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Abstract: Asciminib is a myristoyl site BCR::ABL1 inhibitor approved for patients with chronic-phase chronic myeloid leukemia (CP-CML) failing ≥2 prior lines of therapy. The Australasian Leukaemia and Lymphoma Group conducted the Asciminib Evaluation in Newly Diagnosed CML study to assess efficacy of asciminib for newly diagnosed CP-CML. Patients commenced asciminib 40 mg twice daily. Patients with treatment failure, defined as BCR::ABL1 of >10% at 3 or 6 months, or >1% at 12 or 18 months, received either imatinib, nilotinib, or dasatinib in addition to asciminib. In patients with suboptimal response, defined as levels of 1% to 10% at 6 months, >0.1% to 1% at 12 months, or >0.01% to 1% at 18 months, the asciminib dose was increased to 80 mg twice daily. With a median follow-up of 21 months (range, 0-36), 82 of 101 patients continue asciminib. Most common reasons for treatment discontinuation were adverse events (6%), loss of response (4%), and withdrawn consent (5%). There were no deaths; 1 patient developed lymphoid blast crisis. The coprimary end points were early molecular response (BCR::ABL1 of ≤10% at 3 months), achieved in 93% (96% confidence interval [CI], 86-97%), and major molecular response by 12 months achieved in 79%; (95% CI, 70-87%), respectively. Cumulative incidence of molecular response 4.5 was 53% by 24 months. One patient had 2 cerebrovascular events; no other arterial occlusive events were reported. Asciminib as frontline CP-CML therapy leads to high rates of molecular response with excellent tolerance and a low rate of discontinuation for toxicity. This trial was registered at https://www.anzctr.org.au/ as #ACTRN12620000851965., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Abstract: The efficacy and safety of acalabrutinib plus obinutuzumab and acalabrutinib monotherapy vs zanubrutinib in patients with treatment-naive chronic lymphocytic leukemia/small lymphocytic lymphoma without del(17p) were compared using an unanchored matching-adjusted indirect comparison. Individual patient-level data from ELEVATE-TN (acalabrutinib plus obinutuzumab, n = 162; acalabrutinib monotherapy, n = 163) were weighted to match published aggregate baseline data from SEQUOIA cohort 1, which excluded patients with del(17p) (zanubrutinib, n = 241), using variables that were prognostic/predictive of investigator-assessed progression-free survival (INV-PFS) in an exploratory Cox regression analysis of ELEVATE-TN. After matching, INV-PFS was longer with acalabrutinib plus obinutuzumab (hazard ratio [HR], 0.41; 95% confidence interval [CI], 0.23-0.74) and comparable with acalabrutinib monotherapy (HR, 0.91; 95% CI, 0.53-1.56) vs zanubrutinib. Acalabrutinib monotherapy had significantly lower odds of any grade hypertension vs zanubrutinib (odds ratio [OR], 0.44; 95% CI, 0.20-0.99), whereas acalabrutinib plus obinutuzumab had significantly higher odds of neutropenia (OR, 2.19; 95% CI, 1.33-3.60) and arthralgia (OR, 2.33; 95% CI, 1.37-3.96) vs zanubrutinib. No other significant differences in safety were observed. In summary, acalabrutinib plus obinutuzumab had longer INV-PFS with increased odds of neutropenia and arthralgia than zanubrutinib, whereas acalabrutinib monotherapy had similar INV-PFS with lower odds of any grade hypertension. These trials were registered at www.ClinicalTrials.gov as #NCT02475681 and #NCT03336333., (© 2024 by The American Society of Hematology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Antifibrinolytic drugs are used extensively for on-demand treatment of severe acute bleeding. Controlling fibrinolysis may also be an effective strategy to prevent or lessen chronic recurring bleeding in bleeding disorders such as hemophilia A (HA), but current antifibrinolytics have unfavorable pharmacokinetic profiles. Here, we developed a long-lasting antifibrinolytic using small interfering RNA (siRNA) targeting plasminogen packaged in clinically used lipid nanoparticles (LNPs) and tested it to determine whether reducing plasmin activity in animal models of HA could decrease bleeding frequency and severity. Treatment with the siRNA-carrying LNPs reduced circulating plasminogen and suppressed fibrinolysis in wild-type and HA mice and dogs. In HA mice, hemostatic efficacy depended on the injury model; plasminogen knockdown improved hemostasis after a saphenous vein injury but not tail vein transection injury, suggesting that saphenous vein injury is a murine bleeding model sensitive to the contribution of fibrinolysis. In dogs with HA, LNPs carrying siRNA targeting plasminogen were as effective at stabilizing clots as tranexamic acid, a clinical antifibrinolytic, and in a pilot study of two dogs with HA, the incidence of spontaneous or excess bleeding was reduced during 4 months of prolonged knockdown. Collectively, these data demonstrate that long-acting antifibrinolytic therapy can be achieved and that it provides hemostatic benefit in animal models of HA.

