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

Bispecific Antibodies in Hematologic and Solid Tumors: Current Landscape and Therapeutic Advances

Bispecific antibodies (bsAbs) have emerged as a novel class of therapeutics, offering a dual-targeting strategy to enhance the therapeutic efficacy of monoclonal antibodies, which is often limited by tumor heterogeneity and the occurrence of resistance mechanisms. By simultaneously engaging two distinct antigens or pathways, bsAbs disrupt multiple signaling cascades simultaneously, preventing escape mechanisms and offering a more durable response. Furthermore, they can optimize immune activation, improving immune cell recruitment strategies. In particular, T-cell engager bsAbs facilitate immune cell-mediated tumor destruction by linking T cells to tumor antigens. Instead, dual immune checkpoint inhibitors (CPIs) enhance immune activation by blocking inhibitory signals. Additionally, bsAbs targeting tumor growth factors or receptor tyrosine kinases offer solutions for overcoming drug resistance in solid tumors. Although bsAbs have shown remarkable success in hematologic malignancies, their expansion into solid tumors faces key challenges, including tumor heterogeneity, limited tumor penetration, and the risk of on-target, off-tumor toxicities. Addressing these challenges requires innovative engineering strategies, optimized delivery mechanisms, and careful patient selection to maximize therapeutic benefit while mitigating adverse effects. The efficacy of bsAbs in clinical trials has led to their approval for both hematologic and solid malignancies, with numerous agents in development. Combination strategies with chemotherapy, targeted agents, and immune CPIs could represent a promising strategy to further expand their potential. As research progresses, bsAbs are expected to play a role in reshaping the future of precision oncology, offering more effective and tailored treatment options.

Stem cell transplantation indications for patients with acute leukemia determined by measurable residual disease: what we know and what we do not know

Acute leukemia (AL), which includes acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), is a hematological malignancy characterized by the uncontrolled proliferation of immature myeloid or lymphoid cells. Allogeneic stem cell transplantation (ASCT) remains a therapeutic option for patients with AL. Determination of transplantation indications is a key step in successful ASCT and in curing patients. Currently, the measurable residual disease (MRD) is used as a biomarker for response evaluation, relapse prediction, preemptive therapy, and post-remission treatment selection. In this review, we discuss the advantages and disadvantages of these techniques for MRD detection. We focused mainly on the residual disease-directed selection of transplant indications for patients with either AML or ALL and provided expert opinions in these settings. We also discuss the challenges associated with transplantation indications and propose expert opinions and future directions for the selection of indications for transplantation.

TP53 mutations are associated with CD19- relapse and inferior outcomes after blinatumomab in adults with ALL

ABSTRACT

Despite the success of the CD19 × CD3 T-cell engager blinatumomab in B-cell acute lymphoblastic leukemia (B-ALL), treatment failure is common and can manifest with antigen loss and extramedullary disease (EMD) relapse. To understand the impact of leukemia genetics on outcomes, we reviewed 267 adult patients with B-ALL treated with blinatumomab and used next-generation sequencing to identify molecular alterations. Patients received blinatumomab for relapsed/refractory (R/R) disease (n = 150) and minimal residual disease (MRD; n = 88), upfront as induction (n = 10) or as consolidation in MRD-negative state (n = 19). In the overall cohort, 50 patients (19%) had Philadelphia chromosome (Ph)-positive ALL, 80 (30%) had Ph-like ALL, 35 (13%) had TP53 mutations (TP53m), 7 (3%) had KMT2A rearrangement, and 8 (3%) had PAX5 alterations. For patients treated for R/R ALL, the overall complete remission (CR)/CR with incomplete hematological recovery (CRi) rate was 59%. Only pretreatment high disease burden (P < .01) and active EMD (P < .01) were associated with inferior CR/CRi rate. Of 169 patients in CR/CRi after blinatumomab, 79 (47%) patients relapsed, including 22 (28%) with CD19- and 54 (68%) with CD19+ relapse. In multivariable analysis, TP53m was associated with an increased risk of CD19- relapse (hazard ratio [HR], 6.84; 95% confidence interval [CI], 2.68-17.45; P < .01). Post-blinatumomab allogeneic stem cell transplantation consolidation was associated with a lower risk of CD19- relapse (HR, 0.10; 95% CI, 0.03-0.37; P < .01) and EMD relapse (HR, 0.36; 95% CI, 0.18-0.73; P < .01). In conclusion, leukemia genetics may predict patterns of blinatumomab failure, with TP53m associated with CD19- relapse.

Management of Adult Acute Lymphoblastic Leukemia: A Review

Importance

Research in acute lymphoblastic leukemia (ALL) is translating into rapid changes in therapy and outcomes. Historically, adult ALL was treated with intensive chemotherapy extending over 2.5 to 3 years. This established tradition, accepted because of the high cure rates in childhood ALL, has been challenged by the development of highly active targeted therapies.

Observation

Treatment modalities, combined with less and shorter chemotherapy durations, have produced better results than chemotherapy. The novel therapies include using the more potent BCR::ABL1 tyrosine kinase inhibitors (eg, ponatinib, dasatinib) with the bispecific CD3-CD19 T-cell engager antibody blinatumomab in Philadelphia chromosome-positive ALL and combining blinatumomab and/or inotuzumab (CD22 antibody drug conjugate) with standard chemotherapy in B-cell ALL. These have been associated with improved 4-year survival rates of 85% to 90% in Philadelphia chromosome-positive ALL and 80% to 85% in B-cell ALL.

Conclusions and Relevance

The management of ALL is changing rapidly. Investigators have evaluated frontline and later-line regimens with combinations of tyrosine kinase inhibitors and immunotherapies with less or no chemotherapy. Future research will evaluate CD19, CD20, and CD22 multitargeting antibodies and chimeric antigen receptor T-cell therapies, new antibody formulations, and less intensive/shorter regimens.

Tyrosine kinase inhibitors with blinatumomab versus chemotherapy in Philadelphia-positive acute B-lymphoblastic leukemia

Tyrosine kinase inhibitors (TKIs) and blinatumomab have improved outcomes in Philadelphia-positive B-lymphoblastic leukemia (Ph + B-ALL). However, the efficacy of TKI and blinatumomab as a standalone regimen compared to the standard chemotherapy-plus-TKI approach remains uncertain. We conducted a single-center retrospective analysis of 47 patients, including 18 treated with TKI and blinatumomab (de novo: N = 13; relapsed: N = 5) and 29 treated with chemotherapy and TKI. Patients in the blinatumomab cohort were significantly older (median age 65 years vs. 48 years), had higher rates of active central nervous system disease (27.7% vs. 0%) and were less frequently consolidated with allogeneic stem cell transplantation (33% vs. 79%, p < .05). Despite these differences, overall survival (2-year OS: 87% vs. 78%), progression-free survival (PFS: 81% vs. 54%), and non-relapse mortality (NRM: 6.3% vs. 14%) were comparable. Severe treatment-related adverse events were significantly less frequent in the TKI and blinatumomab cohort, with no difference in early molecular complete response rates. Our findings, consistent with published prospective trials, highlight the safety and efficacy of TKI and blinatumomab in managing Ph + B-ALL.

