Phase Chronic Myeloid Leukemia Research Articles

Exploring treatment decision-making in chronic myeloid leukemia in chronic phase.

The introduction of tyrosine kinase inhibitors (TKIs) has transformed the treatment of chronic myeloid leukemia (CML). Each approved TKI has its own risk-benefit profile, and patients have choices across lines of therapy. Identifying the initial and subsequent treatment that will lead to the best possible outcome for individual patients is challenging. In this review, we summarize data for each approved TKI across lines of therapy in patients with CML in chronic phase, highlighting elements of each agent's safety and efficacy profile that may impact patient selection, and provide insights into individualized treatment sequencing decision-making aimed at optimizing patient outcomes.

Constitutional DNA Polymorphisms Associated with the Plasma Imatinib Concentration in Chronic Myeloid Leukemia Patients

The tyrosine kinase Inhibitor (TKI) imatinib is approved for the treatment of the chronic phase of chronic myeloid leukemia (CP-CML). Pharmacokinetic studies have highlighted the importance of inter-patient variability on imatinib plasma trough concentrations (ima[C]min). In the OPTIM-imatinib trial, we demonstrated that therapeutic drug monitoring (TDM) is able to improve the molecular response of CP-CML patients treated with imatinib. Here, we analyzed the constitutional exomes and RNAseq data of these patients. We performed an association analysis between the constitutional genetic variants of the patients and their ima[C]min, measured after 12 weeks of treatment with 400 mg once daily. Using linear regression, we identified 50 SNPs that showed excess heterozygosity depending on the ima[C]min. Ten SNPs were from non-coding sequences, and among the 40 remaining, 30 (from 25 genes) could be split into two categories. The first group of 16 SNPs concerns genes encoding extracellular matrix, cell junction, and membrane proteins. Coincidentally, cell adhesion proteins were also identified by RNA-seq as being overexpressed in patients with high ima[C]min. The other group of 14 SNPs were from genes encoding proteins involved in transcription/translation. Although most of the SNPs are intronic variants (28), we also identified missense (3), synonymous (4), 5′/3′ (2), splicing (1), and upstream (4) variants. A haplotype analysis of four genes showed a significant association with high ima[C]min. None of the SNPs were significantly associated with the response. In conclusion, we identified a number of ima[C]min-associated SNPs, most of which correspond to genes encoding proteins that could play a role in the diffusion and transit of imatinib through membranes or epithelial barriers.

Asciminib in Patients With CML-CP Previously Treated With ≥ 2 Tyrosine Kinase Inhibitors: 96-Week Results From the Japanese Subgroup Analysis of the ASCEMBL Study

Asciminib is a first-in-class BCR::ABL1 inhibitor that Specifically Targets the ABL1 Myristoyl Pocket (STAMP). It is approved worldwide and in Japan for chronic myeloid leukemia in chronic phase (CML-CP) with resistance or intolerance to previous tyrosine kinase inhibitor (TKI) therapy. In the Phase 3 ASCEMBL study, patients with CML-CP who received ≥ 2 prior ATP-competitive TKIs were randomized (2:1) to asciminib 40 mg twice-daily or bosutinib 500 mg once-daily. Here, we report the 96-week results of the subgroup analysis of Japanese patients (asciminib, n = 13; bosutinib, n = 3) in the ASCEMBL study. The MMR rate at Week 96 was 46.2% in asciminib-treated patients, increasing from Weeks 24 and 48. Patients who achieved MMR at Week 24 remained in MMR up to the Week 96 cutoff. While a high proportion of patients treated with asciminib remained on treatment at cutoff, none randomized to bosutinib were on treatment at Week 96. Despite the longer duration of exposure to asciminib, its safety and tolerability continued to be favorable with no new or worsening safety findings. Overall, the efficacy and safety outcomes in the Japanese subgroup were comparable with the ASCEMBL global study population, which supports the use of asciminib in Japanese patients with previously treated CML-CP.