Abstract: Patients with chronic myeloid leukemia who are eligible for treatment-free remission (TFR) may still relapse after tyrosine kinase inhibitor (TKI) cessation. There is a need for accurate predictors of outcome to enable patients with a favorable profile to proceed while avoiding futile attempts. Sensitive detection of residual disease in total leukocytes at treatment cessation is associated with relapse but is not highly discriminatory, likely because it is a composite measure of residual leukemia derived from different cell lineages, whereas only some lineages are relevant for relapse. We prospectively measured BCR::ABL1 DNA as a predictive yes/no binary test in 5 cellular fractions from 48 patients meeting conventional criteria for TKI discontinuation. The median BCR::ABL1 DNA level was higher in granulocytes and T cells, but not in other lineages, in patients who relapsed. Among the 40 patients undergoing their first TFR attempt, we defined 3 groups with differing relapse risk: granulocyte-positive group (100%), granulocyte-negative/T-cell-positive group (67%), and granulocyte-negative /T-cell-negative group (25%). These data show the critical importance of lineage-specific assessment of residual disease in the selection of patients who can attempt to achieve TFR with a high expectation of success and, concurrently, defer patients who have a high probability of relapse., (© 2023 by The American Society of Hematology.)

B-cell acute lymphoblastic leukaemia (B-ALL) is characterised by diverse genomic alterations, the most frequent being gene fusions detected via transcriptomic analysis (mRNA-seq). Due to its hypervariable nature, gene fusions involving the Immunoglobulin Heavy Chain ( IGH ) locus can be difficult to detect with standard gene fusion calling algorithms and significant computational resources and analysis times are required. We aimed to optimize a gene fusion calling workflow to achieve best-case sensitivity for IGH gene fusion detection. Using Nextflow, we developed a simplified workflow containing the algorithms FusionCatcher, Arriba, and STAR-Fusion. We analysed samples from 35 patients harbouring IGH fusions ( IGH::CRLF2 n = 17, IGH::DUX4 n = 15, IGH::EPOR n = 3) and assessed the detection rates for each caller, before optimizing the parameters to enhance sensitivity for IGH fusions. Initial results showed that FusionCatcher and Arriba outperformed STAR-Fusion (85-89% vs. 29% of IGH fusions reported). We found that extensive filtering in STAR-Fusion hindered IGH reporting. By adjusting specific filtering steps (e.g., read support, fusion fragments per million total reads), we achieved a 94% reporting rate for IGH fusions with STAR-Fusion. This analysis highlights the importance of filtering optimization for IGH gene fusion events, offering alternative workflows for difficult-to-detect high-risk B-ALL subtypes.

