Chromosome-positive Chronic Myelogenous Leukemia Research Articles

Abstract P4-05-08: Cellular localization dictates the role for c-Abl in breast cancer

Abstract c-Abl is a ubiquitously expressed non-receptor tyrosine kinase that regulates numerous aspects of normal mammary epithelial cell (MEC) physiology. However, the exact role of c-Abl during mammary tumorigenesis remains controversial. Clinical trials utilizing the c-Abl antagonist, imatinib mesylate, for the treatment of metastatic breast cancer (BC) patients failed due to disease progression. Additionally, our previous studies overexpressing a constitutively active c-Abl mutant in aggressive murine triple negative breast cancer (TNBC) cells abrogated tumorigenesis when injected into syngeneic mice. Through data mining we found c-Abl expression to be down-regulated across BC subtypes and this correlated with a significantly worse relapse free survival rate for patients of triple negative and luminal A BC subtypes. Furthermore, through in silico analyses we determined that BC patients with high c-Abl expression responded to docetaxel treatment, whereas their low c-Abl expressing counterparts did not. Taken together these findings support a tumor suppressive role for c-Abl in BC and that its targeted activation could inhibit BC tumorigenesis as well as sensitize BC patients to docetaxel treatment. We show here that shRNA mediated depletion of c-Abl elicited docetaxel resistance in malignant MECs through three dimensional (3-D) culture and clonogenic assays on plastic. Furthermore, we show through data mining that c-Abl expression is down-regulated in response to docetaxel treatment in a cohort of BC patients. This finding was recapitulated in malignant MECs through which docetaxel treatment selected for cells that retained lower c-Abl expression highlighting the importance of c-Abl in this cell death pathway. Targeted activation of c-Abl utilizing a novel small molecule activator, DPH, presents a novel therapeutic strategy for sensitizing BC patients to docetaxel treatment. However, we show DPH-mediated c-Abl activation to inhibit the proliferation of luminal A MCF7 BC cells, but enhance proliferation of the TNBC MDA-MB-231-L2 cell line in vitro. The cellular localization of c-Abl is crucial for its tumor suppressive functions. In Philadelphia chromosome positive chronic myelogenous leukemia (CML) the constitutively active BCR-Abl gene fusion has a strict cytoplasmic localization, however when nuclear expression of BCR-Abl is enforced CML cells undergo apoptosis. Cellular fractionation of normal murine MECs cells indicate that c-Abl expression is detected both in cytoplasmic and nuclear compartments before and with greater amounts detected in the nucleus upon activation. A similar trend is seen in the luminal A MCF7 BC cell line, however c-Abl is predominantly expressed in the cytoplasm basally in the TNBC MDA-MB-231-L2 cell line and retains a strict cytoplasmic localization upon activation with DPH. These findings suggest a similar mechanism as CML of cytoplasmic isolation as a means of circumventing the tumor suppressive role of c-Abl across different BC subtypes. Data from ongoing immunohistochemical analyses of a cohort of BC patient tissue microarrays will inform whether nuclear versus cytoplasmic c-Abl will correlate with available patient outcome data to determine if cellular localization dictates a tumor suppressive or tumor promoting role for c-Abl. Citation Format: Chevaun D Morrison, Hannah Gilmore, William P Schiemann. Cellular localization dictates the role for c-Abl in breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-05-08.

Abstract 1717: Downregulation of miR-217 correlates with resistance of ph+ leukemia cells to ABL tyrosine kinase inhibitors

Abstract This study found that long-term exposure of chronic myelogenous leukemia (CML) K562 cells to BCR/ABL thyrosine kinase inhibirors (TKIs) caused drug-resistance in association with an increase in levels of DNA methyltransferases (DNMTs) and a decrease in levels of microRNAs (miRNAs) miR-217. These observations are clinically relevant; an increase in levels of DNMT3A in association with downregulation of miR-217 were noted in leukemia cells isolated from individuals with BCR/ABL TKI-resistant philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) and CML. Further studies with TKI-resistant K562 cells found that forced expression of miR-217 inhibited expression of DNMT3A through a miR-217-binding site within the 3′-untranslated region of DNMT3A and sensitized these cells to growth inhibition mediated by the TKI. Of note, long-term exposure of K562 cells to dasatinib (10 nM) together with 5-Aza-2′-deoxycytidine (5-AzadC) (0.1 μM) potently inhibited proliferation of these cells in association with upregulation of miR-217 and downregulation of DNMT3A in vitro. In addition, a decrease in levels of DNMT3A and an increase in levels of miR-217 were noted in K562 tumors growing in immune deficient mice that were treated by the combination of 5-AzadC and dasatinib. Taken together, Ph+ leukemia cells acquire TKI-resistance via downregulation of miR-217 and upregulation of DNMT3A. Inhibition of DNMT3A by forced expression of miR-217 or 5-AzadC may be useful to prevent drug resistance in individuals who receive TKIs. Citation Format: Takayuki Ikezoe, Chie Nishioka, Jing Yang, Akihito Yokoyama. Downregulation of miR-217 correlates with resistance of ph+ leukemia cells to ABL tyrosine kinase inhibitors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1717. doi:10.1158/1538-7445.AM2014-1717

