Median White Blood Cell Research Articles

Long-Term Results from a Phase II Open-Label Study of Ruxolitinib in Patients with Essential Thrombocythemia Refractory to or Intolerant of Hydroxyurea

Background: Essential thrombocythemia (ET) is a Philadelphia chromosome–negative myeloproliferative neoplasm (MPN) characterized by persistent thrombocytosis, excessive proliferation of megakaryocytes in the bone marrow, and normal erythrocyte mass. As with the other Philadelphia chromosome–negative MPNs, myelofibrosis (MF) and polycythemia vera (PV), ET is associated with dysregulated Janus kinase (JAK)-signal transducer and activator of transcription signaling. Ruxolitinib is an oral JAK1/JAK2 inhibitor that has shown clinical benefit in patients with MF and PV.Objective: To report the long-term efficacy and safety of ruxolitinib in patients with ET from an open-label, phase II study (INCB18424-256; NCT00726232) in patients with ET or PV. Long-term results from the patients with PV have been published (Verstovsek S et al, Cancer. 2014;120:513-520).Methods: Eligible patients had ET refractory to or intolerant of hydroxyurea as assessed by the investigator, platelet count > 650 × 109/L unless receiving treatment, and absolute neutrophil count ≥ 1.2 × 109/L. Efficacy endpoints included achievement of platelet counts ≤ 400 × 109/L in patients with baseline counts > 400 × 109/L, platelet count ≤ 600 × 109/L in patients with baseline counts > 600 × 109/L, white blood cell (WBC) counts ≤ 10 × 109/L in patients with baseline counts > 10 × 109/L, and a ≥ 50% reduction in palpable splenomegaly in patients with a palpable spleen at baseline. Patients assessed their ET-related symptoms (pruritus, bone pain, night sweats, asthenia, and paresthesia) on a scale from 0 (not present) to 10 (worst imaginable) at each study visit, reporting the worst level of symptoms experienced during the 7 days preceding the study visit. Patients who discontinued were counted as nonresponders for all response analyses.Results: At baseline (N = 39), median age was 51.0 years, median disease duration was 87.6 months, median hematocrit was 40.4%, median platelet count was 849.0 × 109/L, and median WBC was 8.15 × 109/L. At the time of data cutoff, the median exposure to ruxolitinib was 205.6 weeks (approximately 4 years; median total daily dose 30.1 mg) and 61.5% of patients were still receiving treatment. The majority of patients (71.8%) received ruxolitinib for ≥ 96 weeks (24 months). Platelet count decreased rapidly after initiation of therapy and remained relatively stable over time (Figure 1). Of the patients with baseline platelet count > 400 × 109/L (n = 38), 2.6%, 10.5%, and 13.2% of patients had a platelet count ≤ 400 × 109/L at week 12, 48, and 192 (month 3, 12, and 48), respectively. Of the patients with baseline platelet count > 600 × 109/L (n = 35), 48.6%, 40.0%, and 57.1% of patients had a platelet count ≤ 600 × 109/L at week 12, 48, and 192, respectively. Of the patients with baseline WBC count > 10 × 109/L (n = 11), 100%, 72.7%, and 72.7% of patients had a WBC count ≤ 10 × 109/L at week 12, 48, and 192, respectively. Of the 4 patients with palpable spleen at baseline (median 5.0 cm), all patients achieved ≥ 50% reduction and 3 patients achieved absence of palpable splenomegaly by the week 36 visit. Rapid reductions in pruritus, bone pain, night sweats, asthenia, and paresthesia symptom scores were reported by patients during the study, which were largely sustained through week 192 (Figure 2). New or worsening grade 3 or 4 leukopenia, neutropenia, and lymphopenia occurred in 3 patients each (7.7%), and new or worsening grade 3 anemia occurred in 1 patient (2.6%). The most common nonhematologic adverse events of any grade regardless of causality were increased weight (35.9%), diarrhea (28.2%), cough (25.6%), and headache (25.6%). Most adverse events were grade 1 or 2. Infections of any grade were reported in 26 patients (66.7%); of these, grade ≥ 3 infections were reported in 2 patients (5.1%; n = 1, bronchitis and n = 1, pneumonia). No patients experienced transformation to post-ET MF or acute myeloid leukemia.Conclusions: Ruxolitinib treatment was generally well tolerated in this population of patients with ET who were refractory or intolerant to hydroxyurea and resulted in improvements in platelet count, WBC count, splenomegaly, and disease-related symptoms. [Display omitted] [Display omitted] DisclosuresVerstovsek:Incyte: Research Funding. Off Label Use: Ruxolitinib is approved for the treatment of patients with intermediate or high risk myelofibrosis in the United States. Ruxolitinib is not approved for the treatment of essential thrombocythemia. . Rambaldi:Amgen: Consultancy. Zhang:Incyte Corporation: Employment. Vannucchi:Novartis: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.

