How I treat chronic myeloid leukemia in children and adolescents. Blood. 2019;133:2374-2384. [PMID: 30917954 DOI: 10.1182/blood.2018882233]

Survival of European children, adolescents and young adults diagnosed with haematological malignancies in the period 2000-2013: Results from EUROCARE-6, a population-based study

BACKGROUND

While cancer survival has steadily improved over time for adolescents and young adults (AYAs), previous studies have shown poorer survival in AYAs compared to children with leukaemia and lymphomas. In this study, we provided updated European 5-year relative survival (RS) estimates for AYAs with haematologic malignancies compared to children and assessed improvements in survival over time.

METHODS

We used the EUROCARE-6 database, with population-based cancer registries data from 29 European countries. Using the period approach, we calculated 5-year RS for European children (0-14 years) and AYAs (15-39 years) in the follow-up period 2010- 2014 separately for leukaemia, lymphomas, relevant morphological subgroups, age- subgroups, and sex. We estimated 5-year RS time trends between 2000 and 2013.

RESULTS

Compared to children, AYAs had a worse RS for all acute lymphoblastic leukaemias (ALL) and acute myeloid leukaemia (AML), but a better survival for chronic myeloid leukaemia (CML). No differences in RS were observed between children and AYAs with acute promyelocytic leukaemia (APL). Compared to children, AYAs had a worse RS for HL and NHL in general, and specifically for lymphoblastic, Burkitt, follicular and NK/T cell lymphomas. In AYAs, RS increased between 2000-2013 for leukaemia overall (by 9% points), ALL (by 11% points), AML (by 8% points) and CML (by 11% points).

CONCLUSION

Despite increasing European survival for AYAs with haematological malignancies, we showed poorer survival in AYAs than in children for most types of leukaemia and lymphomas. These results reflect that further efforts are needed to improve the survival for this distinctive patient group.

Which Is the Best Tyrosine Kinase Inhibitor for Newly Diagnosed Chronic Myelogenous Leukemia?

The choice of frontline therapy for a patient with chronic phase chronic myeloid leukemia (CP-CML) can have a profound effect on the long-term clinical outcome. Currently, five tyrosine kinase inhibitors (TKIs-imatinib, dasatinib, nilotinib, bosutinib, and asciminib) are available for frontline therapy, but no single TKI is optimal for all patients. EUTOS long-term survival (ELTS) risk score, comorbidities, and treatment-free remission (TFR) priority are the key determinants of frontline TKI selection. Higher ELTS score, low age and comorbidity score, and a high priority for achievement of TFR would all favor the frontline use of a more potent TKI than imatinib. However, no TKI has improved survival compared with imatinib. In children with CP-CML, imatinib, dasatinib, and nilotinib have similar long-term efficacy, with ease of administration and impact of toxicities on quality of life being key considerations. Recent adult trials of reduced-dose dasatinib frontline showed that efficacy may be equivalent to standard-dose dasatinib with a better tolerability and safety profile, but experience is limited in patients with high-risk ELTS scores. The ASC4FIRST trial has confirmed that tolerability and molecular response with asciminib are superior to those with both imatinib and the second-generation (2G)-TKIs. While the overall treatment failure rate was lower with asciminib, the rate of BCR::ABL1 mutations that emerged with asciminib appeared to be higher. The risk of emergent mutations appears to be highly associated with the presence of ASXL1 mutations in the CML cells at diagnosis, but more work is needed to understand the implications of this finding.

Therapeutic drug monitoring of imatinib in paediatric chronic myeloid leukaemia: Data from a real-world setting

Imatinib (IMA) therapy for paediatric chronic myeloid leukemia (pCML) requires age-dependent dose adjustments. Assessment of therapeutic drug monitoring (TDM) under 'real-world' conditions was performed. Collection of blood and TDM-relevant data, calculation of individual dosage exposure, measurement of plasma Cmin (IMA, Nor-IMA) by HPLC/MS-MS and recording of adverse event (AE). Two hundred and forty-six specimens from 66 patients were analysed. Individual median IMA dosage exposure was 253 mg/m2 (range: 128-504). Children <13 years received a median of 43 mg/m2 more than older patients (p < 0.0001). Median Cmin of IMA and Nor-IMA was 1017 ng/mL (range: 51-3976) and 269 ng/mL (range: 21-981), respectively, correlating significantly with the prescribed dose. At 5/246 visits, non-adherence was confirmed by very low IMA Cmin in 3/66 patients, all ≥13 years old. Correlation of IMA Cmin >1000 ng/mL with achieving OMR demonstrated in each 63% (N = 24/37, N = 27/43, respectively) patients at months 3 and 6. In the cohort with lower levels, only 23% and 50%, respectively, achieved these milestones. This difference was significant only at month 3. Of 66 patients, 30 reported 125 AEs with gastrointestinal and musculoskeletal as leading complaints. In 9.3% of AEs, the correlated IMA Cmin was ≥3000 ng/mL. TDM is a simple and rapid additional tool for managing pCML under 'real-world conditions'.

Cases of Patients Treated in Countries With Limited Resources and Discussed by Experts of the International CML Foundation (iCMLf)-Case No. 2: Treatment-Free Remission After 9 Years of Imatinib Treatment Without Prior Achievement of Sustained Deep Molecular Response

Pediatric chronic myeloid leukemia (pCML) is a rare malignancy that nowadays is treated upfront with tyrosine kinase inhibitors (TKIs). As demonstrated in adult CML patients, achieving deep molecular response (DMR) and maintaining this status over 2 years results in the opportunity to discontinue TKI therapy. Following cessation, this treatment-free remission (TFR) status is successfully achieved by approximately 50% of the patients, while the other half experience molecular relapse within ≤ 6 months, requiring a TKI restart. As pCML accounts for only 2%-3% of all childhood leukemias, experience and familiarity with this disease, especially with stopping attempts, are still very limited. Small pCML cohorts enrolled in stopping TKI trials, with strict criteria applied for both depth and maintenance of DMR, have demonstrated the achievable TFR success rates seem comparable to adults. However, recommendations for considering TFR in pCML have yet to be defined. We report on a 9-year-old Brazilian boy diagnosed with CML in a chronic phase. He was treated with imatinib and achieved a molecular response (BCR::ABL1 transcript rate < 0.1%) at Month 12. Not achieving DMR, he responded well, but not optimally, to TKI therapy. Contrary to existing guidelines on TKI cessation in adults, after 9 years, imatinib was stopped. With a follow-up of 24 months, the patient is in TFR and now maintains DMR successfully. With the support of the International CML Foundation (iCMLf), which aims to improve outcomes for CML patients globally, this rare case from Brazil is discussed from the perspective of a pediatric hemato-oncologist from a high-income country, a pediatric hemato-oncologist from a low- and middle-income country, an adult CML hematologist, and the treating physician. Sharing cases of pCML in LMICs and highlighting the resources offered by the iCMLf, particularly the Knowledge Center (available online), will hopefully improve the expertise on pCML treatment worldwide.

Favorable outcomes of de novo advanced phases of pediatric chronic myeloid leukemia in the tyrosine kinase inhibitor era

Chronic myeloid leukemia (CML) is a rare disease during childhood, and accelerated phase (AP) and blast phase (BP) CML, also called advanced phases, are even rarer. We retrospectively collected and analyzed clinical data of children younger than 20 years with de novo advanced-phase CML between 1996 and 2017 in Japan. Median follow-up time was 8.9 years for AP-CML (n = 15) and 3.7 years for BP-CML (n = 32). The 5-year overall survival (OS) was 93.3% for AP-CML, and 100.0% for patients who received tyrosine kinase inhibitors (TKIs) in first-line therapy (n = 10). Four of the ten patients who received TKIs in first-line therapy remained in molecular remission without transplantation (median follow-up 5.5 years). The 5-year OS of patients with BP-CML was 79.0%, and most patients received chemotherapy before transplantation, with regimen selection based on blast immunophenotype. Furthermore, among patients who received transplantation after TKI therapy, the 5-year OS was 100.0% for AP and 84.8% for BP. In conclusion, our study confirmed excellent outcomes in children with de novo advanced-phase CML, especially in the TKI-era.

Treatment-Free Remissions in Children With Chronic Myeloid Leukemia (CML): A Prospective Study From the Tata Memorial Hospital (TMH) Pediatric CML (pCML) Cohort

Pediatric chronic myeloid leukemia (pCML) is a rare childhood malignancy, representing 2%-3% of all childhood leukemia. Tyrosine kinase inhibitors (TKIs) have greatly improved survival but pose challenges due to their long-term effects on growth and bone health in children. We prospectively studied treatment-free remission (TFR) in 45 children with pCML in chronic phase on imatinib. Eligibility criteria were as per current NCCN guidelines, with a less stringent qPCR monitoring scheduled every 3 months. TFR was successful in 71.1% (32 out of 45) of patients after a median follow-up of 25 (range: 6-42) months. The TFR rates at 12 and 24 months were 70% and 66%, respectively. Children under 5 years had a TFR rate of 88.9%, compared to 61.8% in those over 5 years (p = 0.18). Eleven of the 13 patients who lost MMR did so within 6 months of discontinuation. The cumulative incidence of loss in MMR at 6, 12, and 24 months was 26.4%, 27%, and 33%, respectively. Ten out of 13 (76.9%) patients with discontinuation failure (DF) regained MMR within 3 (2-20) months of restarting imatinib. A significant correlation was found between higher T-regulatory cell levels at baseline and DF (p = 0.005). More than half patients showed improved bone mineral density after 2 years of TFR. Our findings suggest that high TFR rates can be attained in pCML, with added benefits for bone health. Less frequent molecular monitoring was not associated with adverse outcomes and there seems to be a role of the immune system in sustaining TFR. The study is registered in the Clinical Trials Registry-India (CTRI/2020/11/029199).

