Dasatinib induces notable hematologic and cytogenetic responses in chronic-phase chronic myeloid leukemia after failure of imatinib therapy

µPhos: a scalable and sensitive platform for high-dimensional phosphoproteomics

Mass spectrometry has revolutionized cell signaling research by vastly simplifying the analysis of many thousands of phosphorylation sites in the human proteome. Defining the cellular response to perturbations is crucial for further illuminating the functionality of the phosphoproteome. Here we describe µPhos ('microPhos'), an accessible phosphoproteomics platform that permits phosphopeptide enrichment from 96-well cell culture and small tissue amounts in <8 h total processing time. By greatly minimizing transfer steps and liquid volumes, we demonstrate increased sensitivity, >90% selectivity, and excellent quantitative reproducibility. Employing highly sensitive trapped ion mobility mass spectrometry, we quantify ~17,000 Class I phosphosites in a human cancer cell line using 20 µg starting material, and confidently localize ~6200 phosphosites from 1 µg. This depth covers key signaling pathways, rendering sample-limited applications and perturbation experiments with hundreds of samples viable. We employ µPhos to study drug- and time-dependent response signatures in a leukemia cell line, and by quantifying 30,000 Class I phosphosites in the mouse brain we reveal distinct spatial kinase activities in subregions of the hippocampal formation.

Ferroptosis-related lncRNAs: Distinguishing heterogeneity of the tumour microenvironment and predicting immunotherapy response in bladder cancer

Ferroptosis, a cell death pathway dependent on iron, has been shown in research to play a role in the development, advancement, and outlook of tumours through ferroptosis-related lncRNAs (FRLRs). However, the value of the FRLRs in bladder cancer (BLCA) has not been thoroughly investigated. This research project involved developing a predictive model using ten specific FRLRs (AC099850.4, AL731567.1, AL133415.1, AC021321.1, SPAG5-AS1, HMGA2-AS1, RBMS3-AS3, AC006160.1, AL583785.1, and AL662844.4) through univariate COX and LASSO regression techniques. The validation of this signature as a standalone predictor was confirmed in a group of 65 patients from the urology bladder tumour database at the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, China. Patients were categorized based on their median risk score into either a low-risk group or a high-risk group. Enrichment analysis identified possible molecular mechanisms that could explain the variations in clinical outcomes observed in high-risk and low-risk groups. Moreover, we explored the correlation between FLPS and immunotherapy-related indicators. The ability of FLPS to forecast the effectiveness of immunotherapy was validated by the elevated levels of immune checkpoint genes (PD-L1, CTLA4, and PD-1) in the group at high risk. We also screened the crucial FRLR (HMGA2-AS1) through congruent expression and prognostic conditions and established a ceRNA network, indicating that HMGA2-AS1 may affect epithelial-mesenchymal transition by modulating the Wnt signalling pathway through the ceRNA mechanism. We identified the top five mRNAs (NFIB, NEGR1, JAZF1, JCAD, and ESM1) based on random forest algorithm and analysed the relationship between HMGA2-AS1, the top five mRNAs, and immunotherapy, and their interactions with drug sensitivities. Our results suggest that patients with BLCA have a greater sensitivity to four drugs (dasatinib, pazopanib, erismodegib and olaparib). Our study provides new insights into the TME, key signalling pathways, genome, and potential therapeutic targets of BLCA, with future guidance for immunotherapy and targeted precision drugs.

A safety review of tyrosine kinase inhibitors for chronic myeloid leukemia

INTRODUCTION

Since the introduction of first tyrosine kinase inhibitor (TKI) imatinib, the treatment of chronic myeloid leukemia (CML) has reached excellent survival expectancies. Long survival rates bring about issues regarding TKI safety.

AREAS COVERED

The aim of this review is to compare the side effects of current TKIs both in the first and later lines and outline a safety andprofile of CML treatment. Seminal studies on TKIs and other newer drugs and extended follow-up of these studies; real-life data of each drug were usedduring the course of this. PubMed was used as a search database and onlyarticles in English were included.

EXPERT OPINION

With longer follow-up CML patients, resistant slowgrade adverse events seem to be the major obstacle in the way of treatmentefficacy. If efficacy is the priority, vigorous treatment of side effect and administration of full dose TKI are reasonable. But when treatment goals are reached, dose modifications or alternative treatment regimens may be acceptedpossible. More studies are needed on dose modification protocols and potential benefits and safety of treatment-free remission.

Which Second-Line Tyrosine Kinase Inhibitor(s) for Chronic Myeloid Leukemia?

OPINION STATEMENT

In patients with chronic myeloid leukemia who require second-line tyrosine kinase inhibitor therapy, many options exist. These treatments include alternate generation tyrosine kinase inhibitors and in some cases consideration of allogeneic transplant. Although efficacious, each tyrosine kinase inhibitor possesses distinct side effects and pharmacological profiles that prevent a generalizable treatment approach. Furthermore, there is limited head-to-head trial data that would suggest the superiority of one tyrosine kinase inhibitor over another to help guide treatment decisions in specific clinical settings. Therefore, we treat each patient independently. A patient's treatment plan must be personalized by a variety of clinical factors to optimize response and tolerability. Our general approach is to first examine the reason for treatment failure, which may be due to either intolerance or relapse. Second, we consider the age and patient's comorbidities such as lung disease, diabetes, or cardiovascular disease. In patients who have inadequate responses, we analyze the patient's BCR-ABL1 mutational profile, which is beneficial if that patient harbors a specific tyrosine kinase inhibitor responsive mutation, such as T315I. Using these steps, we can provide a generalizable approach to choosing the appropriate second-line tyrosine inhibitor for chronic myeloid leukemia.

Adverse reactions after treatment with dasatinib in chronic myeloid leukemia: Characteristics, potential mechanisms, and clinical management strategies

Dasatinib, a second-generation tyrosine kinase inhibitor, is recommended as first-line treatment for patients newly diagnosed with chronic myeloid leukemia (CML) and second-line treatment for those who are resistant or intolerant to therapy with imatinib. Dasatinib is superior to imatinib in terms of clinical response; however, the potential pulmonary toxicities associated with dasatinib, such as pulmonary arterial hypertension and pleural effusion, may limit its clinical use. Appropriate management of dasatinib-related severe events is important for improving the quality of life and prognosis of patients with CML. This review summarizes current knowledge regarding the characteristics, potential mechanisms, and clinical management of adverse reactions occurring after treatment of CML with dasatinib.

PROTACting the kinome with covalent warheads

The dawn of targeted degradation using proteolysis-targeting chimeras (PROTACs) against recalcitrant proteins has prompted numerous efforts to develop complementary drugs. Although many of these are specifically directed against undruggable proteins, there is increasing interest in small molecule-based PROTACs that target intracellular pathways, and some have recently entered clinical trials. Concurrently, small molecule-based PROTACs that target protumorigenic pathways in cancer cells, the tumor microenvironment (TME), and angiogenesis have been found to have potent effects that synergize with the action of antibodies. This has led to the augmentation of PROTACs with variable substitution patterns. Several combinations with small molecules targeting undruggable proteins are now under clinical investigation. In this review, we discuss the recent milestones achieved as well as challenges encountered in this area of drug development, as well as our opinion on the best path forward.