A Phase I Study of Carfilzomib for Relapsed or Refractory Acute Myeloid and Acute Lymphoblastic Leukemia

Background: The outcome for patients with relapsed or refractory acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) remains extremely poor; new chemotherapy agents with activity against these leukemias are urgently needed. Proteasome inhibition is a promising therapeutic target in acute leukemias with established efficacy in several other hematologic malignancies. Several published studies have demonstrated the potent in vitro anti-leukemic activity of the selective proteasome inhibitor carfilzomib (CFZ) in leukemia cell lines as well as in primary human AML and ALL blasts. Given the favorable toxicity profile of CFZ, there was a strong rationale to begin the clinical study of this agent in the treatment of acute leukemias. We performed a phase I, single arm, single center, open label study of CFZ in adult patients with relapsed or refractory AML and ALL.Objectives: The primary objective was to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of CFZ in adult patients with relapsed/refractory AML and ALL. Secondary objectives included: determination of disease response, time to response, remission duration, progression-free survival, event-free survival, and overall survival. The study was designed to determine the safety and tolerability of carfilzomib in this patient population.Patients/Methods: Patients with relapsed or refractory AML or ALL after ³ 1 line of therapy, with good performance status and organ function were eligible. CFZ was given on days 1, 2, 8, 9, 15, 16, 22, and 23 in a 28-day cycle at escalating doses of 36, 45, and 56mg/m2. All dose levels included lead-in doses on days 1, 2, 8 and 9. Up to 6 cycles of treatment were allowed.Dose escalation was performed using a 3+3 design; MTD was defined as the highest dose level where DLT occurred in less than 1 of 3 or 2 of 6 patients. Disease response was determined using International Working Group (IWG) criteria for AML.Results: 18 patients were enrolled from Dec 2010-July 2014. Eight patients discontinued prior to completion of cycle 1 for reasons other than study-related toxicity and were replaced.The median age was 70 years (range 32-78). 12 of the 18 patients were male. 17 patients had AML while 1 patient had ALL. The median number of prior therapies was 2 (range 1-4). 2 patients had undergone prior allogeneic stem cell transplantation. The median time from diagnosis to start of protocol was 9.7 months (range 1.4-102.0).Median white blood cell (WBC) count at study start was 3.2x109/L (range 0.6-42.2), with median peripheral blood blasts of 18% (range 0-62), and bone marrow blasts 45.5% (range 11-92). 7 of the 17 patients with AML had complex cytogenetics.10 of the 18 patients were evaluable for disease response. Of the 10 evaluable patients, 2 patients achieved a partial response (PR), and 4 additional patients had stable disease (SD). The median duration on study was 21.5 days (range 1-64), with median overall survival (OS) of 1.9 months.CFZ was generally well tolerated; no DLTs were observed in any cohort. The most common grade 3/4 non-hematologic toxicities regardless of attribution were: dyspnea (17%), activated partial thromboplastin time prolongation (17%), intracranial hemorrhage or hematoma (11%), infection (11%), CHF exacerbation (11%), and hypophosphatemia (11%).Conclusions: Administration of CFZ was well tolerated, and a MTD was not established. The recommended dosage for further studies is 56mg/m2. In this limited phase 1 study of heavily pre-treated patients, we observed modest anti-leukemic activity. However, additional clinical trials incorporating CFZ in combination with other chemotherapeutic agents are now needed to assess the potential efficacy of CFZ in the treatment of AML and ALL.Abstract 5292. Table 1IDDose LevelDiagnosis# of Prior Lines of TherapyPrior SCT# of CyclesBest Response11 (36mg/m2)AML1N3SD21 (36mg/m2)AML3Y<1NA31 (36mg/m2)AML2N2PR41 (36mg/m2)AML2N2SD52 (45mg/m2)AML2N1PD62 (45mg/m2)AML2N<1NA72 (45mg/m2)AML3N<1NA82 (45mg/m2)AML2N<1NA92 (45mg/m2)AML2N2SD102 (45mg/m2)AML3N<1NA112 (45mg/m2)AML2N2SD122 (45mg/m2)AML2N1PD133 (56mg/m2)AML3N1PD143 (56mg/m2)AML4Y2PR153 (56mg/m2)AML1N1PD163 (56mg/m2)AML3N<1NA173 (56mg/m2)ALL1N<1NA183 (56mg/m2)AML2N<1NAAbbreviations: NA- Not Applicable; SD- Stable Disease; PR- Partial Response; PD- Progressive Disease DisclosuresOff Label Use: We performed a phase I, single arm, single center, open label study of the selective proteasome inhibitor carfilzomib (CFZ) in adult patients with relapsed or refractory AML and ALL. CFZ is approved for the treatment of patients with multiple myeloma who have already received at least two other treatments including bortezomib and an immunomodulatory agent (lenalidomide and/or thalidomide), and whose disease has progressed (got worse) on their last therapy or within 60 days of their last therapy.. Vij:Onyx Pharmaceuticals, Inc.: Honoraria, Research Funding.

Long-Term Outcome of Allogeneic Stem Cell Transplantation in Patients with Combined Paroxysmal Nocturnal Hemoglobinuria and Aplastic Anemia (AA/PNH syndrome)

Background:Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal disorder of hematopoietic stem cells characterized by a somatic mutation in the PIG-A gene, encoding the glycosyl phosphatidylinositol (GPI) moiety. PNH clones lack GPI-anchored proteins (GPI-AP) which inhibit the activation and cytolytic functions of complement. Recently, Eculizumab, humanized monoclonal antibody directed against complement component C5, has used increasingly for the patients with hemolytic PNH. However, the patients with PNH clone and bone marrow failure syndrome (i.e. aplastic anemia) should be treated as their predominant clinical manifestation. Allogeneic stem cell transplantation (SCT) can be curative treatment option especially for PNH patients with combined aplastic anemia (AA). The aim of the present study was to evaluate long-term outcome of allogeneic SCT in patients with AA/PNH.Methods: Total of 27 patients with PNH clones underwent allogeneic SCT at our institution between Jan 1998 and Mar 2014. Among them, seven patients had classic PNH and 20 patients with cytopenia had AA/PNH (with bone marrow evidence of a concomitant AA). We analyzed long-term transplant outcomes in 20 patients with AA/PNH.Results: There were 12 male and 8 female patients with a median age of 34 years (range, 13-51 years). The median interval from the diagnosis to transplantation was 8 months (range; 1-201 months). The median transfusions prior to SCT were 33 units (range; 8-208 units). Pre-transplant