Outcomes of Dose Escalation of Imatinib in Chronic Myeloid Leukemia Patients: A Retrospective Analysis From an Indian University Teaching Hospital.

BACKGROUND: Chronic myeloid leukemia (CML) treatment in low- and middle-income countries faces significant financial and logistical constraints. In scenarios where second-line tyrosine kinase inhibitors (TKIs) are unavailable or unaffordable, dose escalation of imatinib provides an alternative. This study evaluates the efficacy, safety, and progression-free survival (PFS) outcomes of dose escalation of imatinib in CML patients who experienced suboptimal response or progression on standard doses. METHODS: A retrospective analysis of 123 CML patients treated at an Indian university teaching hospital from 2013 to 2016 was conducted. Patients who showed progression on a 400 mg dose of imatinib were escalated to 600 mg, and further to 800 mg if required. Demographic data, progression, and toxicity were analyzed. RESULTS: Out of 123 patients, 78 (63.4%) showed a complete hematologic response after dose escalation. The median PFS was 48 months, with a three-year PFS rate of 67%. Notable toxicities included Grade 3/4 neutropenia in 15% and gastrointestinal disturbances in 12%. Comparatively, studies suggest that switching to a second-line TKI in similar settings results in a higher PFS; however, our findings underscore that dose escalation of imatinib remains a viable alternative when financial constraints limit access to second-line therapies. CONCLUSION: In resource-constrained settings, dose escalation of imatinib can be an effective strategy for managing CML patients who progress on standard doses.

[Chronic myeloid leukemia: 2024 update on novel therapeutic strategies].

Many patients with chronic myeloid leukemia (CML) can now maintain response thanks to the advent of tyrosine kinase inhibitors (TKIs) and STAMP inhibitors, but adverse events associated with prolonged TKI therapy have become a problem. Adequate management of adverse events is key to successful treatment, as some can significantly impact the patient's prognosis. The goal of CML treatment was once to prevent acute transformation, but now that many patients achieve deep remission and long-term survival, the goal has shifted to achieving long-term treatment free remission (TFR). It is essential to carefully consider disease risk, patient background, and adverse events of each therapeutic agent in order to make the appropriate choice. This article reviews the treatment of chronic phase CML (CML-CP) as described in the 2023 edition of the Guidelines for Hematopoietic Tumors, focusing on treatment options for first-line CML-CP, dose optimization of ponatinib, outcomes with the new CML drug asciminib, and TFR.

Dasatinib-Induced Bilateral Chylothorax: A Case Report.

Dasatinib, a BCR-ABL tyrosine kinase inhibitor, is used in the management of Philadelphia-positive chronic myeloid leukemia (CML). Several adverse complications of this targeted immunotherapy have been reported. This case report focuses on a 79-year-old female who presented with acute dyspnea and generalized chest pressure while undergoing management with this specific tyrosine kinase inhibitor. Bilateral chylothorax was diagnosed with the aid of imaging, laboratory studies, and diagnostic thoracentesis. No other risk factors, including trauma, lung malignancies, or congenital anomalies, were detected in this patient. Since no other etiologies for the development of chylothorax were identified, it was concluded that dasatinib therapy was the inciting factor. Dasatinib was discontinued and bosutinib was initiated. A low-fat diet was prescribed, which the patient was amenable to. Six months later, the patient remained stable with no recurrence of chylothorax. The mechanism of dasatinib-induced chylothorax is currently under investigation. The purpose of this report is to raise awareness about dasatinib-induced chylothorax, aid in identifying predisposing risk factors, and enhance understanding of the proper management of this rare complication.

BCAT1 contributes to the development of TKI-resistant CML.