Dasatinib and CAR T-Cell Therapy in Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Nonrandomized Clinical Trial

Importance

A combination of tyrosine kinase inhibitors and chimeric antigen receptor (CAR) T cells has made a breakthrough in refractory or relapsed Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). However, it remains unclear if this treatment in newly diagnosed Ph-positive ALL is associated with high rates of complete molecular remission (CMR) and leukemia-free survival.

Objective

To evaluate the efficacy and safety of dasatinib in combination with CAR T cells as frontline therapy in adults with newly diagnosed Ph-positive ALL.

Design, Setting, and Participants

This trial was conducted at a single center, the First Affiliated Hospital of Zhejiang University School of Medicine. Patients were enrolled in this phase 2, single-arm nonrandomized clinical trial between March 5, 2021, and April 13, 2024. The data cutoff date was February 10, 2025. The data analysis was conducted on February 11, 2025. The median duration of follow-up was 23.9 (range, 7.3-47.7) months. A total of 29 adults with newly diagnosed Ph-positive ALL and adequate organ function were screened for eligibility, and 1 patient who received a diagnosis of blast-phase chronic myeloid leukemia was excluded.

Intervention

Dasatinib was administered with a 2-week vindesine and dexamethasone regimen as induction, followed by sequential CD19 and CD22 CAR T-cell therapies and single-agent dasatinib maintenance.

Main Outcomes and Measures

The primary end point was CMR rate after CD19 CAR T-cell therapy. CMR was defined as undetectable BCR/ABL1 transcripts as measured by quantitative reverse transcription polymerase chain reaction with a sensitivity of 10-4 in the bone marrow.

Results

Twenty-eight patients (median [range] age, 48.5 [18.0-69.0] years; 10 female individuals [36%]) were enrolled, and 1 patient withdrew after induction. The CMR rate was 25% (7 of 28) after induction and increased to 85% (23 of 27) after CD19 CAR T-cell therapy. Twenty-five patients (89.3%) received sequential CD22 CAR T-cell therapy, and the CMR rate was 76% (19 of 25). Of the 52 CAR T-cell therapies, only 21 cases of grade 1 cytokine release syndrome occurred. After a median follow-up of 23.9 (range, 7.3-47.7) months, the 2-year overall survival and leukemia-free survival were 92%.

Conclusions and Relevance

The results of this nonrandomized clinical trial suggest that the combination of dasatinib and CAR T-cell therapy showed encouraging efficacy in newly diagnosed Ph-positive ALL with acceptable toxic effects. Further studies with larger cohorts and longer follow-up durations are needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT04788472.

Incorporation of immunotherapy into frontline treatment for adults with B-cell precursor acute lymphoblastic leukemia

ABSTRACT

Although complete remission rates in adults with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) have improved over the last 2 decades, it is still inferior to that of the pediatric population, and once in remission, the risk of relapse is still high. Furthermore, although pediatric-inspired chemotherapy regimens have improved long-term outcomes for adolescents and young adults, these intensive chemotherapy regimens are not well tolerated in older patients and are associated with higher morbidity and mortality. Immunotherapeutic agents offer a potential opportunity to improve response and decrease relapse without increasing toxicity. The incorporation of rituximab (anti-CD20 monoclonal antibody) into chemotherapy regimens has been shown to improve outcomes. The treatment of BCP-ALL in adults has been transformed with the approval of inotuzumab ozogamicin (anti-CD22 antibody-drug conjugate), blinatumomab (CD3/CD19 bispecific antibody construct), and chimeric antigen receptor T cells for relapsed or refractory disease and of blinatumomab for measurable residual disease (MRD)-positive remission. More recently, studies of inotuzumab and blinatumomab have shown promising results when used up front either with or without multiagent chemotherapy. Blinatumomab has also been shown in a randomized trial to provide a survival benefit in patients with MRD-negative first remission when added to chemotherapy, which recently led to its additional US Food and Drug Administration approval for use in consolidation. In this review, we highlight the evolution of chemoimmunotherapy-based treatment approaches in the management of treatment-naïve BCP-ALL.

Genetic subtypes of B-cell acute lymphoblastic leukemia in adults

ABSTRACT

B-cell acute lymphoblastic leukemia (B-ALL) is a rare malignancy in adults, with outcomes remaining poor, especially compared with children. Over the past 2 decades, extensive whole-genome studies have identified numerous genetic alterations driving leukemia, leading to the recognition of >20 distinct subtypes that are closely associated with treatment response and prognosis. In pediatric B-ALL, large correlation studies have made genetic classification a central component of risk-adapted treatment strategies. Notably, genetic subtypes are unevenly distributed according to age, and the spectrum of genetic alterations and their prognostic relevance in adult B-ALL have been less extensively studied, with treatment primarily based on the presence or absence of BCR::ABL1 fusion. This review provides an overview of genetic subtypes in adult B-ALL, including recent biological and clinical insights in well-established subtypes as well as data on newly recognized subtypes. Their relevance for risk classification, disease monitoring, and therapeutic management, including in the context of B-cell-directed therapies, is discussed. This review advocates for continuing efforts to further improve our understanding of the biology of adult B-ALL to establish the foundation of future precision medicine in B-ALL.

Integrating Blinatumomab in the Frontline Treatment in B-Cell Acute Lymphoblastic Leukemia: A New Era in Therapeutic Management

Blinatumomab, a bispecific T-cell engager (BiTE), has shown substantial efficacy in treating both relapsed/refractory (R/R) Philadelphia chromosome (Ph)-positive and Ph-negative acute lymphoblastic leukemia (ALL). With its targeted mechanism of action, favorable safety profile, and ability to induce deep molecular remissions, blinatumomab is increasingly incorporated into frontline treatment regimens for B-ALL. Recently, the Food and Drug Administration (FDA) has approved its use in the frontline setting for Ph-negative ALL. In Ph-negative ALL, combining blinatumomab with intensive chemotherapy has resulted in superior measurable residual disease (MRD) clearance and improved long-term outcomes. In Ph-positive ALL, combination therapies involving tyrosine kinase inhibitors (TKIs), particularly ponatinib and blinatumomab, are challenging the traditional approach of allogeneic hematopoietic stem cell transplantation (allo-SCT). This review explores the current evidence supporting the frontline use of blinatumomab in newly diagnosed adults with B-ALL, its impact on treatment paradigms, and potential future directions, including novel combination therapies and the role of emerging immunotherapeutic approaches.