Bosutinib-induced late-onset severe liver injury preceded by eosinophilia

Tyrosine kinase inhibitors (TKIs) have dramatically changed the way chronic myeloid leukemia (CML) is treated. Although TKI therapy improves the overall survival of patients with CML, the management of various adverse events (AEs) from the therapy has become a major barrier to its adherence. Bosutinib is a second-generation TKI and an effective first-line treatment for CML. The most frequent AE is diarrhea; however, liver toxicity is also a major complication. In general, drug-induced hepatic enzyme elevation occurs within 1-2 weeks after treatment initiation. However, we noticed that, in a certain number of patients, liver injury appeared late (4-7 weeks) and was accompanied by eosinophilia. Herein, we retrospectively analyzed patients with CML treated with bosutinib at the Juntendo University School of Medicine and observed five patients with CML who developed late-onset liver injury with an elevation of the eosinophil count. In all cases, the liver enzyme level was within the normal range or grade 1 during the first 3 weeks of the bosutinib treatment and then elevated steeply thereafter. The pattern of hepatic toxicity was hepatocellular injury. In addition, all cases of eosinophilia tended to precede or coincide with an elevated liver enzyme level. Thus, the elevation of the eosinophil count may be a predictor for bosutinib-induced liver injury. Careful attention should be paid to delayed-onset hepatic injury, especially at 4-6 weeks after bosutinib initiation.

An evaluation of ponatinib as a therapy in adult patients with resistant/intolerant chronic-phase chronic myeloid leukemia

INTRODUCTION

Chronic myeloid leukemia is now a highly treatable leukemia due to the availability of multiple tyrosine kinase inhibitors (TKIs) inhibiting the BCR-ABL1 oncogene. Some patients with CML can display resistance or intolerance to multiple TKIs, oftentimes due to the presence of mutations in BCR-ABL1, such as T315I, which limits effective treatment options. Ponatinib is a third-generation, rationally-designed TKI with clinically meaningful activity in this difficult-to-treat population. Ponatinib is associated with an increased risk of arterial occlusive events (AOEs) which has required a re-examination of its dosing in order to limit the risk of these events.

AREAS COVERED

This review will provide an overview of the mechanism of action of ponatinib and the safety and efficacy data from clinical trials in chronic myeloid leukemia.

EXPERT OPINION

Ponatinib is a potent pan-BCR-ABL1 TKI with substantial activity in patients with more resistant or advanced CML. Its efficacy needs to be balanced with the increased risk of vascular events, which seems to be at least partially diminished by the implementation of mitigation strategies aimed at modifying cardiovascular risk factors and adaptive dosing of the drug.

Effects of tyrosine kinase inhibitors for controlling Ph+ clone and additional clonal abnormalities in a chronic myeloid leukemia

Purpose

The chronic myeloid leukemia (CML) is characterized by the presence of t(9;22)(q34;q11) that results in chimerization of BCR and ABL genes on the rearranged chromosome 22 or Philadelphia chromosome (Ph). Imatinib has been established as the first line of therapy for CML; in case of Imatinib failure or resistance, other second or third generation tyrosine kinase inhibitors (TKIs) are considered. However, acquisition of additional clonal abnormalities (ACAs) interferes in management of CML. We described a complex scenario of cytogenetic remission, relapse, response to TKIs and behavior of ACAs in a case of CML.

Materials and Methods

Conventional G-banding and FISH cytogenetics, and quantitative PCR studies were conducted in the bone marrow for diagnosis and follow up (FU) of the changes of BCR-ABL gene and ACAs at different time intervals.

Results

Ph- chromosome disappeared within 6 months of Imatinib therapy, and re-appeared within a year. Subsequent change of TKI to dasatinib eliminated the Ph+ clone, but established an ACA with trisomy 8 (+8). Further change to Nilotinib, eliminated +8 clone, but re-emergence of Ph+ clone occurred with an ACA with monosomy 7 (-7). Reinstate of Dasatinib eliminated Ph+ and -7 clones, but with gradual reappearance of Ph+ and +8 clones. The patient discontinued FU, though participated in a long term examination.

Conclusion

The complexity of ACAs and Ph+ clones needs frequent monitoring with changes of TKI and technologies.

Incidence of cardiovascular events in patients with chronic myeloid leukaemia treated with tyrosine kinase inhibitors

BACKGROUND

The introduction of imatinib and tyrosine kinase inhibitors as therapeutic strategy for Philadelphia chromosome-positive chronic myeloid leukaemia (CML) has represented an important step forward for treatment of this disease. The aim of this study was therefore to evaluate the incidence of cardiovascular adverse events (CVEs) in patients affected by CML treated with TKI in an observational prospective study.

METHODS

All consecutive patients affected by CML and treated with TKI in our Institution were enrolled in the study from February 2005 to September 2018 with a clinical, laboratory and instrumental follow-up.

RESULTS

Sixty-one consecutive patients were enrolled, 29 with imatinib, 15 with nilotinib, 11 with dasatinib, 3 with bosutinib and 3 with ponatinib. Neither patients in therapy with bosutinib nor with nilotinib had CVE during follow-up. Incidence rates per person/year were 0 for bosutinib and nilotinib, 0.15 for dasatinib, 0.19 for imatinib and 1.69 for ponatinib (Log Rank p < 0.05); differences in terms of incidence of adverse outcomes remained significant also after multivariate correction.

CONCLUSIONS

In patients with CML treated with TKIs, therapy with ponatinib was associated with a higher risk of CVE than other TKIs. The lowest incidence of CVE was associated with bosutinib and nilotinib.

High-Throughput Activity Assay for Screening Inhibitors of the SARS-CoV-2 Mac1 Macrodomain

Macrodomains are a class of conserved ADP-ribosylhydrolases expressed by viruses of pandemic concern, including coronaviruses and alphaviruses. Viral macrodomains are critical for replication and virus-induced pathogenesis; therefore, these enzymes are a promising target for antiviral therapy. However, no potent or selective viral macrodomain inhibitors currently exist, in part due to the lack of a high-throughput assay for this class of enzymes. Here we developed a high-throughput ADP-ribosylhydrolase assay using the SARS-CoV-2 macrodomain Mac1. We performed a pilot screen that identified dasatinib and dihydralazine as ADP-ribosylhydrolase inhibitors. Importantly, dasatinib inhibits SARS-CoV-2 and MERS-CoV Mac1 but not the closest human homologue, MacroD2. Our study demonstrates the feasibility of identifying selective inhibitors based on ADP-ribosylhydrolase activity, paving the way for the screening of large compound libraries to identify improved macrodomain inhibitors and to explore their potential as antiviral therapies for SARS-CoV-2 and future viral threats.

Therapeutic Drug Monitoring and Individualized Medicine of Dasatinib: Focus on Clinical Pharmacokinetics and Pharmacodynamics

Dasatinib is an oral second-generation tyrosine kinase inhibitor known to be used widely in Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL). Notably, although a high pharmacokinetic variability in patients and an increased risk of pleural effusion are attendant, fixed dosing remains standard practice. Retrospective studies have suggested that dasatinib exposure may be associated with treatment response (efficacy/safety). Therapeutic drug monitoring (TDM) is gradually becoming a practical tool to achieve the goal of individualized medicine for patients receiving targeted drugs. With the help of TDM, these patients who maintain response while have minimum adverse events may achieve long-term survival. This review summaries current knowledge of the clinical pharmacokinetics variation, exposure-response relationships and analytical method for individualized dosing of dasatinib, in particular with respect to therapeutic drug monitoring. In addition, it highlights the emerging insights into several controversial issues in TDM of dasatinib, with the aim of presenting up-to-date evidence for clinical decision-making and insights for future studies.

