Second-generation Tyrosine Kinase Inhibitors Research Articles

Outcome of 3q26.2/MECOM rearrangements in chronic myeloid leukemia.

To evaluate the outcomes of patients with 3q26.2/MECOM-rearranged chronic myeloid leukemia (CML). We reviewed consecutive adult patients with 3q26.2/MECOM-rearranged CML between January 1, 1998 and February 16, 2023. Rearrangements of 3q26.2/MECOM were confirmed by conventional cytogenetics, and fluorescence in situ hybridization starting in 2015. We identified 55 patients with MECOM-rearranged CML, including 23 in chronic phase (CP) or accelerated phase (AP) and 32 in blast phase (BP). Nine patients (16%) achieved a major cytogenetic response (MCyR) or deeper. At a median follow-up of 89months, median survival was 14months. The 5-year survival rate was 19% overall, 23% in CML-CP/AP, and 15% in CML-BP. In the 6-month landmark analysis, the 5-year survival rate was 41% for allogeneic stem cell transplantation (allo-SCT) recipients versus 17% for non-recipients (P = 0.050). Multivariate analysis showed that the percentage of marrow blasts and achievement of MCyR or deeper could predict survival. Outcomes of 3q26.2/MECOM-rearranged CML are poor despite the availability of multiple BCR::ABL1 tyrosine kinase inhibitors (TKIs). Third-generation TKIs in combination with novel agents and possible allo-SCT could be considered given the poor outcomes and resistance to second-generation TKIs.

CLINICAL FACTORS PREDECTING T790M MUTATION IN NON-SMALL CELL LUNG CANCER PROGRESSED AFTER FIRST- AND SECOND-GENERATION TKI TREATMENT

Objective: We aimed to identify the T790M mutation rate and clinical factors predicting the occurrence of acquired T790M mutations in advanced non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations after first- and second-generation tyrosine kinase inhibitor (TKI) treatment. Method: The EGFR-mutant NSCLC patients who experienced progression after first- and second-generation TKI treatment and underwent testing for EGFR using plasma samples between January 2021 and April 2023 were enrolled. The T90M mutation rate and related clinical factors were evaluated. We utilized the Chi-square test or Fisher’s exact test for univariate analysis and multivariable logistic binary regression for multivariate analysis. Results: A total of 247 patients were eligible for the study. Patients harbored the exon 19 deletion mutation (Del19), exon 21 L858R point mutation, and uncommon mutations in 63.2%, 34.4%, and 2.4% of cases, respectively. The overall T790M mutation rate was 33.6%. In multivariate analyses, the Del19 mutation versus L858R mutation, duration of first-line TKI exceeding 12 months versus below 12 months, and solitary lesion progression versus multiple lesion progression were identified as favorable prognostic factors for the occurrence of T790M mutation. Conclusion: Patients with EGFR exon 19 deletion, a prolonged treatment duration of first-line EGFR-TKI, and solitary lesion progression pattern are more likely to acquire the T790M mutation, as detected by the PCR method in plasma samples.

Ponatinib-review of historical development, current status, and future research.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

A physiologically-based pharmacokinetic precision dosing approach to manage dasatinib drug-drug interactions.

Dasatinib, a second-generation tyrosine kinase inhibitor, is approved for treating chronic myeloid and acute lymphoblastic leukemia. As a sensitive cytochrome P450 (CYP) 3A4 substrate and weak base with strong pH-sensitive solubility, dasatinib is susceptible to enzyme-mediated drug-drug interactions (DDIs) with CYP3A4 perpetrators and pH-dependent DDIs with acid-reducing agents. This work aimed to develop a whole-body physiologically-based pharmacokinetic (PBPK) model of dasatinib to describe and predict enzyme-mediated and pH-dependent DDIs, to evaluate the impact of strong and moderate CYP3A4 inhibitors and inducers on dasatinib exposure and to support optimized dasatinib dosing. Overall, 63 plasma profiles from perorally administered dasatinib in healthy volunteers and cancer patients were used for model development. The model accurately described and predicted plasma profiles with geometric mean fold errors (GMFEs) for area under the concentration-time curve from the first to the last timepoint of measurement (AUClast) and maximum plasma concentration (Cmax) of 1.27 and 1.29, respectively. Regarding the DDI studies used for model development, all (8/8) predicted AUClast and Cmax ratios were within twofold of observed ratios. Application of the PBPK model for dose adaptations within various DDIs revealed dasatinib dose reductions of 50%-80% for strong and 0%-70% for moderate CYP3A4 inhibitors and a 2.3-3.1-fold increase of the daily dasatinib dose for CYP3A4 inducers to match the exposure of dasatinib administered alone. The developed model can be further employed to personalize dasatinib therapy, thereby help coping with clinical challenges resulting from DDIs and patient-related factors, such as elevated gastric pH.