The road not taken: Exploring non-transplant options in De Novo philadelphia positive acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with diverse molecular cytogenetic characteristics. Philadelphia-positive acute myeloid leukemia, a rare subtype of AML, is traditionally considered a high-risk, with the standard recommendation being an allogeneic hematopoietic cell transplant (HCT) in first remission. More recently, with better characterization and understanding of AML biology, novel therapies have been introduced. Drawing parallels from the advances seen in Philadelphia-positive acute lymphoblastic leukemia (ALL), the question arises whether potent tyrosine kinase inhibitors (TKI), such as ponatinib, in combination with AML-directed therapies, could be used in Philadelphia-positive AML, potentially eliminating the need for HCT in the first remission. In this report, we review the literature on Philadelphia-positive AML, study a case where HCT was omitted, and explore potential signals that could support successful HCT omission.

Adult patients with Philadelphia chromosome positive acute lymphoblastic leukemia undergoing allogeneic hematopoietic stem cell transplantation and tyrosine kinase inhibitors: development and validation of a clinical prediction model based on cytogenetics, IKZF1 deletions and minimal residual disease

The aim of this study was to develop and validate a nomogram predicting progression-free survival (PFS) for adult patients with positive acute lymphoblastic leukemia(Ph + ALL) who have undergone allogeneic hematopoietic stem cell transplantation(allo-HSCT) and tyrosine kinase inhibitor(TKI) treatment. Data were retrospectively collected from 176 adult patients diagnosed with Ph + ALL and treated with allo-HSCT and TKIs at The First Affiliated Hospital, Zhejiang University School of Medicine, between January 2015 and May 2023. 70% of the patients were randomly assigned to the training group(n = 124) and 30% of the patients were assigned to the validation group(n = 52). Univariate Cox regression analysis and Akaike Information Criterion(AIC) were utilized to identify significant predictive factors, leading to the development of a nomogram designed to forecast the probability of PFS at 6, 9, and 12 months post-transplantation. The final nomogram incorporated three key variables: presence of complex additional cytogenetic abnormalities (ACAs), minimal residual disease (MRD) status prior to allo-HSCT, and IKZF1 gene deletions. The calibration curves showed excellent consistency between the nomogram prediction and actual observation for 6-, 9- and 12-month PFS in the training set and validation set. The C-index of the training set was 0.726(95%CI: 0.635-0.816), which was no significantly different from the validation set(C-index = 0.774, 95%CI: 0.674-0.875, P > 0.05). This study may provide a simple and efficient prediction model for patients with Ph + ALL undergoing allo-HSCT and TKIs, which can accurately predict PFS subsequent to transplantation. This tool could potentially aid clinicians in decision-making processes and improve patient outcomes.

Antibody-Based and Other Novel Agents in Adult B-Cell Acute Lymphoblastic Leukemia

Despite notable progress in managing B-cell acute lymphoblastic leukemia (B-ALL) over recent decades, particularly in pediatric cohorts where the 5-year overall survival (OS) reaches 90%, outcomes for the 10-15% with relapsed and refractory disease remain unfavorable. This disparity is further accentuated in adults, where individuals over the age of 40 years undergoing aggressive multiagent chemotherapy continue to have lower survival rates. While the adoption of pediatric-inspired treatment protocols has enhanced complete remission (CR) rates among younger adults, 20-30% of these patients experience relapse, resulting in a subsequent 5-year OS rate of 40-50%. For relapsed B-ALL in adults, there is no universally accepted standard salvage therapy, and the median OS is short. The cornerstone of B-ALL treatment continues to be the utilization of combined cytotoxic chemotherapy regimens to maximize early and durable disease control. In this manuscript, we go beyond the multiagent chemotherapy medications developed prior to the 1980s and focus on the incorporation of antibody-based therapy for B-ALL with an eye on existing and upcoming approved indications for blinatumomab, inotuzumab ozogamicin, other monoclonal antibodies, and chimeric antigen receptor (CAR) T cell products in frontline and relapsed/refractory settings. In addition, we discuss emerging investigational therapies that harness the therapeutic vulnerabilities of the disease through targeting apoptosis, modifying epigenetics, and inhibiting the mTOR pathway.

Tyrosine Kinase Inhibitor Post-Allogeneic Stem Cell Transplantation in Adult Philadelphia-Positive B-Acute Lymphoblastic Leukemia: State of the Art and Future Directions

In a scenario characterized by continuous improvement in outcomes, Philadelphia chromosome-positive (Ph+) ALL, once considered a biologically defined subtype with one of the poorest prognoses, now includes patients achieving long-term survival even without allogeneic stem cell transplantation. First-line therapy is increasingly adopting a chemo-free approach, combining tyrosine kinase inhibitors (TKIs) with immunotherapy-specifically blinatumomab-which has resulted in high rates of complete molecular responses and improved survival outcomes. Within this paradigm shift, the allocation to transplantation is becoming increasingly selective and genomically oriented, focusing on patients with particularly unfavorable prognostic and predictive factors. For patients undergoing transplantation, maintenance therapy with TKIs has emerged as one of the most important strategies to reduce the risk of relapse. However, there remains considerable uncertainty regarding which patients benefit most from this approach, the optimal TKI agents, dosing strategies, and the duration of maintenance therapy. In this review, we aim to consolidate the available evidence on this topic, analyzing it in the context of the most recent clinical experiences.

Always more immunotherapy in the management of B-lineage acute lymphoblastic leukemia

In the FELIX study,1 the CAR-T product obecabtagene autoleucel (obe-cel) was investigated in relapsed/refractory adult B-cell lymphoblastic leukemia (B-ALL). The high responses associated with the low incidence of grade ≥3 side effects make obe-cel an attractive candidate for a broader use of CAR-T cells in B-ALL. Its impact will have to be weighed with the monoclonal antibody blinatumomab in the frontline treatment of B-ALL.