Impact of low-grade adverse events on health-related quality of life in adult patients receiving imatinib or nilotinib for newly diagnosed Philadelphia chromosome positive chronic myelogenous leukemia in chronic phase

Objective:Chronic myeloid leukemia (CML) treatment relies on tyrosine kinase inhibitors (TKIs), but their use can be associated with low-grade adverse events (AEs). This analysis aimed to identify the low-grade AEs which significantly impact the Health Related Quality of Life (HRQoL) of CML patients in chronic phase (CP) and to compare the incidence of such AEs among nilotinib- and imatinib-treated patients.Research design and methods:Data from the 48 month ENESTnd trial were used (N = 593 patients). HRQoL was assessed using generic (SF-36) and leukemia-specific (FACT-Leu) HRQoL surveys. AEs were categorized into 26 system organ classes.Results:In the adjusted regression model, five low-grade AE categories – gastrointestinal disorders, blood and lymphatic system disorders, general disorders and administration site conditions, musculoskeletal disorders, and psychiatric disorders – significantly impaired at least one HRQoL score. The incidence rate of these five AE categories was either significantly lower for nilotinib than imatinib or not different between the two drugs. The AE categories with lower incidence for both nilotinib 300 mg BID and 400 mg BID versus imatinib 400 mg daily were gastrointestinal, blood and lymphatic system, and musculoskeletal; nilotinib 300 mg BID had lower incidence than imatinib for general disorders.Limitations:Low-grade AEs were grouped and analyzed by system organ class category, so the effect of some rare individual AEs on HRQoL may have been missed.Conclusions:The impact of low-grade AEs on HRQoL should be taken into account, along with other factors, when selecting the optimal treatment for patients newly diagnosed with CML-CP.

The European Medicines Agency Review of Bosutinib for the Treatment of Adult Patients With Chronic Myelogenous Leukemia: Summary of the Scientific Assessment of the Committee for Medicinal Products for Human Use

On March 27, 2013, a conditional marketing authorization valid throughout the European Union was issued for bosutinib (Bosulif) for the treatment of adult patients with chronic-phase, accelerated-phase, and blast-phase Philadelphia chromosome positive (Ph⁺) chronic myelogenous leukemia (CML) previously treated with one tyrosine kinase inhibitor or more and for whom imatinib, nilotinib, and dasatinib are not considered appropriate treatment options. Bosutinib is a kinase inhibitor that targets the BCR-ABL kinase. The recommended dose is 500 mg of bosutinib once daily. The main evidence of efficacy for bosutinib was based on a CML subgroup analysis of study 3160A4-200, a phase I/II study of bosutinib in Ph⁺ leukemia in imatinib-resistant or intolerant CML. The subgroup was defined based on the presence of a BCR-ABL kinase domain mutation that would be expected to confer resistance to dasatinib (F317, E255) or nilotinib (E255, Y253, F359) and expected to have sensitivity to bosutinib or based on the presence of medical conditions or prior toxicities that may predispose the patient to unacceptable risk in the setting of nilotinib or dasatinib therapy. A conditional marketing authorization was granted because of the limited evidence of efficacy and safety currently supporting this last-line indication.

Downregulation of miR‐217 correlates with resistance of ph+ leukemia cells to ABL tyrosine kinase inhibitors

This study found that long-term exposure of chronic myelogenous leukemia (CML) K562 cells to BCR/ABL thyrosine kinase inhibitors (TKI) caused drug-resistance in association with an increase in levels of DNA methyltransferases (DNMT) and a decrease in levels of microRNA miR-217. These observations are clinically relevant; an increase in levels of DNMT3A in association with downregulation of miR-217 were noted in leukemia cells isolated from individuals with BCR/ABL TKI-resistant Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) and CML. Further studies with TKI-resistant K562 cells found that forced expression of miR-217 inhibited expression of DNMT3A through a miR-217-binding site within the 3′-untranslated region of DNMT3A and sensitized these cells to growth inhibition mediated by the TKI. Of note, long-term exposure of K562 cells to dasatinib (10 nM) together with 5-Aza-2′-deoxycytidine (5-AzadC) (0.1 μM) potently inhibited proliferation of these cells in association with upregulation of miR-217 and downregulation of DNMT3A in vitro. In addition, a decrease in levels of DNMT3A and an increase in levels of miR-217 were noted in K562 tumors growing in immune-deficient mice that were treated with the combination of 5-AzadC and dasatinib. Taken together, Ph+ leukemia cells acquire TKI resistance via downregulation of miR-217 and upregulation of DNMT3A. Inhibition of DNMT3A by forced expression of miR-217 or 5-AzadC may be useful to prevent drug resistance in individuals who receive TKI.