Biological Markers of Myeloproliferative Neoplasms in Children, Adolescents and Young Adults

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic cancers characterized by hyperproliferation of the myeloid lineages. These clonal marrow disorders are extremely rare in pediatric patients. MPN is reported to occur 100 times more frequently in adults, and thus research is primarily focused on this patient group. At present, modern diagnostic techniques, primarily genetic, facilitate the identification of the biology of these diseases. The key genes are JAK2, MPL, and CALR, namely, driver mutations, which are present in approximately 90% of patients with suspected MPN. Moreover, there are more than 20 other mutations that affect the development of these hematological malignancies, as evidenced by a review of the literature. The pathogenic mechanism of MPNs is characterized by the dysregulation of the JAK/STAT signaling pathway (JAK2, MPL, CALR), DNA methylation (TET2, DNMT3A, IDH1/2), chromatin structure (ASXL1, EZH2), and splicing (SF3B1, U2AF2, SRSF2). Although rare, myeloproliferative neoplasms can involve young patients and pose unique challenges for clinicians in diagnosis and therapy. The paper aims to review the biological markers of MPNs in pediatric populations-a particular group of patients that has been poorly studied due to the low frequency of MPN diagnosis.

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

Chronic myeloid leukemia presenting de novo in the blast phase (CML-BP) is a rare diagnosis among pediatric malignancies. We report on a 16-year-old male who presented with CML-BP lymphoid at diagnosis. He was treated with shortened acute lymphoblastic leukemia induction plus the tyrosine kinase inhibitor (TKI) imatinib followed by dasatinib. After achieving molecular remission (MR), hematopoietic stem cell transplantation (HSCT) was performed early after diagnosis. Despite prophylactic dasatinib, he relapsed 3 months later with the kinase domain mutation T315I. Multiple therapeutic approaches including ponatinib, blinatumomab, a 2nd HSCT from a different donor, donor lymphocyte infusions, and high-dose asciminib all resulted in subsequent relapse. Another molecular response was achieved by combining ponatinib plus asciminib with chemotherapy. In this situation, CD19-directed CAR-T cells (Kymriah®) were administered for compassionate use and tolerated without adverse events. Compared to all prior therapies, CAR T-cells maintained remission. After 12 months of follow-up, complete B-cell aplasia and low numbers of CAR-T cells are detectable in the peripheral blood, potentially mediating long-term disease control.

Cases of Patients Treated in Countries With Limited Resources and Discussed by Experts of the International CML Foundation (iCMLf)-Case No. 1: A Boy Presenting With Priapism and Loss of Vision

Pediatric chronic myeloid leukemia (pCML) is a rare malignancy accounting for only 2%-3% of all childhood leukemias. Due to this rarity, familiarity with pCML is limited among most pediatric practitioners, including even pediatric hemato-oncologists. In low- and middle-income countries (LMICs), limited financial resources and limited data specific to pCML represent obstacles that healthcare providers must face in diagnosing and treating this rare condition in children. The International CML Foundation (iCMLf) is improving outcomes for people with CML in these countries where resources, diagnostics, and access to medicines may be limited (https://www.cml-foundation.org/lmic-programs.html). Virtual meetings with the purpose of teaching participating pediatricians from LMICs of defined geographical regions were organised by the iCMLf in 2023. At a virtual meeting of the South Asia region, the case of a 14-year-old Indian boy was presented diagnosed with CML in a chronic phase complicated by priapism and loss of vision in his left eye due to hyperleukocytosis. Key aspects of this case are discussed in-depth from the perspective of (i) a pediatric hemato-oncologist practicing in a high-income country, (ii) a pediatric hemato-oncologist practicing in a LMIC, (iii) an adult CML hematologist, and (iv) from the iCMLf in improving the care of children with CML worldwide. Thus by discussing a multifaceted complicated case of pCML in written form as well as pointing to the pediatric module of the iCMLf Knowledge Centre will hopefully contribute to minimize existing knowledge gaps in a rare pediatric malignancy.

Treatment and follow-up of children with chronic myeloid leukaemia in chronic phase (CML-CP) in the tyrosine kinase inhibitor (TKI) era-Two decades of experience from the Tata Memorial Hospital paediatric CML (pCML) cohort

Tyrosine kinase inhibitors (TKIs) have drastically improved the outcomes of pCML (paediatric CML) but data on long-term off-target toxicities of TKIs in children are scarce. In this single-centre, retrospective cum prospective study of pCML in chronic phase, we report our experience of treating 173 children with imatinib and following them for long-term toxicities. Mean (SD) time to attain CHR, CCyR and MMR were 3.05 (2.1), 10.6 (8.4) and 43.4 (31.8) months respectively. DMR was not attained in 59 (34%) patients at last follow-up. Ten patients were switched to second-generation TKIs (2G-TKIs; nilotinib = 1/dasatinib = 9) due to poor/loss in response, of which seven had kinase domain mutations. Three patients progressed to the blastic phase. At a median follow-up of 84 (3-261) months, the 5-year EFS and OS for the entire cohort were 96.9% (95% CI: 93.4-100) and 98.7% (95% CI: 96.9-100) respectively. Screening for long-term toxicities revealed low bone density and hypovitaminosis D in 70% and 80% respectively. Other late effects included short stature (27%), delayed puberty (15%), poor sperm quality (43%) and miscellaneous endocrinopathies (8%). Children younger than 5 years at diagnosis were more susceptible to growth and endocrine toxicities (p = 0.009). Regular monitoring for long-term toxicities, timely intervention and trial of discontinuation whenever feasible are likely to improve the long-term outlook of pCML.

Bosutinib in Resistant and Intolerant Pediatric Patients With Chronic Phase Chronic Myeloid Leukemia: Results From the Phase I Part of Study ITCC054/COG AAML1921

PURPOSE

Bosutinib is approved for adults with chronic myeloid leukemia (CML): 400 mg once daily in newly diagnosed (ND); 500 mg once daily in resistant/intolerant (R/I) patients. Bosutinib has a different tolerability profile than other tyrosine kinase inhibitors (TKIs) and potentially less impact on growth (preclinical data). The primary objective of this first-in-child trial was to determine the recommended phase II dose (RP2D) for pediatric R/I and ND patients.

PATIENTS AND METHODS

In the phase I part of this international, open-label trial (ClinicalTrials.gov identifier: NCT04258943), children age 1-18 years with R/I (per European LeukemiaNet 2013) Ph+ CML were enrolled using a 6 + 4 design, testing 300, 350, and 400 mg/m2 once daily with food. The RP2D was the dose resulting in 0/6 or 1/10 dose-limiting toxicities (DLTs) during the first cycle and achieving adult target AUC levels for the respective indication. As ND participants were only enrolled in phase II, the ND RP2D was selected based on data from R/I patients.

RESULTS

Thirty patients were enrolled; 27 were evaluable for DLT: six at 300 mg/m2, 11 at 350 mg/m2 (one DLT), and 10 at 400 mg/m2 (one DLT). The mean AUCs at 300 mg/m2, 350 mg/m2, and 400 mg/m2 were 2.20 μg h/mL, 2.52 μg h/mL, and 2.66 μg h/mL, respectively. The most common adverse event was diarrhea (93%; ≥grade 3: 11%). Seven patients stopped because of intolerance and eight because of insufficient response. Complete cytogenetic and major molecular response to bosutinib appeared comparable with other published phase I/II trials with second-generation TKIs in children.

CONCLUSION

Bosutinib was safe and effective. The pediatric RP2D was 400 mg/m2 once daily (max 600 mg/d) with food in R/I patients and 300 mg/m2 once daily (max 500 mg/d) with food in ND patients, which achieved targeted exposures as per adult experience.

Chronic myeloid leukemia (CML) in children and adolescents-Clinicopathological findings

BACKGROUND

Barely two per million Belgian children/adolescents are diagnosed with chronic myeloid leukemia (CML) annually. In this retrospective study, we aimed to investigate the diagnostic features, clinical and laboratory characteristics, and treatment outcome of this rare entity.

METHODS

Medical records of all pediatric CML patients (age ≤ 17 years) diagnosed at the University Hospitals Leuven between 1986 and 2021 were reviewed.

