Blast Phase Research Articles

Prevention and treatment of transformation of myeloproliferative neoplasms to acute myeloid leukemia.

Philadelphia-chromosome negative (Ph-neg) myeloproliferative neoplasms (MPNs) are hematopoietic stem disorders with a risk of progression to the accelerated-phase (AP) or blastphase (BP) that is influenced by clinical, pathologic, cytogenetic, and molecular variables. Overall survival is limited in MPN-AP/BP with current treatment approaches, particularly in those patients that cannot receive an allogeneic hematopoietic stem cell transplant (allo-HCT). In addition, long-term survival with allo-HCT is predominantly seen in chronic-phase MPNs which suggests that the ideal time for intervention may be before MPNs evolve to AP/BP. Over the course of this review we will focus on the risk factors for progression to MPN-AP/BP, identification of high-risk chronic-phase MPNs, potential early-intervention strategies, and considerations around the timing of allo-HCT. We will also summarize current survival outcomes in MPN-AP/BP, discuss the uncertainty around how to best gauge response to therapy, and outline clinical trial considerations for this patient population. Lastly, we will highlight future directions in the management of high-risk MPNs.

Intensification of upfront chemotherapy for patients with myeloid blast phase CML: a single center experience.

Outcomes for patients with myeloid blast phase chronic myeloid leukemia (CML-MBP) are dismal, and no preferred chemotherapy regimen has been identified. Recent studies have suggested a higher response rate with administration of timed-sequenced regimens (TSR) (purine analog, high-dose cytarabine, anthracycline) in high-risk acute myeloid leukemia patients. We retrospectively evaluated outcomes of newly diagnosed CML-MBP patients consecutively treated at our institution with a TSR or standard-dose cytarabine and an anthracycline ("7 + 3") combined with a tyrosine-kinase inhibitor (TKI) between 2011 and 2023. Endpoints of interest included hematologic response, clinically significant cytogenetic response (CSCR) defined as achieving at least a minor cytogenetic response (Ph + metaphases 0%-≤65%) after induction therapy, event-free survival (EFS), and overall survival (OS). A total of 18 patients with CML-MBP were included of whom 9 (50%) received a TSR and 9 (50%) received "7 + 3". Hematologic response (55.6% vs. 55.6%) and CSCR (25% vs. 37.5%) were similar between TSR- and "7 + 3" treated patients. Twelve patients (66.7%) experienced at least one grade ≥ 3 non-hematologic, end-organ toxicity with 33.3% and 11.1% of TSR- and 7 + 3-treated patients, respectively, experiencing at least two. Our data suggests that intensification of upfront chemotherapy does not appear to improve treatment outcomes in CML-MBP patients however, further studies are warranted to confirm these findings involving a larger cohort.

Ischemic stroke as a presenting feature of promyelocytic blast phase in chronic myeloid leukemia - an uncommon presentation: a case report and literature review in the post imatinib era.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm (MPN characterized by reciprocal translocation in the ABL1 and BCR region of chromosomes 9 and 22 respectively. Progression to the blast phase in chronic myeloid leukemia results in a poorer prognosis. It can be of either myeloid, lymphoid or a mixed lineage. Progression to the promyelocytic blast phase is very rare, and there are no evidence-based guidelines for its management. Thrombosis in CML is not well defined. Thrombosis can be seen in patients with acute promyelocytic leukemia (APL) with venous thrombosis (VTE) being more common than arterial thrombosis. Ischemic stroke as the presenting feature of blast phase progression in CML is extremely rare. We report a case of CML who presented to us with acute ischemic stroke and subsequently was diagnosed as CML transformed to the promyelocytic blast phase. She was successfully treated with dasatinib along with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO).

Case Series: Unveiling mass-forming neoplastic extramedullary hematopoiesis in chronic myeloid leukemia