The effect of eltrombopag in managing thrombocytopenia associated with tyrosine kinase therapy in patients with chronic myeloid leukemia and myelofibrosis

Approximately 20-50% patients with chronic phase chronic myeloid leukemia (CML-CP) treated with tyrosine kinase inhibitors (TKIs) or with myelofibrosis (MF) treated with ruxolitinib develop grade ≥3 thrombocytopenia needing treatment interruptions and dose reductions. We conducted a non-randomized, phase II, single-arm study to determine the efficacy of eltrombopag for patients with CML or MF with persistent thrombocytopenia while on TKI or ruxolitinib. Eltrombopag was initiated at 50 mg/day, with dose escalation up to 300 mg daily allowed every 2 weeks. Twenty-one patients were enrolled (CML=15, MF=6); median age 60 years (range, 31-97 years). The median platelet count was 44x109/L (range, 3-49x109/L) in CML and 62x109/L (range, 21-75x109/L) in MF. After a median of 18 months (range, 5-77 months), 12/15 patients with CML achieved complete platelet response. The median peak platelet count among responders was 154x109/L (range, 74-893x109/L). Among CML patients 5 could re-escalate the TKI dose and 9 improved their response. None of the 6 patients with MF had a sustained response. Therapy was generally well tolerated. One patient discontinued therapy due to toxicity (elevated transaminases). One patient with CML developed significant thrombocytosis (>1000x109/L). Another CML patient developed non occlusive deep venous thrombosis in the right upper extremity without thrombocytosis, and one MF patient had myocardial infarction. Eltrombopag may help improve platelet counts in CML patients receiving TKI with recurrent thrombocytopenia. Further studies are warranted.

Clinical outcome of chronic myeloid leukemia patients who switch from first-line therapy with a second generation tyrosine kinase inhibitor to an alternative TKI

While second generation tyrosine kinase inhibitors (2GTKIs) are highly effective therapies for chronic myeloid leukemia (CML), a significant minority of patients who initiate a 2GTKI will require a switch to an alternative TKI. The long-term outcomes of those who require a change in therapy after front-line 2GTKI therapy are largely undescribed. Here we describe the clinical outcomes associated with switch to an alternative TKI after first-line therapy with a 2GTKI. Of 232 patients who initiated a 2GTKI during the study period, 76 (33 %) switched to an alternative TKI. Reasons for switching included intolerance (79 %) and resistance (21 %). Among the 60 patients who switched due to intolerance, 53 (88 %) were able to achieve or maintain a major molecular response (MMR) with 5-year progression-free survival (PFS) 90.5 % (95 % CI 90.4-90.6 %). Amongst the 16 patients who switched due to resistance, 8 patients (50 %) were able to achieve MMR with 5-year PFS 80.4 % (95 % CI 80.2-80.6 %). Most patients who switched due to intolerance remained on their second-line TKI. Approximately 25 % of patients who initiate first-line 2GTKI in a real world setting will ultimately switch to an alternate TKI due to intolerance. Patients who switch for intolerance continue to enjoy excellent clinical outcomes.

Chronic Myeloid Leukemia: Modern therapies, current challenges and future directions

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm caused by a reciprocal translocation [t(9;22)(q34;q11.2)] that leads to the fusion of ABL1 gene sequences (9q34) downstream of BCR gene sequences (22q11) and is cytogenetically visible as Philadelphia chromosome (Ph). The resulting BCR/ABL1 chimeric protein is a constitutively active tyrosine kinase that activates multiple signaling pathways, which collectively lead to malignant transformation. During the early (chronic) phase of CML (CP-CML), the myeloid cell compartment is expanded, but differentiation is maintained. Without effective therapy, CP-CML invariably progresses to blast phase (BP-CML), an acute leukemia of myeloid or lymphoid phenotype. The development of BCR-AB1 tyrosine kinase inhibitors (TKIs) revolutionized the treatment of CML and ignited the start of a new era in oncology. With three generations of BCR/ABL1 TKIs approved today, the majority of CML patients enjoy long term remissions and near normal life expectancy. However, only a minority of patients maintain remission after TKI discontinuation, a status termed treatment free remission (TFR). Unfortunately, 5-10% of patients fail TKIs due to resistance and are at risk of progression to BP-CML, which is curable only with hematopoietic stem cell transplantation. Overcoming TKI resistance, improving the prognosis of BP-CML and improving the rates of TFR are areas of active research in CML.

Adherence, persistence and efficacy of dasatinib and nilotinib in the treatment of patients resistant or intolerant to imatinib with chronic myeloid leukemia in chronic phase: an Italian multicenter study over two years in real life

BACKGROUND

The use of dasatinib and nilotinib in the treatment of patients with chronic myeloid leukemia represents a valid therapeutic option for patients resistant or intolerant to imatinib. In this multicentre study, adherence, persistence and efficacy in real life over two years of treatment were evaluated.

MATERIALS AND METHODS

Adherence to treatment was calculated as the ratio between the dose received and the prescribed dose. The dose received was calculated using pharmacy refill data. The persistence with treatment was calculated as the difference between the end and the beginning of the treatment. Efficacy was assigned as Progression-Free Survival (PFS) and Events-Free Survival (EFS) and represented through the Kaplan-Meier curve.

RESULTS

The number of patients analysed was 117, 70 treated with dasatinib and 47 with nilotinib. Adherence to treatment for dasatinib and nilotinib at two years was 0.91 and 0.82 respectively. Persistence at two years was 77% while the PFS was 92% for both drugs in the study.

CONCLUSION

Adherence to the treatment calculated over two years showed a superiority of dasatinib over nilotinib. Nevertheless, the efficacy in terms of PFS and EFS is superimposable between the two drugs in the study.

In vivo, ex vivo and in vitro dasatinib activity in chronic lymphocytic leukemia

Dasatinib inhibits the breakpoint cluster region-Abelson murine leukemia 1 (BCR-ABL1) gene along with other kinases known to be overexpressed and abnormally active in patients with chronic lymphocytic leukemia (CLL). The current study used primary leukemic cells obtained from 53 patients with CLL that were treated with dasatinib. A 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and Annexin V staining was performed to assess the cytotoxic effects of dasatinib treatment. The XTT assay revealed that the median cytotoxicity of dasatinib was 8.30% (range, 0.00–77.89%). Due to high dispersion of dasatinib activity, patients were divided into sensitive (n=27; 50.94%; median cytotoxicity, 22.81%) and resistant groups (n=26; 49.06%; median cytotoxicity, 0.00%). A median cytotoxicity of 8.30% was selected as a cut off value. Using Annexin V staining and flow cytometry on exemplary sensitive and resistant CLL samples, it was revealed that 17.71 and 1.84% of cells were apoptotic, respectively. The current study presented a case of a patient with concomitant occurrence of CLL and chronic myeloid leukemia (CML) with a major molecular response after dasatinib treatment. A simultaneous reduction of circulating CLL cells indicated in vivo anti-CLL activity induced by dasatinib. After an in vitro culture of the patient's mononuclear cells with subsequent dasatinib treatment, a higher percentage of CLL cells undergoing apoptosis was obsevered when compared with untreated samples (38.19 vs. 21.99%, respectively). Similarly, the percentage of CLL apoptotic cells (ΔΨm^low) measured by chloromethyl-X-rosamine was higher after incubation with dasatinib (7.28%) than in the negative control (2.86%). In conclusion, dasatinib induced antileukemic effects against CML and CLL cells. The results of the current study indicated that dasatinib may induce apoptosis ex vivo, in vitro and in vivo in CLL.