Changes in chronic myeloid leukemia treatment modalities and outcomes after introduction of second-generation tyrosine kinase inhibitors as first-line therapy: a multi-institutional retrospective study by the CML Cooperative Study Group.

This study investigated changes in treatment modalities and outcomes of chronic myeloid leukemia in the chronic phase (CP-CML) after the approval of second-generation tyrosine kinase inhibitors (2G-TKIs) for first-line therapy. Patients were grouped into those who underwent TKI therapy up to December 2010 (imatinib era group, n=185) and after January 2011 (2G-TKI era group, n=425). All patients in the imatinib era group were initially treated with imatinib, whereas patients in the 2G-TKI era group were mostly treated with dasatinib (55%) or nilotinib (36%). However, outcomes including progression-free survival, overall survival, and CML-related death (CRD) did not differ significantly between groups. When stratified by risk scores, the prognostic performance of the ELTS score was superior to that of the Sokal score. Even though both scoring systems predicted CRD in the imatinib era, only the ELTS score predicted CRD in the 2G-TKI era. Notably, the outcome of patients classified as high-risk by ELTS score was more favorable in the 2G-TKI era group than in the imatinib era group. Thus, expanding treatment options may have improved patient outcomes in CP-CML, particularly in patients classified as high-risk by ELTS score.

[The Effect and Safety of Flumatinib in Patients with Chronic Myelogenous Leukemia Failed First-and Second-line Treatment].

To analyze the efficacy and safety of flumatinib, a second-generation tyrosine kinase inhibitor (TKI) independently developed in China, in patients with chronic myelogenous leukemia in chronic phase (CML-CP) who falied first-line and second-line treatment. The clinical data of 30 CML-CP patients treated with flumatinib in Lianyungang First People's Hospital from January 2020 to September 2022 were collected retrospectively. Among them, 15 patients who received imatinib first-line treatment but failed treatment were included in the second-line group, and the other 15 patients who failed second-line treatment with nilotinib or dasatinib were included in the third-line group. The hematological and molecular responses of the patients in the two groups at 3, 6 and 12 months of treatment, and the event-free survival (EFS) and adverse reactions of patients at the end of follow-up were statistical analyzed. At 3, 6, and 12 months of treatment, 10, 11, and 12 patients in the second line group achieved major molecular response (MMR), which was higher than that of 3, 4, and 5 patients in the third line group (P =0.010, P =0.011, P =0.010). At 3 months of treatment, 12 and 13 patients achieved complete hematological response (CHR) and early molecular response (EMR) in the second-line group, which was higher than that of 9 and 13 patients in the third-line group, but the difference between the two groups was not statistically significant (P =0.232, P =1.000); At 6 and 12 months of treatment, 6 and 7 patients in the second-line group achieved MR4.5, which were higher than of 3 and 2 cases in the third-line group, but the difference was not statistically significant (P =0.427, P =0.713). The hematological adverse reactions of patients in the second-line group during treatment the period were mainly grade 1-2 thrombocytopenia and anemia, and no grade 3-4 of adverse reactions occurred. In the third-line group, there were 2 cases of grade 1-2 thrombocytopenia, grade 1-2 anemia and white blood cell 3 cases were reduced each, 1 case of grade 3-4 anemia, 2 cases of grade 3-4 neutropenia. The non-hematological adverse reactions in the second-line group were rash (2 cases), headache (1 case), diarrhea (1 case), fatigue (1 case), limb pain (1 case). There were 1 cases of diarrhea, 1 cases of nausea, and 1 cases of edema in the third-line group. There was no statistical significance in hematological and non-hematological adverse reactions between the two groups of patients (P >0.05). At the end of follow-up, the EFS rate of patients in the second-line group was higher than that in the third-line group (100% vs 93.3%), but the difference was not statistically significant (P =0.317). The second-generation TKI flumatinib independently developed in China, has good curative effect and safety for CML-CP patients who failed first-line and second-line treatment.