Early dose reduction of dasatinib does not compromise clinical outcomes in patients with chronic myeloid leukemia: A comparative analysis of two prospective trials

Dasatinib is a potent second-generation tyrosine kinase inhibitor (TKI) used as a first-line treatment option for patients with chronic myeloid leukemia (CML). Currently, dose modification due to adverse events (AEs) is common in patients treated with dasatinib. This study compared the outcomes of two sequential prospective trials that enrolled patients with newly diagnosed chronic phase of CML (CP-CML) and initiated dasatinib at a starting dose of 100 mg daily. In the PCR-DEPTH study, CP-CML patients who started dasatinib 100 mg daily were enrolled and followed up, while in the DAS-CHANGE study, when patients achieved early molecular response with any grade of AEs were enrolled and treated with dasatinib 80 mg once daily. A total of 102 patients (PCR-DEPTH) and 90 patients (DAS-CHANGE) were compared. Although the median value of the relative dose intensity (RDI) of dasatinib was significantly higher in PCR-DEPTH than in DAS-CHANGE (99.6 % vs. 80.1 %, p <0.001), the MMR rate at 12months showed a trend toward superiority in DAS-CHANGE compared to PCR-DEPTH (77.1 % vs 65.2 %, p = 0.084). The frequencies of MR4.0 at 24 and 36 months were higher in DAS-CHANGE than in PCR-DEPTH (44.4 % vs 28.8 %, p = 0.052 and 63.6 % vs 40.3 %, p= 0.013, respectively). RDIs were not different according to the MMR, MR4.0 or MR4.5 in analyses using a pooled population. Our results suggest that early dose reduction of dasatinib does not compromise efficacy in patients achieving EMR at 3 months and could be an interventional strategy for improving long term outcomes.

Pharmacokinetics and safety of asciminib (ASC) in pediatric patients (pts) with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia in chronic phase (CML-CP): Interim results from the ASC4KIDS study.

6562 Background: For pediatric pts with Ph+ CML-CP, treatment options with improved efficacy and long-term safety are needed. ASC is a first-in-class tyrosine kinase inhibitor (TKI) Specifically Targeting the ABL Myristoyl Pocket (STAMP), approved for adults with Ph+ CML-CP treated with ≥2 prior TKIs. The phase Ib/II ASC4KIDS study (NCT04925479) aims to characterize the pharmacokinetics (PK) and long-term safety profile of ASC in pediatric pts. Methods: This multi-center, open-label study included pts aged 1–&lt;18 years (yrs) with Ph+ CML-CP, without T315I mutation, treated with ≥1 prior TKIs. The primary endpoint is to characterize the PK of ASC in pediatric pts and identify a dose using the pediatric formulation (PF, taken with food) leading to an ASC exposure comparable to the adult dose and formulation (AF, 40 mg tablet twice daily [BID] fasted). Secondary endpoints include safety, molecular responses and acceptability/palatability of the pediatric formulation. In an exploratory group, pts 14‒&lt;18 yrs old were treated with the AF (fasted). In study Part 1 (dose-determining cohort), pts received PF at an initial dose of 1.3 mg/kg BID (with food) to assess ASC exposure (measured by area under the curve from dosing to the time of the last measured concentration [AUClast] and maximum plasma concentration [Cmax]) and safety. In Part 2 (dose expansion cohort), additional pts will be treated with the dose confirmed in Part 1 (across Part 1 + Part 2; 10 pts per age group: 1‒&lt;12 yrs and 12‒&lt;18 yrs, for a total of 20 pts). In Part 3, another 10 pts will be enrolled (5 pts per age group), who will receive the same total ASC dose as a once daily regimen. Results: 4 and 9 pts were enrolled in the Part 1 AF and PF groups, respectively. At interim data cutoff (03-Aug-2023), all pts were receiving ongoing treatment. Age ranges were 15‒16 yrs (AF group) and 2‒16 yrs (PF group). Averaged ASC exposure in the AF group was comparable to that observed in adults. 3/4 (75.0%) pts on ASC AF experienced adverse events (AEs); none were Grade ≥3. There were no new safety signals as compared to the known safety profile of ASC in adults. Averaged ASC exposure in the PF group was comparable to that observed in adults (median AUClast: 5051 vs 5130 hr*ng/mL; median Cmax: 711 vs 939 ng/mL, respectively). Based on these data, the PF dose of 1.3 mg/kg BID (with food) was confirmed as the pediatric dose. All pts on ASC PF experienced AEs; Grade ≥3 AEs were reported for 2/9 pts (22.2%). No predefined dose-limiting toxicities, serious AEs, or AEs leading to discontinuation were reported in either group. Conclusions: ASC exposure with the PF (with food) in pediatric pts was comparable to that of adult pts treated with ASC 40 mg BID (fasted); the confirmed PF dose of 1.3 mg/kg BID will continue to be tested in Part 2 of the study. ASC was safe and well tolerated in pediatric pts. Clinical trial information: NCT04925479 .