Computational and Biological Investigations on Abl1 Tyrosine Kinase: A Review

Abl1 tyrosine kinase is a validated target for the treatment of chronic myeloid leukemia. It is a form of cancer that is difficult to treat and much research is being done to identify new molecular entities and to tackle drug resistance issues. In recent years, drug resistance of Abl1 tyrosine kinase has become a major healthcare concern. Second and third-generation TKI reported better responses against the resistant forms; still they had no impact on long-term survival prolongation. New compounds derived from natural products and organic small molecule inhibitors can lay the foundation for better clinical therapies in the future. Computational methods, experimental and biological studies can help us understand the mechanism of drug resistance and identify novel molecule inhibitors. ADMET parameters analysis of reported drugs and novel small molecule inhibitors can also provide valuable insights. In this review, available therapies, point mutations, structure-activity relationship and ADMET parameters of reported series of Abl1 tyrosine kinase inhibitors and drugs are summarised. We summarise in detail recent computational and molecular biology studies that focus on designing drug molecules, investigation of natural product compounds and organic new chemical entities. Current ongoing research suggests that selective targeting of Abl1 tyrosine kinase at the molecular level to combat drug resistance in chronic myeloid leukemia is promising.

Efficacy of tyrosine kinase inhibitors on a mouse chronic myeloid leukemia model and chronic myeloid leukemia stem cells

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder caused by constitutively active BCR-ABL1 tyrosine kinase resulting from the t(9;22) Philadelphia translocation. Imatinib, a BCR-ABL1 tyrosine kinase inhibitor (TKI), is a revolutionary molecular target inhibitor for CML. However, leukemic stem cells (LSCs) eventually become resistant to imatinib and thereby cause relapse. The next-generation BCR-ABL1 TKI dasatinib is also unable to eliminate CML LSCs. On the other hand, the third-generation BCR-ABL1 TKI ponatinib is not well studied in terms of its efficacy on CML LSCs. Here, we evaluate the efficacy of ponatinib against CML LSC-containing lin^-Sca-1⁺c-Kit⁺ (LSK) cells using a mouse CML-like model. To this end, we compared the efficacy of imatinib, dasatinib, and ponatinib on CML LSK cells and showed that ponatinib is more effective at eliminating CML LSK cells. Our results suggest that ponatinib could be potentially useful for achieving treatment-free remission in CML patients.

YQFM Alleviates Side Effects Caused by Dasatinib through the ROCK/MLC Pathway in Mice

Dasatinib, as a second-generation broad-spectrum tyrosine kinase inhibitor, presents an antitumor effect by inhibiting tyrosine kinases. However, dasatinib causes serious side effects, such as gastrointestinal bleeding and liver toxicity, possibly through the activation of ROCK kinase and MLC phosphorylation. At present, there is no effective prevention and treatment method. Previous research studies have shown that YQFM (YiQiFuMai powder injection) protects the blood-brain barrier by inhibiting the ROCK/MLC signaling pathway; whether YQFM can alleviate the side effects of dasatinib is unknown. In this study, dasatinib was injected (i.p. 70 mg/kg) and YQFM (i.p. 0.336 g/kg, 0.672 g/kg, 1.342 g/kg) was given in advance for 3 days to mice, to explore the effect of YQFM on side effects induced by Dasatinib. The results confirmed that YQFM significantly decreased Evans blue leakage in the small intestine and increased intestinal blood flow, increased the expression of ZO-1, Occludin, and VE-cadherin, and reduced the contents of D-lactic acid, s-VE-cadherin, Alanine aminotransferase (ALT), and Aspartate aminotransferase (AST) in serum. Finally, YQFM inhibited the expression of ROCK-1 and phosphorylation of MLC induced by Dasatinib. These findings suggested that YQFM could improve the side effects caused by Dasatinib linked with the ROCK/MLC signaling pathway, as shown in the graphical abstract.

Aberrant DNA methylation of PTPRG as one possible mechanism of its under-expression in CML patients in the State of Qatar

Background

Several studies showed that aberrant DNA methylation is involved in leukemia and cancer pathogenesis. Protein tyrosine phosphatase receptor gamma (PTPRG) expression is a natural inhibitory mechanism that is downregulated in chronic myeloid leukemia (CML) disease. The mechanism behind its downregulation has not been fully elucidated yet.

Aim

This study aimed to investigate the CpG methylation status at the PTPRG locus in CML patients.

Methods

Peripheral blood samples from CML patients at time of diagnosis [no tyrosine kinase inhibitors (TKIs)] (n = 13), failure to (TKIs) treatment (n = 13) and healthy controls (n = 6) were collected. DNA was extracted and treated with bisulfite treatment, followed by PCR, sequencing of 25 CpG sites in the promoter region and 26 CpG sites in intron‐1 region of PTPRG. The bisulfite sequencing technique was employed as a high‐resolution method.

Results

CML groups (new diagnosed and failed treatment) showed significantly higher methylation levels in the promoter and intron‐1 regions of PTPRG compared to the healthy group. There were also significant differences in methylation levels of CpG sites in the promoter and intron‐1 regions amongst the groups.

Conclusion

Aberrant methylation of PTPRG is potentially one of the possible mechanisms of PTPRG downregulation detected in CML.

Imatinib-Induced Tremor in a Patient with Chronic Myeloid Leukemia in Chronic Phase

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by three phases: chronic, accelerated, and blast phase. However; first- and second-generation tyrosine kinase inhibitors are used for the treatment of CML with common and uncommon adverse events. Here, we report a 24-year-old male with CML in chronic phase started on imatinib as upfront medication who developed tremor and recovered spontenously after 3 years.

Complexity of chronic-phase CML management after failing a second-generation TKI

The treatment landscape of chronic myeloid leukemia (CML) was radically changed with the introduction of imatinib in 2001. With the emergence of treatment failure with imatinib, more specific and potent second- and third-generation tyrosine kinase inhibitors (TKIs) were developed. Currently, 6 TKIs and one protein synthesis inhibitor are available on the market for CML treatment. Despite the availability of these agents, it is not uncommon for some patients to experience treatment failure across several lines of therapy. Sequencing the available treatment options is a challenging task that becomes more complex after patients fail the more potent second- and third-generation TKIs. The ability to successfully salvage such patients is limited. In this paper, we will briefly review the mechanisms of treatment failure in chronic-phase CML (CP-CML) and focus on the complexity of managing patients who fail a second-generation TKI.