Asciminib plus dasatinib and prednisone for Philadelphia chromosome-positive acute leukemia

ABSTRACT

Dasatinib is an effective treatment for Philadelphia chromosome-positive (Ph+) acute leukemia, but some patients develop resistance. Combination treatment with dasatinib and asciminib, an allosteric inhibitor of BCR::ABL1, may deepen responses and prevent the emergence of dasatinib-resistant clones. In this phase 1 study (NCT03595017), 24 adults with Ph+ acute lymphoblastic leukemia (ALL; n = 22; p190, n = 16; p210, n = 6) and chronic myeloid leukemia in lymphoid blast crisis (n = 2) were treated with escalating daily doses of asciminib in combination with dasatinib 140 mg daily plus prednisone 60 mg/m2 daily to determine the maximum tolerated dose. After a 28-day induction, dasatinib and asciminib were continued indefinitely or until hematopoietic stem cell transplant. The median age was 64.5 years (range, 33-85; 50% aged ≥65 years). The recommended phase 2 dose of asciminib was 80 mg daily in combination with dasatinib and prednisone. The dose limiting toxicity at 160 mg daily was asymptomatic grade 3 pancreatic enzyme elevation without symptomatic pancreatitis. There were no vaso-occlusive events. Among patients with de novo ALL, the complete hematologic remission rates at days 28 and 84 were 84% and 100%, respectively. At day 84, 100% of patients achieved complete cytogenetic remission, 89% achieved measurable residual disease negativity (<0.01%) by multicolor flow cytometry, and 74% and 26% achieved BCR::ABL1 reverse transcription quantitative polymerase chain reaction <0.1% and <0.01%, respectively. Dual BCR::ABL1 inhibition with dasatinib and asciminib is safe with encouraging activity in patients with de novo Ph+ ALL. This trial was registered at www.clinicaltrials.gov as #NCT02081378.

Novel prognostic factors and therapeutic advances in adult acute lymphoblastic leukemia

The prognosis of adult patients with acute lymphoblastic leukemia (ALL) has improved in the last decades. This has been due to the sum of several factors including more precise recognition of the ALL subtypes, refinement of the assessment of prognostic factors, improvement in pediatric-inspired chemotherapy regimens and especially to the incorporation of novel targeted and immune therapeutics, as well as engineered cellular therapies, among others. These therapies were initially developed for relapsed or refractory patients but are now being incorporated into frontline treatment and represent a major step forward in ALL therapy. This review focuses on the recent advances in ALL characterization and especially on the treatment of ALL in adults.

Frontline immunotherapeutic combination strategies in adult B-cell acute lymphoblastic leukemia: reducing chemotherapy intensity and toxicity and harnessing efficacy

Using immunotherapeutic agents like inotuzumab ozogamicin (InO), blinatumomab, or chimeric antigen receptor T (CAR T)-cell therapy in frontline adult B-cell acute lymphoblastic leukemia (B-ALL) therapy is promising. These agents are mostly well tolerated and have different toxicity profiles than conventional chemotherapy, enabling their combination with chemotherapy. Additionally, they have often been shown to overcome the traditional adverse ALL risk features. Recently blinatumomab was approved as part of consolidation therapy in MRD negative B-ALL; however, a significant proportion of patients had progressed or relapsed before reaching the timepoint of blinatumomab administration. Including InO/blinatumomab from induction onwards could induce earlier and deeper remissions. Modifications of dosing and administration schedules, as with the fractionated InO schedule with low-intensity chemotherapy, and subcutaneous blinatumomab, appear to reduce the toxicity and improve the anti-ALL efficacy. CAR T-cell therapies like brexucabtagene autoleucel as a consolidation approach have shown positive outcomes. The feasibility of using CAR T-cells to reduce the need for long-drawn maintenance and the need for allogeneic hematopoietic stem cell transplantation (HSCT) are questions of ongoing clinical trials. Newer generation CAR T-cell products like obecabtagene autoleucel appear as effective and safer. Better disease monitoring through next generation sequencing based measurable residual disease analysis could identify patients where treatment intensification including HSCT, or deintensification, is suitable.

How I treat adult Ph+ ALL

ABSTRACT

The Philadelphia (Ph) chromosome is one of the few genetic aberrations in which a casualty has been proven and, as such, represents a success in the history of medicine. This is also evident in the setting of Ph+ acute lymphoblastic leukemia (ALL), the most frequent genetic subgroup in adult ALL, whose incidence increases with age and whose prognosis, before the advent of tyrosine kinase inhibitors (TKIs), was particularly poor. The outcome and management of patients with Ph+ ALL have greatly improved since the incorporation of first-, second-, and third-generation TKIs in the therapeutic backbone and is further changing with the more recent introduction of immunotherapy. This allows for long-term survival rates currently ranging between 75% and 80%. The clinical scenario of adult Ph+ ALL has thus changed profoundly, and new challenges are emerging. In this article, illustrative clinical cases are used to discuss the current role of systemic chemotherapy and allogeneic stem cell transplant, the difficulty in treating central nervous system relapses and, more in general, relapses in the current therapeutic era, and the possibility of stopping TKIs. Finally, the challenges related to an optimal management of these patients are discussed.

How I treat Philadelphia chromosome-like acute lymphoblastic leukemia in children, adolescents, and young adults

ABSTRACT

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) represents a high-risk B-lineage ALL subtype characterized by adverse clinical features and poor relapse-free survival despite risk-adapted multiagent chemotherapy regimens. The advent of next-generation sequencing has unraveled the diversity of kinase-activating genetic drivers in Ph-like ALL that are potentially amenable to personalized molecularly-targeted therapies. Based upon robust preclinical data and promising case series of clinical activity of tyrosine kinase inhibitor (TKI)-based treatment in adults and children with relevant genetic Ph-like ALL subtypes, several clinical trials have investigated the efficacy of JAK- or ABL-directed TKIs in cytokine receptor-like factor 2 (CRLF2)/JAK pathway-mutant or ABL-class Ph-like ALL, respectively. The final results of these trials are pending, and standard-of-care therapeutic approaches for patients with Ph-like ALL have yet to be defined. In this How I Treat perspective, we review recent literature to guide current evidence-based treatment recommendations via illustrative clinical vignettes of children, adolescents, and young adults with newly diagnosed or relapsed/refractory Ph-like ALL, and we further highlight open and soon-to-open trials investigating immunotherapy and TKIs specifically for this high-risk patient population.

Role of Allogeneic Hematopoietic Stem Cell Transplantation for Philadelphia Chromosome-Positive B-Cell Acute Lymphoblastic Leukemia in the Contemporary Era

The treatment of Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (Ph+ B-cell ALL) has seen substantial progress over the past two decades. The introduction of BCR::ABL1 tyrosine kinase inhibitor (TKIs) has resulted in dramatic improvements in long-term survival. Allogeneic hematopoietic stem cell transplantation (allo-HSCT), with its curative potential, has always been an integral part of the treatment algorithm of Ph+ ALL. Recently, the approval of novel therapies such as blinatumomab, inotuzumab ozogamicin and chimeric antigen receptor T-cell (CAR-T) therapy in relapse and refractory (R/R) ALL have further improved outcomes of B-cell ALL. With potent TKIs and novel targeted therapy, the treatment guidelines for Ph+ ALL are evolving rapidly. Additionally, with improved tools for detecting measurable residual disease (MRD), there has been recent interest in redefining the role of allo-HSCT for some patients. In this context, we discuss the current evidence for the utilization of allo-HSCT for Ph+ ALL, focusing on novel therapies and MRD-directed care.