RESULTS

Fourteen patients (median age at diagnosis 12.5 years) were included, all presenting in chronic phase. Five patients were diagnosed before 2003; main therapy included hydroxyurea (n = 5/5), interferon-alfa (n = 3/5) and allogeneic hematopoietic stem cell transplantation (allo-Tx) (n = 3/5). Complete hematologic response (CHR), complete cytogenetic response (CCyR) and major molecular response (MMR) was reached in resp. 4/5, 4/5 and in 2/3 of evaluable patients. Three patients progressed to accelerated/blast phase (median time 19 months) and 1/5 is alive and disease-free at last follow-up. Nine patients were diagnosed after 2003 and were treated with first generation (1°G) tyrosine kinase inhibitors (TKI): 3/9 subsequently underwent an allo-Tx, 4/9 were switched to 2°G TKI, one patient was additionally switched to 3°G TKI. CHR, CCyR and MMR was reached in 9/9, 9/9 and 8/9 of these patients. No progression to accelerated/blast phase was observed and none of these patients deceased. At last follow-up, 7/9 patients were in MMR or disease free, the two remaining patients did not reach or lost MMR, both related to compliance issues.

CONCLUSION

Our study confirmed that TKI significantly improved the prognosis of pediatric CML. However, drug compliance poses a considerable challenge.

Therapeutic drug monitoring of imatinib - how far are we in the leukemia setting?

INTRODUCTION

Tyrosine kinase inhibitors (TKIs) have revolutionized survival rates of chronic myeloid leukemia (CML) and Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) and replaced hematopoietic stem cell transplantation (hSCT) as the key treatment option for these patients. More recently, the so-called Philadelphia chromosome-like (Ph-like) ALL has similarly benefitted from TKIs. However, many patients shift from the first generation TKI, imatinib, due to treatment-related toxicities or lack of treatment efficacy. A more personalized approach to TKI treatment could counteract these challenges and potentially be more cost-effective. Therapeutic drug monitoring (TDM) has led to higher response rates and less treatment-related toxicity in adult CML but is rarely used in ALL or in childhood CML.

AREAS COVERED

This review summarizes different antileukemic treatment indications for TKIs with focus on imatinib and its pharmacokinetic/-dynamic properties as well as opportunities and pitfalls of TDM for imatinib treatment in relation to pharmacogenetics and co-medication for pediatric and adult Ph+/Ph-like leukemias.

EXPERT OPINION

TDM of imatinib adds value to standard monitoring of ABL-class leukemia by uncovering non-adherence and potentially mitigating adverse effects. Clinically implementable pharmacokinetic/-dynamic models adjusted for relevant pharmacogenetics could improve individual dosing. Prospective trials of TDM-based treatments, including both children and adults, are needed.

BCR/ABL-Positive Chronic Myeloid Leukemia in Children: Current Treatment Approach

PURPOSE OF REVIEW

The purpose of this review is to summarize the most updated treatment recommendations for pediatric CML, and to discuss current areas of investigation.

RECENT FINDINGS

There is new phase 1 data to support the safety of the non-ATP competitive tyrosine kinase inhibitor (TKI) asciminib in the pediatric cohort. Ongoing studies are investigating the role of treatment-free remission in children. Chronic phase CML in children is managed with lifelong TKI therapy; however, evidence of deeper remissions sustained with second-generation TKIs may permit shorter treatment courses. Use of more specific TKIs may mitigate some of the side effects specific to the pediatric cohort. Children with advanced phase CML should achieve a complete hematologic remission with use of a second-generation TKI prior to transplant to achieve the best outcome.

Impact of Tyrosine Kinase Inhibitors (TKIs) on Growth in Children and Adolescents with Chronic Myeloid Leukemia: A Systematic Review

BACKGROUND

Chronic Myeloid Leukemia (CML) is a rare myeloproliferative disease in childhood. Treatment in CML includes Tyrosine Kinase Inhibitors (TKIs), which inhibit the cytoplasmic kinase BCR/ABL. Tyrosine kinases play a key role in the secretion of growth hormone and insulin-like growth factor 1 (IGF-1).

OBJECTIVE

The aim of this systematic review was to study the effect of TKIs on the growth of children and adolescents with CML.

METHODS

English-language publications were searched in the PubMed/Cochrane library/Google Scholar databases (2002-2023), and retrieved studies were assessed according to PRISMA-Statement and Newcastle- Ottawa-scale.

RESULTS

The search strategy yielded 1066 articles. After applying the inclusion/exclusion criteria, 941 were excluded based on title screening and 111 on abstract review. The systematic review included 14 articles (11 retrospective observational studies/3 clinical trials). Twelve studies reported data on the prevalence of growth disorders after the administration of 1st generation TKIs (imatinib). Two studies reported a negative effect of 2nd generation TKIs (dasatinib/nilotinib) on physical growth. Four studies recorded a decrease in height z-score after treatment compared to baseline. Two 1st-generation TKIs studies reported data on children's final height; one reported restoration of final height to normal after the onset of puberty, despite initial slowing, and the final height was lower than mid-parental target height. Serum IGF-1 levels were reported in 2 studies to be within normal range, while in 3 studies, a significant decrease was documented. Considerable study heterogeneity was observed related to dosage/duration of treatment/disease phase/stage of puberty/ethnicity.

CONCLUSION

A negative effect of TKIs on the growth and final height of children was noted.

Tyrosine Kinase Inhibitors in pediatric chronic myeloid leukemia: a focused review of clinical trials

Tyrosine Kinase Inhibitors (TKIs) is revolutionizing the management of pediatric Chronic Myeloid Leukemia (CML), offering alternatives to Allogeneic Hematopoietic Stem Cell Transplantation (AHSCT). We conducted a comprehensive review of 16 Randomized Controlled Trials (RCTs) encompassing 887 pediatric CML patients treated with TKIs including Imatinib, Dasatinib, and Nilotinib. The median patient age ranged from 6.5 to 14 years, with a median white blood cell count of 234 x 10^9/uL, median hemoglobin level of 9.05 g/dL, and median platelet count of 431.5 x 10^9/µL. Imatinib seems to be predominant first line TKI, with the most extensive safety and efficacy data. BCR::ABL response rates below 10% ranged from 60% to 78%, CCyR at 24 months ranged from 62% to 94%, and PFS showed variability from 56.8% to 100%, albeit with differing analysis timepoints. The Safety profile of TKIs was consistent with the known safety profile in adults. With the availability of three TKIs as first line options, multiple factors should be considered when selecting first line TKI, including drug formulation, administration, comorbidities, and financial issues. Careful monitoring of adverse events, especially in growing children, should be considered in long term follow-up clinical trials.

Adherence to tyrosine kinase inhibitor and clinical outcomes in patients with chronic myeloid leukemia

PURPOSE

To ensure optimal care for patients with chronic myeloid leukemia (CML), adherence to tyrosine kinase inhibitors (TKIs) has emerged as a critical component. The objective of this study was to assess the impact of TKIs adherence on clinical outcomes in a cohort of Chinese CML patients who received treatment with TKIs.

METHODS

This retrospective study employed a cross-sectional design utilizing questionnaires to assess adherence to TKIs in a sample of 398 patients diagnosed with CML. Adherence was measured using the Morisky Medication Adherence Scale (MMAS-8), which dichotomizes patients into low, medium, and high adherence groups.

RESULTS

Of the patients included in this study, 34.2% were classified as highly adherent, with 43.2% and 22.6% of patients categorized as having medium and low adherence, respectively. Compared to the low-adherence group, patients in the medium- and high-adherence groups exhibited significantly higher rates of achieving major molecular response (MMR) and lower rates of switching TKIs. Moreover, patients who failed to adhere to TKIs treatment demonstrated significantly lower event-free survival and failure-free survival compared to those in the high-adherence group. Notably, regular molecular monitoring and utilization of the "CML Academy" mobile application were positively associated with increased TKI adherence. On the other hand, patients receiving third-generation or above first-line TKIs treatment displayed reduced adherence.

CONCLUSION

The findings suggest that high adherence to TKIs treatment confers clinical benefits to patients with CML. Accordingly, the implementation of effective guidance and intervention measures aimed at promoting adherence to TKIs therapy in real-world settings is imperative.

Continuous therapy response references for BCR::ABL1 monitoring in pediatric chronic myeloid leukemia

Response to tyrosine kinase inhibitor (TKI) therapy in patients with chronic myeloid leukemia (CML) is monitored by quantification of BCR::ABL1 transcript levels. Milestones for assessing optimal treatment response have been defined in adult CML patients and are applied to children and adolescents although it is questionable whether transferability to pediatric patients is appropriate regarding genetic and clinical differences. Therefore, we analyzed the molecular response kinetics to TKI therapy in 129 pediatric CML patients and investigated whether response assessment based on continuous references can support an early individual therapy adjustment. We applied a moving quantiles approach to establish a high-resolution response target curve and contrasted the median responses in all patients with the median of the ideal target curve obtained from a subgroup of optimal responders. The high-resolution response target curve of the optimal responder group presents a valuable tool for continuous therapy monitoring of individual pediatric CML patients in addition to the fixed milestones. By further comparing BCR::ABL1 transcript levels with BCR::ABL1 fusion gene copy numbers, it is also possible to model the differential dynamics of BCR::ABL1 expression and cell number under therapy. The developed methodology can be transferred to other biomarkers for continuous therapy monitoring.

