Treatment Of CML Research Articles

Real World Analysis Of Duration Of TKI Treatment Among Patients With Chronic Myeloid Leukemia

BackgroundChronic myeloid leukemia (CML) accounts for 10-15% of all adult leukemias in the US. CML treatment has improved in the past few years with the introduction of imatinib in 2001, which has improved overall survival in patients with CML. Despite its success, there remains a subset of individuals who are either imatinib-resistant or imatinib-intolerant. With the approval of 2nd generation TKIs (dasatinib, nilotinib) beginning in 2006, approximately 40–50% of imatinib-resistant and imatinib-intolerant patients achieve complete cytogenetic response (CCyR) when switching TKI. Few studies have estimated duration of TKI use since the approval of 2nd generation TKIs. The objective of this study is to explore current treatment patterns of TKIs by line of therapy in the US. MethodsU.S. health plan claims data from 01 January 2007 through 31 December 2011 were used to examine duration of TKI treatment by line of therapy for patients with CML aged 18 and older. Patients were required to have a prescription fill for a TKI and a CML diagnosis (ICD-9-CM code 205.1). Duration of TKI use was determined based on a gap in TKI coverage of 180 or more consecutive days following TKI initiation or switch to another TKI within the 180 day window. To account for censoring due to disenrollment for the health plan or end of the study period, median duration of 1st and 2nd line treatment is estimated via the Kaplan-Meier estimator. ResultsWe identified 695 who started TKI treatment and had diagnosis for CML from 2007 through 2011. More than half (58%) were male; mean age was 55 years (SD 14 years). The most common first line TKI was imatinib (82%) with dasatinib and nilotinib use equally distributed (9%). Of patients starting a 2nd line TKI, dasatinib represented 59% and nilotinib 37% (Table).TableBaseline Characteristics: Patients with CML1st TKI2nd TKIN695148Age, years, mean (SD)55 (14)54 (14)Male sex, n (%)405 (58)78 (53)TKIImatinib, n (%)571 (82)6 (4)Dasatinib, n (%)65 (9)87 (59)Nilotinib, n (%)59 (9)55 (37)Time to switch, mos, mean (SD)--12 (10)Since 2007, the median duration of 1st line TKI was 39 months and 2nd line TKI was 22 months. Median duration of treatment for 1st line (p=0.4342) and 2nd line treatment (p=0.1762) were not significantly different by TKI (Figure). Among those who initiated 2nd line TKI, the majority were switched from imatinib to dasatinib or nilotinib (86%). Mean time to switch was 12 months and did not differ when switching from imatinib to dasatinib or nilotinib (p=0.7233). ConclusionsDuration of TKI therapy is an informative measure as it is a proxy measure of treatment effectiveness as well as patient adherence, which is important to maintain optimal therapeutic outcomes. Among CML patients, we found median duration of treatment in both the 1st and 2nd line to be similar by TKI. [Display omitted] Disclosures:Henk:OptumInsight: Employment. Woloj:Pfizer Inc.: Employment. Shapiro:Pfizer Inc.: Employment. Whiteley:Pfizer Inc.: Employment.

MDR1 Gene Expression Predicts Response and Progression-Free Survival Of Ph+ CML Patients On Second-Line Nilotinib Therapy After Imatinib Failure - 4-Year Follow-Up

IntroductionThe activity of the drug efflux transporter protein MDR1 reduces the intracellular concentration of nilotinib and thereby impairs its efficacy. Nilotinib has been shown to be efficacious in imatinib-resistant patients. In the face of competing second-generation tyrosine-kinase inhibitors (TKI), early identification of favorable responders is crucially important. We have reported the unexpected positive prognostic impact of high MDR1 gene expression at time of imatinib resistance for subsequent 2nd line nilotinib treatment. Here, we present (i) a 48-month follow-up of our clinical data and (ii) additional functional analyses studied in an established in vitro, transposon-based vector system with stable siRNA mediated knockdown of MDR1. AimWe sought to assess (i) whether high MDR1 expression remains associated with improved cumulative rates of major molecular remission (MMR), complete cytogenetic remission (CCyR) and patients' outcome (progression-free survival, PFS) after 48 months and (ii) the impact of MDR1 expression on nilotinib in vitro sensitivity. Methods(i) We analyzed 83 patients resistant to imatinib frontline treatment in chronic phase CML treated with nilotinib 400 mg bid within the CAMN107A2101 trial. MDR1 and BCR-ABL mRNA expression levels were determined by qRT-PCR using LightCycler™ technology, normalized against beta-glucuronidase (GUS) and standardized according to the international scale (IS). Log-rank tests were performed to compare PFS and the cumulative incidences (CI) of MMR and CCyR at 48 months. (ii) MDR1high overexpressing (K562-DoxH1) and MDR1low knockdown (K562-DoxMM) cell lines were used for in vitro testing (Rumpold et al., Exp Hematol 2005). Results(i) (a) At 24 and 48 months, patients with MDR1/GUS ratios ≥2.0 attained MMR in 39% and 41%, CCyR in 58% (at both time points), and PFS rates of 75% and 67%, whereas patients with initial MDR1/GUS ratios <2.0 had significantly worse response and PFS rates, i.e. MMR in 13% and 16% (p=0.014), CCyR in 35% and 39% (p=0.044), and PFS of 50% and 46% (p=0.032). (b) BCR-ABL tumor burden prior to nilotinib revealed a significant impact on molecular response rates. BCR-ABLIS <28% separated best concerning cumulative incidences of MMR by 24 and 48 months (41% vs 21% and 48% vs 21%, p=0.009). (c) Nilotinib in vitro sensitivity of BCR-ABL kinase domain mutations at time of imatinib resistance was associated with improved PFS under nilotinib therapy: patients without any mutation showed PFS rates of 71% and 63% at 24 and 48 months, whereas those with either sensitive mutations, intermediately sensitive mutations or mutations with unknown IC50attained PFS rates of 67% and 61%; patients with mutations resistant to nilotinib achieved PFS rates of 23% at both time points (p=0.01). (ii) Even though MDR1high K562 cells are less sensitive than MDR1low expressing cells, nilotinib (applying doses from 0.01 µM up to 0.5 µM) was still able to significantly impede proliferation of both MDR1high and MDR1low, whereas imatinib-mediated growth inhibition was only seen in MDR1low, but not in MDR1highcells. Conclusion(i) At the time of imatinib-resistance, a high MDR1 gene expression predicts favorable MMR, CCyR, and PFS on consecutive 2nd line nilotinib treatment. As shown earlier, single nucleotide polymorphisms (SNPs) within MDR1 (1236CT/TT and 2677GT/TT) were significantly associated with higher MDR1 expression. (Agrawal et al., ASH 2010) (ii) Our functional data support our clinical observation that nilotinib remains efficacious in MDR1 overexpressing cells, whereas even dose-escalated imatinib does not reverse resistance. High MDR1 gene expression might select patients whose mode of resistance is essentially determined by increased efflux activity of MDR1 and not by other pathways of resistance that cannot be overcome by nilotinib. Altogether, our data might be used for the clinical risk stratification in case of imatinib resistance before switching to nilotinib and are undergoing prospective validation within the ENEST1st study. Disclosures:Saussele:Novartis: Honoraria, Research Funding, Travel Other; BMS: Honoraria, Research Funding, Travel, Travel Other; Pfizer: Honoraria. Purkayasatha:Novartis: Employment. Woodman:Novartis: Employment. Hehlmann:BMS: Consultancy, Research Funding; Novartis: Research Funding. Hochhaus:Novartis: Consultancy, Honoraria, Research Funding, Travel Other; BMS: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Ariad: Consultancy, Honoraria. Müller:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria, Research Funding.