Abstract Introduction/Objective Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by BCR::ABL1 fusion and predominantly granulocytic proliferation. Three main phases of disease have previously been recognized: chronic, accelerated and blast phase, though accelerated phase has become controversial. During the chronic phase, leukemic cells exist predominantly in the peripheral blood and bone marrow; however, during blast phase, blasts can proliferate in the blood, bone marrow, or extramedullary tissues. Methods/Case Report We present two instances of cutaneous extramedullary hematopoiesis associated with CML at our institution. Results (if a Case Study enter NA) Case 1: A 34-year-old man previously diagnosed with CML presented with painful pustules on his right thigh. Biopsy revealed an infiltration of primarily left-shifted granulocytes, along with scattered megakaryocytes, and rare erythroid precursors. Immunohistochemical studies were consistent with maturing extramedullary hematopoiesis, devoid of sheets or clusters of blasts. Peripheral blood analysis revealed marked neutrophilic leukocytosis with basophilia and eosinophilia. Bone marrow examination depicted left-shifted granulocytic hyperplasia, megakaryocytic hyperplasia, and fewer than 5% blasts. Case 2: A 40-year-old man presented with fatigue, night sweats, weight loss, hepatosplenomegaly and palpable nodules on his left arm and thighs. The biopsy of the thigh nodule uncovered leukemic cells at different developmental stages, along with eosinophils, erythroid precursors, and megakaryocytes. Immunohistochemical staining confirmed their presence, with only a few blasts observed. Blood and bone marrow tests showed leukocytosis with blasts less than 5%, indicating CML in the chronic phase. Molecular analysis confirmed BCR-ABL1 fusion. Conclusion Mass-forming neoplastic extramedullary hematopoiesis in the skin during chronic phase of CML is a feature that is not well-documented in the literature. This entity shows immature granulocytic precursors, but does not exhibit an increase in blasts and therefore should not be called leukemia cutis or myeloid sarcoma. It is important to raise awareness of this entity to prevent misinterpretation as myeloid sarcoma and subsequent unnecessarily aggressive therapy.

Characterization of myeloproliferative neoplasms based on genetics only and prognostication of transformation to blast phase.

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal disorders characterized by aberrant hematopoietic proliferation and an intrinsic risk of progression to blast phase. The WHO classification 2022 identifies chronic myeloid leukemia and the BCR::ABL1 negative MPNs polycythemia vera, primary myelofibrosis and essential thrombocythemia as individual entities. However, overlaps, borderline findings or transitions between MPN subtypes occur and incomplete clinical data often complicates diagnosis. By conducting a thorough genetic analysis, we've developed a model that relies on 12 genetic markers to accurately stratify MPN patients. The model can be simplified into a decision tree for routine use. Comparing samples at chronic and blast phase revealed, that one third of patients lost their MPN driver-gene mutation, while mutations in splicing and chromatin modifying genes were stable, indicating a shared founder clone of chronic and blast phase with different driver mutations and therefore different progressing capacities. This was further supported by gain of typical de novo AML gene mutations, accompanied by gain of complex karyotypes and RAS pathway gene mutations. Our data suggest to perform a broader genetic screening at diagnosis and also at clinical progression, as driver mutations may change and the MPN-driver mutations present at diagnosis may disappear.

CAR-T cells for the treatment of pediatric chronic myeloid leukemia in repeatedly relapsed lymphoid blast phase

CAR-T cells for the treatment of pediatric chronic myeloid leukemia in repeatedly relapsed lymphoid blast phase

T315I – a gatekeeper point mutation and its impact on the prognosis of chronic myeloid leukemia

Abstract Objectives BCR-ABL kinase domain mutations are an important cause of resistance to tyrosine kinase inhibitors (TKIs) in chronic myeloid leukaemia (CML) of which T315I is the most treatment-resilient. This study aimed to observe the frequency of T315I and its impact on disease prognosis in terms of progression and survival. Methods Patients with a response which categorized them into warning zone/or who failed to respond to their TKI treatment completely as per the European LeukemiaNet (ELN) were labeled as non-responders. They were assessed for T315I mutation using Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR) and validated via sequencing. Patients were then longitudinally followed for 96 months for the prognostic impact of the mutation. Results Of the 102 non-responders, T315I mutation was detected in 21.6 % of patients with a female preponderance. Almost 59 % of mutation-harbouring patients were labelled as low Sokal risk at baseline. The disease progression into the blastic phase was reported in 58.8 % of mutation-harbouring patients. Overall survival (study period: 96 months) was 81.8 % in patients harbouring T315I mutation. Patients in the blastic phase had significant odds of harbouring T315I mutation. Conclusions Sub-optimal response or failure to TKI treatment indicates the development of resistance due to the presence of T315I mutation or other mutation(s). Early identification will help redirect the patient’s treatment.

A multicenter phase 2 clinical trial of low-dose subcutaneous decitabine in myelofibrosis

AbstractMyelofibrosis (MF) in the chronic phase is a challenging disease to treat, and conventional treatment options are geared toward symptom palliation. In this prospective, multicenter, phase 2 trial, 21 patients with MF (18 chronic phase, 2 accelerated phase, and 1 blast phase) were treated with a 10-day schedule of subcutaneous decitabine at 0.3 mg/kg per day. The overall response rate was 33% (95% confidence interval, 15-57), primarily manifested as an improvement in cytopenias. The median duration of response was 7 months (range, 3-44). A high International Prognostic Scoring System risk score, high baseline fetal hemoglobin level, and sustained decrease in circulating CD34+ cell counts were associated with response to decitabine. All patients experienced at least 1 grade 3/4 cytopenia. Nonhematologic toxicities were less frequent, with fatigue, anorexia, and hypocalcemia being the most common. Given the lack of effective therapies in MF with severe cytopenias, this study supports further investigation into the use of hypomethylating agents as single agents or in combination therapies. This trial was registered at www.ClinicalTrials.gov as #NCT00095784.