Bosutinib: A Review of Its Use in Patients with Philadelphia Chromosome-Positive Chronic Myelogenous Leukemia

Bosutinib (Bosulif®) is an orally administered small molecule tyrosine kinase inhibitor (TKI) of BCR-ABL and SRC family kinases. It is indicated for the treatment of adult patients with chronic-, accelerated-, or blast-phase Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) with resistance or intolerance to prior therapy (imatinib, dasatinib, or nilotinib) [USA] or for a small subpopulation of these patients for whom imatinib, nilotinib, and dasatinib are not considered appropriate treatment options (EU). In a multinational pivotal trial (n = 547), bosutinib treatment resulted in a major cytogenetic response (MCyR) at 24 weeks in one-third of all treated patients with imatinib-resistant chronic-phase CML who had no previous exposure to any TKIs other than imatinib (primary endpoint), with similar results observed in chronic-phase CML patients who were intolerant of imatinib and naïve to all other TKIs. MCyRs were also seen in more than one-quarter of evaluable patients with chronic-phase CML previously treated with multiple TKIs. Most of the patients with chronic-phase CML achieved a complete hematologic response with bosutinib and some patients with advanced phases of CML achieved an overall hematologic response. Responses were seen irrespective of the type of BCR-ABL mutation at baseline, except T315I. Bosutinib had a manageable tolerability profile in the pivotal trial, with ≤21 % of patients with chronic-phase CML discontinuing the treatment because of adverse events. Diarrhea was the most common adverse event but was generally manageable, with only few patients discontinuing the treatment because of diarrhea. Therefore, bosutinib is a useful TKI option for patients with Ph+ CML in second-line or greater settings.

Chapter Six - Imatinib Mesylate

Imatinib (INN), marketed by Novartis as Gleevec (United States) or Glivec (Europe/Australia/Latin America), received Food & Drug Administration (FDA) approval in May 2001 and is a tyrosine kinase inhibitor used in the treatment of multiple cancers, most notably Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia. Like all tyrosine kinase inhibitors, imatinib works by preventing a tyrosine kinase enzyme. Because the BCR-Abl tyrosine kinase enzyme exists only in cancer cells and not in healthy cells, imatinib works as a form of targeted therapy-only cancer cells are killed through the drug's action. In this regard, imatinib was one of the first cancer therapies to show the potential for such targeted action and is often cited as a paradigm for research in cancer therapeutics. This study presents a comprehensive profile of imatinib, including detailed nomenclature, formulae, physico-chemical properties, methods of preparation, and methods of analysis (including compendial, electrochemical, spectroscopic, and chromatographic methods of analysis). Spectroscopic and spectrometric analyses include UV/vis spectroscopy, vibrational spectroscopy, nuclear magnetic resonance spectrometry ((1)H and (13)C NMR), and mass spectrometry. Chromatographic methods of analyses include electrophoresis, thin layer chromatography, and high-performance liquid chromatography. Preliminary stability investigations for imatinib have established the main degradation pathways, for example, oxidation to N-oxide under oxidative stress conditions. Stability was also carried out for the formulation by exposing to different temperatures 0°C, ambient temperature, and 40°C. No remarkable change was found in the drug content of formulation. This indicates that the drug was stable at the above optimized formulation. Stability studies under acidic and alkaline conditions have established the following main degradation products: α-(4-Methyl-1-piperazinyl)-3'-{[4-(3-pyridyl)-2-pyrimidinyl] amino}-p-tolu-p-toluid-ide methanesulfonate and 4-(4-methylpiperazin-1-ylmethyl)-benzoic acid. The main degradation products under oxidation conditions, that is, 4-[(4-methyl-4-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-enzamide, 4-[(4-methyl-1-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-benzamide, and 4-[(4-methyl-1,4-dioxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-enzamide. Clinical application studies for pharmacodynamics, pharmacokinetics, mechanism of action, and clinical uses of the drug were also presented. Each of the above stages includes appropriate figures and tables. More than 50 references were given as proof of the above-mentioned studies.

Bosutinib in the treatment of patients with Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia: an overview

Bosutinib is an orally bioavailable SRC/ABL tyrosine kinase inhibitor with activity against all phases of resistant chronic myeloid leukemia that do not express the T315I or V299L ABL kinase domain mutations. Bosutinib has a unique toxicity profile that is manageable. This paper provides an overview of bosutinib, covering pharmacodynamics and pharmacokinetic properties, results of treatment in newly diagnosed and previously treated chronic myeloid leukemia patients, as well as common side effects.

Use Of Nilotinib As a First Line Treatment In Adult Patients With Philadelphia Chromosome-Positive and Chronic Phase Myeloid Leukemia