Chronic Myeloid Leukemia After Adjuvant Treatment For Breast Cancer: Is It Therapy Related?

AbstractChronic Myeloid Leukemia (CML) is a rare myeloid neoplasm with an age-adjusted incidence of 1.6 per 100,000 people in the United States (http://seer.cancer.gov/statfacts/html/cmyl.html). Despite the understanding of the pathogenesis of CML – the fusion of BCR-ABL leading to a constitutively activated tyrosine kinase – underlying events that lead to a 9;22 translocation are incompletely elucidated. Although CML was the most common leukemia seen among survivors of Hiroshima and Nagasaki, other causative factors are not well defined.There is a known association between exposure to radiation and/or cytotoxic chemotherapy and therapy-related acute myeloid leukemia (t-AML). This relationship is best described after adjuvant treatment for breast cancer (BC), but has also been reported in patients treated for lymphoma, testicular cancer and colorectal cancer. Based on a number of patients we have seen at Memorial Sloan-Kettering Cancer Center with CML who had prior adjuvant treatment for BC, we hypothesized that a subset of patients with CML have therapy-related disease and the acquisition of a 9;22 translocation may be related to prior exposure to cytotoxic chemotherapy and/or radiation.Using ICD-9 codes for BC, we queried the Memorial Sloan-Kettering institutional database from 1983-2012 to search for patients who had a co-occurring diagnosis of CML, as defined by a bone marrow aspirate or biopsy that was morphologically consistent with CML and either a cytogenetic report that confirmed a 9;22 translocation and/or a BCR-ABL p210 fusion transcript. Charts of patients identified in the institutional database were individually reviewed to confirm their eligibility for this retrospective study.In total, 15 patients who developed a diagnosis of CML after adjuvant treatment of BC were identified (table 1). Of those identified, all had received prior adjuvant chemotherapy (n=11), prior adjuvant radiation (n=12) or both (n=15). The cumulative doses of anthracycline and alkylating agents are detailed in table 1. The interval between the adjuvant treatment of breast cancer and CML was 4.7 years. Patients diagnosed with CML after treatment of BC tended to be younger than those with CML diagnosed in the general population (50.47 years vs. 64 years) and were overwhelmingly Caucasian. All patients were diagnosed in chronic phase and none of the patients had an additional cytogenetic abnormality. The cumulative incidence of CML was markedly higher than in the general population; while 78,000 unique patients with BC were seen at MSKCC between 1985 and 2012, 15 patients subsequently received a diagnosis of CML. This incidence is considerably greater than the age-adjusted incidence of 1.6 per 100,000 in the United States population.To our knowledge, our data represent the first comprehensive description of CML after adjuvant treatment of BC. The markedly elevated incidence of CML after receipt of adjuvant chemotherapy and/or radiation for BC as compared to the general US population suggests that this entity might be classified as a therapy-related leukemia. The exact pathogenesis of CML after adjuvant treatment for BC and reason patients more commonly develop t-AML requires further investigation. Given the remarkable efficacy of tyrosine kinase inhibitors in preventing progression to accelerated or blastic phase disease, the practicing oncologist focused in breast cancer should consider a diagnosis of t-CML in any BC patient, previously treated with adjuvant chemotherapy or radiation, who presents with an elevated white blood count.Abstract Disclosures:Douer:Actinium Pharmaceuticals, Inc.: Research Funding.

Allogeneic HSCT Patients Receiving More RBC Transfusions Are At Increased Risk For Development Of Grade 2-4 Acute Graft-Versus-Host Disease

BackgroundA critical barrier to progress in allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been a lack in understanding regarding why some transplant recipients of HLA-matched transplant grafts develop severe graft-versus-host disease (GvHD) while other recipients have relapse of their cancer without GvHD. Patients who develop a modest degree of acute and/or chronic GvHD have less relapse and optimal survival after allogeneic BMT. Thus, a mechanistic understanding of regulation of donor T-cell activation after allo-HSCT is needed. Using mouse models, Desmarets et al. have shown that pre-transplant leukoreduced RBC transfusions can cause recipient immunization against minor histocompatibility antigens (miHA) and activation and expansion of recipient T-cells that recognize donor miHA, contributing to rejection of subsequent allo-HSCT (Blood. 2009; 114:2315). Preliminary data from our lab suggest that leukoreduced RBC transfusions given concurrently with allo-HSCT can also increase post-transplant activation and expansion of donor T-cells, an effect which may lead to increased GvHD after transplant. Here, we have conducted a retrospective study of post-transplant RBC transfusions and acute GvHD (aGvHD) in allo-HSCT patients. We hypothesized that increased numbers of transfusions during the 30-day post-transplant period would be correlated with increased severity of aGvHD in these patients. MethodsWe conducted a retrospective analysis of RBC transfusion records and aGvHD data collected for 181 adult allo-HSCT patients who received their transplants at Emory University Hospital (EUH) between 2004 and 2009. Nine patients were excluded who died < 50 days post-transplant without developing aGvHD, since this was too early to determine aGvHD occurrence. Of the remaining 172 patients studied (median age 48 yrs at time of transplant, range 18-72), 88 (49%) were male and 84 (51%) were female. Patients had received either matched related HSCT (n=69, 40%) or matched unrelated HSCT (n=103, 60%) for treatment of SAA (n=7), BAL (n=2), ALL (n=18), AML (n=69), hemolytic anemia (n=2), CLL (n=6), CML (n=8), HD (n=5), MDS (n=23), myelofibrosis (n=6), MM (n=7) or NHL (n=19). For pts who developed aGvHD, the onset time ranged from 1 to 139 days post-transplant, with a median of 30 days. No aGvHD (grade 0) was diagnosed in 58 pts (34%), while 37 pts (21%) developed grade 1 aGvHD and 77 pts (45%) developed grade 2-4 aGvHD. The number of ABO matched, irradiated RBC units transfused 0 - 30 days post-transplant was tallied for each patient, ranging from 0 (no transfusions, n=13, 7.6% of pts) to 26 units, with an average of 5.6 and median of 4 units. All transfusions during this timeframe were administered at EUH. The median follow up time was 22 months post-transplant (range, 1.1 – 96.1 months). ResultsPts were assigned to two groups, those who developed grade 0-1 aGvHD (n=95, 55%) or grade 2-4 aGvHD (n=77, 45%) within 140 days post-transplant. This study did not include analysis of late-onset aGvHD or chronic GvHD past this time point. Patients with grade 2-4 aGvHD had a higher average number of transfusions 0 - 30 days post-transplant compared with patients having grade 0-1 aGvHD (6.5 vs. 4.9 units, p = 0.02). Receiver-operator characteristics (ROC) analysis showed that a cutoff value of > 4 transfusions 0 - 30 days post-transplant had 56% sensitivity and 65% specificity to predict development of grade 2-4 aGvHD. When tested by logistic regression in a multivariate model, this cutoff value had a highly significant correlation with grade 2-4 aGvHD, with an odds ratio of 2.83 and p value = 0.0024. Other covariates including patient age, gender, and type of transplant (related vs. unrelated) were not significantly associated with aGvHD outcome. ConclusionOur retrospective analysis identified a significant positive correlation between the number of post-transplant RBC transfusions and severity of aGvHD after allo-HSCT. Additional studies are planned to determine whether RBC transfusions 0 - 30 days post-transplant stimulate allo-reactive T-cells via allo-antigen presentation or by otherwise promoting inflammation, and if one or both of these mechanisms contribute to increased GvHD. If so, it may be possible to develop strategies for optimization of RBC transfusion practices to reduce the risk of severe aGvHD after allo-HSCT. Disclosures:No relevant conflicts of interest to declare.