Feasibility of a home-based home videogaming intervention with a family-centered approach for children with cerebral palsy: a randomized multiple baseline single-case experimental design

BackgroundWorldwide, children with cerebral palsy (CP) living in underserved communities face barriers to accessing motor therapy services. This study assessed the implementation and effectiveness of an 8-week, upper limb (UL) home-based intervention with a movement-tracking videogame (Bootle Blast) in Costa Rican children with CP.MethodsChildren established a weekly playtime goal and two UL activities of daily living (ADLs) that they would like to improve on. A multiple-baseline, single-case experimental design, was used with the Performance Quality Rating Scale (PQRS) as the repeated measure to track changes in performance of the selected ADLs between the baseline (usual care) and intervention (Bootle Blast) phases. The Canadian Occupational Performance Measure (COPM), the Box and Blocks Test (BBT) and the Children’s Hand-Use Experience Questionnaire (CHEQ) were collected before and after the intervention. Technical barriers were documented during weekly video calls with a monitoring therapist. Treatment effect size, slope changes and percentage of non-overlapping data were identified for the PQRS. Descriptive statistics summarized results for the BBT, CHEQ, videogame logs (e.g., playtime) and technical barriers.ResultsFifteen children participated and 13 completed the intervention. Both participants who dropped out did so after completing baseline assessments, but before experiencing Bootle Blast. Children’s mean active playtime (i.e., mini-games targeting the UL) across the 8-weeks was 377 min, while mean total time spent engaging with Bootle Blast (active + passive play time [e.g., time navigating menus, reviewing rewards]) was 728 min. In total, eight technical issues (from five children) were reported, and all but three were resolved within 48 h. Partial effectiveness was associated with the intervention. Specifically, 85% of participants improved on the PQRS and 69% achieved clinically important improvements ≥ 2 points in performance on the COPM. Children improved by 1.8 blocks on average on the BBT, while on the CHEQ, five children had a clinically important increase of 10% of the total number of UL activities performed with both hands.ConclusionBootle Blast is a feasible and effective option to facilitate access and engage children with cerebral palsy in UL home rehabilitation.Trial registration Trial registration number: NCT05403567.

Transplant Outcomes in Myelofibrosis: Impact of Donor Type (Cord Blood Grafts Supported by CD34+ selected Cells [Haplo-Cord] Versus Matched Donors)

BackgroundDespite the established potentially curative role of allogeneic hematopoietic cell transplantation (alloHCT) in managing MF, the choice of alternative donors for patients lacking matched donors remains a challenge, and the optimal graft source in this disease entity continues to be an ongoing debate. ObjectivesWe aimed to evaluate the impact of donor type: umbilical cord blood transplant supported CD34+ haploidentical donor (haplo-cord) vs adult matched related donor (MRD) and matched unrelated donor (MUD) in 40 adult patients with primary or secondary MF, including those progressing to accelerated phase (AP) or blast phase (BP), who underwent their first allo-HCT. The primary objective of this study was to analyze the impact of stem cell source on primary endpoints of overall survival (OS), graft versus host disease (GVHD) and non-relapse mortality (NRM). ResultsMedian follow-up for all alive patients was 53 months (range 0.3-63 months). Nine patients (22.5%) underwent an MRD allo-HCT, 15 patients (37.5%) underwent a MUD allo-HCT, and 16 patients (40%) underwent a haplo-cord allo-HCT. Four patients died without neutrophil engraftment: 3 (19%) in haplo-cord group and one (4%) in MRD/MUD group. The cumulative incidence of ANC engraftment by day 60 was 80% (95%CI 45-94) in the haplo-cord group and 92% (95%CI 65-98) in the MRD/MUD group (p=0.09). The cumulative incidence of platelet engraftment by day 60 was 59% (95%CI 27-81) in haplo-cord group and 75% (95%CI 51-88) in MRD/MUD group (p=0.4). OS was 62% at 1 year (95%CI 49-79) and 34% at 3 years (95%CI 21-55). The 3-yr OS was similar between the haplo-cord group and the MRD/MUD (37% vs 32%, p=0.9). The 1-yr OS for accelerated/blast phase AP/BP patients was 50% (95%CI 27-93) in the haplo-cord group, compared to 40% (95%CI 19-86) in the MRD/MUD. The 1-yr OS for chronic phase CP patients was 83% (95%CI 58-100) in the haplo-cord group, compared to 79% (95%CI 60-100) in the MRD/MUD group. The cumulative incidence of relapse at 3 years in the haplo-cord group was 13% (95%CI 1.8-34), and in the MRD/MUD group was 28% (95%CI 10-49) (p=0.36). 1-yr non-relapse mortality (NRM) was 38% (95%CI 15-61) in the haplo-cord group and 33% (95%CI 15-52) in the MRD/MUD group. 3-yr NRM was 48% (95%CI 19-72) in the haplo-cord group and 54% (95%CI 29-73) in MRD/MUD group(p=0.95). ConclusionWe showed no significant difference in OS, relapse, and NRM outcomes after haplo-cord transplant compared to adult matched donors’ grafts (MRD or MUD) in MF patients. However, there were more graft failures in patients transplanted with a haplo-cord transplants and delayed engraftments with inadequate haplo myeloid bridges. Despite the small sample size in our study, considering our findings and the availability of other alternative donors, using haplo-cord platforms may no longer be justified for myelofibrosis unless the UCB engraftment dynamics can be optimized.