Exploring the enhanced stability and therapeutic efficacy of Sorafenib-Cyclodextrin inclusion complex

Sorafenib (Soraf) is a second-generation tyrosine kinase inhibitor repurposed against different cancers by working on various molecular pathways, playing a vital role in cancer cell proliferation. Sorafenib is a BCS class II drug, and its low solubility further hinders its bioavailability and results in reduced therapeutic efficacy. Therefore, in this study, we aim to explore the potential of β-cyclodextrins (β-CD) derivatives to form an inclusion complex with sorafenib to enhance sorafenib's solubility, stability, and therapeutic efficacy. Our findings suggest that HP-β-CD portrayed a higher affinity towards sorafenib than SBE-β-CD and significantly improved the solubility of sorafenib. Additionally, spectroscopic analysis and solid-state studies provided valuable information regarding the intermolecular interaction between sorafenib and HP-β-CD.Furthermore, the stability of sorafenib in biological fluids and under physiological conditions was maintained under the influence of the inclusion complex, whereas plain sorafenib degraded quickly. In addition, β-CD complexation significantly improved sorafenib's intestinal permeability, as shown in physiologically relevant EpiIntestinal® models. Lastly, the sorafenib inclusion complex demonstrated increased cytotoxicity in NSCLC and HCC cell lines. This study shows the potential of HP-β-CD to improve the solubility and therapeutic efficacy of sorafenib, thus extending its clinical application.

In vitro investigation of the binding characteristics of dacomitinib to human α 1-acid glycoprotein: Multispectral and computational modeling

Dacomitinib is a highly selective second-generation tyrosine kinase inhibitor that can irreversibly bind to tyrosine kinase and is mainly used in the treatment of lung cancer. The binding characteristics of dacomitinib with human α 1-acid glycoprotein (HAG) were analyzed by multispectral and computational simulation techniques. The fluorescence spectra showed that dacomitinib can quench the fluorescence of HAG by forming the HAG-dacomitinib complex with a molar ratio of 1:1 (static quenching). At the temperature similar to that of the human body, the affinity of dacomitinib to HAG (8.95 × 106 M−1) was much greater than that to BSA (3.39 × 104 M−1), indicating that dacomitinib will give priority to binding onto HAG. Thermodynamics parameters analysis and driving force competition experiments showed that hydrogen bonding and hydrophobic forces were the major sources for keeping the complex of HAG-dacomitinib stable. The experimental outcomes also showed that the binding of dacomitinib can lead to the loosening of the skeleton structure of HAG, which led to a slight change in the secondary structure, and also reduces the hydrophobicity of the microenvironment of Trp and Tyr residues. The binding sites of dacomitinib on HAG and the contribution of key amino acid residues to the binding reaction were determined by molecular docking and molecular dynamics (MD) simulation. In addition, it was found that there was a synergistic effect between dacomitinib and Mg2+ and Co2+ ions. Mg2+ and Co2+ could increase the Kb of dacomitinib to HAG and prolong the half-life of dacomitinib.

A Radiomics-clinical Nomogram based on CT Radiomics to Predict Acquired T790M Mutation Status in Non-small Cell Lung Cancer Patients.

To develop and validate a radiomics-clinical nomogram for the detection of the acquired T790M mutation in patients with advanced non-small cell lung cancer (NSCLC) with resistance after the duration of first-line epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment. Thoracic CT was collected from 120 advanced NSCLC patients who suffered progression on first- or second-generation TKIs. Radiomics signatures were retrieved from the entire tumor. Pearson correlation and the least absolute shrinkage and selection operator (LASSO) regression method were adopted to choose the most suitable radiomics features. Clinical and radiological factors were assessed using univariate and multivariate analysis. Three Machine Learning (ML) models were constructed according to three classifiers, including Logistic Regression (LR), Support Vector Machine (SVM), and RandomForest (RF), combining clinical and radiomic features. A nomogram combining clinical features and the rad score signature was built. The predictive ability of the nomogram was assessed by the ROC curve, calibration curve, and decision curve analysis (DCA). Multivariate regression analysis showed that two clinicopathological characteristics and two radiological features were highly correlated with the acquired T790M mutation, including the progression-free survival (PFS) of first-line EGFR TKIs (P = 0.029), the initial EGFR profile (P = 0.01), vascular convergence (P = 0.043), and air bronchogram (P = 0.030). The AUCs of clinical, radiomics, and combined models using RF classifiers for T790M mutation detection were 0.951 (95% confidence interval [CI] 0.911,0.991), 0.917 (95%CI 0.856,0.978), and 0.961 (95%CI 0.927,0.995) in the training cohort, respectively, higher than those of other classifier models.The calibration curve and Hosmer-Lemeshow Test showed good calibration power, and the DCA demonstrated a significant net benefit. A radiomics-clinical nomogram based on CT radiomics proved valuable in non-invasively and efficiently predicting the acquired T790M mutation in patients who suffered progression on first-line TKIs.