Activation Of p53 By MDM2-Inhibition Sensitizes Quiescent Blast Crisis CML Stem/Progenitor Cells To Bcl-2 Inhibitor- and Tyrosine Kinase Inhibitor-Induced Cell Death

The transcriptional activation of pro-apoptotic Bcl-2 family members is a major mechanism of p53-mediated cell death. p53 can also directly contribute to mitochondrial mediated apoptosis by interacting with Bcl-2 family proteins. A number of anti-apoptotic Bcl-2 proteins such as Mcl-1 and Bcl-xL are regulated by the Bcr-Abl tyrosine kinase and confer apoptosis resistance to CML cells. It is therefore not surprising that p53 gene alterations may play a role in the disease progression of CML. The reported p53 mutation rate of 30% suggests potential therapeutic benefit of p53 activation by MDM2 inhibition alone or as sensitization of CML to therapeutic agents.Tyrosine kinase inhibitors (TKIs), the front-line therapy for patients with chronic phase CML, are less effective in patients with blast crisis (BC) CML and inactive against quiescent CML stem/progenitor cells. Here we examine the effects of nutlin3a, which activates p53 by inhibiting MDM2, and its combinations with the Bcl-2 inhibitor ABT-737 and the TKI nilotinib on the viability of proliferating and quiescent CD34+CML stem/progenitor cells obtained from patients with BC CML.Mononuclear cells from patients with BC CML who were resistant to multiple TKIs were stained with the cell division tracking dye carboxyfluorescein succinimidyl ester (CFSE) and then co-cultured with human bone marrow (BM) derived mesenchymal stromal cells (MSCs). Once proliferating and quiescent cells are distinguishable by flow cytometry (within 7 to 12 days), the cells were treated with nutlin3a, ABT-737, nilotinib, nutlin3a plus ABT-737, or nutlin3a plus nilotinib for 48 hours with or without MSC co-culture. The cells were then stained with a CD34 antibody, and apoptosis (annexin V staining) was determined by flow cytometry. Apoptosis in proliferating and quiescent progenitor cells was defined as percentage of annexin V positivity in CD34+CFSEdim and CD34+CFSEbrightcells, respectively.Nutlin3a alone was able to decrease viability of CML cells cultured alone or co-cultured with MSCs in both proliferating (IC50 = 2.50 ± 0.92 μM and 2.54 ± 0.60 μM, respectively) and quiescent (IC50 = 3.70 ± 1.22 μM and 4.27 ± 0.77 μM, respectively) CD34+ CML stem/progenitor cells. Although not very active by itself, ABT-737, when combined with nutlin3a (n = 6), induced apoptosis synergistically in proliferating (CI = 0.24 ± 0.12) and more so in quiescent (CI = 0.09 ± 0.10) CD34+CML stem/progenitor cells, even when cells were co-cultured with MSCs (CI = 0.22 ± 0.09 for proliferating and CI = 0.03 ± 0.05 for quiescent stem/progenitor cells). The combination of nutlin3a with nilotinib (n = 4) was also highly synergistic in proliferating stem/progenitors (CI = 0.02 ± 0.04 without and CI = 0.05 ± 0.04 with co-culture) and in quiescent progenitors (CI = 0.07 ± 0.29 without and CI = 0.03 ± 0.06 with co-culture).Treatment of primary CML blast cells with nultin3a increased p53, and pro-apoptotic Bax and Puma levels in all samples examined, indicating activation of transcriptional activity of p53. In addition, nutlin3a treatment decreased the protein levels of anti-apoptotic Bcl-xL and/or Mcl-1. Nilotinib also decreased the expression, both at the RNA and protein levels, of Mcl-1 and Bcl-xL, even in patients who had not responded to nilotinib treatment clinically. ConclusionsHere we demonstrate that activation of p53 induces apoptosis in proliferating and quiescent BC CML stem/progenitor cells and sensitizes to Bcl-2 inhibitor- and TKI-induced cell death by, at least in part, regulating the expression of Bcl-2 family proteins. Results suggest a potential for utilizing this strategy in the treatment of BC CML, and also for the elimination of quiescent CML stem/progenitor cells. Disclosures:No relevant conflicts of interest to declare.

Disease Relapse After TKI Discontinuation In CML Is Related Both To Low Number and Impaired Function Of NK-Cells:Data From Euro-SKI