Decitabine, venetoclax, and ponatinib for advanced phase chronic myeloid leukaemia and Philadelphia chromosome-positive acute myeloid leukaemia: a single-arm, single-centre phase 2 trial.

Advanced phase Philadelphia chromosome-positive myeloid disease-consisting of chronic myeloid leukaemia in the myeloid blast phase and in the accelerated phase, and Philadelphia chromosome-positive acute myeloid leukaemia-is associated with poor outcomes. Although previous studies have suggested the benefit of chemotherapy and BCR::ABL1 tyrosine kinase inhibitor combinations, the optimal regimen is uncertain and prospective studies for this rare group of diseases are scant. Preclinical and retrospective clinical data suggest possible synergy between the BCL-2 inhibitor venetoclax and BCR::ABL1 tyrosine kinase inhibitors. We therefore aimed to design a study to evaluate the safety and activity of a novel combination of decitabine, venetoclax, and the third-generation BCR::ABL1 tyrosine kinase inhibitor ponatinib in advanced phase Philadelphia chromosome-positive myeloid diseases. For this phase 2 study, patients aged 18 years or older with previously untreated or relapsed or refractory myeloid chronic myeloid leukaemia-blast phase, chronic myeloid leukaemia-accelerated phase, or advanced phase Philadelphia chromosome-positive acute myeloid leukaemia, and an Eastern Cooperative Oncology Group performance status of 0-3 were eligible. Patients were eligible regardless of the number of previous lines of therapy received or previous receipt of ponatinib. Cycle 1 (induction) consisted of a 7-day lead-in of ponatinib 45 mg orally daily (days 1-7), followed by combination therapy with decitabine 20 mg/m2 intravenously on days 8-12, venetoclax orally daily with ramp-up to a maximum dose of 400 mg on days 8-28, and ponatinib 45 mg orally daily on days 8-28. Cycles 2-24 consisted of decitabine 20 mg/m2 intravenously on days 1-5, venetoclax orally 400 mg on days 1-21, and ponatinib orally daily on days 1-28. Response-based dosing of ponatinib was implemented in consolidation cycles, with reduction to 30 mg daily in patients who reached complete remission or complete remission with an incomplete haematological recovery and a reduction to 15 mg daily in patients with undetectable BCR::ABL1 transcripts. The primary endpoint was the composite rate of complete remission or complete remission with incomplete haematological recovery in the intention-to-treat population. Safety was assessed in the intention-to-treat population. This trial was registered with ClinicalTrials.gov (NCT04188405) and is still ongoing. Between July 12, 2020, and July 8, 2023, 20 patients were treated (14 with chronic myeloid leukaemia-blast phase, four with chronic myeloid leukaemia-accelerated phase, and two with advanced phase Philadelphia chromosome-positive acute myeloid leukaemia). The median age was 43 years (IQR 32-58); 13 (65%) patients were male and seven (35%) were female; and 12 (60%) were White, three (15%) were Hispanic, four (20%) were Black, and one (5%) was Asian. 12 (60%) patients had received 2 or more previous BCR::ABL1 tyrosine kinase inhibitors, and 14 (70%) patients had at least one high-risk additional chromosomal abnormality or complex karyotype. The median duration of follow-up was 21·2 months (IQR 14·1-24·2). The complete remission or complete remission with an incomplete haematological recovery rate was 50% (10 of 20 patients); complete remission in one [5%] patient and complete remission with incomplete haematological recovery in nine [45%]). An additional six (30%) patients had a morphologic leukaemia-free state. The most common grade 3-4 non-haematological adverse events were febrile neutropenia in eight (40%) patients, infection in six (30%), and alanine or aspartate transaminase elevation in five (25%). Eight (40%) patients had at least one cardiovascular event of any grade. There were three on-study deaths, none of which was considered related to the study treatment and all from infections in the setting of refractory leukaemia. The combination of decitabine, venetoclax, and ponatinib is safe and shows promising activity in patients with advanced phase chronic myeloid leukaemia, including those with multiple previous therapies or high-risk disease features. Further studies evaluating chemotherapy and venetoclax-based combination strategies using newer-generation BCR::ABL1 tyrosine kinase inhibitors are warranted. Takeda Oncology, the National Institutes of Health, and the National Cancer Institute Cancer Center.