PURPOSE: Although most of chronic myeloid leukemia (CML) patients can be effectively treated by the tyrosine kinase inhibitors (TKIs), such as Imatinib, TKI-resistance still occurs in approximately 15-17% of cases. Although many studies indicate that branched chain amino acid (BCAA) metabolism may contribute to the TKI resistance in CML, the detailed mechanisms remains largely unknown. METHOD: The cell proliferation, colony formation and in vivo transplantation were used to determined the functions of BCAT1 in leukemogenesis. Quantitative real-time PCR (RT-PCR), western blotting, RNA sequencing, BCAA stimulation in vitro were applied to characterize the underlying molecular mechanism that control the leukemogenic activity of BCAT1-knockdown cells. RESULTS: In this report, we revealed that branched chain amino acid transaminase 1 (BCAT1) is highly enriched in both mouse and human TKI-resistant CML cells. Leukemia was almost completely abrogated upon BCAT1 knockdown during transplantation in a BCR-ABLT315I-induced murine TKI-resistant CML model. Moreover, knockdown of BCAT1 led to a dramatic decrease in the proliferation of TKI-resistant human leukemia cell lines. BCAA/BCAT1 signaling enhanced the phosphorylation of CREB, which is required for maintenance of TKI-resistant CML cells. Importantly, blockade of BCAA/BCAT1 signaling efficiently inhibited leukemogenesis both in vivo and in vitro. CONCLUSIONS: These findings demonstrate the role of BCAA/BCAT1 signaling in cancer development and suggest that targeting BCAA/BCAT1 signaling is a potential strategy for interfering with TKI-resistant CML.

Expression of HOTAIR and PTGS2 as potential biomarkers in chronic myeloid leukemia patients in Brazil.

Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm in which all the patients has the translocation (9;22) that generates de BCR::ABL1 tyrosine kinase. Despite this disease possessing a good biomarker (BCR::ABL1 transcripts level) for diagnosis and prognosis, many studies has been performed to investigate other molecules, such as the long noncoding RNAs (lncRNAs) and mRNAs, as potential biomarkers with the aim of predicting a change in BCR::ABL1 levels and as an associated biomarker. A RNAseq was performed comparing 6 CML patients with high BCR::ABL1 expression with 6 healthy control individuals, comprising the investigation cohort to investigate these molecules. To validate the results obtained by RNAseq, samples of 87 CML patients and 42 healthy controls were used in the validation cohort by RT-qPCR assays. The results showed lower expression of HOTAIR and PTGS2 in CML patients. The HOTAIR expression is inversely associated with BCR::ABL1 expression in imatinib-treated CML patients, and to PTGS2 showing that CML patients with high BCR::ABL1 expression showed reduced PTGS2 expression.

Phenotypically plastic drug-resistant chronic myeloid leukaemia cell line displays enhanced cellular dynamics in a zebrafish xenograft model.

Understanding the mechanisms by which cancer cells switch between different adaptive states and evade therapeutic interventions is essential for clinical management. In this study, the in vivo cellular dynamics of a new chronic myeloid leukaemia cell line displaying altered phenotype and resistance to tyrosine kinase inhibitors were investigated in correlation with their parental cells for invasiveness/metastasis, angiogenic potential and population kinetics. We showed that the cells exhibiting drug resistance and plastic phenotype possess an increased capacity for invasion compared to their parental cells, that exposure to imatinib mesylate has the potential to enhance cellular motility and that in a leukaemic cell population, even a minority of plastic cells exhibit improved migratory ability. Furthermore, we show that these plastic cells have angiogenic and extravasation potential. The present study provides significant insights into the cellular dynamics displayed by a TKI-resistant, phenotypically plastic CML cell line, using a zebrafish (Danio rerio) xenograft model.

Antiproliferative Activity of Cephalotaxus Esters: Overcoming Chemoresistance.