Results of the Simultaneous Combination of Ponatinib and Blinatumomab in Philadelphia Chromosome-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 co-primary 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.In this analysis, we update our experience with the chemotherapy-free regimen of blinatumomab and ponatinib in 60 patients with newly diagnosed Philadelphia chromosome (Ph)-positive ALL. At a median follow-up of 24 months, the complete molecular response rate by reverse transcriptase-polymerase chain reaction was 83% (67% at the end of course one), and the rate of measurable residual disease negativity by next-generation clono-sequencing was 98% (45% at the end of course one). Only two patients underwent hematopoietic stem cell transplantation (HSCT). Seven patients relapsed: two with systemic disease, four with isolated CNS relapse, and one with extramedullary Ph-negative, CRLF2-positive pre-B ALL. The estimated 3-year overall survival rate was 91% and event-free survival rate was 77%. Three patients discontinued blinatumomab because of adverse events (related, n = 1; unrelated, n = 2) and nine discontinued ponatinib because of cerebrovascular ischemia, coronary artery stenosis, persistent rash, elevated liver function tests with drug-induced fatty liver, atrial thrombus, severe arterial occlusive disease of lower extremities, pleuro-pericardial effusion, and debilitation. In conclusion, the simultaneous combination of ponatinib and blinatumomab is a highly effective and relatively safe nonchemotherapy regimen. This regimen also reduces the need for intensive chemotherapy and HSCT in first remission in the majority of patients.

Ph+ ALL: new approaches for upfront therapy

Philadelphia chromosome-positive (Ph+) ALL is the most common genetic subtype of ALL and primarily affects adults. Ph+ ALL is characterized by the constitutively active ABL1 kinase and is resistant to conventional chemotherapy. Thus, Ph+ ALL was historically associated with a dismal prognosis, particularly among patients who did not undergo allogeneic hematopoietic stem cell transplantation (alloHCT) in first complete remission (CR). Imatinib, the first tyrosine kinase inhibitor (TKI) effective against ABL1, transformed the treatment and prognosis of Ph+ ALL, allowing more patients to achieve CR and become eligible for alloHCT, thereby improving outcomes. In recent years, there has been an improved understanding of the biology of Ph+ ALL, including recognition of distinct subtypes (multilineage and lymphoblast-only Ph+ ALL). There has also been a dramatic expansion of effective therapeutic and diagnostic tools for management of Ph+ ALL, including more potent TKIs, which have activity against ABL kinase-resistance mutations; refinement of the chemotherapy and alloHCT regimens that accompany TKI therapy; introduction of immunotherapy (blinatumomab); and better assays for measurable residual disease monitoring. This article reviews recent advancements and future directions for the initial treatment of Ph+ ALL in adults.

Transplant in ALL: who, when, and how?

Allogeneic hematopoietic stem cell transplantation (allo-HCT) remains a cornerstone in the treatment of high-risk acute lymphoblastic leukemia (ALL), yet optimal patient selection is challenging in the era of rapidly changing modern therapy. Refined molecular characterization allows for better risk assessment, sparing low-risk patients from allo-HCT toxicity while identifying those who may benefit from intensified approaches. Measurable residual disease (MRD) has emerged as a powerful predictor of relapse irrespective of treatment strategy, challenging the necessity of transplant in MRD-negative patients. Further, expanded donor options, particularly haploidentical transplantation coupled with reduced intensity conditioning, have extended the applicability of allo-HCT to a broader range of patients. Finally, immunotherapies and targeted treatments are increasingly integrated into both initial and relapsed treatment protocols yielding deep remission and allowing for successful transplant in patients with a history of advanced disease. In this review, we provide an overview of the contemporary role of transplant in adult patients with ALL, focusing on indications for allo-HCT in first remission, optimal sequencing of transplant with novel therapies, and advancements in donor selection and conditioning regimens.

IKZF1 in acute lymphoblastic leukemia: the rise before the fall?

Acute lymphoblastic leukemia (ALL) is the most common malignancy in children and adolescents and in recent decades, the survival rates have risen to >90% in children largely due the introduction of risk adapted therapy. Therefore, knowledge of factors influencing risk of relapse is important. The transcription factor IKAROS is a regulator of lymphocyte development and alterations of its coding gene, IKZF1, are frequent in ALL and are associated with higher relapse risk. This concise review will discuss the normal function of IKAROS together with the effect of gene alterations in ALL such as relieved energy restriction and altered response to anti-leukemic drugs. Besides the biology, the clinical impact of gene alterations in the different subtypes of ALL will be discussed. Finally, possibilities for treating ALL with IKZF1 alterations will be considered including novel therapies like cell signaling inhibitors and immunotherapy.

Frontline treatment of adults with newly diagnosed B-cell acute lymphoblastic leukaemia

In the past decade, there has been considerable progress in the treatment of adults with newly diagnosed B-cell acute lymphoblastic leukaemia. This evolution is the product of a more profound understanding of acute lymphoblastic leukaemia biology, innovations in measurable residual disease quantification that led to precise disease-risk stratification, adoption of contemporary paediatric-inspired regimens, inclusion of tyrosine kinase inhibitors in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukaemia, and the introduction of immunotherapy in the frontline setting. Nevertheless, outcomes of acute lymphoblastic leukaemia in adults are inferior compared with those of children, with excessive rates of treatment failure, and therapy-related morbidity and mortality. Simultaneously, transplant consolidation has continued to be used frequently for high-risk adults with acute lymphoblastic leukaemia in first complete remission. Considering the rapid pace of evolution in acute lymphoblastic leukaemia management, novel trial designs are warranted to accelerate advancements and streamline approaches. Here, we summarise progress in the treatment of adults with newly diagnosed acute lymphoblastic leukaemia, which adds to previously published guidelines by focusing specifically on first-line decisions for B-cell acute lymphoblastic leukaemia and how to best personalise treatment. This Viewpoint also includes experiences with regimens and testing approaches currently available not only in Europe, but also on multiple continents with different practices and resources.