The BCR::ABL1 gene fusion initiates chronic myeloid leukemia (CML); however, evidence has accumulated from studies of highly selected cohorts that variants in other cancer-related genes are associated with treatment failure. Nevertheless, the true incidence and impact of additional genetic abnormalities (AGA) at diagnosis of chronic phase (CP)-CML is unknown. We sought to determine whether AGA at diagnosis in a consecutive imatinib-treated cohort of 210 patients enrolled in the TIDEL-II trial influenced outcome despite a highly proactive treatment intervention strategy. Survival outcomes including overall survival, progression-free survival, failure-free survival, and BCR::ABL1 kinase domain mutation acquisition were evaluated. Molecular outcomes were measured at a central laboratory and included major molecular response (MMR, BCR::ABL1 ≤0.1%IS), MR4 (BCR::ABL1 ≤0.01%IS), and MR4.5 (BCR::ABL1 ≤0.0032%IS). AGA included variants in known cancer genes and novel rearrangements involving the formation of the Philadelphia chromosome. Clinical outcomes and molecular response were assessed based on the patient's genetic profile and other baseline factors. AGA were identified in 31% of patients. Potentially pathogenic variants in cancer-related genes were detected in 16% of patients at diagnosis (including gene fusions and deletions) and structural rearrangements involving the Philadelphia chromosome (Ph-associated rearrangements) were detected in 18%. Multivariable analysis demonstrated that the combined genetic abnormalities plus the EUTOS long-term survival clinical risk score were independent predictors of lower molecular response rates and higher treatment failure. Despite a highly proactive treatment intervention strategy, first-line imatinib-treated patients with AGA had poorer response rates. These data provide evidence for the incorporation of genomically-based risk assessment for CML.

The addition of interferon to tyrosine kinase inhibitors (TKIs), to improve deep molecular response (DMR) and potentially treatment-free remission (TFR) rates in chronic-phase chronic myeloid leukaemia (CP-CML) patients is under active investigation. However, the immunobiology of this combination is poorly understood. We performed a comprehensive longitudinal assessment of immunological changes in CML patients treated with nilotinib and interferon-alpha (IFN-α) within the ALLG CML11 trial (n = 12) or nilotinib alone (n = 17). We demonstrate that nilotinib+IFN transiently reduced absolute counts of natural killer (NK) cells, compared with nilotinib alone. Furthermore, CD16 + -cytolytic and CD57 + CD62L - -mature NK cells were transiently reduced during IFN therapy, without affecting NK-cell function. IFN transiently increased cytotoxic T-lymphocyte (CTL) responses to leukaemia-associated antigens (LAAs) proteinase-3, BMI-1 and PRAME; and had no effect on regulatory T cells, or myeloid-derived suppressor cells. Patients on nilotinib+IFN who achieved MR4.5 by 12 months had a significantly higher proportion of NK cells expressing NKp46, NKp30 and NKG2D compared with patients not achieving this milestone. This difference was not observed in the nilotinib-alone group. The addition of IFN to nilotinib drives an increase in NK-activating receptors, CTLs responding to LAAs and results in transient immune modulation, which may influence earlier DMR, and its effect on long-term outcomes warrants further investigation., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