INTRODUCTION: Omacetaxine, a semisynthetic form of Homoharringtonine (HHT), was approved for the treatment of Chronic Myeloid Leukemia (CML). Previously, we have published the synthesis of this natural alkaloid and three of its derivatives: Deoxyharringtonine (DHT), Deoxyhomoharringtonine (DHHT), and Bis(demethyl)-deoxyharringtonine (BDHT), and reported its refractory activity against the HL-60/RV+ cells over-expressing P-glycoprotein 1 (MDR1). METHODS: In this study, we have explored the extent of this resistance by first expanding the panel of established cell lines and using a panel of 21 leukemia patient-derived primary cells. RESULTS: Herein, we have reported consistent resistance to HTT of K562-derived cells and to mitoxantrone of MES-SA/MX2-derived cells; all of them have been found to overexpress MDR1, while we have found U87MG-ABCG2 and H69AR cells to be very sensitive to HTT. In contrast, DHT, DHHT, and BDHT seemingly overcame this resistance due to the changes made to the acyl chain of HTT, rendering the derivatives less susceptible to efflux. Surprisingly, the leukemia primary cells were very sensitive to HHT and its derivatives with low nanomolar potencies, followed by a new class of CDC7 kinase inhibitors, the anthracycline class of topoisomerase inhibitors, the DNA intercalator actinomycin-D, and the vinca alkaloid class of microtubule inhibitors. The mechanism of cell death induced by HTT and DHHT was found to be mediated via caspase 3 cleavage, leading to apoptosis. CONCLUSION: Taken together, our results confirm that HHT is a substrate for MDR1. It opens the door to a new opportunity to clinically evaluate HHT and its derivatives for the treatment of AML and other cancers.

Advanced hybrid nanomaterials based on carboxymethyl-modified biopolymer: Green synthesis and application in sustainable antimicrobial products.

The utilization of agricultural by-products for the synthesis of hybrid nanomaterials represents an environmentally sustainable approach. This research aims to comprehensively investigate high-performance silver and copper nanoparticles hybrid materials based on carboxymethyl-modified cellulose / lignin derived from rice husks (CMC / CML-AgNPs and CMC / CML-CuONPs) and apply them for antimicrobial activities. CMC / CML was used to reduce Ag / Cu cations to the atomic level and then efficiently stabilize Ag / CuO nanoparticles, an eco-friendly method and sustainable development. The hybrid nanomaterials were successfully synthesized with spherical shapes and particle sizes ranging from 4 to 16 nm. The diffraction peaks at 38.46°, 46.57°, 64.93°, and 77.55° were ascribed to the face-centered cubic crystal lattice (111), (200), (220), and (311) of silver nanoparticles in the CMC / CML-AgNPs. The peaks were 32.26°, 46.06°, 52.16°, 61.71°, 63.80°, and 71.23° associating with the (110,20-2), (112), (11-3), (310), and (221) plane orientations of CuO nanoparticles. The proposed materials demonstrated highly efficient antimicrobial performances. Particularly, CMC-AgNPs and CML-CuONPs exhibited an inhibitory capability of up to 100 % against E. coli and S. aureus within 72 h. Simultaneously, the antifungal results showed that hybrid nanomaterials have a better ability to inhibit the A. niger than A. flavus fungus. When experimenting on peanut seeds, hybrid nanomaterials showed an inhibitory capability of up to 99.0 % against A. niger. IC50 values of the hybrid nanomaterials range from 0.872 mg/mL to 1.188 mg/mL, confirming that these materials are non-cytotoxic. These materials exhibit significant stability and enduring antimicrobial efficacy, making them ideal for sustainable development of various antibacterial and antifungal blocks for the near future.

Prognostic Significance of Regulatory T-Cells and PD-1 + CD8 T-Cells in Chronic Myeloid Leukemia Patients Treated with Generic Imatinib.