BackgroundThe inhibition of oncogenic BCR-ABL1 kinase with tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis of CML. Recent reports suggest that approximately 40 % of CML patients who have achieved optimal therapy response (complete molecular remission, CMR) can stop imatinib treatment without recurrence of detectable BCR-ABL1 transcripts. However, no predictive prognostic factors for successful therapy discontinuation have yet been identified. We therefore set up an immunological substudy in the ongoing pan-European EURO-SKI stopping study. We aimed to identify predictive biomarkers for relapse and non-relapse after TKI discontinuation. In addition, we aimed to understand more on the mechanisms of immune surveillance in CML and to study the effects of TKI treatment on the immune system. Materials and methodsPatients in deep molecular remission (MR4, BCR-ABL < 0,01% IS) for at least one year and with TKI treatment for at least 3 years were eligible for the clinical study. Basic lymphocyte immunophenotyping (the proportions and absolute numbers of NK-, T- and B-cells) was performed at the university hospital laboratories at the time of therapy discontinuation, and 1, 6, and 12 months after the TKI discontinuation. In a proportion of patients a more detailed immunophenotypic (analysis of CD45RA, CD57, CD27 and CD62L expressions) and functional analyses were done from fresh blood samples in a central immunology laboratory (Helsinki) at the same time points. The cytotoxicity of NK-cells was studied by measuring the direct killing of target cells (K562) and by the degranulation assay (CD107a/b expression). The secretion of Th1 type of cytokines IFN-γ/TNF-α was studied from both T- and NK-cells. ResultsThus far the basic lymphocyte subclass measurement has been analyzed from 62 patients who have discontinued TKI treatment within the EURO-SKI study. Functional analyses have been performed from 30 patients. 60 patients have used imatinib before treatment discontinuation and 2 patients dasatinib.At baseline, before the treatment discontinuation both CD4+ and CD8+ T-cell counts were within the normal range (median CD4+ 0.73x 109/L, range 0.11-2.4x 109/L; CD8+ 0.35x 109/L, 0.07-1.92 x 109/L). The TKI stop had no significant numerical or functional effect on T-cells, and at 1 month time-point the median T-cell counts were unchanged (CD4+ 0.73x 109/L; CD8+ 0.35x 109/L). Similarly, at the baseline, the median NK-cell count was within a normal range (0.26 x 109/L, range 0.04-1.04 x 109/L), and no significant change was observed 1 month after stopping the treatment (median 0.29 x 109/L). Furthermore, at the baseline and at the 1-month time-point the cytotoxicity of NK-cells and the cytokine secretion of T- and NK-cells did not significantly differ from the healthy controls when all patients were considered as a one group.However, when patients were divided in two groups based on the relapse status, the patients who eventually relapsed had significantly fewer NK-cells already at the baseline (Figure A; absolute count 0.18x 109/L vs. 0.32 109/L, p=0.008; proportions 11% vs. 21%, p=0.001). The phenotype of NK-cells also differed between the two groups, and the patients who relapsed had less NK-cells expressing CD57 (median 58% vs. 69%, p=0.046) and CD16 (median 67% vs. 83%, p=0.018) on the cell surface. Furthermore, the cytotoxicity of NK-cells was impaired in patients who failed to discontinue the TKI treatment successfully and no killing activity was observed in their samples (Figure B; alive K652 cells after co-incubation with effector cells 100% vs. 88%, p=0.07). No clear differences were observed in the function or the numbers of T-cells between relapsing and non-relapsing patients. [Display omitted] ConclusionsThe NK-cell numbers and their function may predict disease relapse after TKI discontinuation. This may have impact on the future stopping trials. In addition, it further illustrates the importance of the immune system in the successful long-term treatment of CML. Disclosures:Ekblom:Novartis: Honoraria; Bristol-Myers Squibb: Honoraria. Hjorth-Hansen:Pfizer, BMS: Honoraria, Travel expenses Other. Porkka:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Richter:Bristol-Myers Squibb: Consultancy, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Mustjoki:Novartis: Honoraria; BMS: Honoraria, Research Funding.

Adverse Events (AE) Under Imatinib Treatment Over 10 Years: Results From 1501 Patients Of The Randomized CML-Study IV

IntroductionTyrosine kinase inhibitors (TKI) have changed the natural course of CML. Their efficacy leads to normal life expectancy in the vast majority of patients. With the advent of 2nd generation TKI and the now available choice of drugs, safety issues have gained interest. We have used the randomized CML-Study IV for a long-term safety evaluation of imatinib. Study and PatientsCML-Study IV comprises 1551 patients randomized to 5 treatment arms with 3 imatinib-based combinations and 2 different imatinib-dose schedules. 1501 patients have received imatinib and were evaluable. Median age at diagnosis was 53 years, 88% were EUTOS low risk. At the last evaluation (04/11/2013) 1003 patients still received imatinib, 164 had died, 275 were switched to a 2nd generation TKI, 106 were transplanted. The longest observation time was 11.5 years, the median observation time was 6.5 years, with a 10-year survival probability of 84 %. The median time to imatinib discontinuation has not been reached after 10.2 years. 80 patients are under observation for more than 10 years, 18 of these have discontinued imatinib. Out of the 1501 patients that had received imatinib, 1375 patients received imatinib as first-line treatment and had a sufficient documentation of treatment. MethodsAE were reported at each follow-up visit. The CTC AE list of the NCI was used for coding of AE and severity grading. Additionally, for detection of hematologic AE lab results were screened for deviations from reference ranges. The AE were analyzed according to the “as treated” principle, using Kaplan-Meier curves (virtually no competing risks, almost all patients died after end of imatinib treatment). Only the first event of the respective type was considered. All analyses started at the first day of imatinib treatment and were censored when the patient discontinued imatinib, received another treatment or died. To assess the differences between men and women, Cox models were estimated. ResultsIn 1137 out of 1375 patients (83%) non-hematologic AE (5160 singular events) were reported during imatinib treatment (all grades), in 322 grade 3/4 AE (23%) (645 singular events). At 3 years, probability of a non-hematologic AE (any grade) was already 76% (95%-CI: 73-79%), at 6 years 85% (95%-CI: 82-88%) and at 8 years 91% (Fig.1). The probability of grade 3/4 non-haematologic AE was 38% (95%-CI: 34-42%) at 6 years and 43% (CI: 37-48%) at 8 years. [Display omitted] 156 patients reported hematologic grade 3/4 AE (187 singular events).The probability of hematologic grade 3/4 AE was 17% at 6 years (95%-CI: 15-21%) with most events observed during the first year of treatment (probability after one year 10.5%).The most frequently reported non-hematologic AE (all grades, any time) were gastrointestinal (6-year-probability 52%, 95%-CI: 48-56%), fluid overload or edema (6y-prob. 45%, 95%-CI: 40-49%), rash (6y-prob. 32%, 95%-CI: 28-36%), myalgia or arthralgia (6y-prob. 30%, 95%-CI: 27-34%), fatigue (6y-prob. 26%, 95%-CI: 22-29%), flu-like symptoms (6y-prob. 22%, 95%-CI: 19-26%), infections (6y-prob. 24%, 95%-CI: 20-28%) and neurological symptoms (6y-prob. 26%, 95%-CI: 22-29%). AE probability profiles over time have been generated for each AE (Figs. 2-3). For women the risk for non-hematologic events was increased 1.35-fold (95% CI: 1.18-1.55) for all grades (Figs. 1-3) and 1.13-fold (95% CI: 0.91-1.41) for grade 3/4, and 1.26-fold (95% CI: 0.91-1.71) for grade 3/4 hematologic AE. [Display omitted] [Display omitted] In 5 patients peripheral arterial occlusive disease grade 2 or 3 was reported, but none could be clearly assigned to imatinib (vascular risk profile of one patient incompletely reported). A definite association between any AE and death was not found. ConclusionAs AE by definition may or may not be considered related to the medical treatment an exact assessment of the safety of imatinib is difficult. Most AE were recorded during the first three years with decreasing frequency later on. The increased AE risk in women was mostly grade 1/2 and is commonly seen also in other treatment areas. Given that no imatinib-related death was recorded and that grade 3/4 AE could typically be properly treated we consider imatinib as a safe, comparably well tolerated TKI even after prolonged treatment. After 10 years imatinib continues to be an excellent choice for the treatment of CML in most patients. Disclosures:Hehlmann:Novartis: Research Funding; BMS: Consultancy, Research Funding. Hochhaus:Novartis: Consultancy, Honoraria, Research Funding, Travel Other; BMS: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Ariad: Consultancy, Honoraria. Müller:Novartis: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding; Ariad: Honoraria. Saussele:Novartis: Honoraria, Research Funding, Travel Other; BMS: Honoraria, Research Funding, Travel, Travel Other; Pfizer: Honoraria.