Nilotinib Exerts a Therapeutic Approach via JAK/STAT Pathway and Cytokine Network in Chronic Myeloid Leukemia Cells

Aim: Chronic myeloid leukemia (CML) displays a constitutive tyrosine kinase (TK) activity which in turn leads to the activation of various signaling pathways and the outcome of leukemic phenotype. Activated STAT5A and STAT5B from JAK/STAT pathway induce cell growth, proliferation, differentiation, and survival of leukemic cells which are promoted by a cytokine network. Since the second-generation tyrosine kinase inhibitor nilotinib has the advantage of inhibiting this oncogenic TK activity; we aimed to investigate the underlying mechanism of its therapeutic approach and how it induced apoptosis via analyzing the forthcoming molecular targets of the pathway. 
 Methods: By Nilotinib treatments, cell viability and proliferation assays, apoptotic analysis, expressional regulations of STAT5A&5B mRNA transcripts, protein expression levels, and also cytokines’ expressional assessments were determined in CML model K562 cells, in vitro.
 Results: Nilotinib treatment in a time and dose-dependent manner assessed a therapeutic approach by decreasing leukemic cell proliferation and survival; inducing leukemic cell apoptosis, down-regulating STAT5A&5B mRNA, and protein expression levels, and regulating cytokine expressional network. 
 Conclusion: Nilotinib-mediated therapeutics could be dependent on targeting JAK/STAT pathway members STAT5A and STAT5B, besides; regulating the cytokine network might be another underlying mechanism for sensitization and response of K562 cells to nilotinib in leukemia pathogenesis.

Treatment status of tyrosine kinase inhibitor for newly-diagnosed chronic myeloid leukemia: a domestic multi-centre retrospective real-world study

Objective: To retrospectively analyze the treatment status of tyrosine kinase inhibitors (TKI) in newly diagnosed patients with chronic myeloid leukemia (CML) in China. Methods: Data of chronic phase (CP) and accelerated phase (AP) CML patients diagnosed from January 2006 to December 2022 from 77 centers, ≥18 years old, and receiving initial imatinib, nilotinib, dasatinib or flumatinib-therapy within 6 months after diagnosis in China with complete data were retrospectively interrogated. The choice of initial TKI, current TKI medications, treatment switch and reasons, treatment responses and outcomes as well as the variables associated with them were analyzed. Results: 6 893 patients in CP (n=6 453, 93.6%) or AP (n=440, 6.4%) receiving initial imatinib (n=4 906, 71.2%), nilotinib (n=1 157, 16.8%), dasatinib (n=298, 4.3%) or flumatinib (n=532, 7.2%) -therapy. With the median follow-up of 43 (IQR 22-75) months, 1 581 (22.9%) patients switched TKI due to resistance (n=1 055, 15.3%), intolerance (n=248, 3.6%), pursuit of better efficacy (n=168, 2.4%), economic or other reasons (n=110, 1.6%). The frequency of switching TKI in AP patients was significantly-higher than that in CP patients (44.1% vs 21.5%, P<0.001), and more AP patients switched TKI due to resistance than CP patients (75.3% vs 66.1%, P=0.011). Multi-variable analyses showed that male, lower HGB concentration and ELTS intermediate/high-risk cohort were associated with lower cytogenetic and molecular responses rate and poor outcomes in CP patients; higher WBC count and initial the second-generation TKI treatment, the higher response rates; Ph(+) ACA at diagnosis, poor PFS. However, Sokal intermediate/high-risk cohort was only significantly-associated with lower CCyR and MMR rates and the poor PFS. Lower HGB concentration and larger spleen size were significantly-associated with the lower cytogenetic and molecular response rates in AP patients; initial the second-generation TKI treatment, the higher treatment response rates; lower PLT count, higher blasts and Ph(+) ACA, poorer TFS; Ph(+) ACA, poorer OS. Conclusion: At present, the vast majority of newly-diagnosed CML-CP or AP patients could benefit from TKI treatment in the long term with the good treatment responses and survival outcomes.

