Identification of a PAK6-Mediated MDM2/p21 Axis That Modulates Survival and Cell Cycle Control of Drug-Resistant Stem/Progenitor Cells in Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a leading example of a malignancy where a molecular targeted therapy revolutionized treatment but has rarely led to cures. Overcoming tyrosine kinase inhibitor (TKI) drug resistance remains a challenge in the treatment of CML. We have recently identified as a predictive biomarker where reduced expression in CD34 treatment-naïve CML cells was associated with TKI resistance.

Outcomes Following Second Allogeneic Stem Cell Transplant for Graft Failure or Poor Graft Function: A Single Centre Experience.

Graft failure is a rare but life-threatening complication following allogeneic hematopoietic stem cell transplantation (HSCT). We aim to review the outcomes of patients who underwent a second HSCT (HSCT2) for graft failure or poor graft function at our centre. Twenty-one patients were identified between February 2001 and July 2021; 11 with primary and 10 with secondary graft failure.

Real-World Impact of Routine Addition of Antithymocyte Globulin to Standard GVHD Prophylaxis in Myeloablative Unrelated Donor Transplants: Important Gains in Graft-versus-Host Disease Prevention though No Difference in Overall Survival.

Introduction: Antithymocyte globulin (ATG) has been demonstrated to reduce the incidence of graft-versus-host disease (GVHD); however, it remains controversial whether these gains are offset by an increase in relapse.

Methods: We conducted a retrospective historical control study consisting of patients (n = 210) who underwent myeloablative allogeneic hematopoietic stem-cell transplantation (HSCT) from 2014 to 2020.

Results: The incidence of acute GVHD was lower in the ATG group (51.

Outcomes with allogeneic stem cell transplant using cryopreserved versus fresh hematopoietic progenitor cell products.

Background: Allogeneic hematopoietic stem cell transplant (alloHSCT) is a mainstay of treatment for hematologic malignancies such as acute leukemias and aggressive lymphomas. Historically, fresh hematopoietic progenitor cell (HPC) products have been preferred to cryopreserved products (cryo-HPC) due to concerns of loss of stem cell viability and number with the cryopreservation procedure.

Objective: We aimed to analyze the outcomes of patients who received cryo-HPCs during the COVID-19 pandemic and compare this against historical cohorts that received fresh HPC.

Identification of multivariable microRNA and clinical biomarker panels to predict imatinib response in chronic myeloid leukemia at diagnosis.

Imatinib Mesylate (imatinib) was once hailed as the magic bullet for chronic myeloid leukemia (CML) and remains a front-line therapy for CML to this day alongside other tyrosine kinase inhibitors (TKIs). However, TKI treatments are rarely curative and patients are often required to receive life-long treatment or otherwise risk relapse. Thus, there is a growing interest in identifying biomarkers in patients which can predict TKI response upon diagnosis.

Final report of TKI discontinuation trial with dasatinib for the second attempt of treatment-free remission after failing the first attempt with imatinib: Treatment-free Remission Accomplished by Dasatinib (TRAD) study.

Multiple studies have reported a significant treatment-free remission (TFR) rate of 50%-60% in patients with chronic myeloid leukaemia (CML) who discontinue tyrosine kinase inhibitor (TKI) therapy. However, the remaining half of these patients still require re-initiation of TKI therapy for leukaemia control. It remains unclear if TKI drugs should be switched for re-therapy in patients who failed the first TFR (TFR1) attempt.

Identification of key microRNAs as predictive biomarkers of Nilotinib response in chronic myeloid leukemia: a sub-analysis of the ENESTxtnd clinical trial.

Despite the effectiveness of tyrosine kinase inhibitors (TKIs) against chronic myeloid leukemia (CML), they are not usually curative as some patients develop drug-resistance or are at risk of disease relapse when treatment is discontinued. Studies have demonstrated that primitive CML cells display unique miRNA profiles in response to TKI treatment. However, the utility of miRNAs in predicting treatment response is not yet conclusive.