CML-399 CARDINAL: A Phase 1, Multicenter, Open-Label, Dose-Escalation and Dose-Optimization Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of TERN-701 in Chronic Myeloid Leukemia

ObjectiveDespite improvements in outcomes achieved with BCR::ABL1 active-site-targeting tyrosine kinase inhibitors (TKIs) for treatment of chronic-phase (CP) chronic myeloid leukemia (CML), many patients need to switch treatments due to disease progression, intolerance, or resistance. Because active-site TKIs utilize similar mechanisms of action, novel treatment options are needed for patients. TERN-701 is a highly selective, oral, investigational, allosteric BCR::ABL1 inhibitor specifically targeting the ABL myristoyl pocket. Preclinical data suggest that TERN-701 is highly potent against native BCR::ABL1 and most common BCR::ABL1 mutations, including T315I, acquired with use of second-generation active-site TKIs. CARDINAL (NCT06163430) is an open-label, global, 2-part, phase 1 study evaluating the safety, tolerability, pharmacokinetics (PK), and efficacy of TERN-701 in patients with previously treated CP-CML. MethodsEligible patients are ≥18 years old with an Eastern Cooperative Oncology Group performance status of 0–2, a confirmed diagnosis of BCR::ABL1-positive CP-CML, with or without the T315I mutation, and treatment failure/intolerance of ≥1 prior second-generation TKI (dasatinib, nilotinib, or bosutinib). Patients intolerant of asciminib without overt resistance are eligible. Patients with CML in accelerated or blast phase are ineligible. Patients will receive TERN-701 orally once daily in continuous 28-day cycles. Part 1 (dose escalation) has been initiated and will include ≈24–36 patients assigned to sequential dose-escalation cohorts, starting at 160 mg, and optional backfill cohorts; dose escalation will be guided by a Bayesian optimal interval algorithm. Primary endpoints of Part 1 include incidence of dose-limiting toxicities during the first treatment cycle and other measures of safety and tolerability; secondary endpoints include PK and efficacy measures, such as hematologic and molecular responses. Based upon the results of Part 1, ≥2 TERN-701 dose levels will be selected for further evaluation in Part 2. In Part 2 (dose expansion), ≈40 patients will be randomized to one of the selected dose levels. Part 2 primary endpoints will measure efficacy (hematologic response, molecular response, and best categorical shift in BCR::ABL1 transcript levels from baseline); secondary endpoints include safety, tolerability, and PK. The study is being conducted in the US, Europe, Australia, and South Korea.

Ischemic Stroke as a Presenting Feature of Promyelocytic Blast Phase in Chronic Myeloid Leukemia – an Uncommon Presentation of an Exceptionally Rare Blastic Transformation of Myeloproliferative Neoplasm

Ischemic Stroke as a Presenting Feature of Promyelocytic Blast Phase in Chronic Myeloid Leukemia – an Uncommon Presentation of an Exceptionally Rare Blastic Transformation of Myeloproliferative Neoplasm

BCR::ABL1 Proteolysis-targeting chimeras (PROTACs): The new frontier in the treatment of Ph+ leukemias?

BCR::ABL1 tyrosine kinase inhibitors (TKIs) have turned chronic myeloid leukemia (CML) from a lethal condition into a chronic ailment. With optimal management, the survival of CML patients diagnosed in the chronic phase is approaching that of age-matched controls. However, only one-third of patients can discontinue TKIs and enter a state of functional cure termed treatment-free remission (TFR), while the remainder require life-long TKI therapy to avoid the recurrence of active leukemia. Approximately 10% of patients exhibit primary or acquired TKI resistance and eventually progress to the blast phase. It is thought that recurrence after attempted TFR originates from CML stem cells (LSCs) surviving despite continued suppression of BCR::ABL1 kinase. Although kinase activity is indispensable for induction of overt CML, kinase-independent scaffold functions of BCR::ABL1 are known to contribute to leukemogenesis, raising the intriguing but as yet hypothetical possibility, that degradation of BCR::ABL1 protein may accomplish what TKIs fail to achieve - eliminate residual LSCs to turn functional into real cures. The advent of BCR::ABL1 proteolysis targeting chimeras (PROTACs), heterobifunctional molecules linking a TKI-based warhead to an E3 ligase recruiter, has moved clinical protein degradation into the realm of the possible. Here we examine the molecular rationale as well as pros and cons of degrading BCR::ABL1 protein. We review reported BCR::ABL1 PROTACs, point out limitations of available data and compoundsand suggest directions for future research. Ultimately, clinical testing of a potent and specific BCR::ABL1 degrader will be required to determine the efficacy and tolerability of this approach.