Mutations in myeloid transcription factors and activated signaling genes predict chronic myeloid leukemia outcomes

AbstractAdvancements in genomics are transforming the clinical management of chronic myeloid leukemia (CML) toward precision medicine. The impact of somatic mutations on treatment outcomes is still under debate. We studied the association of somatic mutations in epigenetic modifier genes and activated signaling/myeloid transcription factors (AS/MTFs) with disease progression and treatment failure in patients with CML after tyrosine kinase inhibitor (TKI) therapy. A total of 394 CML samples were sequenced, including 254 samples collected at initial diagnosis and 140 samples taken during follow-up. Single-molecule molecular inversion probe (smMIP)–based next-generation sequencing (NGS) was conducted targeting recurrently mutated loci in 40 genes, with a limit of detection of 0.2%. Seventy mutations were detected in 57 diagnostic samples (22.4%), whereas 64 mutations were detected in 39 of the follow-up samples (27.9%). Carrying any mutation at initial diagnosis was associated with worse outcomes after TKI therapy, particularly in AS/MTF genes. Patients having these mutations at initial diagnosis and treated with imatinib showed higher risks of treatment failure (hazard ratio, 2.53; 95% confidence interval, 1.13-5.66; P = .0239). The adverse prognostic impact of the mutations was not clear for patients treated with second-generation TKIs. The multivariate analysis affirmed that mutations in AS/MTF genes independently serve as adverse prognostic factors for molecular response, failure-free survival, and progression risk. Additionally, there was an observable nonsignificant trend indicating a heightened risk of progression to advanced disease and worse overall survival. In conclusion, mutations in the AS/MTF genes using smMIP-based NGS can help identify patients with a potential risk of both treatment failure and progression and may help upfront TKI selection.

Synthesis of Novel Nilotinib Analogues and Biological Evaluation of Their Antiplatelet Activity and Functionality towards Cancer Cell Proliferation In Vitro.

Nilotinib, a second-generation tyrosine kinase inhibitor for the treatment of chronic myelogenous leukemia (CML), inhibits Bcr-Abl tyrosine kinase activity and proliferation of Bcr-Abl-expressing cells, as well as other malignancies. In the present study, new nilotinib analogues were synthesized and fully characterized. A platelet aggregation assay was performed, and the expression of P-selectin and PAC-1, as well as the effect on the proliferation of healthy endothelial cells, were evaluated. The expression and antimetastatic effects of E-cadherin and N-cadherin were assessed. The analogues inhibited platelet aggregation in a statistically significant manner compared to nilotinib, while they exhibited a strong inhibitory effect on P-selectin and PAC-1 expression when activated by AA. All three analogues caused arrest in the mitosis phase of the HepG2 cell cycle, while analogue-1 exhibited the most potent apoptotic effect compared to nilotinib. Interestingly, none of them promoted apoptosis in HUVECs. All the analogues reduced the expression of E- and N-cadherin in different amounts, while the analogues-1 and -3 exhibited similar antimigratory effects on HepG2 cells. The results of this study reveal considerable potential to develop new tyrosine kinase inhibitors with improved antiplatelet and antitumor properties.

Efficacy of Definitive Radiotherapy for Patients with Clinical Stage IIIB or IIIC Lung Adenocarcinoma and Epidermal Growth Factor Receptor (EGFR) Mutations Treated Using First- or Second-Generation EGFR Tyrosine Kinase Inhibitors.

The effectiveness of definitive radiotherapy (RT) for patients with clinical stage IIIB or IIIC lung adenocarcinoma and epidermal growth factor receptor (EGFR) mutations who received first- or second-generation EGFR tyrosine kinase inhibitors (TKIs) is unclear. Taiwan Cancer Registry data were used in this retrospective cohort study to identify adult patients diagnosed with EGFR-mutated stage IIIB or IIIC lung adenocarcinoma between 2011 and 2020. Patients treated with first- or second-generation EGFR TKIs were classified into RT and non-RT groups. Propensity score (PS) weighting was applied to balance covariates between groups. The primary outcome was overall survival (OS), and the incidence of lung cancer mortality (ILCM) was considered as a supplementary outcome. Additional supplementary analyses were conducted to assess the robustness of the findings. Among 270 eligible patients, 41 received RT and 229 did not. After a median follow-up of 46 months, PS-weighted analysis showed the PS-weighted hazard ratio of death for the RT group compared to the non-RT group was 0.94 (95% CI: 0.61-1.45, p = 0.78). ILCM rates did not differ significantly between the two groups. Supplementary analyses yielded consistent results. The addition of definitive RT to first- or second-generation EGFR TKI treatment does not significantly improve OS of patients with EGFR-mutated stage IIIB or IIIC lung adenocarcinoma. NCT03521154NCT05167851.

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.