Effect of the tyrosine kinase inhibitors on the growth in children with Philadelphia chromosome-positive acute lymphoblastic leukemia: a case-control study

Background

First-generation ABL-targeted tyrosine kinase inhibitor (TKI) imatinib is known to retard growth in children but it is not known if the second-generation ABL-targeted TKI dasatinib has the same effect. We aimed to determine the impact of the first- or second-generation TKI on the growth of children treated for Philadelphia chromosome-positive (Ph+) childhood acute lymphoblastic leukemia (ALL).

Methods

We evaluated the longitudinal growth changes in 140 children with Ph+ ALL treated with imatinib or dasatinib in additional to intensive cytotoxic chemotherapy and 280 matched controls treated with the same intensity of cytotoxic chemotherapy without TKI on Chinese Children's Cancer Group ALL-2015 protocol between 2015 and 2019. We retrospectively reviewed the height data obtained during routine clinic visits at 4 time points: at diagnosis, the end of therapy, 1 year and 2 years off therapy. Height z Scores were derived with the aid of WHO Anthro version 3.2.2 and WHO AnthroPlus version 1.0.4, global growth monitoring tool.

Findings

This study consisted only patients who have completed all treatment in continuous complete remission without major events, including 33 patients randomized to receive imatinib, 43 randomized to receive dasatinib, and 64 assigned to receive dasatinib. Similar degree of loss of height z scores from diagnosis to the end of therapy was observed for the 33 imatinib- and the 107 dasatinib-treated patients (median △ = -0.84 vs. -0.88, P = 0.41). Adjusting for height z score at diagnosis, puberty status, and sex, there was no significant difference in the longitudinal mean height z scores between patients treated with imatinib and those with dasatinib (0.08, 95% CI, -0.22 to 0.38, P = 0.60). The degree of loss of height z scores from diagnosis to end of therapy was significantly greater in the 140 TKI-treated patients than the 280 controls (median △ = -0.88 vs. -0.18, P < 0.001). The longitudinal mean height z scores in the TKI-treated patients were significantly lower than those of the controls (-0.84, 95% CI, -0.98 to -0.69; P < 0.001).

Interpretation

These data suggest that dasatinib and imatinib have the similar adverse impact on the growth of children with Ph+ ALL.

Funding

This study was supported by the National Natural Science Foundation of China (grant 81670136 [JCai and JT]), the fourth round of Three-Year Public Health Action Plan (2015-2017; GWIV-25 [SS]), Shanghai Health Commission Clinical Research Project (202140161 [JCai]), the US National Cancer institute (CA21765 [C-H Pui]), and the American Lebanese Syrian Associated Charities (CC, JJY, and C-HP). The content of this paper is solely the responsibility of the authors and does not necessarily represent the official views of the US National Institutes of Health.

Asciminib in the Treatment of Philadelphia Chromosome-Positive Chronic Myeloid Leukemia: Focus on Patient Selection and Outcomes

Tyrosine kinase inhibitors (TKIs) have significantly changed the treatment of chronic myeloid leukemia (CML) and improved outcomes for patients with CML in chronic phase (CML-CP) and accelerated phase (AP). Now armed with numerous effective therapeutic options, clinicians must consider various patient- and disease-specific factors when selecting the most appropriate TKI across lines of therapy. While most patients with CML expected to have a near-normal life expectancy due to the success of TKIs, emphasis has expanded beyond response and survival to include factors like quality of life, tolerability, and long-term toxicity management. Importantly, a subset of patients can achieve sustained deep molecular response and can attain treatment-free remission. Despite these successes, unmet needs remain related to CML treatment, including the persistent challenge of treatment resistance and intolerance, broadening treatment options for patients with resistance mutations or serious comorbidities, and focus on specific populations such as children and young adults. In particular, the only previously available treatments for patients with CML-CP with the T315I mutation were ponatinib, olverembatinib (exclusively approved for use in China at the time of this writing), omacetaxine, and hematopoietic stem cell transplantation. Asciminib has entered the CML treatment landscape as a new option for adult patients with CML-CP who have received ≥2 prior TKIs or those with the T315I mutation. Asciminib's unique mechanism of action, Specifically Targeting the ABL Myristoyl Pocket, sets it apart from traditional adenosine triphosphate-competitive TKIs. While asciminib may overcome unmet needs for patients with CML-CP and continues to be studied in other novel settings, guidance on how to integrate asciminib in treatment algorithms is needed. This review focuses on clinical data and how asciminib can overcome current unmet needs, discusses how to individualize patient selection, and highlights future directions to investigate asciminib in earlier lines of therapy and in children and adolescents.

Chronic Myeloid Leukemia in Children and Adolescents

Acute leukemia is the most common malignancy in childhood, while chronic myeloid leukemia is rare, accounting for only 2% to 3% of all leukemia in childhood and 9% in adolescents, with an annual incidence of 1 and 2.2 cases per million in the two groups. The goal in Pediatrics is remission and cure with tyrosine kinase inhibitors (TKIs) and monitoring closely for long-term effects of TKI use.

Front-Line Tyrosine Kinase Inhibitors in Pediatric Chronic Myeloid Leukemia: A Study on Efficacy and Safety

We conducted a retrospective study on 51 pediatric patients with newly diagnosed chronic myeloid leukemia chronic phase or accelerated phase. The patients were classified into the IMA group (N = 33), treated with imatinib, and the DSA group (N = 18), treated with dasatinib, as front-line tyrosine kinase inhibitors (TKIs). At 12 months, the rates of complete cytogenetic response were similar between the IMA group (92.3%) and DSA group (100%) (p = 0.305). However, the rate of early molecular response was higher in the DSA group than in the IMA group (100.0% vs. 80.0%, p = 0.043). By 12 and 24 months, the DSA group showed faster and higher cumulative rates of both major (DSA group: 72.2% and 100%, respectively; IMA group: 41.2% and 68.7%, respectively; p = 0.002) and deep molecular responses (DSA group: 26.0% and 43.6%, respectively; IMA group: 13.8% and 17.5%, respectively; p = 0.004). Both TKIs were well tolerated. Although the height standard deviation scores decreased in both groups, the height decline was greater in the DSA group between one and two years from the start of TKI therapy. In this study, dasatinib achieved faster and higher molecular responses with an acceptable safety profile. Further follow-up is necessary to assess the long-term outcomes of TKI treatment in children.

Priapism at Diagnosis of Pediatric Chronic Myeloid Leukemia: Data Derived from a Large Cohort of Children and Teenagers and a Narrative Review on Priapism Management

Pediatric chronic myeloid leukemia (CML) is a very rare malignancy (age-related incidence 0.1/100,000) typically presenting with leucocyte counts >100,000/µL. However, clinical signs of leukostasis are observed at diagnosis in only approximately 10% of all cases and among these, priapism is infrequent. Here, we analyze data from pediatric CML registries on the occurrence of priapism heralding diagnosis of CML in 16/491 (3.2%) boys (median age 13.5 years, range 4-18) with pediatric CML. In the cohort investigated, duration of priapism resulting in a diagnosis of CML was not reported in 5 patients, and in the remaining 11 patients, occurred as stuttering priapism over 3 months (n = 1), over 6 weeks (n = 1), over 1-2 weeks (n = 2), over several days (n = 2), or 24 h (n = 1), while the remaining 4 boys reported continuous erection lasting over 11-12 h. All patients exhibited splenomegaly and massive leukocytosis (median WBC 470,000/µL, range 236,700-899,000). Interventions to treat priapism were unknown in 5 patients, and in the remaining cohort, comprised intravenous fluids ± heparin (n = 2), penile puncture (n = 5) ± injection of sympathomimetics (n = 4) ± intracavernous shunt operation (n = 1) paralleled by leukocyte-reductive measures. Management without penile puncture by leukapheresis or exchange transfusion was performed in 3 boys. In total, 7 out 15 (47%) long-term survivors (median age 20 years, range 19-25) responded to a questionnaire. All had maintained full erectile function; however, 5/7 had presented with stuttering priapism while in the remaining 2 patients priapism had lasted <12 h until intervention. At its extreme, low-flow priapism lasting for longer than 24 h may result in partial or total impotence by erectile dysfunction. This physical disability can exert a large psychological impact on patients' lives. In a narrative review fashion, we analyzed the literature on priapism in boys with CML which is by categorization stuttering or persisting as mostly painful, ischemic (low-flow) priapism. Details on the pathophysiology are discussed on the background of the different blood rheology of hyperleukocytosis in acute and chronic leukemias. In addition to the data collected, instructive case vignettes demonstrate the diagnostic and treatment approaches and the outcome of boys presenting with priapism. An algorithm for management of priapism in a stepwise fashion is presented. All approaches must be performed in parallel with cytoreductive treatment of leukostasis in CML which comprises leukapheresis and exchange transfusions ± cytotoxic chemotherapy.