IntroductionNilotinib, a more potent and selective drug than imatinib, was approved by the FDA and EMA initially for the treatment of chronic and accelerated phase Philadelphia chromosome positive (Ph+) chronic myelogenous leukemia (CML) patients resistant or intolerant to prior therapy including imatinib and subsequently for the treatment of newly-diagnosed Ph+ CML patients in the chronic phase (CML-CP). The aim of the present study was to investigate efficacy and safety profile of nilotinib in a Turkish population of newly-diagnosed Ph+ CML-CP patients and to evaluate the effects of these results on prognosis according to current treatment guidelines. MethodsThe study was planned as a multicenter, open-label, one-arm phase II clinical trial. All patients were planned to be treated with nilotinib (AMN107, Tasigna®) 300 mg BID for 24 months. Herein, efficacy results of the patients who completed the first year of the study are presented. ResultsOf the 112 patients included in the study, data for 94 patients who completed 12 months of the study up to April 29, 2013 were analyzed. Of these 94 patients, 16 were excluded within this period and 78 completed the first year of the study within the median 371 days (range, 339-401 days) or median 12.4 months (range, 11.3-13.4 months). General characteristics of the patients are presented in Table 1.Table 1General characteristics of the patientsCharacteristicsAge, year46.5 (range 19-78)Gender (Female/Male)37 (%39.4)/57 (%60.6)Palpable spleen size (maximum distance below the rib margin) (baseline), cm0.0 (0-17)Baseline Leukocyte count (range), K/mm329.2 (1.7-289.4)Baseline Platelet count (range), K/mm3343.0 (75-1,268)Treatment-related characteristics of the patients are presented in Table 2.Table 2Treatment-related characteristics of the patientsN80% Confidence IntervalCumulative MMR rate by 12th month9458 (61.7)54.6-68.4Time to MMR58Days184.8±84.7Months6.2±2.8BCR-ABL level at 3rd month87<%1075 (86.2)80.2-90.8≥%1012 (13.8)9.2-19.8CCyR rate at 6th month8476 (90.5)85.0-94.4CCyR rate at 12th month7467 (90.5)84.6-94.7Data are presented as mean±standard deviation or number (%), where appropriate.MMR (Major molecular rate): BCR-ABL/control gene ratio of ≤%0.1 measured by RQ-PCR as %CCyR (Complete cytogenetic response): Patients with 0% Ph+ metaphasesCumulative MMR rates at 3rd, 6th 9th, and 12th months of the patients are shown in Figure 1. [Display omitted] ConclusionsAccording to the results of interim analysis of this first prospective CML study conducted on Turkish population, the cumulative MMR rate by 12th month (primary endpoint) (61.7%) appears to be similar to that of the ENESTnd study. From the 3rd month, rapid and increasing MMR rates were reported and median time to MMR was 6.5 months. At both 6th and 12th month, high CCyR rates (both 90.5%) were also established. At all landmark evaluations, most of the patients rapidly achieved high rates of cytogenetic and molecular responses to nilotinib assessed by both 2009 and 2013 ELN optimal response criteria, and only one patient had disease progression. These results suggest that more rapid and greater efficacy was achieved with nilotinib during the 1st year of the study in comparison to historical data with imatinib and that nilotinib might improve short-term responses when started in the first-line setting.The rate of patients with BCR-ABL ≤10% at 3rd month, which is very important according to the current treatment guidelines, was 86.2%.The results of the present study revealed that efficacy of nilotinib, which is a licensed alternative for the treatment of newly diagnosed Ph+ CML-CP in Turkey, might provide a new standard of treatment. Disclosures:Saydam:Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation, Turkey: Consultancy, Membership on an entity's Board of Directors or advisory committees. Haznedaroglu:Novartis Pharmaceuticals Corporation, Turkey: Honoraria, Research Funding. Yavuz:Novartis Pharmaceuticals Corporation, Turkey: Membership on an entity's Board of Directors or advisory committees. Ali:Novartis Pharmaceuticals Corporation, Turkey: Membership on an entity's Board of Directors or advisory committees. Guvenc:Novartis Pharmaceuticals Corporation, Turkey: Membership on an entity's Board of Directors or advisory committees. Sonmez:Novartis Pharmaceuticals Corporation, Turkey: Membership on an entity's Board of Directors or advisory committees. Akkaynak:Novartis Pharmaceuticals Corporation, Turkey: Employment. Dag:Novartis Pharmaceuticals Corporation, Turkey: Employment.

Impact Of Low-Grade Adverse Events (AEs) On Health-Related Quality Of Life (HRQoL) In Adult Patients With Newly Diagnosed Philadelphia Chromosome-Positive Chronic Myelogenous Leukemia In Chronic Phase (Ph+ CML-CP) From The Enestnd Trial: 48-Month Follow-Up

BackgroundIn the randomized, phase 3 ENESTnd (Evaluating Nilotinib Efficacy and Safety in Clinical Trials–Newly Diagnosed Patients) trial, the superior efficacy of nilotinib (NI) compared with imatinib (IM) has been firmly established in patients with newly diagnosed Ph+ CML-CP. Based on the 36 month ENESTnd data, both NI and IM demonstrated good safety and AE profiles, with low-grade AEs (grades 1/2) being reported more frequently than grade 3/4 AEs. AEs, even mild and moderate in nature, may negatively impact HRQoL. This post-hoc analysis evaluated the association between low-grade AEs and HRQoL using the 48-month update of ENESTnd. Methods846 newly diagnosed Ph+ CML-CP patients were randomized to NI 300 mg BID (n = 282), NI 400 mg BID (n =281), or IM 400 mg QD (n = 283). HRQoL was assessed using the Functional Assessment of Cancer Therapy – Leukemia (FACT-Leu) and the Short Form 36 Health Survey (SF-36). Derived HRQoL scores included FACT-Leu Total (FLT), SF-36 mental component summary (MCS) and SF-36 physical component summary (PCS). Questionnaires were scheduled to be administered at enrollment and the end of 3, 12, 24, 36 and 48 months or at early discontinuation. Low-grade AEs were classified based on the 26 system organ classes (SOCs) and assessed during a 7-day and 28-day observation period prior to each administration date of FACT-Leu and SF-36 questionnaires, respectively, which corresponds to the periods over which these HRQoL outcomes were measured. Only AEs with a prevalence ≥1% during the observation period were analyzed. The change in HRQoL outcomes from baseline was compared between patients with low-grade AEs and those without any AEs during the observation period (excluding patients with grade 3/4 AEs) using linear mixed effects models, adjusting for potential confounders. Subsequently, adjusted Poisson regression models were used to compare frequencies of low-grade AEs that were found to significantly impact HRQoL over the course of 48 months among the three treatment arms. ResultsOverall, the occurrence of gastrointestinal (GI) (e.g. nausea, diarrhea), general (e.g. fatigue, peripheral edema), musculoskeletal (e.g. muscle spasms, arthralgia) and psychiatric disorders (e.g. insomnia, anxiety) had a statistically significant negative impact on change in HRQoL from baseline (Table 1). Both NI treatment arms had a significantly lower incidence of GI and musculoskeletal disorders compared with IM (Table 2). ConclusionsSome low-grade AEs impaired HRQoL in patients treated with NI or IM. These AEs were less frequent in patients treated with NI.1. Linear mixed effect models adjusted for demographics, prior treatment, clinical measures and other low grade AEs with < 1% prevalence during the observation period combined together.2. “-“ indicates that the AE SOC prevalence was < 1% during the observation period.3. N represents the number of individual HRQoL assessments across all patients included in the analysis.1. Poisson regression models adjusted for demographics, prior treatment and clinical measures. Disclosures:Chen:Novartis: Employment, Equity Ownership. Guerin:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Marynchenko:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Ionescu-Ittu:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Hiscock:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Nitulescu:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Pooja:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Hsu:Novartis: Employment, Intern Other. Keir:Novartis: Employment, Equity Ownership. Wu:Novartis Pharmaceuticals: Consultancy, employee of Analysis Group Inc., which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding.