Dysregulation of immune-checkpoint receptors has been reported at diagnosis of chronic myeloid leukemia (CML), however, their role in the maintenance of remission after tyrosine kinase inhibitor (TKI) cessation is unclear. We assessed programmed cell death-1 (PD-1), T-cell immunoglobulin, and mucin-domain containing protein-3 (TIM-3), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), lymphocyte-activation gene-3 (LAG-3), and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains (TIGIT) expression on T-cell subsets, regulatory T cells (T-regs), and natural killer (NK) cells at the time of TKI cessation in 44 patients (22 patients sustained treatment-free remission [TFR] and 22 experienced molecular relapse [MolR]). We confirmed our previous finding that absolute numbers of T-regs are increased in patients who experienced MolR compared with those who sustained TFR. The immune-checkpoint receptors PD-1, CTLA-4, LAG-3, and TIGIT on T or NK cells were not differentially expressed between the MolR and TFR groups. However, TIM-3 was consistently upregulated on bulk T cells (CD3+) and T-cell subsets including, CD4+ T cells, CD8+ T cells, and T-regs, in patients who relapsed in comparison with those who maintained TFR after discontinuation. Furthermore, gene expression analysis from publicly available data sets showed increased TIM-3 expression on CML stem cells compared with normal hematopoietic stem cells. These findings suggest that among the targetable immune-checkpoint molecules, TIM-3 blockade may potentially improve effector immune response in patients with CML stopping TKI, while concomitantly targeting leukemic stem cells and could be a promising therapeutic strategy for preventing relapse after cessation of TKI in patients with CML., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: Immune thrombocytopenia (ITP) has been reported following COVID-19 vaccination. After index case fatalities, there was concern among patients both with and without a prior history of ITP in Australia., Objectives: To describe treatment outcomes of ITP after COVID-19 vaccination and compare relapsed vs historical pre-COVID-19 ITP cohorts., Methods: We collected ITP cases in Australia within 6 weeks of receiving any COVID-19 vaccination as part of primary vaccination (up to October 17, 2021). Second, we reviewed platelet charts in a historical ITP cohort to determine whether platelet variability was distinct from relapsed ITP after vaccination., Results: We report on 50 patients (37 de novo , 13 relapsed ITP) vaccinated from March 22, 2021, to October 17, 2021. Although there was 1 fatality, bleeding was otherwise mostly minor: (70% WHO bleeding grade <2). De novo ITP was more likely after AstraZeneca ChAdOx1 nCoV-19 (89%) than Pfizer BNT162b2 (11%). Most patients responded quickly (median, 4 days; complete response, 40 of 45 [89%]). In the historical cohort, only 6 of 47 patients exhibited platelet variability (>50% decrease and platelets <100 × 10 9 /L), but median platelet nadir was significantly higher than vaccination relapse (27 vs 6 × 10 9 /L, P  =.005)., Conclusion: ITP was more frequently reported after AstraZeneca ChAdOx1 nCoV-19 than Pfizer BNT162b2 vaccination. Standard ITP treatments remain highly effective for de novo and relapsed ITP (96%). Although thrombocytopenia can be severe after vaccination, bleeding is usually mild. Despite some sampling bias, our data do not support a change in treatment strategies for patients with ITP after vaccination., (© 2022 The Authors.)

Successful treatment of acute myeloid leukemia (AML) with chimeric antigen receptor (CAR) T cells is hampered by toxicity on normal hematopoietic progenitor cells and low CAR T cell persistence. Here, we develop third-generation anti-CD123 CAR T cells with a humanized CSL362-based ScFv and a CD28-OX40-CD3ζ intracellular signaling domain. This CAR demonstrates anti-AML activity without affecting the healthy hematopoietic system, or causing epithelial tissue damage in a xenograft model. CD123 expression on leukemia cells increases upon 5'-Azacitidine (AZA) treatment. AZA treatment of leukemia-bearing mice causes an increase in CTLA-4 negative anti-CD123 CAR T cell numbers following infusion. Functionally, the CTLA-4 negative anti-CD123 CAR T cells exhibit superior cytotoxicity against AML cells, accompanied by higher TNFα production and enhanced downstream phosphorylation of key T cell activation molecules. Our findings indicate that AZA increases the immunogenicity of AML cells, enhancing recognition and elimination of malignant cells by highly efficient CTLA-4 negative anti-CD123 CAR T cells., (© 2021. The Author(s).)