GPI-AP deficient neutrophils and erythrocytes were 46% (0-99) and 15.6% (0-88), respectively. Median white blood cell, absolute neutrophil count, hemoglobin, and platelet at transplant were 2.3×109/L, 0.7×109/L, 7.9 g/dL, and 21×109/L, respectively. Median LDH level was 714 U/L (range; 273-6499 U/L) and 11 (55%) patients had LDH ≥1.5x upper normal limit. PNH patients with SAA (n=14), VSAA (n=4), or non-SAA (n=2) received SCT from sibling (s) donor (n=15) or unrelated (u) donor (n=5). The conditioning regimen for s-SCT consisted of fludarabine (180 mg/m2) + cyclophosphamide (CY, 100 mg/kg) + ATG (10 mg/kg) (n=11), or busulfex (12.8 mg/kg) + CY (120mg/kg) (n=4). The conditioning regimen for u-SCT was TBI (fractionated, 800 cGy) + CY (100-120 mg/kg) ± ATG (2.5 mg/kg). GVHD prophylaxis consisted of CsA + MTX in s-SCT and FK506 + mini-MTX in u-SCT, respectively. After a median follow-up of 57 months (range 4.7-122.1), the 5-year estimated OS rates were 90.0 ± 6.7%. Two patients died of treatment-related mortality (TRM), including acute GVHD (n=1) and cerebral hemorrhage (n=1), respectively. Except one patient with early TRM, 19 patients engrafted with no secondary graft-failure. The cumulative incidence of acute GVHD (≥grade II) and chronic GVHD was 25.0 ± 1.0% and 26.3 ± 10.4%, respectively. PNH clones disappeared at median 1.8 months (range 0.9-11.9) after SCT and reemerging of PNH clone was not observed in all patients.Conclusion: This study showed that long-term transplant outcome in patients with AA/PNH were comparable to that of allogeneic SCT in SAA (the 3-year estimated OS rates were 92.7 and 89 % for s-SCT and u-SCT, respectively) at our institution (ASH Annual Meeting Abstracts 2012;120:4151). Therefore, application of allogeneic SCT should be considered in PNH patients with AA in case of availability of well matched donor. DisclosuresNo relevant conflicts of interest to declare.

Phase I/II Study of Vosaroxin and Decitabine in Newly Diagnosed Older Patients (pts) with Acute Myeloid Leukemia (AML) and High Risk Myelodysplastic Syndrome (MDS)

Background: Vosaroxin, is a first-in-class anti-cancer quinolone derived (AQD) DNA topoisomerase II inhibitor, which is not a substrate for p53 or P-glycoprotein, has limited toxicity, and is currently under evaluation for the treatment of pts with AML and high-risk MDS. Methods: Pts were eligible if they had AML or high-risk MDS (defined as having ³ 10% blasts in the bone marrow), were 60 years of age or older, and had adequate performance status (ECOG ² 2) and organ function. Pts younger than 60 who were unsuitable for standard chemotherapy were also eligible. In the phase I part of the study the first six pts received vosaroxin 90 mg/m2 daily on days 1 and 4 with decitabine 20 mg/m2 daily for 5 days. This dose was well tolerated with no dose limiting toxicity identified and pts were then enrolled on phase II at this dose and schedule. However, due to mucositis in a few subsequent pts, the induction dose of vosaroxin was reduced to 70 mg /m2, starting with pt #25. The vosaroxin dose could be maintained at 70 mg/m2 or reduced to 50 mg/m2 in consolidation cycles, which were repeated in approximately 4 to 5-week intervals for a total of up to 7 cycles. Dose adjustments and dose delays of one or both agents, were allowed based on