Pediatric and adolescent chronic myeloid leukemia: A follow-up study in Western India

Background

Chronic myeloid leukemia (CML) is relatively rare in pediatric and adolescent age groups. The purpose of this study was to evaluate the clinical, hematopathological, and biochemical parameters of CML in pediatric and adolescent age groups, along with an assessment of the treatment response with first-line tyrosine kinase inhibitors (TKI) and its correlation with the prognostic scoring systems of adults.

Materials and Methods

A retrospective study of 44 Breakpoint Cluster Region-Abelson leukemia virus (BCR-ABL1)-positive pediatric and adolescent CML cases registered at our hospital was done. The clinical and laboratory parameters were evaluated using hospital software. The treatment response was monitored and scoring was performed using mathematical calculations.

Results

The mean age was 11.6 (±4.7) years. The median hemoglobin was 8.4 g/dL and 63.6% of the cases showed white blood cell (WBC) counts >250,000/μL. The average follow-up was 21 months. A total of 97.7 and 78.1% cases achieved complete hematological response (CHR) and molecular response, respectively, during the treatment course. The maximum number of patients had low Sokal and European treatment and Outcomes Study (EUTOS) scores. Seventy-five per cent of the cases achieved CHR at 3 months, while 73.6 and 78.6% CML-Chronic phase (CP) cases with low Sokal and EUTOS scores achieved CHR at 3 months, respectively.

Conclusion

This study revealed that the CML cases in pediatric and adolescent age groups are normally present with higher WBC counts at the time of diagnosis. The association of the prognostic scoring system with treatment response was statistically insignificant. However, a larger cohort study is needed to determine the treatment response of TKI in children and adolescent CML and its correlation with the prognostic scoring systems.

Pediatric Autologous Hematopoietic Stem Cell Transplantation: Safety, Efficacy, and Patient Outcomes. Literature Review

Autologous stem cell transplantation (auto-HSCT) is a part of the therapeutic strategy for various oncohematological diseases. The auto-HSCT procedure enables hematological recovery after high-dose chemotherapy, otherwise not tolerable, by the infusion of autologous hematopoietic stem cells. Unlike allogeneic transplant (allo-HSCT), auto-HSCT has the advantage of lacking acute-graft-versus-host disease (GVHD) and prolonged immunosuppression, however, these advantages are counterbalanced by the absence of graft-versus-leukemia. Moreover, in hematological malignancies, the autologous hematopoietic stem cell source may be contaminated by neoplastic cells, leading to disease reappearance. In recent years, allogeneic transplant-related mortality (TRM) has progressively decreased, almost approaching auto-TRM, and many alternative donor sources are available for the majority of patients eligible for transplant procedures. In adults, the role of auto-HSCT compared to conventional chemotherapy (CT) in hematological malignancies has been well defined in many extended randomized trials; however, such trials are lacking in pediatric cohorts. Therefore, the role of auto-HSCT in pediatric oncohematology is limited, in both first- and second-line therapies and still remains to be defined. Nowadays, the accurate stratification in risk groups, according to the biological characteristics of the tumors and therapy response, and the introduction of new biological therapies, have to be taken into account in order to assign auto-HSCT a precise role in the therapeutic strategies, also considering that in the developmental age, auto-HSCT has a clear advantage over allo-HSCT, in terms of late sequelae, such as organ damage and second neoplasms. The purpose of this review is to report the results obtained with auto-HSCT in the different pediatric oncohematological diseases, focusing on the most significant literature data in the context of the various diseases and discussing this data in the light of the current therapeutic landscape.

Dose optimization strategy of the tyrosine kinase inhibitors imatinib, dasatinib, and nilotinib for chronic myeloid leukemia: From clinical trials to real-life settings

With the advent of tyrosine kinase inhibitors (TKIs), the treatment prospects of chronic myeloid leukemia (CML) have changed markedly. This innovation can lengthen the long-term survival of patients suffering from CML. However, long-term exposure to TKIs is accompanied by various adverse events (AEs). The latter affect the quality of life and compliance of patients with CML, and may lead to serious disease progression (and even death). Recently, increasing numbers of patients with CML have begun to pursue a dose optimization strategy. Dose optimization may be considered at all stages of the entire treatment, which includes dose reduction and discontinuation of TKIs therapy. In general, reduction of the TKI dose is considered to be an important measure to reduce AEs and improve quality of life on the premise of maintaining molecular responses. Furthermore, discontinuation of TKIs therapy has been demonstrated to be feasible and safe for about half of patients with a stable optimal response and a longer duration of TKI treatment. This review focuses mainly on the latest research of dose optimization of imatinib, dasatinib, and nilotinib in CML clinical trials and real-life settings. We consider dose reduction in newly diagnosed patients, or in optimal response, or for improving AEs, either as a prelude to treatment-free remission (TFR) or as maintenance therapy in those patients unable to discontinue TKIs therapy. In addition, we also focus on discontinuation of TKIs therapy and second attempts to achieve TFR.

Management of children and adolescents with chronic myeloid leukemia in blast phase: International pediatric CML expert panel recommendations

Treatment of chronic myeloid leukemia has improved significantly with the introduction of tyrosine kinase inhibitors (TKIs), and treatment guidelines based on numerous clinical trials are available for chronic phase disease. However for CML in the blast phase (CML-BP), prognosis remains poor and treatment options are much more limited. The spectrum of treatment strategies for children and adolescents with CML-BP has largely evolved empirically and includes treatment principles derived from adult CML-BP and pediatric acute leukemia. Given this heterogeneity of treatment approaches, we formed an international panel of pediatric CML experts to develop recommendations for consistent therapy in children and adolescents with this high-risk disease based on the current literature and national standards. Recommendations include detailed information on initial diagnosis and treatment monitoring, differentiation from Philadelphia-positive acute leukemia, subtype-specific selection of induction therapy, and combination with tyrosine kinase inhibitors. Given that allogeneic hematopoietic stem cell transplantation currently remains the primary curative intervention for CML-BP, we also provide recommendations for the timing of transplantation, donor and graft selection, selection of a conditioning regimen and prophylaxis for graft-versus-host disease, post-transplant TKI therapy, and management of molecular relapse. Management according to the treatment recommendations presented here is intended to provide the basis for the design of future prospective clinical trials to improve outcomes for this challenging disease.

Children with chronic myeloid leukaemia treated with front-line imatinib have a slower molecular response and comparable survival compared with adults: a multicenter experience in Taiwan

BACKGROUND

The direct comparison of molecular responses of front-line imatinib (IM) monitored at the same laboratory between children and adults with chronic phase (CP) of chronic myeloid leukaemia (CML) had not been reported. In this multicenter study, we compared the landmark molecular responses and outcomes of paediatric and adult CML-CP cohorts treated with front-line IM in whom the BCR::ABL1 transcript levels were monitored at the same accredited laboratory in Taiwan.

METHODS

Between June 2004 and July 2020, 55 newly diagnosed paediatric and 782 adult CML-CP patients, with molecular diagnosis and monitoring at the same reference laboratory in Taiwan, were enrolled. The criteria of 2020 European LeukemiaNet were applied to evaluate the molecular responses.

RESULTS

By year 5, the cumulative incidences of IS <1%, MMR, MR4.0 and MR4.5 of paediatric patients were all significantly lower than those of adult patients (58 vs 75%, 48 vs 66%, 25 vs 44%, 16 vs 34%, respectively). The 10-year progression-free survival (PFS) (90%) and overall survival (OS) (94%) of paediatric patients did not differ from those (92%) of adult patients.

CONCLUSIONS

We demonstrated the paediatric cohort had slower molecular responses to front-line IM and similar outcomes in 10-year PFS and OS in real-world practice.

Current childhood chronic myeloid leukemia management under tyrosine kinase inhibitor treatment

Chronic myeloid leukemia (CML) is very rare during childhood. Tyrosine kinase inhibitors (TKI) provide very good results in terms of survival. The medical records of 15 chronic phase (CP)-CML patients in a university hospital pediatric hematology department between 1997 and 2022 were reviewed retrospectively. Complete hematological response was documented in all patients between 20 and 68 (median 30) days of treatment. Major molecular response was achieved in seven patients within 6 months. Median follow-up for the study group was 79 (range 3-330) months and overall survival was 100%. Three patients (2 blastic transformation, 1 therapy resistant) underwent bone marrow transplantation (BMT) and one with blastic transformation is scheduled to undergo BMT. TKI were discontinued in three patients after a median of 86 (range 73-177) months. The complete molecular remission maintenance period before discontinuation of TKI was 81 (range 62-122) months. While no molecular relapse was seen before the last follow-up, the median overall follow-up period was 152 (range 131-300) months. In conclusion, recent advances have led to a very good prognosis for children with CP-CML. With TKI treatment, most patients continue their lives without disease progression. Additionally, in selected patients TKI can be discontinued without molecular relapse.