The impact of T-regulatory cells (Tregs), PD-1 + CD8 T-cells, and their dynamics during treatment with imatinib mesylate remains poorly understood in patients with chronic myeloid leukemia (CML). We conducted a prospective study on newly diagnosed, treatment-naïve adult (> 18 years old) patients with CML in the chronic phase (CP) and age- and sex-matched controls. Peripheral blood samples were collected at diagnosis and after three months of imatinib therapy to assess Tregs and PD-1 + CD8 T-cell levels using flow cytometry. The study comprised 57 patients with a median age of 39 years, including 27 males (47%). At baseline, the mean percentage of Tregs was significantly higher in CML patients (3.6 ± 0.32%) compared to controls (1.58 ± 0.21%) (p < 0.0001) but decreased significantly after three months of imatinib treatment (1.73 ± 0.35%) (p < 0.0001). Baseline Treg% exhibited positive correlations with Sokal (r = 0.29), Hasford (r = 0.33), EUTOS (r = 0.28), and ELTS (r = 0.31) risk scores (p < 0.05), as well as with the BCR-ABL transcript levels at three months (p = 0.03). Furthermore, the mean baseline percentage of PD-1 + CD8 T-cells was significantly elevated in CML patients (7.66 ± 0.36%) compared to controls (2.65 ± 0.32%) (p < 0.0001) and also decreased after treatment (3.44 ± 0.37%) (p < 0.0001). The baseline percentage of PD-1 + T-cells demonstrated positive correlations with Sokal (r = 0.26), Hasford (r = 0.27), and ELTS (r = 0.41) risk scores (p < 0.05). Our findings reveal a significantly higher proportion of Tregs and PD-1 + CD8 T-cells in patients with CML-CP compared to healthy controls, notably diminished following imatinib treatment. These observations suggest the potential for immunotherapy as a promising approach to managing immune exhaustion in CML patients.

A Retrospective Analysis of BCR-ABL-1 Kinase Domain Mutations in Frontline TKI Resistant Chronic Myeloid Leukemia Patients: A Single Centre Experience.

CML is a commonly diagnosed myeloproliferative neoplasm in India. Tyrosine kinase inhibitors (TKIs) are the current standard of care for management of CML. Mutations in Tyrosine kinase Domain (TKD) result in resistance to TKIs. The aim of this study is to evaluate the pattern of TKD mutations in CML patients having inadequate response or resistance to first line TKIs and to analyse the outcome of CML patients with and without mutations. It is a retrospective observational study. Medical records of 1633 CML patients from year 2014 to 2021 were analysed. Out of these 108 patients (6.6%) lost their response or did not achieve it in defined time points. 62 patients (71%) were found to have TKD mutations. On analysing specific mutations T315I was the most common mutation seen in 29 (46%) cases followed by M351T in 10 (16%) cases and G250E in 7 (11%) cases. ATP binding region was found to be the most common site in tyrosine kinase domain (50% cases) followed by P-loop (22%) and A loop (9.6%). 13 (20%) cases had ≥2 TKD mutations. The study showed inferior overall survival (OS) in patients with TKD mutations involving T315I mutations and ATP binding domain. Patients may have have underlying TKD mutations at prestation or may develop during course of disease. In case of TKI resistance, testing for specific mutations must be done and appropriate TKI sensitive to underlying mutation is to be used which translates into improved OS.

Digital Ischemia and Gangrene: An Unusual Presentation of Chronic Myeloid Leukemia.

Digital ischemia with gangrene is a rare manifestation of chronic myeloid leukemia (CML). We report a rare CML case with severe thrombocytosis presenting clinically as digital ischemia and gangrene, the sole primary symptom. A 40-year-old patient presented with pain and discoloration of the tips of the ring and little fingers of the right hand for 20 days, which later progressed to dry gangrene with a line of demarcation and pre-gangrenous changes in the index and middle fingers. He was a chronic smoker and alcoholic with no other comorbidities. On investigation, he was found to have abnormal leukocytosis (153,000/mm3) and moderate thrombocytosis (969,000/mm3) with anemia. In view of abnormal leukocytosis, he was investigated for leukemia. He was found to be positive for BCR-ABL by reverse transcription polymerase chain reaction (RT-PCR), thus confirming the diagnosis of CML. He received imatinib 400 mg/day and subsequently experienced resolution of symptoms and complete hematological response by the 12th week of therapy.

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

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

Direct determination of chronic myeloid leukemia prevalence in Lombardy-Italy: Global implications.