An Unusual Case of Philadelphia Chromosome–Positive Chronic Myelogenous Leukemia With Trisomy 19 Presenting With Megakaryoblastosis and Myelofibrosis

Initial identification of chronic myelogenous leukemia is very important since targeted therapy leads to life-saving remission. Rarely, chronic myelogenous leukemia presents with an unusual picture, making the diagnosis challenging. We describe such a case of chronic myelogenous leukemia in blast crisis in a previously healthy 61-year-old woman. The patient presented with fever, myalgias, and night sweats and was first worked up for an infectious etiology. Because of persistent anemia, a bone marrow biopsy was performed that revealed fibrosis with increased megakaryoblasts. Even though initial cytogenetic studies could not be performed because of "dry tap" aspirate, persistent efforts for cytogenetic studies were made, including a "squeeze preparation" from the core biopsy, which revealed t(9;22)(q34;q11.2) and trisomy 19. The patient was treated with tyrosine kinase inhibitors, chemotherapy, and subsequently an allogeneic stem cell transplant. She is in persistent remission. This case illustrates a complex presentation of chronic myelogenous leukemia and provides an overview of morphologic cues and the importance of performing cytogenetic studies that led to the diagnosis.

Tyrosine kinase inhibition increases functional parkin‐ B eclin‐1 interaction and enhances amyloid clearance and cognitive performance

Tyrosine kinase inhibitors (TKIs) are effective therapies for leukaemia. Alzheimer is a neurodegenerative disease characterized by accumulation of β-amyloid (plaques) and hyper-phosphorylated Tau (tangles). Here we show that AD animals have high levels of insoluble parkin and decreased parkin-Beclin-1 interaction, while peripheral administration of TKIs, including Nilotinib and Bosutinib, increases soluble parkin leading to amyloid clearance and cognitive improvement. Blocking Beclin-1 expression with shRNA or parkin deletion prevents tyrosine kinase (TK) inhibition-induced amyloid clearance, suggesting that functional parkin-Beclin-1 interaction mediates amyloid degradation. Isolation of autophagic vacuoles (AVs) in AD mouse brain shows accumulation of parkin and amyloid, consistent with previous results in AD brains, while Bosutinib and Nilotinib increase parkin-Beclin-1 interaction and result in protein deposition in the lysosome. These data suggest that decreased parkin solubility impedes parkin-Beclin-1 interaction and amyloid clearance. We identified two FDA-approved anti-cancer drugs as potential treatment for AD.Two FDA-approved tyrosine kinase inhibitor drugs, Bosutinib and Nilotinib, are shown to ameliorate Alzheimer's disease pathology in mouse models by increasing soluble parkin and leading to amyloid clearance and cognitive improvement.

Evaluation of novel aryloxyalkyl derivatives of imidazole and 1,2,4-triazole as heme oxygenase-1 (HO-1) inhibitors and their antitumor properties

A novel series of aryloxyalkyl derivatives of imidazole and 1,2,4-triazole, 17–31, was designed and synthesized as inhibitors of heme oxygenase-1 (HO-1) and heme oxygenase-2 (HO-2). Some of these compounds were found to be good inhibitors of HO-1, in particular those carrying an imidazole moiety as azolyl group and a 3-bromo or 4-iodophenyl as aryl moiety. The most potent compounds 6 and 30 were selected and studied for their antitumor properties in a model of LAMA-84 R cell line overexpressing HO-1 and resistant to imatinib mesylate (IM), a tyrosine-kinase inhibitor used in the treatment of multiple types of cancer, most notably Philadelphia Chromosome positive (Ph+) Chronic Myelogenous Leukemia (CML). Results show that both 6 and 30 sensitized LAMA-84 R cell line to antitumor properties of IM.