Prevalence of anemia at diagnosis of pediatric chronic myeloid leukemia and prognostic impact on the disease course

The clinical presentation of chronic myeloid leukemia (CML) at diagnosis differs in children compared to adults. At younger age, anemia appears to be frequent at diagnosis, but its prevalence and its impact on prognosis are not well known. In the International Registry of Childhood CML, we selected children and adolescents in chronic phase at diagnosis of CML and treated upfront with imatinib. We examined their hemoglobin level at diagnosis according to the WHO grades to assess the prevalence of anemia and its impact on response to tyrosine kinase inhibitors (TKIs). Data on 430 patients were included. Anemia at diagnosis was observed in 350 patients (81%), with a mean hemoglobin level of 96.4 g/l (SD 23.6). Among them, 182 patients (52%) presented with moderate anemia and 110 (31%) with severe anemia while 58 (17%) had mild anemia. Compared with mild and no anemia, moderate and severe forms were significantly associated with younger age at diagnosis, asthenia, splenomegaly, and increased leukocyte and basophil counts. Delays in achieving major and deep molecular responses were significantly increased for patients with moderate and severe anemia, and also failure of imatinib treatment was more frequent in these two sub-cohorts. However, hemoglobin level was not significantly associated with survival. Anemia at diagnosis of pediatric CML was frequent and may be considered as a prognostic factor.

Treatment of blast phase chronic myeloid leukaemia: A rare and challenging entity

Despite the success of BCR-ABL-specific tyrosine kinase inhibitors (TKIs) such as imatinib in chronic phase (CP) chronic myeloid leukaemia (CML), patients with blast phase (BP)-CML continue to have a dismal outcome with median survival of less than one year from diagnosis. Thus BP-CML remains a critical unmet clinical need in the management of CML. Our understanding of the biology of BP-CML continues to grow; genomic instability leads to acquisition of mutations which drive leukaemic progenitor cells to develop self-renewal properties, resulting in differentiation block and a poor-prognosis acute leukaemia which may be myeloid, lymphoid or bi-phenotypic. Similar advances in therapy are urgently needed to improve patient outcomes; however, this is challenging given the rarity and heterogeneity of BP-CML, leading to difficulty in designing and recruiting to prospective clinical trials. This review will explore the treatment of BP-CML, evaluating the data for TKI therapy alone, combinations with intensive chemotherapy, the role of allogeneic haemopoietic stem cell transplantation, the use of novel agents and clinical trials, as well as discussing the most appropriate methods for diagnosing BP and assessing response to therapy, and factors predicting outcome.

Minimal residual disease in BCR::ABL1-positive acute lymphoblastic leukemia: different significance in typical ALL and in CML-like disease

Recently, we defined "CML-like" subtype of BCR::ABL1-positive acute lymphoblastic leukemia (ALL), resembling lymphoid blast crisis of chronic myeloid leukemia (CML). Here we retrospectively analyzed prognostic relevance of minimal residual disease (MRD) and other features in 147 children with BCR::ABL1-positive ALL (diagnosed I/2000-IV/2021, treated according to EsPhALL (n = 133) or other (n = 14) protocols), using DNA-based monitoring of BCR::ABL1 genomic breakpoint and clonal immunoglobulin/T-cell receptor gene rearrangements. Although overall prognosis of CML-like (n = 48) and typical ALL (n = 99) was similar (5-year-EFS 60% and 49%, respectively; 5-year-OS 75% and 73%, respectively), typical ALL presented more relapses while CML-like patients more often died in the first remission. Prognostic role of MRD was significant in the typical ALL (p = 0.0005 in multivariate analysis for EFS). In contrast, in CML-like patients MRD was not significant (p values > 0.2) and inapplicable for therapy adjustment. Moreover, in the typical ALL, risk-prediction could be further improved by considering initial hyperleukocytosis. Early distinguishing typical BCR::ABL1-positive ALL and CML-like patients is essential to enable optimal treatment approach in upcoming protocols. For the typical ALL, tyrosine-kinase inhibitors and concurrent chemotherapy with risk-directed intensity should be recommended; in the CML-like disease, no relevant prognostic feature applicable for therapy tailoring was found so far.

Management of Chronic Myeloid Leukemia in Children and Young Adults

Purpose of Review

Due to lack of pediatric-specific data, the management of chronic myeloid leukemia (CML) in pediatric, adolescents, and young adults is guided by adult CML evidence-based recommendations. Pediatric CML presents differently than adult CML and is often a more aggressive disease with different biological and host factors, yet there is sparse literature on how to address those differences.

Recent Findings

Over the past two decades, tyrosine kinase inhibitors (TKIs) have changed the way CML is treated. There are currently three FDA-approved TKIs (imatinib, dasatinib, and nilotinib) for pediatric patients. When choosing which TKI to begin treatment with, there are many factors that should be considered on a case-to-case basis to obtain optimal outcomes. The safety profiles for long-term TKI use in pediatrics require further study. Unlike adults, children are still actively growing during TKI use, and the effect on development can be detrimental. TKI therapy is not recommended during pregnancy with variable but significant risk of fetal abnormalities and miscarriage, warranting counseling for young female patients prior to beginning TKIs. Attempts for treatment-free remission (TFR) by planned TKI cessation in eligible adult patients in deep and sustained molecular remission are now done as a standard of practice. However, data is sparse in the pediatric population. There is currently an ongoing Children’s Oncology Group (COG) study to determine the feasibility of TFR as a treatment goal.

Summary

Further research and additional pediatric trials are needed to characterize the unique aspects of CML in children and adolescents and optimize outcomes.

Skin and soft tissue infections in adolescent chronic myeloid leukemia under dasatinib treatment

Although skin complications are common adverse events from tyrosine kinase inhibitors (TKIs) for the treatment of chronic myeloid leukemia (CML), no reports have focused on skin and soft tissue infections (SSTIs) associated with TKI use. We herein present five episodes of SSTIs in three CML patients under dasatinib treatment. All patients were adolescents and had been receiving dasatinib for more than 4 years. In contrast, none of 41 adult CML patients experienced SSTIs in a retrospective analysis. Our findings suggest that long-term dasatinib treatment in adolescent patients may be associated with the increased risk of SSTIs.

Discontinuation of tyrosine kinase inhibitors in pediatric chronic myeloid leukemia

BACKGROUND

The feasibility of tyrosine kinase inhibitor (TKI) discontinuation in pediatric chronic myeloid leukemia (CML) remains to be fully elucidated.

PROCEDURES

TKI was prospectively discontinued in patients who were diagnosed with CML at <20 years of age, treated with TKI for ≥3 years, and sustained molecular response 4.0 (MR4.0) for ≥2 years. Molecular relapse was defined as a single loss of major molecular response (MMR) (BCR-ABL1^IS >0.1%). Relapsed patients resumed the same TKI therapy administered before discontinuation.

RESULTS

Twenty-two patients with chronic-phase CML were enrolled, and the median ages at diagnosis and at TKI discontinuation were 9 (range: 1-14) years and 16 (5-26) years, respectively. The median follow-up time after TKI discontinuation was 37 months (range: 24-41 months). The median duration of TKI treatment before discontinuation was 100 (42-178) months, and that of MR4.0 was 53.5 (25-148) months. The treatment-free remission (TFR) rate at 12 months was 50.0% (90% confidence interval: 31.7%-65.8%). Eleven patients experienced loss of MMR within 4 months after TKI discontinuation and resumed TKI as originally prescribed. No progression was observed, and all 11 patients regained MR4.0 after TKI resumption. No patient had a withdrawal syndrome. The quality-of-life analysis suggested that successful TFR may improve academic performance in some patients. In patients who discontinued TKI therapy before puberty, the possibility of improvement in growth velocity upon TKI discontinuation was observed.

CONCLUSIONS

TKI could be discontinued safely in patients with pediatric CML showing a sustained deep MR.

Physician risk perceptions and surveillance practices for tyrosine kinase inhibitor long-term effects in pediatric CML

Chronic myeloid leukemia (CML) is effectively treated with long-term tyrosine kinase inhibitor (TKI) therapy, yet little is known about risks of prolonged TKI exposure in young patients, and long-term effect monitoring is not standardized. We surveyed North American pediatric oncologists (n = 119) to evaluate perceived risk of and surveillance practices for potential toxicities associated with prolonged TKI exposure in children and adolescents/young adults (AYAs) with CML. Survey domains included general and specific risk perceptions and surveillance practices for asymptomatic patients on chronic TKI therapy. We analyzed data descriptively and explored relationships between risk perceptions and surveillance. Risk perceptions varied among oncologists but were similar across six categories (thyroid, cardiac, vascular, metabolic, fertility, psychologic), with less than one-third rating each risk as moderate or high in pediatric and AYA patients. More oncologists perceived moderate or high risk of growth abnormalities in children (62% pediatric, 14% AYA) and financial toxicity in all patients (60% pediatric, 64% AYA). A greater proportion of oncologists with moderate or high perceived risk of thyroid abnormalities reported testing thyroid function compared to those with lower perceived risk; patterns for metabolic risk/lipid tests and cardiac risk/tests were similar. In summary, we found that pediatric oncologists had variable risk perceptions and surveillance practices for potential toxicities associated with prolonged TKI exposure. Standardizing surveillance would help quantify risks and refine recommendations.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.2017085 .