Evaluating the endometabolic and bone health effects of Tyrosine Kinase Inhibitors in Chronic Myeloid Leukaemia: a systematic review protocol

INTRODUCTION

Chronic Myeloid Leukaemia (CML) constitutes 15% of new adult leukaemia cases as well as 2%-3% of leukaemia in children under 15% and 9% of leukaemias in adolescents 15-19 years of age annually. The introduction of Tyrosine Kinase Inhibitors (TKI) therapy has dramatically improved survival in these patients, yet the off-target effects of this treatment may have long-term health impacts on CML survivors. The risk of adverse health outcomes is especially important in children, where TKI exposure may occur during critical windows of growth and puberty, and patients require treatment for prolonged periods of time. The aim of this systematic review protocol is to report on the methods used to conduct a systematic review to investigate the endometabolic and bone health effects of TKI therapy in CML.

METHODS AND ANALYSIS

Searches will be conducted in the Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE from inception on August 1st, 2019. Searches may be updated while performing the systematic review to ensure new evidence is included if applicable. Grey literature search will include ClinicalTrials.gov and ProQuest Dissertations and Theses A&I. We will perform a meta-analysis if there are at least two studies reporting similar populations, interventions, methods and tracking the same outcome measures. The studies should also have similar age and sex distributions.

ETHICS AND DISSEMINATION

As this is a systematic review protocol, it does not include patient data; therefore, Research Ethics Board approval is not indicated. The systematic review will be published in a peer-reviewed journal and presented at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018091175.

[Recommendations from the French CML Study Group (Fi-LMC) for BCR-ABL1 kinase domain mutation analysis in chronic myeloid leukemia]

In the context of chronic myeloid leukemia (CML) resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL1 tyrosine kinase domain (TKD) mutations still remain the sole biological marker that directly condition therapeutic decision. These recommendations aim at updating the use of BCR-ABL1 mutation testing with respect to new available therapeutic options and at repositioning different testing methods at the era of next generation sequencing (NGS). They have been written by a panel of experts from the French Study Group on CML (Fi-LMC), after a critical review of relevant publications. TKD mutation testing is recommended in case of treatment failure but not in case of optimal response. For patients in warning situation, mutation testing must be discussed depending on the type of TKI used, lasting of the treatment, kinetic evolution of BCR-ABL1 transcripts along time and necessity for switching treatment. The kind and the frequency of TKD mutations occasioning resistance mainly depend on the TKI in use and disease phase. Because of its better sensitivity, NGS methods are recommended for mutation testing rather than Sanger's. Facing a given TKD mutation, therapeutic decision should be taken based on in vitro sensitivity and clinical efficacy data. Identification by sequencing of a TKD mutation known to induce resistance must lead to a therapeutic change. The clinical value of testing methods more sensitive than NGS remains to be assessed.

Responses to Dasatinib as a Second- and Third-Line Tyrosine Kinase Inhibitor in Chronic Phase Chronic Myeloid Leukaemia Patients

We retrospectively evaluated the efficacy and safety of dasatinib among 48 Chinese patients with chronic phase chronic myeloid leukaemia. The proportions of patients achieving the optimal molecular responses at 3, 6, and 12 months, a major molecular response (MMR) rate and a complete cytogenetic response (CCyR) rate were 87.0, 87.0, 72.2, 45.8, and 72.7% for patients with dasatinib as second-line therapy, and 34.8, 34.8, 33.3, 20.8, and 46.2% as third-line therapy, respectively. A BCR-ABL1 transcript level on the International Scale (BCR-ABL1IS) of ≤10% at the initiation of -dasatinib treatment was found to be associated with a higher probability of achieving MMR. Among patients with a -BCR-ABL1IS higher than 10% at initiation of dasatinib treatment, dasatinib showed better performance as a second-line therapy than as a third-line therapy. The patients who achieved an optimal molecular response at 3 months had a superior cumulative incidence of MMR and CCyR compared with patients who failed to achieve such a response. Dasatinib induced considerable responses as a second-line treatment, especially in patients with a BCR-ABL1IS ≤10% at initiation of treatment, whereas the efficacy was limited in patients receiving third-line therapy with a BCR-ABL1IS >10% at the initiation of treatment.

Concise Review: Exploiting Unique Biological Features of Leukemia Stem Cells for Therapeutic Benefit

Cancer stem cells play a critical role in disease initiation and insensitivity to chemotherapy in numerous hematologic malignancies and some solid tumors, and these stem cells need to be eradicated to achieve a cure. Key to successful targeting of cancer stem cells is to identify and functionally test critical target genes and to fully understand their associated molecular network in these stem cells. Human chronic myeloid leukemia (CML) is well accepted as one of the typical types of hematopoietic malignancies that are derived from leukemia stem cells (LSCs), serving as an excellent model disease for understanding the biology of LSCs and developing effective, selective, and curative strategies through targeting LSCs. Here, we discuss LSCs in CML with a focus on identification of unique biological features of these stem cells to emphasize the feasibility and significance of specific targeting of LSCs while sparing normal stem cell counterparts in leukemia therapy. stem cells translational medicine2019;8:768&774

[Efficacy and safety of domestic dasatinib as second-line treatment for chronic myeloid leukemia patients in the chronic phase]

Objective: To investigate the efficiency and safety of domestic tyrosine kinase inhibitor (TKI) dasatinib (Yinishu) as second-line treatment for patients with chronic myeloid leukemia in chronic phase (CML-CP). Methods: A retrospective analysis of clinical data of CML-CP patients who received domestic dasatinib as second-line treatment in the CML collaborative group hospitals of Hubei province from March 2016 to July 2018 was performed. The optimal response rate, the cumulative complete cytogenetic response (CCyR), the cumulative major molecular responses (MMR), progression free survival (PFS), event free survival (EFS) and adverse effects (AEs) of the patients were assessed at 3, 6 and 12 months of treatment. Results: A total of 83 CML-CP patients were enrolled in this study. The median follow-up time was 23 months. The optimal response rates at 3, 6 and 12 months in 83 CML-CP patients treated with dasatinib were 77.5% (54/71), 72.6% (61/75) and 60.7% (51/69), respectively. By the end of follow-up, the cumulative CCyR and MMR rates were 65.5% (55/80) and 57.1% (48/73), respectively. The median time to achieving CCyR and MMR was 3 months. During follow-up time, the PFS rate was 94.0% (79/83) and the EFS rate was 77.4% (65/83). The most common non-hematological AEs of dasatinib were edema (32.5%), rash itching (18.1%) and fatigue (13.3%). The common hematological AEs of dasatinib were thrombocytopenia (31.3%), leukopenia (19.3%) and anemia (6.0%). Conclusion: Domestic dasatinib was effective and safe as the second-line treatment of CML-CP patients and it can be used as an option for CML-CP patients.

Prevalence of BCR-ABL T315I Mutation in Malaysian Patients with Imatinib-Resistant Chronic Myeloid Leukemia

Objective:

Chronic Myeloid Leukemia (CML) is caused by a reciprocal translocation between chromosomes 9 and 22, t(9;22) (q34;q11) which encodes for the BCR-ABL fusion protein. Discovery of Imatinib Mesylate (IM) as first line therapy has brought tremendous improvement in the management of CML. However, emergence of point mutations within the BCR-ABL gene particularly T315I mutation, affects a common BCR-ABL kinase contact residue which impairs drug binding thus contribute to treatment resistance. This study aims to investigate the BCR-ABL T315I mutation in Malaysian patients with CML.