Incidence and socioeconomic factors in older adults with acute myeloid leukaemia: Real-world outcomes from a population-based cohort.

Objectives: Acute myeloid leukaemia (AML) is a disease of older adults, who are vulnerable to socio-economic factors. We determined AML incidence in older adults and the impact of socio-economic factors on outcomes.

Methods: We included 3024 AML patients (1996-2016) identified from a population-based registry.

BCR-ABL1 transcript doubling time as a predictor for treatment-free remission failure after imatinib discontinuation in chronic myeloid leukaemia in chronic phase.

The doubling time (DT) of the BCR-ABL1 quantitative polymerase chain reaction (qPCR) transcript level reflects the re-growing fraction of leukaemic cells after discontinuation of tyrosine kinase inhibitor (TKI). The present study analyzed monthly DT within six months after imatinib discontinuation in 131 patients. Monthly DT was calculated as x = ln(2)/K, where x is the DT and K is the fold BCR-ABL1 change from the previous value divided by the number of days between each measurement.

Optimal duration of imatinib treatment/deep molecular response for treatment-free remission after imatinib discontinuation from a Canadian tyrosine kinase inhibitor discontinuation trial.

Although total duration of tyrosine kinase inhibitor (TKI) therapy and of molecular response at 4 log reduction or deeper (MR4) correlates with treatment-free remission (TFR) success after TKI discontinuation, the optimal cut-off values of the duration remain unresolved. Thus, 131 patients were enrolled into the Canadian TKI discontinuation study. The molecular relapse-free survival (mRFS) was defined from imatinib discontinuation till molecular recurrence, that is, major molecular response (MMR) loss and/or MR4 loss.

Mortality from Multiple Myeloma Within One Year Following Autologous Stem Cell Transplantation: Defining an Ultra-high Risk Population.

Despite improvements in therapy, approximately 5% of patients who undergo autologous stem cell transplantation (ASCT) experience early mortality (EM), death within 1 year of transplant (EM post-ASCT). Such patients tend to have few comorbidities suggesting their EM is owing to aggressive underlying disease. We sought to characterize this ultra-high risk population through a retrospective review of patients with newly diagnosed multiple myeloma (MM) treated with first-line ASCT.

Integrin-Linked Kinase Mediates Therapeutic Resistance of Quiescent CML Stem Cells to Tyrosine Kinase Inhibitors.

Patients with chronic myeloid leukemia (CML) often require lifelong therapy with ABL1 tyrosine kinase inhibitors (TKIs) due to a persisting TKI-resistant population of leukemic stem cells (LSCs). From transcriptome profiling, we show integrin-linked kinase (ILK), a key constituent of focal adhesions, is highly expressed in TKI-nonresponsive patient cells and their LSCs. Genetic and pharmacological inhibition of ILK impaired the survival of nonresponder patient cells, sensitizing them to TKIs, even in the presence of protective niche cells.

The miR-185/PAK6 axis predicts therapy response and regulates survival of drug-resistant leukemic stem cells in CML.

Overcoming drug resistance and targeting cancer stem cells remain challenges for curative cancer treatment. To investigate the role of microRNAs (miRNAs) in regulating drug resistance and leukemic stem cell (LSC) fate, we performed global transcriptome profiling in treatment-naive chronic myeloid leukemia (CML) stem/progenitor cells and identified that miR-185 levels anticipate their response to ABL tyrosine kinase inhibitors (TKIs). miR-185 functions as a tumor suppressor: its restored expression impaired survival of drug-resistant cells, sensitized them to TKIs in vitro, and markedly eliminated long-term repopulating LSCs and infiltrating blast cells, conferring a survival advantage in preclinical xenotransplantation models.

Day 14 Bone Marrow Evaluation During Acute Myeloid Leukemia Induction in a Real-world Canadian Cohort.