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

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

Results of ponatinib as frontline therapy for chronic myeloid leukemia in chronic phase.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with robust activity in Philadelphia chromosome-positive leukemias. Herein, we report the long-term follow-up of the phase 2 trial of ponatinib in chronic myeloid leukemia in chronic phase. Patients received ponatinib 30 to 45 mg/day. The primary end point was the rate of 6-month complete cytogenetic response (CCyR). The study was held in June 2014 because of the risk of cardiovascular toxicity, requiring patients to change TKI. Fifty-one patients were treated with ponatinib (median dose, 45 mg/day). Median age was 48 years (range, 21-75); 30 (59%) had baseline cardiovascular comorbidities. Median treatment duration was 13 months (range, 2-25). Fourteen patients (28%) discontinued ponatinib because of toxicities, 36 (71%) after the Food and Drug Administration warning/study closure, and one for noncompliance. Dasatinib was the most frequently chosen second-line TKI (n=34; 66%). Among 46 patients evaluable at 6 months, 44 (96%) achieved CCyR, 37 (80%) major molecular response, 28 (61%) MR4, and 21 (46%) MR4.5. The cumulative 6-month rates of CCyR, major molecular response, MR4, and MR4.5 were 96%, 78%, 50%, and 36%, respectively. Durable MR4 ≥24 or ≥60 months was observed in 67% and 51% of patients, respectively. The 24-month event-free survival rate was 97%. After a median follow-up of 128 months, the 10-year overall survival rate was 90%. Eight patients (16%) had serious grade 2 to 3 cardiovascular adverse events, leading to permanent discontinuation in five (10%). Ponatinib yielded high cytogenetic and molecular responses in newly diagnosed chronic myeloid leukemia in chronic phase. Its use in the frontline setting is hindered by arterio-/vaso-occlusive and other severe toxicities.

Distribution of BCR::ABL1 Transcripts in the Different Clinical Phases of Chronic Myeloid Leukemia: Effect on Hematological Parameters and Patient Survival.

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by the presence of the Philadelphia chromosome, a product of the reciprocal translocation t(9;22)(q34;q11), in the BCR and ABL genes. These rearrangements in both genes lead to the formation of various fusion mRNA products, with preferential expression of b2a2, b3a2, and other BCR::ABL1 mRNA variants, combined with additional chromosomal abnormalities. Notably, the distribution and frequency of different mRNA variants vary in different populations. However, studies concerning this in Mexico are limited, and the results have been inconclusive. This study therefore aimed to determine the distribution of BCR::ABL1 mRNA variants in different clinical phases of CML and their effect on hematological parameters and patient survival. This study included 33 patients, whose demographic, clinical, and molecular data on BCR::ABL1 mRNA variants and hematological parameters were collected to identify potential associations. A total of 84.8% (n = 28) of patients had BCR::ABL1 translocation and increased platelet and basophil counts. The most frequent mRNA variant was b3a2 (64.3%), followed by b2a2 (28.6%) and e1a2 (3.6%). Concerning the clinical phases of CML, 75.8% (n = 25), 21.2% (n = 7), and 3% (n = 1) of patients were in the chronic, blast, and accelerated phases, respectively. Moreover, the b3a2 mRNA variant was more commonly identified in patients in the chronic phase. No correlation was observed between mRNA variant expression and patient survival. However, b2a2 was indicative of patients with longer survival as well as those treated with imatinib or nilotinib. Additionally, platelet count could be a marker of BCR::ABL1 translocation.

Combination of dasatinib and venetoclax in newly diagnosed chronic phase chronic myeloid leukemia.