Association between severe toxicity of nilotinib and UGT1A1 polymorphisms in Japanese patients with chronic myelogenous leukemia

Nilotinib is a BCR-ABL kinase inhibitor approved for the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia (CML). The UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphism UGT1A1*28 (*28)/*28 has been linked to an increased risk of hyperbilirubinemia in patients with CML who receive nilotinib. Beside *28, UGT1A1*6 (*6) is another important variant allele in Japanese patients because it is associated with adverse events of irinotecan, metabolized by UGT1A1. We retrospectively investigated the association between severe toxicity of nilotinib and UGT1A1 polymorphisms (*6 and*28) in Japanese patients with CML. Eight patients with cytogenetically confirmed CML who were receiving nilotinib were studied to explore the association of UGT1A1 polymorphisms with severe nilotinib-related toxicity. Genotyping analyses were determined for *6 and *28. All 3 patients with the *6/*6 or *6/*28 genotype had severe toxicity, including QT interval prolongation (grade 3), elevated lipase levels (grade 3) plus hyperbilirubinemia (grade 2), and anemia (grade 3) plus hepatic cyst hemorrhage (grade 2) in 1 patient each. Among the 5 patients with the *6/*1 or *1/*1 genotype, 1 had elevated lipase levels (grade 3) and another had severe pain in the lower extremities (grade 3). These findings suggest that UGT1A1 polymorphisms are important determinants of severe toxicity of nilotinib in Japanese patients.

Multiple TKIs approved in recent months

Evolution of TKIs Patients with CML and ALL Imatinib (Gleevec—Novartis) was approved more than a decade ago as a targeted leukemia therapy (i.e., Bcr-Abl TKI). Since that time, researchers have uncovered much information regarding its resistance mechanisms and potential ways to overcome resistance. Imatinib resistance reportedly occurs in approximately 33% of patients and can be subclassifi ed as Bcr-Abl–dependent or Bcr-Abl–independent. The BcrAbl–dependent mechanisms involve Bcr-Abl mutation and amplifi cation, resulting in an alteration of imatinib’s binding affi nity to the Bcr-Abl tyrosine kinase. One of the most frequently identifi ed mutations is T315l. Second-generation TKIs such as dasatinib (Sprycel—Bristol-Myers Squibb) and nilotinib (Tasigna—Novartis) are more potent than imatinib and can be used as fi rst-line agents for the management of chronic-phase CML as well as for imatinib-resistant or -intolerant patients. The new agent bosutinib is also classifi ed as a second-generation TKI. It targets the Bcr-Abl kinase and inhibits Scr-family kinases including Src, Lyn, and HcK. Pharmacologic data have shown that bosutinib inhibits 16 of 18 imatinib-resistant forms of Bcr-Abl kinases expressed in experiential cell lines. This agent, however, has no effect on T315I mutant cells. Ponatinib is classifi ed as a thirdgeneration TKI. The agent is unique in that it targets cells with a T315I mutation, which makes these cells resistant to all other currently approved TKIs. Medullary thyroid cancer Cabozantinib has a different indication and, therefore, targets another set of tyrosine kinases. It has been shown to inhibit proinvasive receptor tyrosine kinases implicated in tumor growth, metastasis, and angiogenesis, including RET, MET, and VEGFR-1, -2, and -3. Activating mutations in RET have been shown to play a central role in tumorigenesis in both inherited and sporadic forms of medullary thyroid cancer. MET and VEGF have also been implicated in the pathogenesis of this rare thyroid disease.

Permanent Sensorineural Deafness in a Patient with Chronic Myelogenous Leukemia Secondary to Intracranial Hemorrhage

A 52-year-old male presented with tinnitus and fullness in left ear for one day. Workup revealed a white blood cell count of 685 × 103/μL with marked increase in granulocyte series and myeloid precursors on peripheral smear. The initial impression was chronic myelogenous leukemia with hyperleukocytosis, and patient was started on hydration, hydroxyurea, and allopurinol. Patient tolerated bone marrow biopsy well but continued to bleed excessively from the biopsy site. Results confirmed Philadelphia chromosome positive chronic myelogenous leukemia (chronic phase). On day three of hospitalization, patient developed sudden slurred speech along with shaking movements involving extremities. Magnetic resonance imaging revealed multiple hemorrhages throughout the brain. Hydroxyurea was continued until insurance coverage for nilotinib was getting approved. On day nine of hospitalization, patient developed sudden bilateral sensorineural deafness. Repeat magnetic resonance imaging revealed multiple new hemorrhages throughout the brain. Computer tomography of the temporal bones showed inflammatory changes in right and left mastoid cells. Nilotinib was started on day eleven of hospitalization. Patient's white blood cell count continued to decrease, but there was no improvement in hearing. Four months later, patient was treated with bilateral transmastoid cochlear implants. This case highlights permanent deafness as a hemorrhagic complication secondary to chronic myelogenous leukemia.