Six-Year Follow-Up Of Dasatinib-Related Pulmonary Arterial Hypertension (PAH) For Chronic Myeloid Leukemia In Single Center

IntroductionRecent randomized trial (DASISION trial), compared clinical outcomes between dasatinib and imatinib in newly diagnosed (chronic myeloid leukemia) CML patients. Results showed that dasatinib had faster and deeper responses compared with imatinib, and thus dasatinib became to be considered as a first-line therapy in CML patients. However, the long-term administration of dasatinib has been reported to have a risk of pleural effusion and dasatinib-related (pulmonary arterial hypertension) PAH. So, we have prospectively evaluated for emergence of PAH in all CML patients treated with dasatinib in our institute. Materials and methodsBetween May 2005 and July 2013, a total of 89 CP CML patients on dasatinib treatment were tested with laboratory studies, Brain natriuretic peptide (BNP), echocardiography (echo) in the Catholic University of Korea, Seoul, and baseline functional capacity (NYHA or WHO functional class) was assessed. PAH was defined as mean pulmonary artery pressure (mPAP) of >25mmHg at rest, with wedge pressure < 15mmHg, or Rt. Ventricular systolic pressure (RVSP) of 40 mmHg on echocardiography. And patients who had abnormal RVSP and/or symptoms (New York heart association-NYHA class 3, 4) were performed with additional studies such as pulmonary angiographic catheterization or pulmonary arterial computed tomography. ResultsSo far, 62 patients (70%) of total 89 were evaluated with echocardiography (46 male, 16 female). The median age was 48 year old (range, 22∼72). The median duration of disease was 8.5 years (range, 0.8∼16.1). The median mean daily dosage of dasatinib was 102mg (range, 73∼140mg). The duration of dasatinib treatment was 34.6 months (range, 0.5∼99.6). 8 of 66 patients (12.1%) showed abnormal echocardiographic findings as increased right ventricular systolic pressure or symptom. All of 8 patients had treated with dasatinib as second line, and had exertional dyspnea (2 patients on class 2, and 5 patients on class 3 of NYHA). 5 patients of these showed abnormal BNP levels. The mean RVSP in screened patients was 65.2 mmHg (range, 40∼108mmHg), 2 of 8 patients were confirmed diagnosis with overt PAH on as pulmonary angiographic catheterization, and right ventricular hypertrophy on pulmonary angiographic computed tomography. Clinical, functional, or hemodynamic improvements were observed within 5 months of dasatinib discontinuation and then, in 5 patients the treatment was switched to radotinib, and another 3 patients received reduced dosage of dasatinib. ConclusionAlthough the lowest estimate of incident PAH occurring in patients exposed to dasatinib was 0.45% in France group. our preliminary data show more higher incidence rates (8 of 66 patients, 12.1%) in Korea. So, we suggest that the long-term dasatinib treatment for CML requires careful attention to cardiopulmonary adverse effects. and routine cardiovascular and pulmonary evaluation on regular basis is strongly recommended before and during treatment with dasatinib. Disclosures:No relevant conflicts of interest to declare.

Dose Interruption/Reduction Of Tyrosine Kinase Inhibitors In The First 3 Months Of Treatment of CML Is Associated With Inferior Early Molecular Responses and Predicts For An Increased Likelihood Of Discontinuation Of The 1st Line Agent

![Graphic][1] In CML, rapid reductions in tumor load, as defined by at least 65% Ph-negativity and/or a RT-qPCR 14 days (IM>14 [11], DA>14 [45]). More patients on DA missed days of dosing (28%) than on IM (17%) with a median number of missed days for DA of 16 (range 1-62) compared to 12.5 (range 1-42) for IM p=0.008. Achievement of a RT-qPCR 14 was 78.6%, 63.2% and 63.5% p=0.033 and 93.8%, 91.9% and 77.8% for DA-0, DA1-14 and DA>14 respectively p=0.001. Predictably the chance of a RT-qPCR 14 cohorts p=0.5, and 96%, 88.6% and 79.5% p=0.026 for the DA0, DA1-4 and DA>14 cohorts, confirming superiority of DA over IM for MR2 and the potential impact of missing early doses of DA. Whether this is related to inadequate dosing or whether failure to tolerate the recommended dose is indicative of higher risk disease is not yet clear. We then studied whether missing drug in the first 3 months predicts the ability to stay on trial. The proportion of patients able to take the study drug consistently through mths 3-12 were 91%, 71% and 57% in the IM0/DA0, IM1-14/DA1-14 and IM>14/DA>14 groups respectively. This correlated with discontinuing the study (treatment failure) for 12.5%, 38.1% and 35.7% of patients in the IM0, IM1-14 and IM>14 cohorts and 4.4%, 12.8% and 18.8% in the equivalent DA cohorts. Thus the ability to tolerate daily drug in the first 3 mths predicts future tolerability and efficacy over the subsequent 9 mths and long-term compliance with the first line therapy. RT-qPCR monitoring was provided long-term for all patients entered into the study irrespective of their continuation in the study, so we were able to study the achievement of MR3 at 12 mths in an intention to treat analysis in all patients. With respect to average dosing over the first 3 mths MR3 was seen in 50%, 52.8% and 54.9% p=0.17 of patients who took >95%, 80-95% and 95%), 59.4% (80-95%) and 53.1% (<80%) p=0.038 for the equivalent doses of DA. Similar results were obtained using the number of days of missed drug (data not shown), suggesting that early failure to tolerate IM as 1st line does not impact on subsequent responses as effective alternative therapy is available for the majority of patients. In contract failure to tolerate DA is associated with a reduced chance of MR3 at 12 mths. Patients who experience drug cessation/reduction of either drug in the first 3 mths are less likely to obtain RT-qPCR <10%IS at 3 mths and are more likely to require a change of drug in the longer-term and therefore require close observation during the first year. Disclosures: Apperley: Ariad: Honoraria; Bristol Myers Squibb: Honoraria; Novartis: Honoraria, Research Funding; Pfizer: Honoraria. Clark: Novartis : Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity’s Board of Directors or advisory committees. O'Brien: Bristol Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria; Pfizer: Honoraria. [1]: /embed/inline-graphic-2.gif

Dramatic Down-Regulation Of MNDA Expression In CP-CML Cells From The LSC Compartment