ETV6::ABL1 fusion: from overlooked minor clone in myeloproliferative neoplasm to major player in leukemic transformation.

The ETV6::ABL1 fusion defines a subgroup of myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions. We report a case of extramedullary involvement and leukemic transformation in myeloproliferative neoplasm (MPN), where ETV6::ABL1 was initially overlooked but later detected in the blast phase. ETV6::ABL1 burden was very low during the MPN phase but increased substantially during the blast phase. This correlation between ETV6::ABL1 burden and disease phenotype indicated that an immature leukemic clone is the sole carrier of ETV6::ABL1, suggesting that ETV6::ABL1 is not the primary driver of the MPN phase. Moreover, only the blast phase revealed somatic mutations in RUNX1 and STAG2, or complex karyotype, while the MPN phase revealed no molecular and cytogenetic abnormalities. Therefore, it remains uncertain whether the small clone of ETV6::ABL1 influenced the manifestation of MPN or if another underlying driver was responsible for the MPN phase, necessitating further research.

Prognostic Factors and Clinical Outcomes in Patients with Blast Phase Chronic Myeloid Leukemia.

Given the low incidence of patients with advanced chronic myeloid leukemia (CML), comprehensive clinical characteristics and outcomes of cohort studies of patients diagnosed with blast phase chronic myeloid leukemia (BP-CML) are limited. We examined the clinical features of blast phase CML, including the TKI selection, treatment response, and whether they have had hematopoietic stem cell transplantation (HSCT) or not. We performed a retrospective cohort study, including BP-CML patients diagnosed in our center from January 2013 to December 2022. Clinical features, treatment therapy, and overall survival (OS) were investigated. Out of the 11 patients, 2 were myeloid type, eight patients were B-lymphoid, and one was T-lymphoid. Four patients suffered from chromosome abnormalities. Four patients were identified with BCR-ABL1 kinase domain mutation, including T315I, E255K, M244v, and E279K. The overall CR, CRi, PR, and MLFS rates were 9%, 54%, 27%, and 9%, respectively. The median follow-up was 21 months (9.5 - 33 months). At the end of the follow-up time, seven patients died. CML patients with lymphoids tended to get a better OS than patients with a type of myeloid, but the difference was not statistically significant (p > 0.05). Patients who received HSCT had an improved OS by two years compared to those who had not received HSCT. The prognosis of BP-CML patients was poor. Given the rarity of BP-CML and the limitation of clinical trial data, large-scale multi-center prospective studies are urgently needed to confirm and improve the treatment of patients with BP-CML in the future.

Analysis of the pharmacoeconomic effectiveness of the tyrosine kinase inhibitors therapy in patients with chronic myeloid leukemia in a Single Hematology Center in Plovdiv, Bulgaria