Introduction: The 2017 National Comprehensive Cancer Network guidelines for acute myeloid leukemia have recommended performing bone marrow (BM) aspiration and BM trephine biopsy (BMTB) 14 to 21 days after starting induction therapy (commonly referred to as "day 14 [D14] marrow"). Those who do not achieve a hypoplastic marrow, with cellularity < 20% and blasts < 5%, are recommended to undergo 2-cycle induction (2CI). We performed a retrospective analysis to determine the impact of D14 BM characteristics in predicting for remission, association with overall survival (OS), and the effect of 2CI according to the D14 BM results.

Outpatient Autologous Stem Cell Transplants for Multiple Myeloma: Analysis of Safety and Outcomes in a Tertiary Care Center.

Background: Autologous stem cell transplant (ASCT) is the preferred consolidation strategy to treat eligible patients with multiple myeloma (MM) and related plasma cell dyscrasias. Given the increasing volume of patients and longer wait time, outpatient ASCT for MM is the standard of care at the Vancouver General Hospital.

Patients And Methods: Patients with MM, POEMS syndrome, and amyloidosis undergoing ASCT were included in this analysis.

Response to Comment on "PP2A inhibition sensitizes cancer stem cells to ABL tyrosine kinase inhibitors in BCR-ABL human leukemia".

LB100 sensitizes resistant chronic phase CML stem and progenitor cells to TKIs and spares healthy bone marrow cells.

Canadian chronic myeloid leukemia outcomes post-transplant in the tyrosine kinase inhibitor era.

The majority of patients with TKI failure respond to HCT. However, the relapse risk remains high. This study has evaluated transplant outcomes in 223 CML patients with TKI failure due to resistance (n = 132) or intolerance (n = 29), as well as those that were TKI naïve/responding with advanced disease (n = 35) or with chronic phase (CP, n = 27).

Outcomes of Intermediate Risk Karyotype Acute Myeloid Leukemia in First Remission Undergoing Autologous Stem Cell Transplantation Compared With Allogeneic Stem Cell Transplantation and Chemotherapy Consolidation: A Retrospective, Propensity-score Adjusted Analysis.

Introduction: Optimal post-remission therapy (PRT) for intermediate risk acute myeloid leukemia remains an area of ongoing research. We aimed to retrospectively compare outcomes following autologous stem cell transplantation (autoSCT) with allogeneic SCT (alloSCT) and consolidation chemotherapy (CMT) in patients with intermediate-risk karyotype AML in first complete remission.

Patients And Methods: We compared overall survival (OS) and leukemia-free survival (LFS) using propensity score (PS)-adjusted analysis of patients receiving PRT with autoSCT, matched sibling (MSD) alloSCT, unrelated/mismatch (UD/MM) alloSCT, and CMT.

Excellent real-world outcomes of adults with Burkitt lymphoma treated with CODOX-M/IVAC plus or minus rituximab.

Treatment of Burkitt lymphoma (BL) with intensive, multi-agent chemotherapy with aggressive central nervous system (CNS) prophylaxis results in high cure rates, although no regimen is standard of care. We examined population-based survival outcomes of adults with BL treated with a modified combination of cyclophosphamide, vincristine, doxorubicin, prednisone and systemic high-dose methotrexate (MTX) (CODOX-M) with IVAC (ifosfamide, mesna, etoposide, cytarabine and intrathecal MTX) (CODOX-M/IVAC) ± rituximab over a 15-year period in British Columbia. For the 81 patients identified (including 8 with CNS involvement and 18 with human immunodeficiency virus-associated BL), 5-year progression-free survival (PFS) and overall survival (OS) were 75% [95% confidence interval (CI): 63-83%] and 77% (95% CI: 66-85%), respectively, with no treatment-related deaths.

Improving Revised International Prognostic Scoring System Pre-Allogeneic Stem Cell Transplantation Does Not Translate Into Better Post-Transplantation Outcomes for Patients with Myelodysplastic Syndromes: A Single-Center Experience.