IntroductionChronic Phase - Chronic Myeloid Leukemia (CP-CML) is a myeloproliferative disorder characterized by malignant proliferation of the granulocytic lineage without the arrest of cell differentiation. Tyrosine Kinase Inhibitors (TKI) have revolutionized CML treatment but several studies showed that a combination of TKI and Interferon alpha (IFNα) provides better clinical response.Myeloid Nuclear Differentiation Antigen (MNDA), which belongs to the hematopoietic interferon-inducible nuclear proteins with the 200-amino-acid repeat (HIN200) gene family, encodes a protein expressed in myeloid cells but whose function remains poorly understood. Because of its high expression in polymorphonuclear cells, its involvement in cell differentiation and apoptosis, and its induction by IFNα, we evaluated MNDA expression in CML cells and its modulation after incubation with IFNα. Material and methodsWe tested MNDA expression in several cell lines (K562, KCL22, LAMA84, TF1 and U937 (positive control)), in polymorphonuclear cells from healthy donors (HD-PMN, n=13) and in primary cells from patients with CP-CML at diagnosis (CP-CML; n=17). The relative expression of the MNDA transcript was analyzed using the 2-ΔΔCt method and was normalized to the endogenous reference gene GAPDH. HD-PMN were used as calibrator. We developed a multiparametric flow cytometry assay (CD45-V500/CD14-APC-H7/CD15-PerCpCy5.5/CD34-PC7/CD38-V450/MNDA-FITC) to detect MNDA protein in the different cell subsets, particularly in CD34+cells. ResultsAs previously described, MNDA was poorly expressed in the K562 cell line. Similarly, mRNA was detected at low levels in two other CML cell lines (KCL22, LAMA84) and in TF1 cells, but at a high level in the U937 cell line, used as a positive control. In each cell line, the transcript expression was correlated to the protein level, as evaluated by flow cytometry (MFI ratio: 2.04±0.21, 2.36±0.24, 1.59±0.14, 1.88±0.11 and 8.77±0.54 for K562, KCL22, LAMA84, TF1 and U937, respectively (n=3)). In CP-CML primary cells, MNDA expression was greatly diminished as compared with HD-PMN in both mRNA (0.20±0.08 (n=17) vs. 1.32±0.21 (n=10); p=1.52x10-6) and protein (MFI ratio: 6.9±0.98 vs. 16.31±1.25, p=0.001).After having verified that IFNα (2000 U/ml, 16 hours) induced MNDA expression in HD mononuclear cells but not in PMN, we observed that induction of MNDA was moderate in CML cell lines K562 and LAMA84 (2-fold increase, n=3) whereas the level of MNDA mRNA was significantly increased in TF1 cells (28-fold increase, n=4). Induction in primary CML cells was variable (3/5 patients).Aiming to evaluate the expression of MNDA in leukemic stem cells (LSC), we first analyzed MNDA expression in CD34+ and CD34+/CD38- cells from HD. We observed that MNDA is down-regulated in healthy CD34+ and CD34+/CD38- cells compared to mature cells (mRNA: about 4 logs, protein: 8-10 fold lower, n=4), but we always detected a significant signal in CD34+cells (MFI ratio: 2.76±0.46, n=3). However, MNDA was not expressed by CML cells from the LSC compartment (n=4). This inhibition does not seem to be antagonized by nilotinib or IFNα (n=2). Discussion/ConclusionMNDA expression appears to be clearly down-regulated in CP-CML cells and dramatically so in the LSC compartment. In some patients, we observed sustained sensitivity to IFNα, but only in the compartment of more mature cells. This suggests early deregulation of MNDA expression which seems to be only partially dependant on differentiation. The mechanisms involved in this down-regulation remain to be elucidated but could be independent to TK activity of BCR-ABL protein and resistant to IFNα in the LSC compartment. This marked deregulation of MNDA in the LSC compartment is an additional argument in favor of intrinsic changes specific to primitive cells. Disclosures:No relevant conflicts of interest to declare.

MJ05, a Novel p53 Activating Compound, Effectively and Selectively Eliminates Human CML Stem/Progenitor Cells

Abstract Tyrosine kinase inhibitors (TKI) are the mainstay of CML treatment but fail to eliminate leukemia stem cells (LSC), leading to high risk of disease recurrence when treatment is stopped. There is considerable interest in developing new strategies to target CML LSC. We have previously shown that p53 activation following SIRT1 deacetylase inhibition can inhibit growth and survival of TKI-treated CML LSC (Cancer Cell 2012, 21:266). We are therefore interested in investigating other strategies to activate p53 as potential approaches to target CML LSC. While conducting a screen of 20,000 small molecules for ability to activate p53-dependent transcription in TP53 wild-type ARN8 human melanoma cells we identified MJ05 amongst the top-ranking compounds. Importantly MJ05 did not activate p53-dependent transcription in T22 fibroblast cells. Increased p53 protein levels in ARN8 cells were seen within 6 hours and were accompanied by an increase in p21, pig3 and mdm2 mRNA and protein levels. Dependency on p53 was confirmed using p53-null and wild-type H1299 cells. Activation of p53 occurred without concurrent increase in DNA damage evidence by g-H2AX labeling, increased p53 Ser 15-phosphorylation, or inhibition of p53-HDM2 interaction. MJ05 treatment inhibited S-Phase progression of ARN8 cells without inhibition of ATM, ATR or DNA-PK phosphorylation, suggesting a unique mechanism of action. We tested the effect of MJ05 on primary normal or CML CD34+ cell by itself and in combination with TKI inhibitor Nilotinib, and compared with effects on Nutlin, a well studied inhibitor of p53-HDM2 interactions. Apoptosis was assessed by Annexin V labeling, proliferation by CFSE labeling, and colony forming cell (CFC) frequency, in methylcellulose progenitor assays. Treatment with MJ05 (5 and 10μM), with or without Nilotinib (1μM), for 72 hours in the presence of low concentrations of growth factor significantly and selectively increased apoptosis, inhibited proliferation and reduced colony CFC frequency in CML CD34+ cells compared to normal CD34+ cells. Combination of MJ05 with Nilotinib (1μM) resulted in significant increase in apoptosis of CML but not normal CD34+ cells. In contrast treatment with Nutlin (2 and 5 μM) resulted in similar increase in apoptosis in CML and normal CD34+ cells. We next evaluated the effect of treatment with MJ05 (10μM), Nilotinib and the combination for 72 hours on purified CML and normal CD34+CD38- stem/primitive progenitor cells and CD34+CD38+ committed progenitor cells. MJ05 significantly enhanced apoptosis of CML but not normal CD34+CD38- cells and CD34+CD38+ cells. Apoptosis was further enhanced by combination with Nilotinib (Table). MJ05 also resulted in significant reduction of proliferation in CML CD34+38+ and CD34+38- cells, with significantly less inhibition of proliferation of normal cells. MJ05 treatment markedly reduced CFU-GM and BFU-E generation from CML compared to normal CD34+CD38- and CD34+CD38+ cells. The combination with Nilotinib resulted in almost complete abrogation of CML CFC (Table). MJ05 resulted in significantly less inhibition of normal CFC, with greater effect on normal BFU-E compared to CFU-GM. Ongoing xenograft experiments are testing the effect of in vitro treatment with MJ05, Nilotinib or the combination on engraftment of CML and normal stem cells in NSG mice. Our studies indicate that MJ05, a unique, potent and selective p53 activating compound, is remarkably effective in inducing apoptosis and inhibiting growth of primitive CML stem/progenitor cells by itself and to an even greater extent in combination with Nilotinib. MJ05 treatment has significantly lesser effects on normal stem cells, and may offer a promising approach to selectively target CML LSC in combination with Nilotinib.Table 1NormalCMLUntreatedMj05+NilMj05+NilUntreatedMj05NilMj05+NilCD34+38+% Apoptosis4.5±0.19.0±1.14.13±018.8±7.17.5±0.815.9±4.412.3±1.723±7.4CFU-GM86±757.3±4.191±3.852±278.7±19.95±336±141±0BFU-E166±15.315±3.2155.7±9.314±1.595±19.30.7±0.721.3±5.50.3±03CD34+38-% Apoptosis4.2±0.26.1±0.34.2±0.15.3±0.423.0±1.230±4.114.6±3.850.1±7.2CFU-GM67.3±15.941.7±5.549±4.730.3±4.9192.7±50.66±2.372.67±48.70.7±0.7BFU-E58.7±20.211±2.526.3±2.97.6±0.9150.3±58.71±0.672±440.3±0.3 Disclosures: No relevant conflicts of interest to declare.