Philadelphia Chromosome as a Clinically Favorable Prognostic Factor of B-cell Acute Lymphoblastic Leukemia/Lymphoblastic Lymphoma in Transplant-Ineligible Elderly Patients in the Era of Molecular-Targeted Therapy

Background and objective There is scarce data on the treatment outcomes of B-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (B-ALL/LBL) in elderly patients in the era of tyrosine kinase inhibitors (TKIs), blinatumomab, and inotuzumab ozogamicin. In light of this, we aimed to address this gap in data by conducting this retrospective study. Methods Treatment outcomes were retrospectively evaluated by using data from transplant-ineligible patients aged 65 years or older with newly diagnosed B-ALL/LBL (n=29) at two hospitals in Oita, Japan between 2013 and 2023. Results The median age of the cohort was 72 (65-88) years, and 10 patients were male; 17 patients had Philadelphia chromosome (Ph)-positive ALL, and the others had Ph-negative ALL. Dasatinib combined with prednisolone was the most common induction therapy for Ph-positive ALL (88.2%). Complete response (CR) was achieved in 93.1%, and the CR rate did not differ significantly between Ph-positive ALL (100%) and Ph-negative ALL (83.3%) (p=0.16). The median observation period was 1.52 (range: 0.03-8.98) years. Overall survival (OS) and event-free survival (EFS) were significantly longer in Ph-positive ALL patients than in Ph-negative ALL patients on univariate analysis (OS: p=0.011, EFS: p=0.041). Multivariate analyses showed that the presence of Ph was significantly and independently associated with longer OS [hazard ratio (HR): 0.29, 95% confidence interval (CI): 0.10-0.87, p=0.027] and EFS (HR: 0.34, 95% CI: 0.12-0.91, p=0.03). There was no difference in relapse-free survival (RFS); 13 patients (76.5%) with Ph-positive ALL were treated with ponatinib (salvage therapy, n=7; consolidation or maintenance therapy in CR, n=6). Six of seven patients (85.7%) with ponatinib salvage therapy achieved CR, and all six patients treated with ponatinib consolidation or maintenance therapy retained CR at the last follow-up. Six patients (Ph-positive ALL: n=4; Ph-negative ALL: n=2) were treated with blinatumomab, including salvage therapy for primary refractory or relapse (n=3), and consolidation therapy due to intolerance to conventional chemotherapies (n=3). Two of three patients with blinatumomab salvage therapy achieved CR, and all three patients with blinatumomab consolidation therapy maintained CR in follow-up. Two patients (Ph-positive ALL: n=1; Ph-negative ALL: n=1) were treated with inotuzumab ozogamicin for relapsed or refractory ALL. A patient with Ph-positive ALL for the third relapse achieved CR, which was sustained for three years. The other patient with Ph-negative ALL for primary refractory achieved CR but relapsed after the fourth course of inotuzumab ozogamicin. Conclusions Elderly patients with Ph-positive ALL showed significantly longer OS and EFS than those with Ph-negative ALL in the era of molecular-targeted therapy.

Immunotherapy in first line treatment of adult acute lymphoblastic leukemia

PURPOSE OF REVIEW

The use of immunotherapy in recent years has changed the paradigm of treatment in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), improving outcomes in the relapsed/refractory setting. New strategies are incorporating immunotherapy into front-line regimens to reduce the toxicity of chemotherapy, prolong survival and increase the possibility of treating older patients. The aim of this review was to describe the new strategies, which have incorporated these drugs into front-line regimens for BCP-ALL patients.

RECENT FINDINGS

Recent studies have demonstrated that immunotherapy can be included in front-line induction, consolidation and/or maintenance regimens for the treatment of BCP-ALL patients by its addition to chemotherapy, by substituting some chemotherapy cycles or even including immunotherapy in chemotherapy-free strategies.

SUMMARY

The implications of these relevant findings will allow treating older patients, reducing the toxicity of chemotherapy and increasing patient outcomes. In addition, these findings have raised the possibility of avoiding the need for hematologic stem cell transplant in some selected patients.

Advances in the treatment of adults with newly diagnosed B-cell acute lymphoblastic leukemia: the role of frontline immunotherapy-based regimens

Blinatumomab and inotuzumab ozogamicin (INO) are both active in relapsed/refractory B-cell acute lymphoblastic leukemia (ALL) and improve outcomes compared with conventional chemotherapy in this setting. Several prospective clinical trials have explored the use of these agents in adults with newly diagnosed B-cell ALL, with promising outcomes observed in younger and older adults and in both Philadelphia chromosome (Ph)-positive and Ph-negative ALL. These novel regimens result in high rates of deep measurable residual disease (MRD) negativity and may improve survival compared with chemotherapy-only approaches, allowing for less reliance on intensive chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). This review discusses novel approaches to integrating INO and/or blinatumomab into frontline ALL regimens, including the potential role of chemotherapy-free regimens in some subgroups. The role of MRD monitoring is also discussed, including how this can inform decisions for consolidative allogeneic HSCT or investigational approaches with CD19 CAR T-cells.

A critical review of management of allogeneic transplant-eligible adults with Ph+ acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) in 20%-30% of adult patients contains the Philadelphia (Ph+) chromosome. Historically, Ph+ ALL denoted a markedly inferior outcome and long-term survival in the absence of an allograft was uncommon. However, the advent of targeted therapy directed against the BCR::ABL1 fusion protein with various tyrosine kinase inhibitors (TKIs) has markedly improved the prognosis, resulting in a number of treatment controversies in allograft-eligible patients. Which is the best TKI to use in induction? What is the clinical relevance of the subdivision of Ph+ ALL into multilineage vs lymphoid types? Do all patients in first morphological complete remission (CR1) after induction and consolidation with chemotherapy/TKI require an allograft? If not, what risk factors predict a poor outcome without an allograft? Can chemotherapy-free approaches, such as blinatumomab in conjunction with more potent TKIs, obviate the need for an allograft in high-risk patients? What is the best strategy to deal with persistent or emerging minimal residual disease both pre- and post-transplant? Is maintenance TKI indicated in all patients post allograft? Can salvage therapy and a subsequent allograft cure patients who relapse after not being transplanted in CR1? This manuscript reviews the latest data influencing contemporary management and discusses these controversies.

Significance of Measurable Residual Disease in Adult Philadelphia Chromosome-Positive ALL: A GRAAPH-2014 Study

PURPOSE

BCR::ABL1 quantification is widely regarded as the standard for monitoring measurable residual disease (MRD) in Philadelphia chromosome-positive (Ph+) ALL. However, recent evidence of BCR::ABL1 multilineage involvement questions the significance of BCR::ABL1 MRD. We aimed to define the prognostic role of MRD as assessed by BCR::ABL1 or lymphoid-specific immunoglobulin/T-cell receptor (IG/TR) gene markers.

PATIENTS AND METHODS

We conducted BCR::ABL1 and IG/TR quantification after each treatment cycle in 264 patients treated in the GRAAPH-2014 trial, which used four cycles of reduced-intensity chemotherapy with nilotinib, followed by hematopoietic stem-cell transplantation (HSCT).