Objective: Obesity is a risk factor for developing venous thromboembolism (VTE). Optimal dosage of enoxaparin has not been established in the obese population. We aimed to study clinical outcomes and complications with enoxaparin in obese patients., Methods: A retrospective, single centre observational study of obese patients treated with enoxaparin for VTE (n = 47) using a body mass index (BMI)-stratified dosing, thromboprophylaxis (n = 46), and non-obese controls (n = 20) was performed. Anti-Xa was used to measure enoxaparin efficacy., Results: Patients with a median BMI of 36.3 kg/m 2 (range 30-52.7) with a median weight of 136 kg (range 68-240) received therapeutic enoxaparin at median 120 mg BID (range 60-200). A median targeted anti-Xa level of 0.79 (95% CI 0.72-1.03) IU/mL was achieved in 58% of patients. Dose reduction, or increase was needed in 25%, and 16% patients respectively. Mild or major haemorrhage, or VTE occurred in 10%, 2% and 2% patients respectively. Patients with a median weight of 160 kg (range 130-245) received thromboprophylaxis with 40 mg BID enoxaparin. Targeted median anti-Xa of 0.22 IU/mL (95% CI 0.19-0.24) was achieved in 59% patients. Mild haemorrhage was seen in 2%, while none developed major haemorrhage or VTE. Control patients who received enoxaparin 40 mg daily did not develop VTE; 5% had minor bleeding events., Conclusions: BMI-stratified therapeutic enoxaparin dosing regimen is safe and effective therapy in obese patients. Fixed dosing without monitoring may not be appropriate. Thromboprophylaxis with 40 mg BID in obese patients was efficacious in preventing VTE without excess bleeding compared to control patients., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: The objective of this exploratory study was to determine the presence and correlates of self-reported cognition in a sample of haematological cancer patients who had undergone allogeneic stem cell transplantation (SCT)., Methods: Haematological cancer patients (n = 30) who had undergone allogeneic SCT between one and five years previously and age-matched control participants (n = 30) completed questionnaires assessing cognition, affect, sleep quality and fatigue and an assessment of premorbid IQ., Results: Patients reported significantly poorer perceived cognitive ability (d = 1.12) and greater perceived cognitive impairment (d = 0.96) than controls. Lower fatigue was significantly associated with greater perceived cognitive ability (r = 0.75 patients and controls) and less perceived cognitive impairment (r = 0.80 patients; r = 0.57 controls). Interestingly, depression was significantly correlated with perceived cognitive ability in the control group only (r = 0.80). Hierarchical multiple regressions showed that fatigue was a significant predictor of perceived cognitive ability in patients, accounting for 56% of the variance., Conclusions: This study established that self-reported cognitive ability and cognitive impairment was significantly poorer in haematological cancer patients than controls. Furthermore, fatigue was significantly associated with perceived cognitive ability in patients. Future research should focus on identifying interventions that target fatigue in allogeneic SCT recipients in order to improve quality of life throughout survivorship., (© 2021 John Wiley & Sons Ltd.)

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia in adults in the UK. Ibrutinib, an oral Bruton tyrosine kinase inhibitor (BTKi) for CLL approved by the UK's National Institute for Health and Care Excellence in January 2017, represented a major shift in CLL management. Real-world data on ibrutinib use in routine clinical practice will inform patients' and physicians' decision-making. We conducted a retrospective medical chart review of UK patients with CLL who initiated ibrutinib between January 2017 and July 2018. Data for 259 patients were contributed by 34 haematology-oncology specialists, with a median follow-up duration of 16.7 months. Median age at ibrutinib initiation was 71 years. Ibrutinib first-line monotherapy was prescribed in 20.1% of patients. Ibrutinib was permanently discontinued in 15.4% of patients, mostly owing to progressive disease. Adverse events (AEs) were reported in 151 patients (58.3%). The most common were bruising (19.3% of patients), cytopenias (17.0%) and diarrhoea (11.6%). Ibrutinib dose reduction was observed in 14.3% of patients and was temporarily discontinued in 10.4% of patients, with the main reason for both being toxicity. These results expand the real-world evidence on ibrutinib therapy and demonstrate a high burden of AEs, highlighting the need for more tolerable BTKis., (© 2021 The Authors. eJHaem published by British Society for Haematology and John Wiley & Sons Ltd.)