Abstract B266: Ponatinib, a potent KIT inhibitor, suppresses the emergence of secondary resistance mutations in a gastrointestinal stromal tumor (GIST) model system.

Abstract Background: Approximately 80% of GISTs contain primary activating mutations in KIT, the majority of which cluster in exon 11. Imatinib is approved for treatment of metastatic and/or unresectable GIST; however patients often relapse due to the acquisition of secondary resistance mutations in KIT, typically located in the ATP-binding pocket or activation loop (A-loop). Sunitinib is approved for 2nd line treatment, but does not effectively inhibit A-loop mutants. Ponatinib is a multi-targeted tyrosine kinase inhibitor (TKI) with potent activity against BCR-ABL that has been approved for treatment of CML and Ph+ ALL patients resistant or intolerant to prior TKIs. We have previously shown that ponatinib also potently inhibits both activated KIT and KIT containing imatinib- or sunitinib-resistance mutations, including those at the gatekeeper residue and within the A-loop. V654A was identified as the most recalcitrant mutant, although ponatinib was still capable of significantly inhibiting tumor growth in a V654A mouse model. To survey more broadly for mutations that might confer substantial resistance to ponatinib, an accelerated KIT mutagenesis screen was performed. Results: Ba/F3 cells dependent on exon 11 mutant KIT (Δ557-8) were chemically mutagenized to introduce random mutations and grown in the presence of TKIs to identify secondary resistance mutations. Importantly, resistant clones that grew in the presence of imatinib or sunitinib recapitulated the spectrum of mutations observed clinically. In the presence of imatinib, mutations in the ATP pocket and A-loop were observed, with the T670I gatekeeper mutation conferring the highest level of resistance. In the presence of sunitinib, mutations were observed primarily in the A-loop (D816, D820, N822 and Y823), but not the ATP pocket. In contrast, in the presence of 40 nM ponatinib, only the V654A mutation persisted, in a small number of clones. In the presence of 80 nM ponatinib the development of resistance mutations was completely suppressed. Importantly, levels of ponatinib achieved in patients dosed once daily with 45 mg ponatinib (145 nM peak; 64 nM trough) exceed these target levels. The results of mutagenesis studies using other primary mutant backgrounds, and the newly approved TKI regorafenib, will also be described. Conclusion: Preclinical analysis suggests that, in an exon 11 mutant KIT background, ponatinib can inhibit development of a broad spectrum of potential resistance mutations, including multiple problematic mutations within the A-loop. Thus far, the only secondary mutation identified that is not completely suppressed at clinically achievable trough concentrations is V654A. These studies provide further support for an ongoing phase 2 study of ponatinib in patients with TKI-resistant GIST (NCT01874665). Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B266. Citation Format: Alexa B. Schrock, Tzu-Hsiu Chen, Victor M. Rivera, Joseph M. Gozgit. Ponatinib, a potent KIT inhibitor, suppresses the emergence of secondary resistance mutations in a gastrointestinal stromal tumor (GIST) model system. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B266.

Multiple neoplasms including hematological malignancies in elderly

Introduction.– Chronic myelogeneous leukemia (CML) is, so called, stem cell leukemia. There was a major change in CML treatment last two decades. Now CML therapy strategy gets special medicine, tyrosine kinase inhibitor. This special medicine brings good prognosis and good general condition. So we report a review of elderly CML cases. Methods.– From 2003 to 2012, we intended for 229 patients whom suffered from hematological malignancies. Sixty-five years old or older, 15 cases in thatdiagnosedCMLand15patientswere followed up until death or until December 2012. And we studied about age, gender, diagnosises, prognosis, and cause of death. Result.– From 2003 to 2012, CML patients are 39 cases in that 65years or over years patients are 15 cases. Gender is male 8 cases, female 7 cases, median age is 70 years. Clinical phase are chronic phase, and the chance to diagnosis were medical health check. 14 cases received imatinib therapyand1casewasbest supporting care because patient did not want to treat because he needed his own time. Imatinib therapy is 400mg/day po, and almost all patients are outer ward. Side effects aremainly edema, neutropenia and pain of lower limb, but all side effects was undercontrolable by medicine. Clinical outcome is that achieved complete remission is in 13 cases out of 15 cases. One case was remission failure, 1 case was best supporting care.Median overall survival time is 27months (ranged 10–122 months). Key conclusion.–Treatment inCML ishopeful in elderly, it is possible to treat the same as adult.

Chronic myelogeneous leukemia in elderly

Introduction.– Chronic myelogeneous leukemia (CML) is, so called, stem cell leukemia. There was a major change in CML treatment last two decades. Now CML therapy strategy gets special medicine, tyrosine kinase inhibitor. This special medicine brings good prognosis and good general condition. So we report a review of elderly CML cases. Methods.– From 2003 to 2012, we intended for 229 patients whom suffered from hematological malignancies. Sixty-five years old or older, 15 cases in thatdiagnosedCMLand15patientswere followed up until death or until December 2012. And we studied about age, gender, diagnosises, prognosis, and cause of death. Result.– From 2003 to 2012, CML patients are 39 cases in that 65years or over years patients are 15 cases. Gender is male 8 cases, female 7 cases, median age is 70 years. Clinical phase are chronic phase, and the chance to diagnosis were medical health check. 14 cases received imatinib therapyand1casewasbest supporting care because patient did not want to treat because he needed his own time. Imatinib therapy is 400mg/day po, and almost all patients are outer ward. Side effects aremainly edema, neutropenia and pain of lower limb, but all side effects was undercontrolable by medicine. Clinical outcome is that achieved complete remission is in 13 cases out of 15 cases. One case was remission failure, 1 case was best supporting care.Median overall survival time is 27months (ranged 10–122 months). Key conclusion.–Treatment inCML ishopeful in elderly, it is possible to treat the same as adult.

Leukemia in elderly

Introduction.– Chronic myelogeneous leukemia (CML) is, so called, stem cell leukemia. There was a major change in CML treatment last two decades. Now CML therapy strategy gets special medicine, tyrosine kinase inhibitor. This special medicine brings good prognosis and good general condition. So we report a review of elderly CML cases. Methods.– From 2003 to 2012, we intended for 229 patients whom suffered from hematological malignancies. Sixty-five years old or older, 15 cases in thatdiagnosedCMLand15patientswere followed up until death or until December 2012. And we studied about age, gender, diagnosises, prognosis, and cause of death. Result.– From 2003 to 2012, CML patients are 39 cases in that 65years or over years patients are 15 cases. Gender is male 8 cases, female 7 cases, median age is 70 years. Clinical phase are chronic phase, and the chance to diagnosis were medical health check. 14 cases received imatinib therapyand1casewasbest supporting care because patient did not want to treat because he needed his own time. Imatinib therapy is 400mg/day po, and almost all patients are outer ward. Side effects aremainly edema, neutropenia and pain of lower limb, but all side effects was undercontrolable by medicine. Clinical outcome is that achieved complete remission is in 13 cases out of 15 cases. One case was remission failure, 1 case was best supporting care.Median overall survival time is 27months (ranged 10–122 months). Key conclusion.–Treatment inCML ishopeful in elderly, it is possible to treat the same as adult.