Summary: Chronic myelogenous leukemia (CML) is a pluripotent hemopoietic stem cell malignancy characterized by the presence of a BCR-ABL1 fusion gene derived from a balanced translocation between the long arms of chromosomes 9 and 22 [t(9;22) (q34; q11)] known as the Philadelphia (Ph) chromosome. CML is an acquired hematopoietic stem cell disease common to myelo- and lymphopoiesis, characterized by uncontrolled proliferation of granulopoiesis (Shuvaev et al. 2015; Yordanov and Varbanova 2019). Relevance and goals: Second-generation tyrosine kinase inhibitors (TKIs) (nilotinib, dasatinib, and bosutinib) have an advantage over imatinib (first-generation) in the frequency and speed of achieving cytogenetic and molecular responses in the treatment of chronic myelogenous leukemia (CML), but they cause severe adverse effects and are much more expensive than imatinib, especially if we compare them to the prices of the registered generic products of Imatinib and Dasatinib. “Novartis Tasigna® trial shows superior results to Glivec® in patients with early-stage chronic myeloid leukemia”, reported on 10/20/2021 by Pierre Perrin-Montlouis. In the first direct comparison of these two oral therapies back in 2009 (Тasigna (nilotinib) 2009), as first-line treatment for CML, the results of Tasigna showed statistically significant improvement over Glivec in every measure of efficacy, including major molecular response (MMR), complete cytogenetic response (CCyR) and prevention of progression to accelerated or blast phase, with responses achieved faster in the Tasigna group than in the Glivec group. Furthermore, in the last ten years, CML patients who have achieved a stable deep molecular response for at least 2 years have been included in clinical trials for the management of treatment-free remission (TFR) (Kim et al. 2013; Saußele et al. 2016). On the other hand, the ever-increasing costs of diagnosis, treatment and monitoring of the response of CML to the various therapeutic strategies require conducting pharmacoeconomic analyses of the cost-effectiveness and cost-utility types in order to evaluate which are the cost-effective strategies with a view to introducing them into therapeutic practice. The present study aims to analyze the pharmacoeconomic efficiency of the TKI inhibitors used by the patients with CML-CP in the first and second lines, treated in the hematology clinic at UMHAT “St. George”, MU- Plovdiv during the period 2018–2022. Methods: An economic analysis of the medicinal use of TKIs for a 5-year period (2018–2022) was performed at the national level according to data from the National Health Insurance Fund and the availability, accessibility, and usability of original and generic TKIs in Bulgaria were evaluated. The direct medical costs for the therapy of all patients were calculated, including the costs of the TKI therapy, laboratory tests, and monitoring of the molecular response for the entire treatment period from the appointment of the TKI therapy until the end of 2022. A comparative analysis was conducted to assess the cost-effectiveness of the different therapeutic strategies with TKIs on the first and second lines of treatment of patients with CML-CP in the hematology clinic at UMHAT “St. George” Medical University, Plovdiv, using the decision analysis method and conducting one-way and probalistic sensitivity analyses. Results: The sensitivity analyzes of all pharmacoeconomic models showed the robustness and reliability of the obtained results. The threshold limits of medical costs and the frequency of achieving a deep molecular response determining the choice of first- and second-generation tyrosine kinase inhibitors as first- and second-line therapy for patients with chronic myeloid leukemia in the chronic phase have been determined. Prescribing doctors prefer the original MPs to generic analogues, which is also assumed by the current regulations, according to which even for expensive MPs dispensing by protocols, the prescription is by trade and not by international non-proprietary names (INN), which is why the use of the much cheaper generic MPs is negligibly low compared to original MPs. A personalized approach to the patient’s therapy and monitoring the patient’s molecular response to it, as well as stopping therapy in 25–30% of patients suitable to stop it safely when in TFR phase with a probability of more than 50% of not having a relapse will save additional costs that, by improving the cost-effectiveness of therapy for patients with CML, will be directed towards the treatment of new patients with this or other diseases. Conclusion: These pharmacoeconomic models can be applied to improve diagnostic and therapeutic standards in clinical practice and for the efficient use of the very limited resources for health care in countries like Bulgaria. The conducted cost-effectiveness analyses confirmed that the hematologists at the University Center in Plovdiv adhere to the recommendations of Leukemia Net and the Bulgarian Medical Society of Hematology and achieve not only good therapeutic but also pharmacoeconomic efficiency in the treatment of CML-СР patients in first- and second- line therapy.

Assessment of Total Antioxidant Capacity, 8-Hydroxy-2'-deoxy-guanosine, the Genetic Landscape, and Their Associations in BCR::ABL-1-Negative Chronic and Blast Phase Myeloproliferative Neoplasms.

Myeloproliferative neoplasms (MPNs), namely, polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are clonal stem cell disorders defined by an excessive production of functionally mature and terminally differentiated myeloid cells. MPNs can transform into secondary acute myeloid leukemia (sAML/blast phase MPN) and are linked to alterations in the redox balance, i.e., elevated concentrations of reactive oxygen species and markers of oxidative stress (OS), and changes in antioxidant systems. We evaluated OS in 117 chronic phase MPNs and 21 sAML cases versus controls by measuring total antioxidant capacity (TAC) and 8-hydroxy-2'-deoxy-guanosine (8-OHdG) concentrations. TAC was higher in MPNs than controls (p = 0.03), particularly in ET (p = 0.04) and PMF (p = 0.01). MPL W515L-positive MPNs had higher TAC than controls (p = 0.002) and triple-negative MPNs (p = 0.01). PMF patients who had treatment expressed lower TAC than therapy-free subjects (p = 0.03). 8-OHdG concentrations were similar between controls and MPNs, controls and sAML, and MPNs and sAML. We noted associations between TAC and MPNs (OR = 1.82; p = 0.05), i.e., ET (OR = 2.36; p = 0.03) and PMF (OR = 2.11; p = 0.03), but not sAML. 8-OHdG concentrations were not associated with MPNs (OR = 1.73; p = 0.62) or sAML (OR = 1.89; p = 0.49). In conclusion, we detected redox imbalances in MPNs based on disease subtype, driver mutations, and treatment history.

Outcomes of blast-phase MPN and JAK2, MPL, and CALRmutated de novo AML: A propensity score-adjusted cohort study.