RESULTS

Comparing BCR::ABL1 and IG/TR MRD revealed residual BCR::ABL1-positive non-ALL cells in 98 (43%) of 228 patients, defining multilineage Ph+ ALL. Despite poorer BCR::ABL1 responses, patients with multilineage Ph+ ALL had similar disease-free survival (DFS; hazard ratio [HR], 0.83 [95% CI, 0.49 to 1.41]; P = .50). Although BCR::ABL1 response failed to predict outcomes, IG/TR positivity (≥0.01%) was strongly associated with lower DFS (after cycle 2, HR, 2.49 [95% CI, 1.40 to 4.40]; P = .002; after cycle 4, HR, 4.13 [95% CI, 1.82 to 9.38]; P = .001). In multivariable analysis, both IG/TR positivity after cycle 2 and initial WBC count ≥30 × 109/L predicted poorer DFS, enabling to define a high-risk group having a 4-year DFS of 56.5% compared with 87.6% (HR, 3.72 [95% CI, 1.93 to 7.15]; P < .001). Moreover, allogeneic HSCT significantly improved DFS in the high-risk group (HR, 0.33 [95% CI, 0.18 to 0.60]; P < .001), whereas the standard-risk group had favorable outcomes regardless of allogeneic HSCT.

CONCLUSION

Our findings challenge the significance of BCR::ABL1 monitoring in adult Ph+ ALL and demonstrate the prognostic role of IG/TR MRD. This study provides a framework for using MRD to guide treatment strategies in adults with Ph+ ALL.

The combination of a tyrosine kinase inhibitor and blinatumomab in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia or Philadelphia chromosome-like acute lymphoblastic leukemia

Tyrosine kinase inhibitors (TKIs) have revolutionized Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) treatment. The combination of blinatumomab and a TKI in the frontline setting has shown the safety and efficacy of the chemotherapy-free treatment approach in patients with Ph + ALL. This retrospective analysis included 19 patients with Ph + ALL and Ph-like ALL treated with the combination of blinatumomab and a TKI. Of the 14 newly diagnosed patients, the overall response, complete remission (CR), and molecular response (CMR) rates after one cycle of blinatumomab were 100% (10/10), 90% (9/10), and 57% (8/14), respectively. Of the five relapsed patients, the CR and CMR rates were 50% (2/4) and 40% (2/5). Blinatumomab in combination with TKIs is safe and effective and hence this combination therapy could be a viable therapeutic option in front-line treatment of patients with Ph + ALL.

CD146 Molecule Expression in B Cells Acute Lymphoblastic Leukemia (B-ALLs): A Flow-Cytometric Marker for an Accurate Diagnostic Workup

Background

B-lineage acute lymphoblastic leukemias (B-ALL) harboring the t(9;22)(q34;q11)/BCR::ABL1 rearrangement represent a category with previously dismal prognosis whose management and outcome dramatically changed thanks to the use of tyrosine kinase inhibitors (TKIs) usage and more recently full chemo-free approaches. The prompt identification of these cases represents an important clinical need.

Objectives

We sought to identify an optimized cytofluorimetric diagnostic panel to predict the presence of Philadelphia chromosome (Ph) in B-ALL cases by the introduction of CD146 in our multiparametric flow cytometry (MFC) panels.

Methods

We prospectively evaluated a total of 245 cases of newly diagnosed B-ALLs with a CD146 positivity threshold >10% referred to the Division of Hematology of 'Sapienza' University of Rome. We compared the results of CD146 expression percentage and its mean fluorescence intensity (MFI) between Ph+ ALLs, Ph-like ALLs, and molecularly negative ALLs.

Results

Seventy-nine of the 245 B-ALL cases (32%) did not present mutations at molecular testing, with 144/245 (59%) resulting in Ph+ ALL and 19/245 (8%) Ph-like ALLs. Comparing the 3 groups, we found that Ph+ B-ALLs were characterized by higher expression percentage of myeloid markers such as CD13, CD33, and CD66c and low expression of CD38; Ph+ B-ALL showed a higher CD146 expression percentage and MFI when compared with both molecular negative B-ALL and Ph-like ALLs; neither the mean percentage of CD146 expression neither CD146 MFI were statically different between molecular negative B-ALL and Ph-like ALLs.

Conclusions

Our data demonstrate the association between CD146 expression and Ph+ ALLs. CD146, along with myeloid markers, may help to identify a distinctive immunophenotypic pattern, useful for rapid identification in the diagnostic routine of this subtype of B-ALLs that benefits from a specific therapeutic approach.

Blinatumomab in the Therapy of Acute B-Lymphoid Leukemia

Blinatumomab, a CD19-CD3 bispecific T cell engager (BiTE), has two recombinant single-chain variable fragments that temporarily link CD3+ T cells and CD19+ B cells, leading to the T cell-mediated lysis of neoplastic B cells. Improved minimal residual disease (MRD)-negative response rates and long-term overall survival have been observed in B-ALL patients who received this drug. These therapeutic successes have led to FDA approval for refractory/relapsed and MRD-positive B-ALL patients. Furthermore, recent studies in newly diagnosed B-ALL patients have led in Philadelphia chromosome-positive patients to the development of chemotherapy-free regimens based on tyrosine kinase inhibitors plus Blinatumomab and in Philadelphia chromosome-negative patients to improvement in outcomes using chemotherapy regimens that have incorporated Blinatumomab in the consolidation phase of treatment.

Philadelphia-chromosome positive acute lymphoblastic leukemia: ten frequently asked questions

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) constitutes a distinctive cytogenetic entity associated with challenging outcomes, particularly in adult patients. Current upfront chemotherapy-tyrosine kinase inhibitor (TKI)-based therapies include first, second and third-generation TKIs that have revolutionized patient outcomes including molecular remission and overall survival. Chemotherapy-free regimens such as blinatumomab-dasatinib or blinatumomab-ponatinib offer exciting possibilities, yet challenges arise, particularly in preventing central nervous system relapse. Monitoring measurable residual disease is now a cornerstone particularly using next-generation sequencing (NGS)-Clonoseq for accurate assessment. Controversy regarding the ability to omit consolidation with allogeneic stem cell transplantation, specifically for patients achieving early molecular remission, is related to the excellent survival achieved with novel combinations in the upfront setting, however challenged by the lower disease control when transplant is utilized beyond first remission. Post-transplant maintenance introduces new dilemmas: the optimal TKI, dosing, and duration of therapy are open questions. Meanwhile, a myriad of new combinations and cellular therapies are used for relapsed Ph+ ALL, prompting us to unravel the optimal sequencing of these promising regimen. In this review, we delve into the breakthroughs and controversies in Ph+ ALL with ten commonly asked questions.

Targeting the tyrosine kinase Src in endothelium attenuates inflammation and atherogenesis induced by disturbed flow

BACKGROUND AND PURPOSE

Previous studies have shown that Src can regulate inflammation and tumour progression. However, the mechanisms by which Src regulates the inflammatory response of vascular endothelium and atherogenesis are currently poorly understood. This study aimed to investigate the role of Src in endothelial inflammation and atherogenesis, as well as the underlying mechanisms.