The dual inhibition of the BCR::ABL1 tyrosine kinase and BCL-2 could potentially deepen the response rates of chronic myeloid leukemia in chronic phase (CML-CP). This study evaluated the safety and efficacy of the combination of dasatinib and venetoclax. In this phase 2 trial, patients with CML-CP or accelerated phase (clonal evolution) received dasatinib 50 mg/day for three courses; venetoclax was added in course 4 for 3 years. The initial venetoclax dose was 200 mg/day continuously but reduced later to 200 mg/day for 14 days, and to 100 mg/day for 7 days per course once a molecular response (MR)4.5 was achieved. After 3 years of combination, patients were maintained on single-agent dasatinib. The primary end point was the rate of major molecular response (MMR) by 12 months of combination. Sixty-five patients were treated. Their median age was 46 years (range, 23-73). By 12 months of combination, the MMR, MR4, and MR4.5 rates were 86%, 53%, and 45%, respectively. After a median follow-up of 42 months, the 4-year event-free and overall survival rates were 96% and 100%, respectively. Outcomes with the combination were comparable to historical outcomes with single-agent dasatinib (cumulative 12-months MMR rate of 79% with both strategies). The incidence of grade 3-4 neutropenia was 22% with the combination and 11% with single-agent dasatinib (p<.001). Treatment with dasatinib and venetoclax was safe and effective in CML-CP. The cumulative response rates with the combination were similar to those with single-agent dasatinib. Further follow-up is needed to evaluate the rates of durable deep molecular response and treatment-free remission.

Impact of MDR-1 Gene Polymorphism (rs1128503) on Response to Imatinib or Nilotinib in Iraqi Patients with Chronic Myeloid Leukemia: An Observational Study

Background: There is a significant molecular response to imatinib given at standard doses in individuals with chronic myeloid leukemia (CML) whose ABCB1 polymorphisms are present. Objective: To investigate the impact of the polymorphism in the ABCB1 gene rs1128503 on the effectiveness of nilotinib or imatinib therapy. Methods: From May 2022 until the end of January 2023, the current study was carried out in a single research institution, the National Center of Hematology, Baghdad Teaching Hospital at Medical City, Iraq. 76 people with chronic phase myeloid leukemia (CML-CP), who had previously received a diagnosis using the European Leukemia Net (ELN) criteria, enrolled in the trial. The PCR product was delivered to Macrogen Corporation, Korea, for Sanger sequencing on an automated DNA sequencer, the ABI3730XL. After receiving the results by email, Geneious Prime software was used for analysis. Results: Patients receiving imatinib or nilotinib did not differ significantly in terms of age or gender. In contrast, BCR-ABL1 transcript levels were considerably greater at sampling in patients receiving nilotinib. Different types of the MDR-1 gene rs1128503 genotype were not found in groups that were treated with either imatinib or nilotinib. Conclusions: BCR-ABL1 transcript levels are lower in patients still receiving imatinib than in those receiving nilotinib.

Long-term outcomes after upfront second-generation tyrosine kinase inhibitors for chronic myeloid leukemia: managing intolerance and resistance

Second-generation tyrosine kinase inhibitors (2GTKI) are more effective in inducing rapid molecular responses than imatinib when used first-line in patients with chronic myeloid leukemia in chronic phase (CML-CP). However, failure of first line-2GTKI (1L-2GTKI) still occurs and there is no consensus regarding subsequent management. We retrospectively analyzed the outcome of 106 CML-CP patients treated with 1L-2GTKI and with a median follow-up of 91 months. 45 patients (42.4%) switched to an alternative TKI, 28 for intolerance (26.4%) and 17 (16%) for resistance. Most patients who remained on 1L-2GTKI achieved deep molecular responses (DMR) and 15 (14.1%) are in treatment-free remission (TFR). Intolerant patients also obtained DMR, although most required multiple TKI changes and were slower to respond, particularly if treated with 2L-imatinib. Inferior outcomes were observed in resistant patients, who failed alternative 2L-2GTKI and required 3/4GTKI and/or allogeneic hematopoietic stem cell transplant (alloSCT). 7yr-OS was significantly lower for these individuals (66.1%) than for intolerant patients and those who remained on 1L-2GTKI (100% and 97.9%, respectively; p = 0.001). It is apparent that failure of 1L-2GTKI is a challenging problem in modern CML therapy. Intolerance can be effectively managed by switching to an alternative 2GTKI, but resistance requires early consideration of 3/4GTKI.