Case Report: Granulocytic Sarcoma of the Parotid in Chronic Myeloid Leukemia: A Case Report and Literature review

Granulocytic sarcomas are infrequent, extramedullary malignant occurrences, generally seen with or secondary to acute myeloid leukemia (AML). Their association with chronic myeloid leukemia (CML) is rare and their appearance in parotid gland is sparsely reported in the literature, as per our literature search. In this report, we present an unusual and rare case of imatinib resistant BCR-ABL1 positive secondary granulocytic sarcoma to CML in chronic phase. The rarity of this clinical presentation presents a diagnostic dilemma, which required the pathologist and the clinician to combine a strong clinical suspicion with cytopathological features to diagnose this case, in order to ensure timely therapeutic modifications (shift from imatinib to second-generation tyrosine kinase inhibitor), considering the improvements in prognosis of imatinib resistant granulocytic sarcomas.

KIR-генетические факторы и ответ на терапию ингибиторами тирозинкиназ при хроническом миелоидном лейкозе

The development of tyrosine kinase inhibitors (TKIs) and their introduction into clinical practice considerably improved the prognosis for chronic myeloid leukemia (CML) patients. About 50 % of patients with achieved deep molecular response are eligible for safe TKI discontinuation. Despite these advances, no reliable biomarkers are known to predict a response and sustaining treatment-free remission after TKI withdrawal. As TKIs do not destroy leukemic stem cells, which can be responsible for relapse, critical importance in CML is attached to natural killers (NK-cells) having antitumor activity. Functional activity of NK-cells is evaluated by expression level and repertoire of killer cell immunoglobulin-like receptors (KIR). Current studies demonstrate that a patient’s KIR genotype affects the probability of achieving early and deep molecular responses to first- and second-generation TKIs, progression-free and overall survivals, and sustaining treatment-free remission. On that ground, KIR-genetic factors can be regarded as promising predictors of response to TKI therapy in CML. Early clinical studies, which dealt with monoclonal antibodies blocking the inhibitory KIR in order to increase NK-cell activity, revealed an acceptable safety profile and efficacy in some hematological diseases (such as acute myeloid leukemia, multiple myeloma, Т-cell lymphoma) if used in combination with cytostatic drugs or antitumor monoclonal antibodies. KIR genotype determination can contribute to the development of effective therapies of this malignant hematological tumor.

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

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

Crenolanib and Intensive Chemotherapy in Adults With Newly Diagnosed FLT3-Mutated AML.

Crenolanib is a second-generation tyrosine kinase inhibitor with activity against FLT3-ITD- and TKD-mutant AML. We conducted a trial of crenolanib plus intensive chemotherapy in adults with newly diagnosed FLT3-mutant AML. Eligible patients were 18 years and older. Induction chemotherapy consisted of cytarabine (100 mg/m2) continuous infusion on days 1-7 and anthracycline (daunorubicin 60-90 mg/m2 or idarubicin 12 mg/m2, once daily) on days 1-3 followed by consolidation with high-dose cytarabine (1-3 g/m2 twice daily on days 1, 3, 5) and/or allogeneic transplant. Crenolanib (100 mg thrice a day) was given from day 9 until 72 hours before the next cycle, after consolidation, and for 12 months after consolidation or transplant. Forty-four patients (median age, 57; range, 19-75 years) were enrolled. Thirty-six had FLT3-ITD, and 11 had FLT3-TKD mutations. European LeukemiaNet 2017 disease risk was favorable in 34%, intermediate in 30%, and adverse in 36%. The overall response rate was 86% (complete remission [CR], 77%; CR with incomplete count recovery [CRi], 9%): 90% in patients 60 years and younger and 80% in older patients. Measurable residual disease-negative CR/CRi rates were 89% and 45%, respectively. With a 45-month follow-up, median overall survival has not been reached and the median event-free survival was 44.7 months. Among younger patients, the estimated 3-year survival was 71.4% with 15% cumulative incidence of relapse. Treatment-related serious adverse events included febrile neutropenia, diarrhea, and nausea. The median time to platelets ≥100,000/µL and absolute neutrophil count ≥1,000/µL during induction was 29 and 32 days, respectively. No new FLT3-mutant clones were detected at relapse in patients completing consolidation. Crenolanib plus intensive chemotherapy in adults with newly diagnosed FLT3-mutant AML results in high rate of deep responses and long-term survival with acceptable toxicity. A randomized trial of crenolanib versus midostaurin plus chemotherapy in younger patients is ongoing.

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.