EXPERIMENTAL APPROACH

Real-time quantitative PCR was used to measure the mRNA levels of inflammatory genes. The phosphorylation and localization of proteins were examined using western blotting and immunofluorescence, respectively. The level of p-Src Y416 in mouse endothelium was directly determined using en face staining. Endothelial-specific knockdown of Src was achieved by tail vein injection of AAV-sgSrc in ApoE-/-; Cas9LSL/LSL; Cdh5-cre mice. Atherosclerosis was induced by partial ligation of the carotid artery.

KEY RESULTS

Oscillatory shear stress (OSS) promotes the phosphorylation of Src at Y416 in endothelial cells, and Piezo1 is required for this regulatory process. Overexpression of constitutively active Src promotes endothelial inflammation, as well as phosphorylation of Stat3 (at Y705) and its nuclear translocation. Endothelial inflammation induced by OSS was abolished by the Src inhibitor dasatinib or si-Src. Dasatinib, when administered orally, reduced endothelial inflammation and plaque formation in ApoE-/- mice induced by partial carotid artery ligation. Additionally, plaque formation was decreased in the ligated left carotid artery of mice with endothelial-specific Src knockdown.

CONCLUSION AND IMPLICATIONS

Disturbed flow promotes endothelial inflammation and atherogenesis through the Piezo1-Src-Stat3 pathway. Therefore, inhibiting Src in endothelial cells could be a promising therapeutic strategy to treat atherogenesis.

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.

Ponatinib-review of historical development, current status, and future research

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

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.

Bispecific and multispecific antibodies in oncology: opportunities and challenges

Research into bispecific antibodies, which are designed to simultaneously bind two antigens or epitopes, has advanced enormously over the past two decades. Owing to advances in protein engineering technologies and considerable preclinical research efforts, bispecific antibodies are constantly being developed and optimized to improve their efficacy and to mitigate toxicity. To date, >200 of these agents, the majority of which are bispecific immune cell engagers, are in either preclinical or clinical evaluation. In this Review, we discuss the role of bispecific antibodies in patients with cancer, including history and development, as well as innovative targeting strategies, clinical applications, and adverse events. We also discuss novel alternative bispecific antibody constructs, such as those targeting two antigens expressed by tumour cells or cells located in the tumour microenvironment. Finally, we consider future research directions in this rapidly evolving field, including innovative antibody engineering strategies, which might enable more effective delivery, overcome resistance, and thus optimize clinical outcomes.

SOHO State of the Art Updates and Next Questions, Measurable Residual Disease in Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

Assessment of measurable residual disease (MRD) provides important prognostic information and can inform decision-making about appropriate consolidative therapy in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Many contemporary treatment protocols for Ph+ ALL achieve high rates of MRD negativity, and several analyses suggest that allogeneic hematopoietic stem cell transplant in first remission can be safely deferred in most patients who achieve MRD negativity by PCR for BCR::ABL1 within 3 months. Given the close association between achievement of MRD negativity and favorable long-term outcomes in Ph+ ALL, MRD response rates may aid in the evaluation of novel regimens, particularly in the absence of randomized data or robust survival data. While most studies in Ph+ ALL have used PCR for BCR::ABL1 to measure MRD and correlate with outcomes, this assay has several limitations. PCR or next-generation sequencing-based assays for immunoglobin or T-cell receptor (IG/TR) gene rearrangements may provide a more accurate assessment of clinically significant MRD in Ph+ ALL, particularly in patients with multilineage involvement of BCR::ABL1. Herein, we discuss the prognostic and therapeutic role of MRD in Ph+ ALL. We review the available methods of MRD assessment in Ph+ ALL and discuss the advantages of MRD assays that track IG/TR rearrangements rather than BCR::ABL1.

Acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) is a haematological malignancy characterized by the uncontrolled proliferation of immature lymphoid cells. Over past decades, significant progress has been made in understanding the biology of ALL, resulting in remarkable improvements in its diagnosis, treatment and monitoring. Since the advent of chemotherapy, ALL has been the platform to test for innovative approaches applicable to cancer in general. For example, the advent of omics medicine has led to a deeper understanding of the molecular and genetic features that underpin ALL. Innovations in genomic profiling techniques have identified specific genetic alterations and mutations that drive ALL, inspiring new therapies. Targeted agents, such as tyrosine kinase inhibitors and immunotherapies, have shown promising results in subgroups of patients while minimizing adverse effects. Furthermore, the development of chimeric antigen receptor T cell therapy represents a breakthrough in ALL treatment, resulting in remarkable responses and potential long-term remissions. Advances are not limited to treatment modalities alone. Measurable residual disease monitoring and ex vivo drug response profiling screening have provided earlier detection of disease relapse and identification of exceptional responders, enabling clinicians to adjust treatment strategies for individual patients. Decades of supportive and prophylactic care have improved the management of treatment-related complications, enhancing the quality of life for patients with ALL.

Nilotinib with or without cytarabine for Philadelphia-positive acute lymphoblastic leukemia

ABSTRACT

We previously demonstrated that a reduced-intensity chemotherapy schedule can safely replace hyper-CVAD (cyclophosphamide-vincristine-doxorubicin [Adriamycin]-dexamethasone) cycle 1 when combined with imatinib in adults with Philadelphia-positive acute lymphoblastic leukemia. In the present randomized GRAAPH-2014 trial, we used nilotinib and addressed the omission of cytarabine (Ara-C) in consolidation. The primary objective was the major molecular response (MMR) rate measured by BCR::ABL1 quantification after cycle 4 (end of consolidation). All patients were eligible for allogeneic stem cell transplant (SCT), whereas those in MMR could receive autologous SCT, followed by 2-year imatinib maintenance in both cases. After the enrollment of 156 of 265 planed patients, the data and safety monitoring board decided to hold the randomization because of an excess of relapse in the investigational arm. Among the 155 evaluable patients, 76 received Ara-C during consolidation (arm A) and 79 did not (arm B). Overall, 133 patients (85%) underwent SCT, 93 allogeneic and 40 autologous. The noninferiority end point regarding MMR was reached with 71.1% (arm A) and 77.2% (arm B) of patients reaching MMR. However, the 4-year cumulative incidence of relapse was higher in arm B compared with arm A (31.3% [95% confidence interval {CI}, 21.1%-41.9%] vs 13.2% [95% CI, 6.7%-21.9%]; P = .017), which translated to a lower relapse-free survival. With a median follow-up of 3.8 years, 4-year overall survival was 79.0% (95% CI, 70.6%-89.3%) in arm A vs 73.4% (95% CI, 63.9%-84.4%) in arm B (P = .35). Despite a noninferior rate of MMR, more relapses were observed when ARA-C was omitted without impact on survival. ClinicalTrials.gov ID, NCT02611492.