Bosutinib in the management of chronic myelogenous leukemia

Bosutinib (SKI-606) is an orally available, once-daily dual Src and Abl kinase inhibitor, approved by the US Food and Drug Administration for the treatment of adults with chronic, accelerated, or blast-phase Philadelphia chromosome-positive chronic myelogenous leukemia who are intolerant of or resistant to first- or second-generation tyrosine kinase inhibitors. Bosutinib effectively overcomes the majority of imatinib-resistance-conferring BCR-ABL mutations except V299L and T315I. In the Bosutinib Efficacy and Safety in chronic myeloid LeukemiA (BELA) trial, bosutinib attained a faster and deeper molecular response than imatinib in newly diagnosed chronic-phase chronic myelogenous leukemia patients. Treatment-emergent adverse events are usually very manageable. Low grade, mostly self-limiting diarrhea represents the most frequently observed toxicity of bosutinib. Anti-diarrheal drugs, antiemetic agents, and/or fluid replacement should be used to treat these patients. The improved hematological toxicity of bosutinib compared with other tyrosine kinase inhibitors has been ascribed to its minimal activity against platelet-derived growth factor receptor and KIT. In this review, we give an overview on the profile of bosutinib, the clinical potential and treatment-emergent adverse events.

Synthesis and Biopharmaceutical Studies of JLTN as Potential Dasatinib Prodrug

Dasatinib was identified as a potent orally administered Src/Abl kinase inhibitor with excellent antiproliferative activity against Philadelphia chromosome-positive chronic myelogenous leukemia in chronic phase. The low bioavailability of Dasatinib may be due to both incomplete oral absorption and first-pass metabolism. A prodrug, JLTN, was synthesized to minimize the first-pass effect of Dasatinib and improve the oral bioavailability following oral administration via targeting intestinal peptide transporter and enhancing chemical stability. Biological evaluation data indicated that there was a 150%-fold increase in oral bioavailability of this prodrug compared to the parent drug Dasatinib in monkeys.

Assessment of Patient Reported Outcomes (PROs) From the Enestnd Trial with Minimum Follow-up of 36 Cycles.

AbstractAbstract 3166 Background:In ENESTnd, nilotinib (NI) significantly reduced progression and demonstrated superior molecular response rates vs. imatinib (IM) in patients newly diagnosed with Philadelphia chromosome positive chronic phase chronic myelogenous leukemia (CML-CP). Additionally, fewer NI patients discontinued therapy vs. IM (Table 1). Previously reported 24-month analyses of PROs indicated similar health-related quality of life (HRQoL) and functioning mean scores between the treatment arms, and scores similar to general population norms. Aim:To evaluate the PROs for patients in ENESTnd with minimum follow-up of 36 cycles and to understand cohort-level (per treatment arm) HRQoL outcomes Methods:In ENESTnd, nNewly diagnosed CML-CP patients were randomized to NI 300 mg twice daily (BID), NI 400 mg BID, or IM 400 mg once daily (QD). HRQoL was assessed using the Functional Assessment of Cancer Therapy – Leukemia (FACT-Leu) and the Short Form 36 Health Survey (SF-36). The FACT-Leu has two components: a) the FACT-General (FACT-G) which measures physical, social/family, emotional, and functional well-being and b) a 17-item leukemia specific subscale. The SF-36 assesses eight domains (physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health) that enable a mental component score (MCS) and physical component score (PCS). Questionnaires were administered at enrollment and end of cycles 3, 12, 24, and 36. Mixed effects models for longitudinal data were used to compare trends over time between treatment arms. Study discontinuation prevented collection of PROs from patients with inadequate response or intolerance to treatment. Pattern-mixture models were fit to attempt to control for missing PRO data resulting from discontinuation or other reasons. Separately, missing data were imputed consistently across arms for cohort-level analysis of the FACT-Leu subscale so mean cohort scores could be reported (Table 1). Results:In both mixed effects and pattern-mixture models, FACT-Leu subscale, FACT-G, and SF-36 scores (PCS and MCS) were similar across treatment arms over time. Of the patients remaining on study and completing PRO questionnaires, SF-36 PCS and MCS scores at cycle 36 in all arms were comparable to the general US population; FACT-G scores were slightly better (Table 2). In the cohort-level analysis with imputation according to reason, IM FACT-Leu subscale scores began to trend increasingly lower vs. NI arms beginning at day 168 (Figure 1). By day 1008, the IM arm mean score is 10% and 13% lower than the NI 300 mg and NI 400 mg arms, respectively (Figure 1). Higher rates of discontinuation in the IM arm are the main factors that lead to the HRQoL deficit. Conclusions:In ENESTnd, patients who respond to and tolerate treatment have consistent HRQoL that is comparable to the general population. Cohort-level analysis indicates that discontinuation rates due to inadequate response and intolerance must be considered when determining the HRQoL across the entire cohort. These results suggest that in a population of newly diagnosed patients with CML-CP, NI results in higher HRQoL than IM. These findings may have particularly important implications for payers and policy makers when evaluating treatment options.Table 1IM 400mg QD (n=283) (%)NI 300mg BID (n=282) (%)NI 400mg BID (n=281) (%)Imputed FACT-LEUbStill on treatment61.870.973.7MeanDisease progression3.50.71.40Suboptimal response/treatment failure4.21.82.814Adverse events/lab abnormalities11.09.914.214Death0.41.40.40Other a6.77.86.414aIncludes abnormal test result(s), condition no longer requires study drug, consent withdrawn, lost to follow-up, administrative problems, protocol deviationbImputed values per time point, 14 represents the lowest recorded scoreTable 2Mean (SD)IM 400mg QD (n=152)NI 300mg BID (n=176)NI 400mg BID (n=185)General US Pop.SF-36 PCS49.1 (9.0)47.9 (9.5)49.1 (8.2)49.6 (10.0)cSF-36 MCS51.3 (9.6)50.2 (9.7)49.9 (9.0)50.5 (9.9)cFACT-G86.0 (15.7)84.5 (15.4)85.1 (15.0)80.1 (18.1)dFACT-Leu subscale54.7 (9.4)54.9 (8.9)55.4 (8.5)NAcFor ages 45–54 (http://www.sf-36.org/research/sf98norms.pdf)dEval Health Prof 2005; 28:192–211. [Display omitted] Disclosures:Beaumont:Novartis: Research Funding. Magestro:Novartis: Employment. Coombs:Novartis: Employment. Fan:Novartis Pharmaceuticals Corp: Employment. Kemp:Novartis Pharmaceuticals Corp: Employment. Waltzman:Novartis: Employment.