With treatment-free remission (TFR) rapidly becoming the ultimate goal of therapy in chronic myeloid leukemia (CML), there is a need to develop strategies to maximize sustained TFR by improving our understanding of its key determinants. Chronic-phase CML patients attempting TFR were evaluated to identify the impact of multiple variables on the probability of sustained TFR. Early molecular response dynamics were included as a predictive variable, assessed by calculating the patient-specific halving time of BCR-ABL1 after commencing tyrosine kinase inhibitor (TKI) therapy. Overall, 115 patients attempted TFR and had ≥12 months of follow-up. The probability of sustained TFR, defined as remaining in major molecular response off TKI therapy for 12 months, was 55%. The time taken for the BCR-ABL1 value to halve was the strongest independent predictor of sustained TFR: 80% in patients with a halving time of <9.35 days (first quartile) compared with only 4% if the halving time was >21.85 days (last quartile) (P < .001). The e14a2 BCR-ABL1 transcript type and duration of TKI exposure before attempting TFR were also independent predictors of sustained TFR. However, the BCR-ABL1 value measured at 3 months of TKI was not an independent predictor of sustained TFR. A more rapid initial BCR-ABL1 decline after commencing TKI also correlated with an increased likelihood of achieving TFR eligibility. The association between sustained TFR and the time taken for BCR-ABL1 to halve after commencing TKI was validated using an independent dataset. These data support the critical importance of the initial kinetics of BCR-ABL1 decline for long-term outcomes., (© 2021 by The American Society of Hematology.)

Background: The incidence of acute myeloid leukemia (AML) in older patients is increasing, but practice guidelines balancing quality-of-life, time outside of hospital and overall survival (OS) are not established., Methods: We conducted a retrospective analysis comparing time outside hospital, OS and end-of-life care in AML patients ≥60 years treated with intensive chemotherapy (IC), hypomethylating agents (HMA) and best supportive care (BSC) in a tertiary hospital., Results: Of 201 patients diagnosed between 2005 and 2015, 54% received IC while 14% and 32% were treated with HMA and BSC respectively. Median OS was significantly higher in patients treated with IC and HMA compared with BSC (11.5 versus 16.2 versus 1.3 months; p < .0001). Median number of hospital admissions for the entire cohort was 3 (1-17) and patients spent <50% of their life after the diagnosis in the hospital setting. Compared to BSC, IC (HR 0.27, p < .0001) and HMA therapy (HR 0.16, p < .0001) were associated with the lower likelihood of spending at least 25% of survival time in hospital. Although 66% patients were referred to palliative care, the interval between referral to death was 24 (1-971) days and 46% patients died in the hospital., Conclusion: Older patients with AML, irrespective of treatment, require intensive health care resources, are more likely to die in hospital and less likely to use hospice services. Older AML patients treated with disease modifying therapy survive longer than those receiving BSC, and spend >50% of survival time outside the hospital. These data are informative for counselling older patients with AML., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

The adhesion of blood clots to wounds is necessary to seal injured vasculature and achieve hemostasis. However, it has not been specifically tested if adhesive failure of clots is a major contributor to rebleeding and what mechanisms prevent clot delamination. Here, we quantified the contribution of adhesive and cohesive failure to rebleeding in a rat model of femoral artery injury, and identified mechanisms that contribute to the adhesive strength of bulk clots in a lap-shear test in vitro. In the rat bleeding model, the frequency of clot failures correlated positively with blood loss (R = 0.81, p = 0.014) and negatively with survival time (R =  - 0.89, p = 0.0030), with adhesive failures accounting for 51 ± 14% of rebleeds. In vitro, adhesion depended on fibrinogen and coagulation factor XIII (FXIII), and supraphysiological FXIII improved adhesive strength. Furthermore, when exogenous FXIII was topically applied into the wound pocket of rats, eleven adhesive failures occurred between eight rats, compared to seventeen adhesive failures between eight untreated rats, whereas the number of cohesive failures remained the same at sixteen in both groups. In conclusion, rebleeding from both adhesive and cohesive failure of clots decreases survival from hemorrhage in vivo. Both endogenous and exogenous FXIII improves the adhesive strength of clots.