The natural history of patients with myelodysplastic syndromes (MDS) is variable. The Revised International Prognostic Score (IPSS-R) is commonly used in practice to predict outcomes in patients with MDS at both diagnosis and before hematopoietic stem cell transplantation (HSCT). However, the effect of change in the IPSS-R before allogeneic HSCT with chemotherapy or hypomethylating agents on post-transplantation outcomes is currently unknown.

PP2A inhibition sensitizes cancer stem cells to ABL tyrosine kinase inhibitors in BCR-ABL human leukemia.

Overcoming drug resistance and targeting leukemic stem cells (LSCs) remain major challenges in curing BCR-ABL human leukemia. Using an advanced drug/proliferation screen, we have uncovered a prosurvival role for protein phosphatase 2A (PP2A) in tyrosine kinase inhibitor (TKI)-insensitive leukemic cells, regulated by an Abelson helper integration site-1-mediated PP2A-β-catenin-BCR-ABL-JAK2 protein complex. Genetic and pharmacological inhibition of PP2A impairs survival of TKI nonresponder cells and sensitizes them to TKIs in vitro, inducing a dramatic loss of several key proteins, including β-catenin.

Comparison of a pediatric-inspired treatment protocol versus standard-intensity chemotherapy for young adults with standard-risk BCR-ABL negative acute lymphoblastic leukemia.

We investigated the utility of a pediatric-inspired protocol in adults aged 18-40 years with standard-risk BCR-ABL negative acute lymphoblastic leukemia (ALL). Retrospective outcomes of 25 patients treated with a pediatric protocol between 2008 and 2014 were compared with 22 similarly aged patients treated with an adult protocol between 2003 and 2008. Twenty-five (100%) and 19 (86%) patients achieved complete remission, respectively.

Allogeneic Hematopoietic Stem Cell Transplantation Is an Effective Salvage Therapy for Patients with Chronic Myeloid Leukemia Presenting with Advanced Disease or Failing Treatment with Tyrosine Kinase Inhibitors.

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only known curative therapy for chronic myeloid leukemia (CML); however, it is rarely utilized given the excellent long-term results with tyrosine kinase inhibitor (TKI) treatment. The purpose of this study is to examine HSCT outcomes for patients with CML who failed TKI therapy or presented in advanced phase and to identify predictors of survival, relapse, and nonrelapse mortality (NRM). Fifty-one patients with CML underwent HSCT for advanced disease at diagnosis (n = 15), TKI resistance as defined by the European LeukemiaNet guidelines (n = 30), TKI intolerance (n = 2), or physician preference (n = 4).

Outcome of Patients With Non-Hodgkin Lymphomas With Concurrent MYC and BCL2 Rearrangements Treated With CODOX-M/IVAC With Rituximab Followed by Hematopoietic Stem Cell Transplantation.

Background: Double-hit lymphoma is characterized by the presence of concurrent MYC (myelocytomatosis oncogene) and BCL2 (B-cell lymphoma 2) gene rearrangements. Prognosis is poor with standard chemoimmunotherapy. Since 2003, the British Columbia Cancer Agency has used CODOX-M/IVAC+R (cyclophosphamide, vincristine, doxorubicin, methotrexate, cytarabine, ifosfamide, and etoposide, combined with rituximab) followed by consolidative hematopoietic cell transplantation as definitive treatment for double-hit lymphoma.

The core autophagy protein ATG4B is a potential biomarker and therapeutic target in CML stem/progenitor cells.

Previous studies demonstrated that imatinib mesylate (IM) induces autophagy in chronic myeloid leukemia (CML) and that this process is critical to cell survival upon therapy. However, it is not known if the autophagic process differs at basal levels between CML patients and healthy individuals and if pretreatment CML cells harbor unique autophagy characteristics that could predict patients' clinical outcomes. We now demonstrate that several key autophagy genes are differentially expressed in CD34(+) hematopoietic stem/progenitor cells, with the highest transcript levels detected for ATG4B, and that the transcript and protein expression levels of ATG4 family members, ATG5 and BECLIN-1 are significantly increased in CD34(+) cells from chronic-phase CML patients (P < .