Methods:

A total of 285 patients diagnosed with CML were included in this study. Mutation detection was performed using qualitative real-time PCR (qPCR).

Results:

Fifteen out of 285 samples (5.26%) were positive for T315I mutations after amplification with real-time PCR assay. From the total number of positive samples, six patients were in accelerated phase (AP), four in chronic phase (CP) and five in blast crisis (BC).

Conclusion:

Mutation testing is recommended for choosing various tyrosine kinase inhibitors (TKIs) to optimize outcomes for both cases of treatment failure or suboptimal response to imatinib. Therefore, detection of T315I mutation in CML patients are clinically useful in the selection of appropriate treatment strategies to prevent disease progression.

Compound mutations involving T315I and P-loop mutations are the major components of multiple mutations detected in tyrosine kinase inhibitor resistant chronic myeloid leukemia

To analyze the pattern of multiple mutations detected by Sanger sequencing (SS), we performed subcloning sequencing using 218 samples from 45 patients with tyrosine kinase inhibitor resistant chronic myeloid leukemia. At the first time of multiple mutation detection by SS (baseline), a total of 19 major mutations from 45 samples were detected; these mutations were found in the following order: T315I (68.9%), E255 K (33.3%), Y253H (13.3%), G250E (13.3%), and F317 L (11.1%). Subcloning sequencing of 900 baseline colonies identified 556 different mutant types, and 791 among the 900 were colonies with major mutations (87.9%). The mutations were found in the following order: T315I (36.4%), E255 K (16.2%), Y253H (7.0%), G250E (6.7%), M351 T (6.6%), and E255 V (5.3%). In subcloning sequencing with 4357 colonies of 218 serial samples, 2506 colonies (57.5%) had compound mutations, among which 2238 colonies (89.3%) had at least one major mutation. The median number of mutations in compound mutant colonies was 2 (range, 2-7), and most were double (52.9%) or triple (28.7%) mutations. Additionally, some mutations in allosteric binding sites were detected as low level mutation in 13 patients. With the available retrospective samples before baseline, subcloning sequencing identified low-level mutations of various frequencies (median, 10%) to be major mutations in 20 patients. Thus, compound mutations involving T315I and P-loop mutations were the major components of multiple mutations, and some low-level mutations with potential clinical significance were detected by subcloning sequencing. Hence, more sensitive sequencing assays are needed in patients with multiple mutations.

Incidence, outcomes, and risk factors of pleural effusion in patients receiving dasatinib therapy for Philadelphia chromosome-positive leukemia

Dasatinib, a second-generation BCR-ABL1 tyrosine kinase inhibitor, is approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia, both as first-line therapy and after imatinib intolerance or resistance. While generally well tolerated, dasatinib has been associated with a higher risk for pleural effusions. Frequency, risk factors, and outcomes associated with pleural effusion were assessed in two phase 3 trials (DASISION and 034/Dose-optimization) and a pooled population of 11 trials that evaluated patients with chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia treated with dasatinib (including DASISION and 034/Dose-optimization). In this largest assessment of patients across the dasatinib clinical trial program (N=2712), pleural effusion developed in 6-9% of patients at risk annually in DASISION, and in 5-15% of patients at risk annually in 034/Dose-optimization. With a minimum follow up of 5 and 7 years, drug-related pleural effusion occurred in 28% of patients in DASISION and in 33% of patients in 034/Dose-optimization, respectively. A significant risk factor identified for developing pleural effusion by a multivariate analysis was age. We found that overall responses to dasatinib, progression-free survival, and overall survival were similar in patients who developed pleural effusion and in patients who did not. clinicaltrials.gov identifier 00481247; 00123474.

Pleural adverse drugs reactions and protein kinase inhibitors: Identification of suspicious targets by disproportionality analysis from VigiBase

AIMS

To evaluate the risk of pleural disorders (PD) associated with 33 protein kinase (PK) inhibitors (PKIs) through a disproportionality analysis and to identify which PKs and pathways are involved in PKI-induced PD.

METHODS

To evaluate the risk of PD, reporting odds ratios (RORs) were calculated for 33 PKIs through data registered in the World Health Organization safety report database (VigiBase). We undertook a literature review to identify PKs that were possibly involved in PD caused by PKIs. Pearson correlation coefficients (r) between RORs and affinity data of 19 PKIs were calculated to identify the cellular target most likely to be involved in PKI-induced PD.

RESULTS

A total of 235 110 individual case safety reports were extracted from the database for 33 available PKIs. Among these reports, 5001 concerned PD (2.1%). Significant and positive disproportionality for PD was found for 29 of 33 PKI included in our study with top values for dasatinib [ROR = 115.3; 95% confidence interval (CI): 110.1-120.8], bosutinib (ROR = 20.4; 95% CI: 15.8-26.4) and ponatinib (ROR = 12; 95% CI: 9.2-15.6). Correlation analyses between the product of dissociation constant and ROR highlighted possibly Lyn involvement in PD with PKI (r = 0.73, P = 0.0004).

CONCLUSIONS

Our study showed that 28 of the 33 tested PKIs were associated with PD. Besides, the study highlighted the role of Lyn in PD caused by PKIs through an immune-mediated process.

Comparison of Frequency and Sensitivity of BCR-ABL1 Kinase Domain Mutations in Asian and White Patients With Imatinib-resistant Chronic-Phase Chronic Myeloid Leukemia

INTRODUCTION

BCR-ABL1 mutations require consideration during second-line tyrosine kinase inhibitor selection for patients with chronic myeloid leukemia (CML). The present retrospective analysis compared the frequency of BCR-ABL1 mutations in Asian and white patients in whom imatinib therapy had failed.

PATIENTS AND METHODS

A nonstudy cohort (76 Asian patients from community clinical practices) and 2 study cohorts (29 Asian and 352 white patients from dasatinib phase II and III clinical trials) were identified.

RESULTS

In the nonstudy cohort, 80 mutations were identified; the most frequent was T315I (15%), followed by phosphate-binding loop mutations E255K (11%), G250E (10%), and Y253H (10%). Asian patients had a greater proportion of T315I and phosphate-binding loop mutations compared with the white patients. The nonstudy cohort was less likely to have multiple mutations compared with either study cohort. Single mutations highly resistant to dasatinib, nilotinib, and bosutinib were more frequent in the Asian than in the white cohorts.

CONCLUSION

These results suggest that mutational analysis findings will be invaluable for choosing an appropriate second-line tyrosine kinase inhibitor in Asia.

Novel combined Ato-C treatment synergistically suppresses proliferation of Bcr-Abl-positive leukemic cells in vitro and in vivo

Chronic myelogenous leukemia (CML) accounts for 15-20% of all leukemias affecting adults. Despite recent advances in the development of specific Bcr-Abl tyrosine kinase inhibitors (TKIs), some CML patients suffer from relapse due to TKI resistance. Here, we assessed the efficacy of a novel combinatorial arsenic trioxide (ATO) and cisplatin (CDDP) treatment (Ato-C) in human Bcr-Abl-positive leukemic cells. Combination index analyses revealed that a synergistic interaction of ATO and CDDP elicits a wide range of effects in K562, KU-812, MEG-A2, and KCL-22 cells. Notably, Ato-C synergistically enhanced apoptosis and decreased the survival of both acquired TKI-resistant CML cells and the cells expressing mutant Bcr-Abl^T315I. In addition, Ato-C dramatically decreased the phosphorylation level of forkhead transcription factor FOXO1/3a and STAT5 as well as c-Myc protein level. Interestingly, results of gene set enrichment analysis showed that Ato-C significantly downregulates the expression of MYC- and/or E2F1-target genes. Furthermore, Ato-C significantly suppressed the proliferation of MEG-A2-derived tumor when compared with that following monotherapy in vivo. Collectively, these results suggest that combined Ato-C treatment could be a promising alternative to the current therapeutic regime in CML.