Effectively targeting treatment-naïve CML stem/progenitor cells from imatinib-nonresponders with combination treatments of new JAK2 and ABL inhibitors in vitro and in vivo

Introduction of Imatinib Mesylate (IM) and other tyrosine kinase inhibitor (TKI) therapies has had a major impact on treatment of chronic phase CML, but early relapses and persistence of leukemic stem cells remain problematic. We recently identified a new AHI-1-BCR-ABL-JAK2 protein complex that contributes to the transforming activity of BCR-ABL and IM-resistance of CML stem/progenitor cells. We have therefore hypothesized that combined suppression of BCR-ABL and JAK2 activities might be more effective in eliminating primitive CML cells in vitro and in vivo.

Data and implication based comparison of two chronic myeloid leukemia models

Chronic myeloid leukemia, a disorder of hematopoietic stem cells, is currently treated using targeted molecular therapy with imatinib. We compare two models that describe the treatment of CML, a multi-scale model (Model 1) and a simple cell competition model (Model 2). Both models describe the competition of leukemic and normal cells, however Model 1 also describes the dynamics of BCR-ABL, the oncogene targeted by imatinib, at the sub-cellular level. Using clinical data, we analyze the differences in estimated parameters between the models and the capacity for each model to predict drug resistance. We found that while both models fit the data well, Model 1 is more biologically relevant. The estimated parameter ranges for Model 2 are unrealistic, whereas the parameter ranges for Model 1 are close to values found in literature. We also found that Model 1 predicts long-term drug resistance from patient data, which is exhibited by both an increase in the proportion of leukemic cells as well as an increase in BCR-ABL/ABL Model 2, however, is not able to predict resistance and accurately model the clinical data. These results suggest that including sub-cellular mechanisms in a mathematical model of CML can increase the accuracy of parameter estimation and may help to predict long-term drug resistance.

What challenges remain in chronic myeloid leukemia research?

In the last fifteen years, the advent of imatinib has opened a new era in the treatment of CML. The challenge now is to eradicate the disease. To do this, groundbreaking scientific and biological studies should lead to the development of new techniques that can eliminate the last leukemic cells.

Study of different mutations in chronic myeloid leukemia in India and their co-relation with drug resistance.

7083 Background: Emergence of ABL point mutations is the most frequent cause for imatinib resistance in CML. Aim of our study is to investigate two potential resistance mechanisms i.e.,mutations of BCR-ABL tyrosine kinase domain (TKD) and Additional Chromosomal Abnormalities during TKI treatment in CML. Methods: Karyotyping and BCR-ABL TKD mutation screening are performed in 100 imatinib resistant CML patients who were on imatinib at the time of loss of hematologic response, cytogenetic or molecular response. Imatinib–Resistance Mutation Analysis (Qualitative) were detected by Nested RTPCR and Sanger’s Sequencing. In 100 cases, 34 received escalated imatinib, 34 nilotinib and another 32 dasatinib. Results: In 100 BCR-ABL positive imatinib, nilotinib and dasatinib resistant cases, 11 different BCR-ABL TKD mutations were detected. Analysis revealed no mutations-43 cases, M351T-12 cases, G250E-10 cases, F317L-8 cases, M244V-5 cases, E255K-4 cases, V379I-4 cases, F359V-3 cases, H396R-3 cases, Y253F-3 cases, E355G-3 cases, T315I-2 cases. 11 novel mutations (F317L, G250E, M244V, Y253F, E255K, M351T, F359V, H396R, V379I, E355G, T315I) conferring imatinib resistance, 10 nilotinib–resistant mutations (M244V, F359V, T315I, E355G, G250E) and 8 dasatinib-resistant mutations (H396R, F317L, H396R, T315I, M351T) were seen in our patient population. T315I was found more frequently in cases on dasatinib than on imatinib therapy. Conclusions: T315I which confers resistance to all TKIs was detected only in 2/100 patients who demonstrated loss of response in our population. As compared with other western studies, incidence of T315I mutation was very low in our study. In addition analysis of mutation patterns at baseline may help in stratifying patients for treatment. For cases with TKI resistance, mutation and ACA screening may play role in identifying patients with poorer prognosis. In our practice if nilotinib–resistant mutation was detected, dasatinib was preferred and for dasatinib-resistant mutation, nilotinib was preferred. We are planning for using bosutinib, panotinib and omacetaxine (SC route) in third line therapy in imatinib resistant different mutation positive chronic myeloid leukemia.

Use of ponatinib to inhibit kinase mutations associated with drug-resistant gastrointestinal stromal tumors (GIST).

10509 Background: Ponatinib (PO) is a multi-targeted tyrosine kinase inhibitor with potent pan-BCR-ABL activity that has recently been approved for treatment of CML and Ph+ ALL. PO also inhibits the kinase activity of KIT. Approximately 80% of gastrointestinal stromal tumors (GIST) contain primary activating KIT mutations, the majority of which cluster in exon 11. Imatinib (IM) is approved for the 1st line treatment of GIST; however, patients frequently relapse due to the acquisition of secondary resistance mutations located in either the KIT ATP-binding pocket or the activation (A) loop. Sunitinib (SU) is approved for 2nd line treatment of GIST but does not effectively inhibit A-loop mutants. Here we explored the activity of PO against major primary and secondary KIT mutants found in GIST. Methods: The drug sensitivity of KIT mutants was determined using engineered Ba/F3 cells harboring mutant forms of KIT exon 11 with or without ATP binding pocket or A-loop mutations. The abilities of PO, IM, SU, and regorafenib (RE) to inhibit viability and/or KIT kinase activity were compared using this system as well as an isogenic CHO cell system. We also profiled these same drugs using a panel of GIST cell lines, including cell lines with IM-resistant secondary KIT mutations. Results: In all in vitro systems, PO potently inhibited KIT exon 11 mutant kinases, with an IC50 of &lt; 30 nM. PO also potently inhibited a range of secondary KIT mutants, including multiple A-loop mutant kinases. PO induced substantial tumor regression in Ba/F3 tumor models expressing a KIT exon 11 mutant with or without an A-loop mutation (D816H). Using GIST cell lines, PO inhibited the viability of those harboring primary KIT exon 11 and secondary resistance mutations more effectively than IM, SU, and RE. Importantly, in patients dosed once daily with 45 mg ponatinib, plasma concentrations achieved are predicted to lead to inhibition of all KIT mutants tested with the possible exception of V654A. Conclusions: PO potently inhibits the majority of clinically relevant KIT mutant kinases and has a broader spectrum of activity compared to IM, SU, or RE. Based on these data, a phase 2 study of PO in drug-resistant GIST is being initiated.