Real-World Efficacy and Safety of China-Made Flumatinib Mesylate in the Treatment of Chronic Myeloid Leukemia in Chronic Phase

To evaluate the efficacy and safty of China-made flumatinib mesylate in the treatment of chronic myeloid leukemia in chronic phase (CML-CP). 42 CML-CP patients treated with Chinese produced flumatinib (oral, 600 mg, 1/d) were included in the study, including 14 newly diagnosed patients and 28 patients underwent conversion therapy. The hematological, cytogenetic and molecular response and safety were observed and evaluated after 3, 6 and 12 months of treatment. 35 patients were treated for more than 3 months, among which 31 patients were treated for more than 6 months and 17 patients were treated for more than 12 months. After 3 months of treatment, 33 patients underwent hematological, cytogenetic and molecular examination. Of these, 32 patients achieved complete hematological response (CHR), 13 patients achieved complete cytogenetic response (CCyR), 20 patients showed BCR-ABLIS≤10% and 7 patients reached major molecular response (MMR). After 6 months of treatment, all 30 patients who could evaluate efficacy achieved CHR, of which 17 patients achieved CCyR, 18 patients showed BCR-ABLIS≤1% and 16 patients reached MMR. After 12 months of treatment, all 17 patients were evaluated for efficacy, all achieved CHR, 10 patients obtained CCyR, 7 patients reached MMR. Grade III or IV thrombocytopenia, leukopenia and anemia occurred in 7, 2 and 1 patients, respectively. The non-hematological adverse reactions were diarrhea in 6 cases, renal function damage in 4 cases, rash and pruritus in 3 cases, liver function damage in 3 cases, nausea in 1 case, fever in 1 case, bone/joint or muscle pain in 1 case. In the real world, China-made flumatinib mesylate has a positive short-term efficacy and reliable safety in the treatment of CML-CP patients, whether as first-line treatment or second- and third-line conversion therapy.

Clinical Efficacy and Safety of Flumatinib in the Treatment of Patients with Newly Diagnosed Chronic Myeloid Leukemia in Chronic Phase

To explore the clinical efficacy and safety of flumatinib mesylate produced in China in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP). 32 newly diagnosed CML-CP patients admitted to the Hematology Department of the Affiliated Hospital of Southwest Medical University from March 1, 2020 to March 31, 2022, who had never received any tyrosine kinase inhibitor (TKI) were included in the study. The patients were treated by flumatinib mesylate 600mg once daily. The hematologic, cytogenetic and molecular responses were assessed at 3-, 6- and 12-month, and adverse effects of the drug were evaluated. 31 patients were treated with flumatinib for≥3 months, of which 24 patients were treated for ≥6 months and 14 patients were treated for≥12 months. At 3rd month of treatment, 30 out of 31 patients achieved complete hematologic response (CHR); 24 patients underwent cytogenetic testing and 22 cases achieved major cytogenetic response(MCyR), of which 21 cases achieved complete cytogenetic response (CCyR); Among 25 patients who underwent molecular testing, 22 patients had BCR-ABLIS≤10%, including 10 patients with BCR-ABLIS≤0.1%, and 6 patients with BCR-ABLIS≤0.01%. At 6th month of treatment, 23 out of 24 patients achieved CHR; 17 patients underwent cytogenetic testing and all achieved CCyR; Among 23 patients who underwent molecular testing, 20 patients had BCR-ABLIS≤1%, including 16 patients with BCR-ABLIS≤0.1% and 12 patients with BCR-ABLIS≤0.01%. At 12nd month of treatment, all 14 patients achieved CHR and CCyR; Among them, 10 patients had BCR-ABLIS≤0.1%, including 9 patients with BCR-ABLIS≤0.01%. The grade Ⅲ/Ⅳ leukopenia, thrombocytopenia and anemia rates in the patients were 13.3%, 20.0% and 3.3%, respectively. One patient stopped flumatinib therapy due to severe and persistent hematologic toxicity. The major non-hematologic adverse events were abnormal liver function (20%), diarrhea (10%), bone/joint pain (10%), muscle spasm (10%), rash (6.7%), acute kidney injury (6.7%) and nausea(3.3%), most of which were grade I-II. No patient experienced grade Ⅳ non-hematologic adverse events. No drug toxicity-related death occurred. Flumatinib mesglate, as the first-line treatment for newly diagnosed CML-CP, can enable the patients to achieve early and deep molecular and cytogenetic responses, and shows good safety.