Nilotinib modulates LPS-induced cognitive impairment and neuroinflammatory responses by regulating P38/STAT3 signaling

BACKGROUND

In chronic myelogenous leukemia, reciprocal translocation between chromosome 9 and chromosome 22 generates a chimeric protein, Bcr-Abl, that leads to hyperactivity of tyrosine kinase-linked signaling transduction. The therapeutic agent nilotinib inhibits Bcr-Abl/DDR1 and can cross the blood-brain barrier, but its potential impact on neuroinflammatory responses and cognitive function has not been studied in detail.

METHODS

The effects of nilotinib in vitro and in vivo were assessed by a combination of RT-PCR, real-time PCR, western blotting, ELISA, immunostaining, and/or subcellular fractionation. In the in vitro experiments, the effects of 200 ng/mL LPS or PBS on BV2 microglial cells, primary microglia or primary astrocytes pre- or post-treated with 5 µM nilotinib or vehicle were evaluated. The in vivo experiments involved wild-type mice administered a 7-day course of daily injections with 20 mg/kg nilotinib (i.p.) or vehicle before injection with 10 mg/kg LPS (i.p.) or PBS.

RESULTS

In BV2 microglial cells, pre- and post-treatment with nilotinib altered LPS-induced proinflammatory/anti-inflammatory cytokine mRNA levels by suppressing AKT/P38/SOD2 signaling. Nilotinib treatment also significantly downregulated LPS-stimulated proinflammatory cytokine levels in primary microglia and primary astrocytes by altering P38/STAT3 signaling. Experiments in wild-type mice showed that nilotinib administration affected LPS-mediated microglial/astroglial activation in a brain region-specific manner in vivo. In addition, nilotinib significantly reduced proinflammatory cytokine IL-1β, IL-6 and COX-2 levels and P38/STAT3 signaling in the brain in LPS-treated wild-type mice. Importantly, nilotinib treatment rescued LPS-mediated spatial working memory impairment and cortical dendritic spine number in wild-type mice.

CONCLUSIONS

Our results indicate that nilotinib can modulate neuroinflammatory responses and cognitive function in LPS-stimulated wild-type mice.

Successful eradication of chronic myeloid leukemia in a child despite allogeneic graft rejection

Background

Chronic myeloid leukemia (CML) is a rare disease in children and treated with tyrosine kinase inhibitors (TKI) and with allogeneic hematopoietic stem cell transplantation (HSCT) still in many cases.

Case

We describe an 8‐year‐old patient with CML treated with two different TKIs before proceeding to allogeneic HSCT. Despite successful engraftment, prompt rejection of the graft was followed by autologous reconstitution. TKI therapy was reintroduced post‐rejection in anticipation of relapse but shortly discontinued due to low white blood cell and neutrophil counts. The patient has remained disease‐free over 5 years after graft rejection and without further therapy.

Conclusion

This case suggests that even a short antileukemic effect by an allogeneic transplant may succeed in eradicating CML.

Treatment of Cancer Gene Changes in Chronic Myeloid Leukemia by Big Data Analysis Platform-Based Dasatinib

Based on data mining, an innovative big data analysis platform was utilized to discuss the treatment of cancer in chronic myeloid leukemia (CML) by dasatinib, aiming to offer help to the diagnosis and treatment of cancer. An integrated gene expression analysis system (IEAS) was firstly constructed to automatically classify data in the online human Mendelian genetic database using clustering algorithms. At the same time, the gene expression profile was analyzed by principal component analysis (PCA) in the analysis system. In addition, the efficacy of dasatinib in the treatment of patients with advanced CML was then retrospectively analyzed. The results showed that the IEAS system could incorporate the gene expression analysis vectors it contained by JAVA-related technologies, and the generated clustering genes showed similar functions. The clustering algorithm could homogenize data and generate visual clustering heat maps. The analysis results of major elements were diverse under different experimental conditions. The characteristic value of the first major element was the largest. Messenger ribonucleic acid (mRNA) datasets of CML patients were selected from cancer genomic map, including 120 samples and 20,614 mRNA in total. In micro-RNA (miRNA) datasets, there were 202 samples including 1,406 miRNAs. Data were screened by miRNA-mRNA regulation template, and 20 differentially expressed mRNAs were obtained. In conclusion, the proposed IEAS system could mine and analyze the gene expression data. Dasatinib showed good efficacy in the treatment of patients with advanced CML. Besides, it could improve visual queries, and data mining had a broad application prospect in clinical application. Dasatinib was considered to be a good option for patients with advanced CML.

Outcome prediction of chronic myeloid leukemia (CML) in children

We evaluated the feasibility of existing risk assessment tools for chronic myeloid leukemia (CML) in children. Fifty-five patients with newly diagnosed CML between 1996 and 2019 were included. Forty-nine patients presented in chronic phase, thirty-six of whom were treated with upfront tyrosine kinase inhibitor (CP-TKI group); one presented in accelerated phase and four in blastic phase. Treatment, survival, responses, and tolerance were evaluated. All patients in the CP-TKI group received imatinib as their first TKI treatment. The 10-year overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) of TKI-treated group was 97%, 91.4%, and 72.3%, respectively. At 60 months, the rates of major molecular response were 81.2% and deep molecular response was 67.5%. The EUTOS long-term survival (ELTS) risk grouping did not predict OS, PFS, or EFS. The IMAFAIL risk groups were correlated with the risk of imatinib failure. Further studies are required to modify the existing risk assessment tools for children.

Combinational treatment of TPEN and TPGS induces apoptosis in acute lymphoblastic and chronic myeloid leukemia cells in vitro and ex vivo

TPEN and TPGS have recently shown selective cytotoxic effects in vitro and ex vivo leukemia cells. In this study, we aimed to test the synergistic effect of combined TPEN and TPGS agents (thereafter, T2 combo) on Jurkat (clone-E61), K562, Ba/F3, and non-leukemia peripheral blood lymphocytes (PBL). The ED50 doses (i.e., TPEN ED50: 3.2 μM and TPGS ED50: 34 μM, potency ratio R = 10.62 = TPGS (ED50)/TPEN (ED50)) were identified as dose-effect curve (%DNA fragmentation (sub-G₁ phase) versus agent concentration). The most effective synergistic doses were determined according to isobole analysis. The apoptotic and oxidative stress effects of combined doses (TPEN 0.1, 0.5, 1 μM) and TPGS (5, 10, 20 μM)) were evaluated by DNA fragmentation (sub-G₁ phase), mitochondrial membrane potential, oxidation of stress sensor protein DJ-1, and activation of executer protein CASPASE-3. They testified to the synergistic effect of the T2 combo (e.g., TPEN 1: TPGS 20, combination index (CI) 0.90 < 1; 1/3.2+ 20/34, > 90% induced apoptosis) in all 3 cell lines. As proof of principle, we challenged complete bone marrow (n = 5) or isolated cells from bone marrow (n = 3) samples from acute pediatric acute B-cell patients and found that T2 combo (1:20; 10:200) dramatically reduced (- 50%) the CD34+/CD19+cell population and increased significantly CD19+/CASP-3+ positive B-ALL cells up to 960%. The T2 combo neither induced DNA fragmentation, altered ΔΨm, nor induced oxidation of stress sensor protein DJ-1, nor activated CASP-3 in PBL cells. We conclude that by using different combinations of TPEN and TPGS, a more efficient treatment strategy can be developed for leukemia patients.

The prognosis biomarkers based on m6A-related lncRNAs for myeloid leukemia patients

Background

Chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) are two common malignant disorders in leukemia. Although potent drugs are emerging, CML and AML may still relapse after the drug treatment is stopped. N6-methyladenosine (m6A) and lncRNAs play certain roles in the occurrence and development of tumors, but m6A-modified LncRNAs in ML remain to be further investigated.

Methods

In this study, we extracted and analyzed the TCGA gene expression profile of 151 ML patients and the clinical data. On this basis, we then evaluated the immune infiltration capacity of ML and LASSO-penalized Cox analysis was applied to construct the prognostic model based on m6A related lncRNAs to verify the prognostic risk in clinical features of ML. Quantitative reverse transcription PCR was used to detect the expression level of LncRNA in in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1.

Results

We found 70 m6A-related lncRNAs that were related to prognosis, and speculated that the content of stromal cells and immune cells would correlate with the survival of patients with ML. Next, Prognostic risk model of m6A-related lncRNAs was validated to have excellent consistency in clinical features of ML. Finally, we verified the expression levels of CRNDE, CHROMR and NARF-IT1 in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1, which were significant.

Conclusions

The research provides clues for the prognosis prediction of ML patients by using the m6A-related lncRNAs model we have created, and clarifies the accuracy and authenticity of it.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02428-3.

