates to target the leukemic BM microenvironment. Some of these microenvironment-targeting strategies are already in preclinical or clinical experimentation, and if coupled with leukemia-directed therapies, could represent a valuable option to improve the prognosis of relapsed/refractory patients, whose management represents an unmet medical need.

SOHO State of the Art Updates and Next Questions: Mini-Hyper-CVD Combinations for Older Adults: Results of Recent Trials and a Glimpse into the Future

Acute lymphoblastic leukemia (ALL) is an aggressive blood cancer that affects both children and adults. Although the majority of children diagnosed with ALL are now cured and outcomes are improving for younger adults, older adults diagnosed with ALL usually succumb to their disease. Traditional chemotherapy regimens are poorly tolerated and ineffective in most older adults. Recently, novel chemotherapy agents such as inotuzumab ozogamicin and venetoclax have been successfully combined with dose reduced chemotherapy (mini-hyper-CVD) with promising results. Further study is needed to define the optimal combination and sequencing of novel agents and chemotherapy for different patient populations. This review discusses the challenge of treating older adults with traditional chemotherapy, experience to date with novel agents in combination with mini-hyper-CVD, as well as future directions and unanswered questions.

[The efficacy and safety of low-dose chemotherapy combined with tyrosine kinase inhibitors in the treatment of Philadelphia-chromosomal-positive acute lymphoblastic leukemia]

Objective: The study aims to explore the efficacy and safety of low-dose chemotherapy combined with tyrosine kinase inhibitor (TKI) as an induction therapy for Philadelphia-chromosomal-positive acute lymphoblastic leukemia (Ph(+) ALL) . Methods: The data of the consecutive newly diagnosed patients with Ph(+) ALL were reviewed. The efficacy and safety of low-dose chemotherapy and conventional-dose chemotherapy combined with TKI were compared. Results: A total of 217 patients with a median age of 38 (10-69) years old were included in this study. 78 patients were in the low-dose chemotherapy group, and 139 patients were in the conventional-dose chemotherapy group. There were no significant differences in the 4-week complete remission (CR) rate (98.7% vs 97.0%, P=0.766) and overall CR rate (100% vs 100%, P=1.000) between the two groups. Multivariate analyses showed that the chemotherapy intensity was not related to the disease-free survival rate and overall survival rate. However, the lower incidence of infection (P=0.017) , the shorter duration of neutropenia (P=0.001) and PLT<20 × 10(9)/L (P=0.057) , and the lower red blood cell transfusion volume (P=0.002) were more common in the low-dose chemotherapy group than in the conventional-dose chemotherapy group. Conclusions: The low-dose chemotherapy is superior to the conventional-dose chemotherapy combined with TKI as induction therapy in Ph(+) ALL with similar efficacy but is safer.