Navigating the Management of Chronic Phase CML in the Era of Generic BCR::ABL1 Tyrosine Kinase Inhibitors.

Over the past several years, advances in research, treatment, and market dynamics have impacted treatment strategies in chronic myeloid leukemia in chronic phase (CML-CP). They include the broader availability of cost-effective generic imatinib, and soon other generic second-generation tyrosine kinase inhibitors (TKIs). Access to affordable generics means that all patients with CML-CP should have access to safe and highly effective lifelong therapies. When overall survival is the treatment endpoint, imatinib provides a good treatment value. Second-generation TKIs may be the best frontline strategy when treatment-free remission is the goal. Recent studies have shown maintained efficacy and reduced toxicity when TKIs are used at reduced dosing. Reduced-dose schedules of second-generation TKIs (which are less toxic and induce faster deep molecular responses) may render generic second-generation TKIs a more attractive treatment option. Adjusting the dose of TKI in the presence of mild-to-moderate, or even severe but reversible, adverse events may be preferable to switching to a different TKI. The selection of second-line and beyond therapies depends on the evolving patterns observed with frontline treatment. Dose-adjusted ponatinib schedules have demonstrated improved efficacy and safety in patients resistant to second-generation TKIs or those with T315I-mutated disease. For asciminib, longer-term follow-up is needed to better evaluate its safety and efficacy compared with ponatinib. Allogeneic stem cell transplantation represents a valid alternative to newer-generation TKIs, with a better treatment value when TKIs are priced at >$40,000/year.

Beyond BCR::ABL1-The Role of Genomic Analyses in the Management of CML.

Chronic myeloid leukemia (CML) is a model of genomically based diagnosis and management where BCR::ABL1 is successfully targeted by tyrosine kinase inhibitor (TKI) therapy in most patients. The dynamics of BCR::ABL1 transcript decline during therapy is a dependable biomarker of response, relapse, and drug resistance. Missense mutations acquired within the BCR::ABL1 kinase domain that disrupt TKI binding can evolve during therapy and are frequently detected in patients for whom TKI treatment fails. Importantly, specific BCR::ABL1 missense mutations are targetable alterations and direct therapeutic decisions based on the individual mutant TKI sensitivity profile. Nevertheless, BCR::ABL1 mutations are only implicated in approximately half of the cases of acquired resistance. Furthermore, not all patients with a single BCR::ABL1 mutation that is predicted to be sensitive to a specific TKI will experience a response when switched to that TKI. Progression to blast phase heralds independence from BCR::ABL1, and this phase of the disease is notoriously difficult to treat. The independent drivers of resistance and disease progression have long been investigated to both predict progression and to find targets for therapeutic intervention. Recent data reaffirm that drug resistance and disease progression is a mutation-driven process in CML, and somatic variants in genes that are known to drive acute myeloid and lymphoid leukemia have been detected in patients in the advanced phases of CML. Genomic testing over the last few decades for patients with blood cancer has revealed of variety of genomic aberrations that drive disease. Consequently, incorporation of genomic factors into patient management for a range of blood cancers has led to the implementation of high-throughput gene testing to detect clinically actionable variants. Is it time to integrate broader genomic screening into clinical management strategies for patients with CML?

Myeloid Sarcoma Masquerading as a Breast Lump: A Unique Presentation of Chronic Myeloid Leukaemia in Chronic Phase

Myeloid Sarcoma Masquerading as a Breast Lump: A Unique Presentation of Chronic Myeloid Leukaemia in Chronic Phase

Molecular Pathogenesis and Treatment Strategies of Chronic Myeloid Leukemia (CML)