toxicity. The primary endpoint was to determine the overall response rate including complete response (CR) + CR without platelet recovery (CRp) + CR with insufficient hematological recovery (CRi). Secondary endpoints were: CR duration, disease-free survival, overall survival, safety, and early mortality. Results: To date, 35 pts (32 AML, 3 high-risk MDS) with a median age of 71 years (range, 41-78) have been enrolled; 34 (97%) pts were older than 60 years. They included 15 (43%) pts with diploid cytogenetics, 12 (34%) with complex cytogenetic abnormalities including chromosome 5 and/or 7 abnormalities, and 8 (23%) with other miscellaneous abnormalities. 13 (37%) pts with AML had antecedent hematological disorders (AHD) including 7 (20%) with MDS, 4 (11%) with myeloproliferative neoplasm and 2 (6%) with MDS/MPN. Three pts with AHD had received prior therapy including 5-azacytidine (n=1), ruxolitinib + 5-azacytidine (n=1), and lenalidomide (n=1). Additionally, 5 (15%) pts had therapy-related disease with prior exposure to chemotherapy or radiation therapy. Median bone marrow blast %, median white blood cell, hemoglobin, &amp; platelet counts were 40% (9-97), 4.1 x 109/L (0.4-57.0), 9.4 g/dL (6.8-11.5), and 40 x 109/L (7-333), respectively. 34 pts were evaluable for response; 17 (50%) achieved CR, 6 (18%) CRp, and 3 (9%) CRi for an overall response rate of 77%. One pt is too early for response assessment. Responses by age, cytogenetic and molecular characteristics are shown in table 1. The median follow-up is 5.1 months (range, 0.9-11.0). Pts have received a median of 2 (1-6) treatment cycles with the median number of cycles to response being 1 (1-4). Three pts have relapsed and the median duration of CR/CRp/CRi has not been reached (0.5-9.9+ months). Four (12%) pts have proceeded to allogeneic stem cell transplant (ASCT). 4-week and 8-week mortality were 0% and 14%, respectively. The regimen is well tolerated with the main grade ³ 3 toxicity being mucositis in 9 (26%) pts and liver enzyme elevation in 3 (9%). Conclusion: Combination of vosaroxin and decitabine is effective and feasible in older pts with AML and high-risk MDS. Enrollment is ongoing. Table 1: Response by baseline characteristics Parameter Category N Overall response Too early to evaluate Age* 60-70 16 14/16 (88%) 0 &gt;70 18 12/17 (71%) 1 Cytogenetics Diploid 15 11/14 (79%) 1 -5/-7/other adverse 12 8/12 (67%) 0 Miscellaneous 8 5/8 (63%) 0 Mutation Status IDH2 7 7/7 (100%) 0 IDH1 5 1/4 (25%) 1 TP53 9 6/9 (67%) 0 RAS 9 4/9 (44%) 0 *1 pt below the age of 60 years was unsuitable for standard chemotherapy and was enrolled on study. Disclosures Naval: Sunesis: Advisory board membership Other, Research Funding. Off Label Use: Vosaroxin (Qinprezo) has not been approved for AML. In this clinical trial we are evaluating the efficacy and safety of vosaroxin (Qinprezo) in combination with decitabine in elderly patients with AML. . Kantarjian:ARIAD, Pfizer, Amgen: Research Funding. Kadia:GSK: Research Funding; ARIAD: Honoraria. Borthakur:Tetralogic Pharmaceuticals: Research Funding. Jabbour:Ariad, Novartis, BMS, Pfizer, and Teva: Consultancy. Cortes:Ariad: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Consultancy, Research Funding. Craig:Sunesis: Employment. Ravandi:Sunesis: Advisory board membership Other, Research Funding.