Discontinuation of tyrosine kinase inhibitors based on BCR-ABL1 monitoring by digital droplet PCR in pediatric chronic myeloid leukemia

Lifelong treatment of pediatric chronic myeloid leukemia (CML) patients with tyrosine kinase inhibitors (TKIs) can affect their growth and development. For these reasons, clinical trials have explored the feasibility of TKI discontinuation in children with a sufficient TKI response. We evaluated the analytical performance of digital droplet PCR (ddPCR) to quantify BCR-ABL1 and compared the results with reverse transcription quantitative polymerase chain reaction (RT-qPCR). We further investigated whether ddPCR could be used to determine TKI discontinuation in a clinical setting. Performance of ddPCR was evaluated using standard materials for BCR-ABL1, and a total of 197 clinical samples from 45 pediatric CML patients was included for comparison with RT-qPCR. ddPCR showed excellent analytical sensitivity with 0.001% international scale (IS) and linearity with R ² > 0.99 in log scale. BCR-ABL1 % IS results correlated well with those of RT-qPCR (R ² = 0.9435), however, they showed a moderate strength for agreement with a Cohen's kappa of 0.41 due to higher sensitivity of ddPCR. Among 45 pediatric CML patients, 42 were treated with first-line TKIs including imatinib (n = 27, 64%) and dasatinib (n = 12, 29%), and three patients that were started with imatinib were switched to dasatinib. When we evaluated whether follow-up samples fulfilled ABL1 copies ≥ 10,000 required for deep molecular response (DMR), all samples were acceptable by ddPCR, whereas 18% by RT-qPCR did not reached acceptable ABL1 copies. Moreover, 52 and 13% reached ABL1 copies ≥ 32,000 required for MR4.5 by ddPCR and RT-qPCR, respectively. Seven patients discontinued TKI and the median TKI treatment duration was 73 months prior to discontinuation. Prior to discontinuation, the median duration of sustained undetected BCR-ABL1 was 60 months. Two patients experienced loss of major MR (MMR) during follow-up and restarted dasatinib 5 months after discontinuation. They achieved MMR again and maintained better than DMR afterward. Results from those patients demonstrated that RT-qPCR did not match the need for adequate ABL1 copies for MR4.5 while majority of ddPCR could. Therefore, ddPCR was technically more acceptable to decide and monitor pediatric CML patients before and after TKI discontinuation.

Targeting SOS1 overcomes imatinib resistance with BCR-ABL independence through uptake transporter SLC22A4 in CML

Resistance to the BCR-ABL inhibitor imatinib mesylate poses a major problem for the treatment of chronic myeloid leukemia. Imatinib resistance often results from a secondary mutation in BCR-ABL that interferes with drug binding. However, sometimes there is no mutation in BCR-ABL, and the basis of such BCR-ABL-independent imatinib mesylate resistance remains to be elucidated. SOS1, a guanine nucleotide exchange factor for Ras protein, affects drug sensitivity and resistance to imatinib. The depletion of SOS1 markedly inhibits cell growth either in vitro or in vivo and significantly increases the sensitivity of chronic myeloid leukemia cells to imatinib. Furthermore, LC-MS/MS and RNA-seq assays reveal that SOS1 negatively regulates the expression of SLC22A4, a member of the carnitine/organic cation transporter family, which mediates the active uptake of imatinib into chronic myeloid leukemia cells. HPLC assay confirms that intracellular accumulation of imatinib is accompanied by upregulation of SLC22A4 through SOS1 inhibition in both sensitive and resistant chronic myeloid leukemia cells. BAY-293, an inhibitor of SOS1/Ras, was found to depress proliferation and colony formation in chronic myeloid leukemia cells with resistance and BCR-ABL independence. Altogether these findings indicate that targeting SOS1 inhibition promotes imatinib sensitivity and overcomes resistance with BCR-ABL independence by SLC22A4-mediated uptake transport.

Health-related quality of life in children with chronic myeloid leukemia in the chronic phase

PURPOSE

This study aimed to explore the health-related quality of life (HRQoL) and associated variables in children with chronic myeloid leukemia in the chronic phase (CML-CP) receiving tyrosine kinase inhibitors (TKIs).

METHODS

A cross-sectional questionnaire was given to children with CML and their parents, who were < 18 years at diagnosis of CML and < 19 years at study. The questionnaire comprised three parts, including demographic information, clinical information, and the Chinese version of Pediatric Quality of Life Inventory^™ (PedsQL^™) Cancer Module 3.0 as HRQoL questionnaire.

RESULTS

A total of 240 respondents data were analyzed. Multivariate analysis showed that children with symptoms had worse pain (- 10.2; P < 0.001), nausea (- 17.3; P = 0.001), more treatment anxiety (- 7.2; P = 0.005), worse self-assessment appearance (- 7.1; P = 0.001), communication problems (- 6.4; P = 0.001), and worse HRQoL (- 7.0; P < 0.001). Children with mothers having low educational qualifications had worse pain (- 6.0; P = 0.014), more worried about future (- 5.4; P = 0.042), worse cognition problems (- 7.1; P = 0.002), worse communication problems (- 5.5; P = 0.008), and worse HRQoL (- 4.3; P = 0.005). Younger age children at study had more procedural anxiety (2.7; P = 0.001), treatment anxiety (- 1.7; P = 0.014) and cognition problem (3.6; P < 0.001), as well as worse HRQoL (1.8; P = 0.008). However, older age children at diagnosis were more worried about future (- 2.8; P = 0.001), worse self-assessment appearance (- 1.1; P = 0.042) and worse HRQoL (- 1.8; P = 0.007). Other variables significantly associated with worse HRQoL included female gender, rural household registration and their father's low education level. Parents reported more gastrointestinal disorders, were worried about the future and had less concern about appearance than their children.

CONCLUSIONS

Female gender, older age at diagnosis, younger age at study, lower mother's education level, and TKI-related symptoms are significantly associated with worse HRQoL in Children with CML. Children and their parents have different priorities in the HRQoL.

Transcriptomic profile of human erythroleukemia cells in response to Sargassum fusiforme polysaccharide and its structure analysis

Sargassum fusiforme (S. fusiforme) has been used as an ingredient in Chinese herbal medicine for thousands of years. However, there are a limited number of studies concerning its therapeutic mechanism. High performance gel permeation chromatography (HPGPC) analysis showed that the average molecular weight of the S. fusiforme polysaccharide, SFPS 191212, is 43 kDa. SFPS 191212 is composed of mannose, rhamnose, galactose, xylose, glucose, and fucose (at a molar ratio: 2.1 : 2.9 : 1.8 : 15.5 : 4.6 : 62.5) with α- and β-configurations. The present research evaluated the anti-tumor potential of the S. fusiforme polysaccharide in human erythroleukemia (HEL) cells in vitro. To explore the SFPS 191212's apoptosis mechanism in HEL cells, transcriptome analysis was performed on HEL cells that were incubated with SFPS 191212. The inhibitory effect of SFPS 191212 on HEL cell growth was also analyzed. It was found that SFPS 191212 inhibited HEL cell proliferation, reduced cell viability in a concentration-dependent manner, and induced an insignificant toxic effect on normal human embryonic lung (MRC-5) cells. Compared with the control group, transcriptome analysis identified a total of 598 differentially expressed genes (DEGs), including 243 up-regulated genes and 355 down-regulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on all DEGs, and 900 GO terms and 52 pathways were found to be significantly enriched. Finally, 23 DEGs were randomly selected and confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, SFPS 191212 down-regulated the PI3K/Akt signal transduction pathway. Our results provide a framework for understanding the effect of SFPS 191212 on cancer cells and can serve as a resource for delineating the anti-tumor mechanisms of S. fusiforme.

Chronic Myeloid Leukemia in Children: Immune Function and Vaccinations

Children with CML need TKI treatment for many years, and the lack of knowledge about immune dysfunction with TKI has hindered routine immunizations. This review attempts to provide an overview of the effects of TKIs licensed for children (e.g., imatinib, dasatinib, and nilotinib) on immune function, as well as its implications on immunizations. We discuss surveillance strategies (e.g., immunoglobulin blood serum levels and hepatitis B reactivation) and immunizations. All inactivated vaccines (e.g., influenza, pneumococcal, and streptococcal) can be given during the treatment of CML in the chronic phase, although their efficacy may be lower. As shown in single cases of children and adults with CML, live vaccines (e.g., varicella, measles, mumps, rubella, and yellow fever) may be administered under defined circumstances with great precautions. We also highlight important aspects of COVID-19 in this patient population (e.g., the outcome of COVID-19 infection in adults with CML and in children with varying hemato-oncological diseases) and discuss the highly dynamic field of presently available different vaccination options. In conclusion, TKI treatment for CML causes humoral and cellular immune dysfunction, which is mild in most patients, and thus infectious complications are rare. Routine immunizations are important for health maintenance of children, but vaccinations for children with CML on TKI therapy should be carefully considered.