Chronic Myeloid Leukemia (CML) is a myeloproliferative disease diagnosed in bone marrow, arising from a chromosomal translocation between chromosomes 9 and 22, resulting in the formation of fusion oncogene BCR–ABL. The product of this fusion oncogene is a new oncoprotein bcr–abl which possesses abnormal tyrosine kinase activity. In response to this, abnormal signaling pathway activation occurs, leading to cell transformation. BCR–ABL oncogene could be targeted by tyrosine kinase inhibitors (TKIs) to delay or inhibit the disease progression. Imatinib is the first drug designed against CML but resistance to this has led to the development of the second- and third generations of inhibitors that are active against many types of BCR–ABL gene mutations. However, somehow, due to disease progression, TKIs do not remain as effective. There are three well-characterized phases of CML: The chronic phase (CP), the accelerated phase, and the terminal stage which is the blast crisis (BC) stage. In the CP of CML, mature granulocytes and myeloid precursors become aggregated majorly in the bone marrow and peripheral blood. The accelerated phase is marked by increased disease severity and an increase in progenitor/precursor cell number. In the BC stage, undifferentiated blast cells grow in number. Many patients with CML are diagnosed during the CP of the disease, so the survival rate of CML is high. However, 20% of CML patients proceed to advanced stages that result in drug resistance, intolerance, and mortality. So, for proper CML treatment, drugs are needed to target multiple BCR– ABL mutations, delay or stop disease progression, and overcome resistance caused by BCR–ABL independent mechanisms, especially during advanced phases of CML. Moreover, drugs could be developed to eradicate the stem cells of CML. These targets could be achieved by understanding mechanisms of disease progression, disease relapse, and drug resistance by utilizing high throughput molecular genetics, cell biology and immunology techniques.

Unusual presentation of extramedullary blast crisis in chronic myeloid leukemia: A case report

BACKGROUND Extramedullary blast crisis in chronic myeloid leukemia (CML) is an uncommon occurrence of leukemic blast infiltration in regions other than the bone marrow. Malignant infiltration of the serosal membranes should be considered in cases where CML presents with ascites or pleural effusion. CASE SUMMARY A 23-year-old female with CML presented with progressively worsening ascites and pleural effusion despite first-line tyrosine kinase inhibitor treatment. Her blood work indicated leukocytosis with myelocyte bulge and 2% blasts. Analysis of the patient’s bone marrow confirmed the chronic phase of CML. Abdominal ultrasound revealed hepatosplenomegaly with ascites. The fluid investigation of both ascites and pleural effusion revealed a predominance of neutrophils with exudate. However, no acid-fast bacilli or growth was observed after culturing. Although hydroxyurea reduced cell counts, there was no observed effect on ascites or pleural effusion. Repeat investigation of the ascitic and pleural fluid revealed a polymorphous myeloid cell population consisting of myelocytes, metamyelocytes, band forms, neutrophils and a few myeloblasts. Extramedullary blast crisis was suspected, and mutation analysis was performed. We switched the patient to dasatinib. The patient’s symptoms were relieved, and ascites and pleural effusion diminished. CONCLUSION Serosal membrane involvement in CML is extremely rare. In this case, the patient responded well to dasatinib treatment.

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.

Pain Management in Blast Crisis Phase of Chronic Myeloid Leukemia: A Case Report

Background: Chronic myeloid leukemia (CML) is a slow-growing type of cancer that begins in the bone marrow's blood-forming cells and is caused by a chromosomal mutation that is assumed to develop spontaneously. As CML advances into the rapid or blast phase, it can cause significant pain. This study aimed to describe pain management in the blast crisis (BC) phase of CML.&#x0D; Case presentation: A 48-year-old female diagnosed with CML in the BC phase complained of severe pain in the head, shoulders, back, and tailbone area with a numeric rating scale (NRS) of 9/10. The patient received multimodal analgesic therapy with continuous IV fentanyl at a rate of 0.25 mcg/kg/hour and ketamine at 1.3 mcg/kg/minute for 24 hours. The dosage was gradually increased through titration with a target NRS of 4/10. On the fifth day, we replaced fentanyl with morphine at 0.04 mg/kg/hour and ketamine at 1.3 mcg/kg/minute, and we reduced the titration dose according to the patient’s NRS, and her pain was controlled with NRS 3-4/10 after 7 days of treatment. On the 9th day, she was discharged with oral therapy.&#x0D; Conclusion: Multimodal analgesia has been shown to effectively reduce the intensity of the pain in blast crisis phase.