Life after ponatinib failure: outcomes of chronic and accelerated phase CML patients who discontinued ponatinib in the salvage setting

Ponatinib is a pan-tyrosine kinase inhibitor (TKI) with efficacy in multirefractory CML patients who have failed other TKIs. Despite excellent response rates, resistance or intolerance may develop. We conducted a retrospective review of the outcome of patients with chronic (CP) and accelerated (AP) phase CML refractory to prior TKI who discontinued ponatinib for resistance or intolerance. Nineteen CP patients, discontinued due to resistance (n = 13), toxicity (n = 5) and to pursue stem cell transplantation (n = 1). At discontinuation, 14 were still in CP, three had progressed to AP and two to blast phase (BP). Three CP patients improved their cytogenetic response (CyR) to complete CyR (CCyR), two after SCT and one on omacetaxine. None of the 12 patients, without a major cytogenetic response at ponatinib discontinuation, including all patients treated with subsequent TKIs, responded to therapy. Seventeen AP patients, stopped ponatinib due to resistance (n = 15) or intolerance (n = 2). At discontinuation, 14 were still in AP and three had progressed to BP. Four patients were treated with SCT and one achieved major molecular response. None of the 12 patients treated with non-SCT approaches responded to subsequent therapy. Median survival for all patients was 16.6 months after ponatinib discontinuation (31, 9 and 13 months for patients in CP, AP and BP, respectively). Median survival was 60 months for patients who discontinued ponatinib for toxicity and 11 months for those who discontinued for resistance. Long-term outcome of patients with ponatinib failure are poor with estimated one-year OS and EFS rates of 54% and 40%, respectively. New treatment options are required for this subset of patients.

A Review of Omacetaxine: A Chronic Myeloid Leukemia Treatment Resurrected

The paradigm of targeted therapy was pioneered for chronic myeloid leukemia (CML). The advent of tyrosine kinase inhibitors (TKIs) has led to marked improvements in responses and overall survival; however, there is still a subset of patients that are either resistant through a multitude of mechanisms or intolerant to standard TKI therapy. Omacetaxine mepesuccinate (omacetaxine), a semisynthetic purified homoharringtonine compound, has been studied for over 40 years and was approved in 2012 by the Food and Drug Administration (FDA) for patients with CML refractory or intolerant to two or more TKIs. Omacetaxine has a novel mechanism of action-inhibition of protein synthesis, which does not overlap with kinase inhibition. Multiple studies have demonstrated that omacetaxine can achieve responses in heavily treated patients with either chronic-phase or accelerated-phase CML, regardless of the presence of mutations in the tyrosine kinase domain. This review will outline the tortuous story of omacetaxine, including preclinical and clinical studies of homoharringtonine, current indications, and management guidelines.

Targeting the PIM protein kinases for the treatment of a T-cell acute lymphoblastic leukemia subset

New approaches are needed for the treatment of patients with T-cell acute lymphoblastic leukemia (T-ALL) who fail to achieve remission with chemotherapy. Analysis of the effects of pan-PIM protein kinase inhibitors on human T-ALL cell lines demonstrated that the sensitive cell lines expressed higher PIM1 protein kinase levels, whereas T-ALL cell lines with NOTCH mutations tended to have lower levels of PIM1 kinase and were insensitive to these inhibitors. NOTCH-mutant cells selected for resistance to gamma secretase inhibitors developed elevated PIM1 kinase levels and increased sensitivity to PIM inhibitors. Gene profiling using a publically available T-ALL dataset demonstrated overexpression of PIM1 in the majority of early T-cell precursor (ETP)-ALLs and a small subset of non-ETP ALL. While the PIM inhibitors blocked growth, they also stimulated ERK and STAT5 phosphorylation, demonstrating that activation of additional signaling pathways occurs with PIM inhibitor treatment. To block these pathways, Ponatinib, a broadly active tyrosine kinase inhibitor (TKI) used to treat chronic myelogenous leukemia, was added to this PIM-inhibitor regimen. The combination of Ponatinib with a PIM inhibitor resulted in synergistic T-ALL growth inhibition and marked apoptotic cell death. Treatment of mice engrafted with human T-ALL with these two agents significantly decreased the tumor burden and improved the survival of treated mice. This dual therapy has the potential to be developed as a novel approach to treat T-ALL with high PIM expression.

Minimal Residual Disease Eradication in CML: Does It Really Matter?

BCR-ABL1 tyrosine kinase inhibitors (TKIs) have improved the prognosis of chronic phase chronic myeloid leukemia (CP-CML) to an extent that survival is largely determined by non-CML mortality. Monitoring for minimal residual disease by measuring BCR-ABL1 messenger RNA is a key component of CML management. CP-CML patients who achieve a stable deep molecular response may discontinue (TKIs) with an ~ 50% chance of entering treatment-free remission (TFR). So far discontinuation of TKIs has largely been limited to clinical trials, but is on the verge of becoming a part of wider clinical practice. Careful patient selection, dense molecular monitoring, and prompt reinstitution of treatment in the event of relapse are all vital to reproduce the same level of success. Much effort has been dedicated to identifying therapeutic strategies to eliminate CML stem cells and enable to TFR in more patients. Unfortunately, despite promising preclinical data, as yet, none of the various approaches have entered clinical practice.

Dasatinib

Dasatinib is an oral available short-acting inhibitor of multiple tyrosine kinases. It was designed to inhibit ABL and SRC, but also has activity in multiple other kinases, including c-KIT, PDGFR-α, PDGFR-β, and ephrin receptor kinases. Dasatinib is a very potent inhibitor of BCR-ABL and an effective treatment for the BCR-ABL-driven diseases chronic myeloid leukemia (CML) and Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), characterized by the constitutively active tyrosine kinase, BCR-ABL. Dasatinib is approved for the treatment of CML (all phases) including children and for the treatment of Ph+ ALL, resistant or intolerant to prior imatinib treatment. Randomized trials in CML comparing dasatinib with imatinib show that first-line dasatinib causes significantly deeper and faster molecular remissions. In accelerated and blastic phase CML, as well as in Ph+ ALL, dasatinib frequently induces complete hematologic and cytogenetic remissions even in imatinib pretreated patients. Remissions however are often short. Dasatinib is administered independent of food intake as a once-daily dose of 100 mg in chronic phase CML and 140 mg in Ph+ ALL or blastic phase. Side effects of dasatinib are frequent but mostly moderate and manageable and include cytopenias and pleural effusions. The review presents the preclinical and clinical activity of dasatinib with a focus on clinical studies in CML.