There is currently no biomarker that reliably predicts treatment-free remission (TFR) in chronic myeloid leukaemia (CML). We characterised effector and suppressor immune responses at the time of tyrosine kinase inhibitor (TKI) cessation in patients from the CML8 and CML10 clinical studies. Natural killer (NK) cells with increased expression of activating NK receptors were higher in patients who achieved TFR. There was no difference in the proportion of CD4 + or CD8 + T cells. Furthermore, we found that FoxP3 + regulatory T cells (T reg) and monocytic myeloid-derived suppressor cells (Mo-MDSCs) were concomitantly decreased in TFR patients, suggesting that the effector and suppressor arms of the immune system work in concert to mediate TFR. A discovery cohort (CML10) was used to generate a predictive model, using logistic regression. Patients classified into the high-risk group were more likely to relapse when compared with the low-risk group (HR 7·4, 95% CI 2·9-19·1). The model was successfully validated on the independent CML8 cohort (HR 8·3, 95% CI 2·2-31·3). Effective prediction of TFR success may be obtained with an effector-suppressor score, calculated using absolute NK cell, T reg, and Mo-MDSC counts, at TKI cessation, reflecting the contribution of both immune suppressors and effectors in the immunobiology underlying successful TFR., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Approximately half of patients with chronic myeloid leukemia (CML) in sustained deep molecular response who discontinue tyrosine kinase inhibitors (TKIs) remain in treatment-free remission (TFR). Some of these patients have measurable residual disease (MRD) by BCR-ABL1 mRNA testing, and most have detectable BCR-ABL1 DNA by highly sensitive methods. We used fluorescence-activated cell sorting and BCR-ABL1 DNA PCR to investigate the lineage of residual CML cells in TFR. Twenty patients in TFR for >1 year provided blood for sorting into granulocytes, monocytes, B cells, T cells, and NK cells. MRD was identified predominantly in the lymphoid compartment and never in granulocytes. B cells were more often BCR-ABL1 positive than T cells (18 vs 11/20 patients) and at higher levels (median 10 -4.9 vs 10 -5.7 ; P = 0.014). In 13 CML patients studied at diagnosis lymphocytes expressing BCR-ABL1 mRNA comprised a small proportion of total leukocytes. These data improve our understanding of TFR biology, since it is now clear that MRD in the blood of TFR patients need not imply the persistence of multipotent CML cells. Lineage-specific assessment of MRD could be explored as a means to improve the prediction of TFR.

Introduction,: Graft-versus-host disease (GVHD) is a recognized complication of allogeneic stem cell transplantation (allo-SCT) and may affect muscle. We investigated the incidence and subtypes of inflammatory myopathy (IM) in South Australian recipients of allo-SCT., Methods: Recipients of allo-SCT from 2004 to 2014 at the Royal Adelaide Hospital were identified. Records were reviewed to identify patients with weakness, creatine kinase (CK) elevation, and muscle biopsy confirming IM., Results: Weakness was present in 32 of 224 patients who received allo-SCT patients reviewed, and CK was raised in 7 of 20 patients with weakness. Six patients developed biopsy-confirmed IM; 3 patients had chronic GVHD-related myopathy, 2 had necrotizing myopathy, and 1 had dermatomyositis (DM) associated with anti-melanoma differentiation associated protein 5 (MDA5) antibodies. The incidence of IM was calculated to be 2 cases per thousand annually., Discussion: Among recipients of allo-SCT, weakness is common, and the incidence of IM is increased. Histopathological diagnoses are varied, and we report findings of necrotizing myopathy and anti-MDA5-associated DM. Muscle Nerve 58:790-795, 2018., (© 2018 Wiley Periodicals, Inc.)