Lombardy represents the largest region of Italy by population, with almost 10 million residents, a dimension similar to a medium size country like Sweden or Belgium. The CML subcommittee of the Lombardy Hematology Network (REL-CML) conducted a study at the beginning of 2023. Prevalence was calculated by direct input from the 21 centers participating in REL-CML. Tyrosine Kinase Inhibitors (TKI) prescription records collected from the ARIA regional registry were used to estimate the number of CML patients followed in smaller centers not participating in REL-CML. A total of 2285 patients were registered, representing a prevalence of 0.23 ‰. These data were compared to a similar census conducted in 2005, at the beginning of the TKI era, where a prevalence of 0.029‰ was calculated. This indicates that an almost 10 times increase took place during this period of time. Imatinib represents the most frequently prescribed first-line TKI; its use in 2022 still represented 75% of total first line prescriptions. An increased concentration of the care of CML patients in specialized REL centers with a decreased dispersion of patients in small centers was also evident over this 18 year period of time. Nineteen % of patients discontinued treatment, highlighting persisting logistical and biological challenges; one some recommendations on CML management are included to this aim.

Structure optimization, synthesis and bioactivity evaluation of novel BCR-ABL tyrosine kinase inhibitor targeting T315I mutation.

Chronic Myeloid Leukemia (CML) is a malignant hematologic tumor caused by BCR-ABL fusion protein that binds with ATP to exert tyrosinase activity and persistently activates downstream phosphorylation pathways. The tyrosine kinase inhibitors (TKIs) represented by Imatinib are the key clinical therapy to the CML. While the mutations on the target lead to the serious drug resistance problems, especially the T315I mutation remains an unresolved challenge, and the cardiotoxicity has limited the clinical application of the third generation TKI Ponatinib despite its favorable efficacy against the T315I mutation. Even though, structural optimization of Ponatinib remains a potential strategy to overcome the resistance imposed by the mutation. Herein, we present a series of novel BCR-ABL/T315I tyrosine kinase inhibitors obtained by virtual screening using ZINC21710815, a BCR-ABL/T315I inhibitor reported earlier by our team, as a lead compound, and structural optimization of lead compounds against the T315I mutation, as well as screening of two novel compounds by activity evaluation and mechanistic studies, W4 and W8. W4 and W8 have better cell death-inducing effects and special selectivity against BaF3/T315I, which are worthy of further in-depth study to obtain more desirable anti-CML drugs as lead compounds.

Minimal Requirements for Cancer Initiation: A Comparative Consideration of Three Prototypes of Human Leukemia.

Even if its completed form is complex, cancer originates from one or two events that happened to a single cell. A simplified model can play a role in understanding how cancer initiates at the beginning. The pathophysiology of leukemia has been studied in the most detailed manner among all human cancers. In this review, based on milestone papers and the latest research developments in hematology, acute promyelocytic leukemia (APL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML) with RUNX1-RUNX1T1 are selected to consider minimal requirements for cancer initiation. A one-hit model can be applied to the initiation of APL and CML whereas a two-hit model is more suitable to the initiation of AML with RUNX1-RUNX1T1 and other AMLs. Even in cancer cells with multiple genetic abnormalities, there must be a few mutant genes critical for the mutant clone to survive and proliferate. Such genes should be identified and characterized in each case in order to develop individualized target therapy.

Oxidative lipid damage by naringenin selectively sensitizes chronic myeloid leukemia cell lines and patient samples to Bcr-Abl tyrosine kinase inhibitors.