6526 Background: Progression to blast phase (BP) occurs in about 10% of patients with BCR-ABL-negative myeloproliferative neoplasms (MPN) and is associated with an extremely poor prognosis with no defined standard of care. The VIALE-A trial, which showed that venetoclax (VEN) improves overall survival (OS) in patients with acute myeloid leukemia (AML) when combined with azacitidine, excluded patients with MPN-BP. Rarely, patients develop de novo AML with a genetic profile like an MPN, harboring JAK2, MPL, or CALR mutations. However, there are a lack of data on the outcomes of these patients. Methods: We conducted a single-center retrospective cohort study to compare composite complete response (CCR), OS and event-free survival (EFS) of patients with MPN-BP or de novo AML with underlying JAK2, MPL, or CALR mutations (AML-D-MPN). CCR was defined as complete response (CR) or CR with incomplete count recovery. Propensity score (PS) modeling was used to adjust for baseline characteristics at AML diagnosis: age, sex, race, comorbidities, ECOG status, cytogenetics, and underlying mutations. Results: Of 750 patients treated from 2015 to 2023, 61 had MPN-BP and 12 had AML-D-MPN. The table describes baseline characteristics. The median time for MPN to BP transformation was 8 years (IQR: 2.8-13.6). With a median follow-up of 8.2 months (mo) (95CI: 1.6-59.6), the median OS for MPN-BP was 4.8 mo (95CI: 2.7-8) and for AML-D-MPN was 6.1 mo (95CI: 1.6-NC). In the MPN-BP, 40 received therapy, which included: intensive regimen [7+3 (n=13); CPX-351 (n=1)], hypomethylating agents (HMA) (n=11), HMA+VEN (n=11) and others (n=4). All AML-D-MPN received therapy, which included 7+3 (n=4), HMA (n=1), HMA+VEN (n=2), and others (n=5). In the whole treated population (n=52), the unadjusted CCR was 60% in intensive regimen, 20% in HMA, 20% in HMA+VEN and 0% in others (p=0.3). The PS-adjusted median (m) OS in mo (95%CI) was: 2.6 (1.4-NC) in intensive regimen, 6.2 (1.2-NC) in HMA, 15 (10-15) in HMA+VEN and 1.7 (0.46-NC) in others (p=0.1). The adjusted m-EFS in the same treatment groups was 1.5 (0.43-NC), 6.2 (1.2-NC), 15 (4.3-15) and 0.92 (0.46-NC) (p=0.16), respectively. In MPN-BP group, the adjusted m-EFS in mo (95%CI) was: 0.62 (0.43-NC) in the intensive regimen, 6.2 (1.2-NC) in HMA, 15 (4.2-15) in HMA+VEN and 0.92 (0.92-NC) in others (p=0.25). Conclusions: Patients with MPN-BP and AML-D-MPN have poor survival with similar responses to therapy. These patients have variable outcomes with different treatments; however, there is a trend toward improved survival with the use of HMA+VEN. [Table: see text]

Imatinib with intensive chemotherapy in AML with t(9;22)(q34.1;q11.2)/BCR::ABL1. A DATAML registry study

Acute myeloid leukemia (AML) with t(9;22) (q34.1; q11.2)/BCR::ABL1, a distinct entity within the group of AML with defining genetic abnormalities, belong to the adverse-risk group of the 2022 ELN classification. However, there is little data on outcome since the era of tyrosine kinase inhibitors. Among 5819 AML cases included in the DATAML registry, 20 patients with de novo BCR::ABL1+AML (0.3%) were identified. Eighteen patients treated with standard induction chemotherapy were analyzed in this study. Imatinib was added to chemotherapy in 16 patients. The female-to-male ratio was 1.25 and median age was 54 years. The t(9;22) translocation was the sole chromosomal abnormality in 12 patients. Main gene mutations detected by NGS were ASXL1, RUNX1 and NPM1. Compared with patients with myeloid blast phase of chronic myeloid leukemia (CML-BP), de novo BCR::ABL1+AML had higher WBC, fewer additional chromosomal abnormalities, lower CD36 or CD7 expression and no ABL1 mutations. Seventeen patients (94.4%) achieved complete remission (CR) or CR with incomplete hematologic recovery. Twelve patients were allografted in first remission. With a median follow-up of 6.3 years, the median OS was not reached and 2-year OS was 77% (95% CI: 50–91). Four out of five patients who were not transplanted did not relapse. Comparison of BCR::ABL1+AML, CML-BP, 2017 ELN intermediate (n = 643) and adverse-risk patients (n = 863) showed that patients with BCR::ABL1+AML had a significant better outcome than intermediate and adverse-risk patients. BCR::ABL1+AML patients treated with imatinib and intensive chemotherapy should not be included in the adverse-risk group of current AML classifications.