Genomic events associated with poor outcome in chronic myeloid leukemia (CML) are poorly understood. We performed whole-exome sequencing, copy-number variation, and/or RNA sequencing for 65 patients to discover mutations at diagnosis and blast crisis (BC). Forty-six patients with chronic-phase disease with the extremes of outcome were studied at diagnosis. Cancer gene variants were detected in 15 (56%) of 27 patients with subsequent BC or poor outcome and in 3 (16%) of 19 optimal responders ( P = .007). Frequently mutated genes at diagnosis were ASXL1 , IKZF1 , and RUNX1 The methyltransferase SETD1B was a novel recurrently mutated gene. A novel class of variant associated with the Philadelphia (Ph) translocation was detected at diagnosis in 11 (24%) of 46 patients comprising fusions and/or rearrangement of genes on the translocated chromosomes, with evidence of fragmentation, inversion, and imperfect sequence reassembly. These were more frequent at diagnosis in patients with poor outcome: 9 (33%) of 27 vs 2 (11%) of 19 optimal responders ( P = .07). Thirty-nine patients were tested at BC, and all had cancer gene variants, including ABL1 kinase domain mutations in 58%. However, ABL1 mutations cooccurred with other mutated cancer genes in 89% of cases, and these predated ABL1 mutations in 62% of evaluable patients. Gene fusions not associated with the Ph translocation occurred in 42% of patients at BC and commonly involved fusion partners that were known cancer genes (78%). Genomic analysis revealed numerous relevant variants at diagnosis in patients with poor outcome and all patients at BC. Future refined biomarker testing of specific variants will likely provide prognostic information to facilitate a risk-adapted therapeutic approach., (© 2018 by The American Society of Hematology.)

Chronic myeloid leukemia (CML) is a hematological cancer, characterized by a reciprocal chromosomal translocation between chromosomes 9 and 22 [t(9;22)], producing the Bcr-Abl oncogene. Tyrosine kinase inhibitors (TKIs) represent the standard of care for CML patients and exert a dual mode of action: direct oncokinase inhibition and restoration of effector-mediated immune surveillance, which is rendered dysfunctional in CML patients at diagnosis, prior to TKI therapy. TKIs such as imatinib, and more potent second-generation nilotinib and dasatinib induce a high rate of deep molecular response (DMR, BCR-ABL1  ≤ 0.01%) in CML patients. As a result, the more recent goal of therapy in CML treatment is to induce a durable DMR as a prelude to successful treatment-free remission (TFR), which occurs in approximately half of all CML patients who cease TKI therapy. The lack of overt relapse in such patients has been attributed to immunological control of CML. In this review, we discuss an immunological timeline to successful TFR, focusing on the immunology of CML during TKI treatment; an initial period of immune suppression, limiting antitumor immune effector responses in newly diagnosed CML patients, linked to an expansion of immature myeloid-derived suppressor cells and regulatory T cells and aberrant expression of immune checkpoint signaling pathways, including programmed death-1/programmed death ligand-1. Commencement of TKI treatment is associated with immune system re-activation and restoration of effector-mediated [natural killer (NK) cell and T cell] immune surveillance in CML patients, albeit with differing frequencies in concert with differing levels of molecular response achieved on TKI. DMR is associated with maximal restoration of immune recovery in CML patients on TKI. Current data suggest a net balance between both the effector and suppressor arms of the immune system, at a minimum involving mature, cytotoxic CD56 dim NK cells may be important in mediating TFR success. However, a major goal remains in CML to identify the most effective pathways to target to maximize an advantageous immune response and promote TFR success.

Although there are now fewer allo-SCTs performed for CML, leukemic relapse post transplant remains a persistent problem. To better define clinical and biological parameters determining postrelapse outcome, we studied 59 patients with CML relapsing after HLA-identical sibling allo-SCT between 1993 and 2008. Eighteen (30.5%) were transplanted in advanced phase and 41 (69.5%) in chronic phase. With a median follow-up from relapse of 7.9 years, 5-year post relapse survival (PRS) was 62%. Multivariate analysis found disease status at transplant, time to diagnosis of relapse from transplant and pretransplant tyrosine kinase inhibitor (TKI) use as significant factors associated with PRS. Analysis of BCR-ABL transcript expression in the hematopoietic progenitor compartment was performed in 36 patients (22 relapsed, 8 non-relapsed and 6 TKI alone controls). Patients with BCR-ABL expression in their early hematopoietic stem cell compartment (Lineage(-)CD34(+)CD38(-)CD90(+)) had worse survival irrespective of the disease status. We conclude that disease status remains the strongest clinical prognostic factor for PRS in CML following allo-SCT. The persistence of BCR-ABL expression in the progenitor cell compartment in some patients after SCT emphasizes the need to target CML-leukemia stem cells.