The BCL2L11 deletion polymorphism is not associated with imatinib resistance in chronic myeloid leukemia patients: meta-analysis

A common deletion polymorphism of the gene Bcl-2 like protein 11 (BCL2L11, BIM) has been reported to cause tyrosine kinase inhibitors (TKIs) resistance in several malignant tumors. However, the conclusions were not consistent in chronic myeloid leukemia (CML) individuals. In order to obtain a reliable conclusion, we systematically searched PubMed, Embase, Web of Science, Chinese Biomedical Database, and China National Knowledge Infrastructure and performed the meta-analysis. Six published articles contain 760 East Asian patients were identified from these electronic databases. The methodological quality of one included trial was high, and the others were moderate. Meta-analysis showed that the rate of TKI resistance between the BIM deletion and wild-type group were no statistical significance (OR = 1.24, 95% CI 0.79-1.95). In conclusion, BIM deletion may not a predictor of TKI resistance in CML individuals in East Asia.

Imatinib Intolerance Is Associated With Blastic Phase Development in Philadelphia Chromosome-Positive Chronic Myeloid Leukemia

BACKGROUND

Over the past years, the survival of patients with Philadelphia-positive chronic myeloid leukemia (CML Ph(+)) has increased as a result of therapy with tyrosin kinase inhibitors (TKIs). Intolerance to TKIs has been described in approximately 20% of patients receiving treatment. We studied the incidence of imatinib intolerance in patients with CML Ph(+) and their outcome in our CML reference site, as there is no information about the evolution of patients intolerant to TKIs.

PATIENTS AND METHODS

A group of 86 patients with CML Ph(+) receiving imatinib monotherapy who abandoned treatment were the basis for this study. We present the trends of their disease evolution.

RESULTS

The median of age at diagnosis was 42 years. Within a year, 19 (22%) of 86 patients developed imatinib intolerance, all of them with grade III or IV disease that required imatinib dose reduction or discontinuation. Of these patients, 16 (84%) of 19 developed transformation to blastic phase. The cumulative incidences of blastic phase development were 47% in the nonintolerant group and 84% in the intolerant group. There was a relative risk for those with imatinib intolerance to develop blastic phase of 1.78 (95% confidence interval, 1.28 to 2.42) (P < .05).

CONCLUSION

Most imatinib-intolerant patients develop blastic phase transformation, with a poor survival of 3 to 6 months; no effective rescue treatment is available. Future research should to determine whether the origin of this evolution is really due to the intolerance itself or whether it is due to a more aggressive form of the disease, perhaps related to genetic transformation.

Multiparameter Analysis of Off-Target Effects of Dasatinib on Bone Homeostasis in Patients With Newly Diagnosed Chronic Myelogenous Leukemia

BACKGROUND

We assessed patients with chronic myelogenous leukemia (CML) for serum calcium (Ca), phosphate (PO4), bone alkaline phosphatase, N-telopeptide (NTx), osteoprotegerin (OPG) levels, and trabecular bone area (TBA) in bone marrow (BM) specimens before and after treatment with dasatinib. We identified a significant increase in percentage of TBA in postdasatinib BM (P = .022). This suggests that dasatinib therapy can increase TBA without significant changes in bone and mineral metabolism. Interferences with bone homeostasis and mineral metabolism have been described in patients receiving imatinib for CML or gastrointestinal stromal tumors. Dasatinib is a potent second-generation tyrosine kinase inhibitor designed to inhibit ABL and SRC kinases while also interfering with the c-Kit, platelet-derived growth factor receptor, and STAT5 pathways.

PATIENTS AND METHODS

We used a multiparameter approach to examine the off-target effects of dasatinib in 30 patients with CML treated between 2009 and 2012. We recorded serum Ca and PO4 levels, analyzed markers of bone formation (bone alkaline phosphatase/bone-specific alkaline phosphatase [BAP]) and bone resorption (NTx), measured OPG levels, and digitally analyzed changes in TBA in paired BM biopsy specimens before and after treatment. We correlated all findings with each other and with the results of conventional cytogenetic and molecular analyses.

RESULTS

We identified a significant increase in the percentage of TBA in postdasatinib BM biopsy specimens (P = .022) and noted a decrease in serum OPG levels in 75% of patients. Ca, PO4, BAP, and NTx levels remained steady, without significant changes. There was no correlation between biomarker levels, percentage of TBA, and/or cytogenetic or molecular response.

CONCLUSION

These findings suggest that dasatinib therapy (within the therapeutic range) can increase trabecular bone, without causing significant changes in bone and mineral metabolism. Nonetheless, monitoring of bone health and skeletal integrity should be included into the long-term management of patients treated with dasatinib to further enhance our understanding of its safety profile and its potential role as a treatment modality for other bone diseases.

Long-term patient-reported outcomes from an open-label safety and efficacy study of bosutinib in Philadelphia chromosome-positive chronic myeloid leukemia patients resistant or intolerant to prior therapy

BACKGROUND

Health‐related quality of life (HRQOL) in patients with chronic‐phase chronic myeloid leukemia (CML) is important because of the requirement for long‐term treatment. This study assessed HRQOL in bosutinib‐treated patients with Philadelphia chromosome–positive CML and resistance or intolerance to 1 (chronic‐phase second‐line [CP2L]) or more (chronic‐phase third‐line [CP3L]) tyrosine kinase inhibitors who had 264 weeks or more of follow‐up (ClinicalTrials.gov identifier NCT00261846).

METHODS

Patient‐reported HRQOL was assessed with the EuroQol 5‐Dimensions Questionnaire (EQ‐5D) and the Functional Assessment of Cancer Therapy–Leukemia (FACT‐Leu).

RESULTS

In total, 284 and 119 patients composed the CP2L and CP3L cohorts, respectively. At treatment completion, more than 50% of the patients in the CP2L and CP3L cohorts completed the EQ‐5D and FACT‐Leu assessments. The EQ‐5D and EQ‐5D visual analog scale scores were stable in both cohorts throughout treatment. The mean FACT‐Leu scores were generally stable over time but were lower in magnitude in the CP3L cohort versus the CP2L cohort. The FACT‐Leu scale scores of a subset of patients with chronic diarrhea (CP2L, n = 101; CP3L, n = 30) were similar to the scores of the larger cohorts. Minimally important differences (MIDs) from baseline for the FACT‐Leu scale scores were observed for the following: emotional well‐being (EWB), Functional Assessment of Cancer Therapy–General (FACT‐G) Total, FACT‐Leu Total, and Functional Assessment of Cancer Therapy Trial Outcome Index (FACT‐TOI) in the CP2L cohort and FACT‐Leu Total in the CP3L cohort. Among patients with chronic diarrhea, MIDs were observed for EWB, FACT‐G Total, FACT‐Leu Total, and FACT‐TOI in the CP2L cohort and for EWB, FACT‐G Total, and FACT‐Leu Total in the CP3L cohort.

CONCLUSIONS

HRQOL was maintained with long‐term bosutinib treatment for patients with CP2L and CP3L CML. Cancer 2018;124:587‐95. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Health‐related quality of life (assessed with the Functional Assessment of Cancer Therapy–Leukemia) and the general health status (assessed with the EuroQol 5‐Dimensions Questionnaire) were largely maintained in chronic‐phase chronic myeloid leukemia patients receiving bosutinib for 264 weeks or longer. Health‐related quality of life was maintained by patients who receive bosutinib as a second‐ or third‐line treatment for chronic‐phase chronic myeloid leukemia.