Comparison of Treatment Changes for Patients with Chronic Myelogenous Leukemia in Chronic Phase Switched From Imatinib to Nilotinib or Dasatinib As Second-Line Therapy

AbstractAbstract 4443 Background:Nilotinib and dasatinib are two therapies approved by the US Food and Drug Administration for pts with Philadelphia chromosome positive chronic myelogenous leukemia in chronic phase (Ph+ CML-CP) who are resistant or intolerant to 1st-line imatinib. Although these therapies were shown to be generally effective and tolerable, sometimes they are not, requiring treatment changes (e.g., discontinuation, dose modification, and drug holidays). To date, no head-to-head study has been conducted to compare treatment changes between 2nd-line nilotinib and dasatinibin clinical practice. Methods:Through an online chart abstraction form, participating community physicians retrospectively submitted de-identified information on Ph+ CML-CP pts ≥ 18 years old who switched after 10/28/2007 from imatinib to 2nd-line nilotinib or dasatinibwith at least 30 days of follow-up. When multiple pts met the selection criteria, pts were selected randomly by physicians. Pts enrolled in clinical trials or with concurrent malignancies were excluded. Information was collected on clinical characteristics and therapy changes in 2nd-line treatment, including dose modification (increase or decrease), drug holiday, and discontinuation of current therapy with or without switch to a 3rd-line therapy. Reasons for therapy changes were also collected, and treatment changes were classified as due to (1) lack of effectiveness if reasons included progression to accelerated phase or blast crisis, failure to achieve satisfactory response, or loss of satisfactory response; (2) intolerance if reasons included adverse events; (3) other reasons, including non-adherence, vacation, pregnancy, or economic reasons. Rates of treatment changes were compared between treatment groups using chi-square tests. Results:122 hematologists and oncologists provided information on 597 pts (301 nilotinib pts and 296 dasatinib pts). The median follow-up was 11 months (range 1–54 months) for pts on nilotinib and 10 months (range 1–56 months) for those on dasatinib. The two groups had similar age, sex, race, and comorbidities. Overall, treatment change was infrequent for both nilotinib and dasatinib patients (10% vs. 13%, p=0.40), but nilotinib pts had significantly fewer dose increases vs. dasatinib pts (0.0% vs. 1.4%, p=0.04), and they tended to have fewer drug holidays (1.7% vs. 4.4%, p=0.05). When treatment changes were classified by reason for change, nilotinib pts were less likely to change treatment due to lack of effectiveness vs. dasatinib pts (2.0% vs. 5.1%, p=0.04). Further, among pts who discontinued, fewer nilotinib pts discontinued due to lack of effectiveness (29% vs. 61%, p=0.03). Nilotinib and dasatinib pts had similar rates of treatment changes due to intolerance or other reasons, except for drug holiday, where nilotinib pts had fewer events than dasatinibpts (0% vs. 1.7%, p=0.02). The table below summarizes the changes in treatment by reason for treatment change. Conclusions:For Ph+ CML-CP pts on 2nd-line nilotinib or dasatinib, pts on nilotinib were less likely than those on dasatinibto change treatment due to lack of effectiveness.NilotinibDasatinibP-value(n=301)(n=296)Treatment change due to lack of effectiveness, n (%)6 (2.0)15 (5.1)0.04Discontinuation with or without switch to 3rd-line6 (2.0)14 (4.7)0.06Dose increase0 (0.0)4 (1.4)0.04Treatment change due to intolerance, n (%)11 (3.7)11 (3.7)0.97Discontinuation with or without switch to 3rd-line2 (0.7)3 (1.0)0.64Drug holiday0 (0.0)5 (1.7)0.02Dose decrease9 (3.0)3 (1.0)0.09Treatment change due to other reasons, n (%)18 (6.0)13 (4.4)0.38Discontinuation with or without switch to 3rd-line13 (4.3)6 (2.0)0.11Drug holiday5 (1.7)8 (2.7)0.38 Disclosures:Macalalad:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Chen:Novartis Oncology: Employment, Own stock in Novartis Other. Guerin:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Luo:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Wu:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Griffin:Novartis: Consultancy, Research Funding.