Chronic myeloid leukemia (CML) treatment with Bcr-Abl tyrosine kinase inhibitors (TKIs) has significantly improved patient outcomes, yet challenges such as drug resistance and persistence of leukemic stem cells persist. This study explores the potential of naringenin, a natural flavonoid, to enhance the efficacy of Bcr-Abl TKIs in CML therapy. We showed that naringenin reduces viability of a panel of CML cell lines regardless of varying cellular origin and genetic mutations, and acts synergistically with dasatinib and ponatinib. Importantly, naringenin is effective in targeting blast crisis CML CD34+ cells by decreasing their colony formation, self-renewal and viability. Compared to CML, naringenin is significantly less effective against normal bone marrow (NBM) counterparts. In addition, naringenin significantly enhances the inhibitory effects of dasatinib in CML but not NBM CD34+ cells. Mechanism studies showed that naringenin's inhibitory effects were associated with the induction of oxidative stress and lipid damage, as evidenced by increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Notably, naringenin upregulated genes related to mitochondrial biogenesis while downregulating antioxidant defense genes. Pretreatment with α-tocopherol, which inhibits lipid-mediated ROS production, completely abolished the ROS increase and restored cell viability, indicating that lysosomal lipid peroxidation plays a crucial role in naringenin's mechanism of action. In a CML xenograft mouse model, the combination of naringenin and dasatinib resulted in remarkably more tumor growth suppression compared to single drug alone. Importantly, this combination was well-tolerated, with no adverse effects on body weight observed. These findings suggest that naringenin, by inducing oxidative lipid damage, enhances the anti-leukemic effects of Bcr-Abl TKIs, offering a promising therapeutic strategy for CML.

Establishment of genomic RNA reference materials for BCR-ABL1 P210 measurement.

Quantitation of BCR-ABL1 with the quantitative reverse transcriptase polymerase chain reaction (RT-PCR) is very important in monitoring chronic myeloid leukemia (CML), which relies on an RNA reference material. A genomic RNA reference material (RM) containing the BCR-ABL1 P210 fusion mutation was developed, and an absolute quantitative method based on one-step reverse transcription digital PCR (RT-dPCR) was established for characterizing the RM. The proposed dPCR method demonstrates high accuracy and excellent analytical sensitivity, as shown by the linear relationship (0.94 < slope < 1.04, R2≧0.99) between the measured and nominal values of b2a2, b3a2, and ABL1-ref within the dynamic range (104-101 copies/reaction). Homogeneity and stability assessment based on dPCR indicated that the RM was homogeneous and stable for 24 months at -80 °C. The RM was used to evaluate inter-laboratory reproducibility in eight different laboratories, demonstrating that participating laboratories could consistently produce copy concentrations of b3a2 and ABL1-ref, as well as the BCR-ABL1/ABL1 ratio (CV < 2.0%). This work suggests that the RM can be employed in establishing metrological traceability for detecting mutations in the BCR-ABL1 fusion gene, as well as in quality control for testing laboratories.

Evaluation of contraception methods in chronic myeloid leukemia patients: A Turkish multicenter study.

BACKGROUND AND AIM: Chronic myeloid leukemia (CML) incidence has recently increased in younger individuals. With time, given the nature of the disease and available therapies, as well as the existing paucity and inconsistency of advice, worries about fertility have surfaced. With all these clear unknowns, we designed this study to raise awareness among both physicians and CML patients about whether male and female patients of childbearing age were using contraception at the time of diagnosis, and if so, which methods they were using. In this context, this study aimed to evaluate the contraception methods in patients with CML. MATERIALS AND METHODS: Eighteen centres from Turkey participated in the study. Male and female patients of childbearing age diagnosed with chronic and accelerated phase CML between the years 2000 and 2024 were evaluated retrospectively. RESULTS: Of the two hundred and thirty-two patients included, one hundred and twenty-five (53.9%) of these patients were female and 107 (46.1%) were male. At diagnosis, all female patients were in the childbearing age, and male patients were sexually active. The median age at diagnosis of the patients was 38 (range, 18-77) years. Eighty-six (68.8%) female patients were using any contraception method, while this was 53.2% (n = 57) among male patients. CONCLUSION: In conclusion, since CML patients are diagnosed at an earlier age and the desire of these patients to have children, adequate information and evaluation should be provided regarding fertility and contraception issues, especially in female patients, from the moment of diagnosis.