A Novel Prognostic Model in Heavily Treated Patients with Myelodysplastic Syndromes (MDS)

BackgroundThe Revised International Prognostic Scoring System (IPSS-R) was developed to risk stratify untreated patients (pts) with MDS. It has since been validated in pts treated with a single line of drug therapy, and has been modified in untreated pts to include mutational data; however, these approaches do not reflect typical MDS pts who receive different types of treatment in different sequences. We propose a prognostic model that incorporates mutational data and predicts outcome in pts with primary and secondary MDS regardless of their initial or subsequent treatments.MethodsClinical and mutational data of 333 pts with newly diagnosed MDS who were treated at out institution between 1/2000-1/2012 were analyzed. The IPSS-R was calculated at diagnosis. Survival was calculated from the date of diagnosis to last follow up or death. A panel of 62 gene mutations obtained by next generation targeted deep sequencing selected based on the frequency observed in a separate cohort of MDS patients analyzed by whole exome sequencing (WES). A Cox proportional multivariate analysis including age, IPSS-R score and mutations that are present in >/= 10 pts was used to select independent prognostic factors. The fit of the proposed model to the data was assessed by using the Akaike information criterion (AIC).ResultsPt clinical characteristics are summarized in Table 1. Median age was 68 years (range, 20-87); 214 pts (64%) had de novo MDS, 39 (12%) had prior antecedentl hematologic disorders, 37 (11%) secondary MDS, and 43 (13%) had chronic myelomonocytic leukemia (CMML). Pts received between 0-7 lines of therapy: 15% did not receive any treatment, 85% received at least one treatment, 40% received >/=2 treatments, 20% received >/= 3 treatments and 14% of pts eventually underwent hematopoietic cell transplant (HCT). First line therapies included: growth factors (30%), azacitidine +/- combination (32%), decitabine +/- combination (7%), single agent lenalidomide (5%), investigational agents (5%), induction chemotherapy with cytarabine and an anthracycline (7+3, 2%), and immunosuppressive therapy (4%). With a median follow-up of 38 months (mo) (range, 0.4-128.5), 70 pts (21%) progressed to AML and the median OS was 35.1 mo (range, 0.4-128.5). Per IPSS-R risk groups, median OS for very low was 35 mo, low 35 mo, intermediate 22 mo, high 19 mo, and very high 12 mo, Figure 1. Among the 62 gene mutations, 25 were present in >/= 10 pts: TET2 (17%), ASXL1 (15%), SF3B1 (14%), STAG2 (11%), DNMT3A (11%), RUNX1 (10%), U2AF1 (9%), GPR98 (8%), ZRSR2 (7%), BCOR (6%), TP53 (5%), NF1 (5%), EZH2 (5%), APC (5%), SUZ12 (5%), BCORL1 (4%), CBL (4%), PRPF8 (4%), NRAS (3%), CUX1 (3%), DDX54 (3%), IDH2 (3%), KDM6A (3%), PHF6 (3%), and SETBP1 (3%). A Cox proportional hazard analysis including age, IPSS-R score, and the 25 genes mutations listed above identified the following as independent prognostic factors: age, IPSS-R, ASXL1, BCOR, BCORL1, EZH2, IDH2, SF3B1,TP53. The linear predictive Cox model score obtained using the fitted coefficients of each prognostic factor was: ASXL1 X 0.65+BCOR X 0.92+BCORL1 X (-1.65)+EZH2 X 0.71+IDH2 X (-1.0)+SF3B1 X (-0.59)+TP53 X 1.24+Age X 0.04+IPSS-R score X 0.43. Four prognostic groups were proposed: low (score 0-3.4, 80 pts, median OS 47.3 mo), intermediate-1 (score 3.5-4, 69 pts, median OS 30.2 mo), intermediate-2 (score 4.1-5.4, 131 pts, median OS 19.9 mo), and high (score >/= 5.5, 53 pts, median OS 12.2 mo), p < 0.001, Figure 2. The new model demonstrated a markedly better fit, reflected in an AIC of 2026, compared to 2058 for the IPSS-R.ConclusionWe propose a new mathematical model that incorporates age, IPSS-R score and several gene mutations that can accurately predict OS in pts with primary and secondary MDS as well as CMML regardless of initial or subsequent treatments, including HCT. This model also highlights the importance of mutational data along with clinical data for risk stratification in MDS. [Display omitted] [Display omitted] Table 1Patient characteristicsNo.(%) / [Range]Total333Median age, years68[20-87]Male205(62)Female128(38)Median white blood cell (WBC) X 109/L3.8[0.69-125.9]Median absolute neutrophil count (ANC) X 109/L1.62[0.02-170]Median hemoglobin,g/dl9.6[3.9-14.6]Median platelets X 109/L93[4-776]Median bone marrow blasts %2[0-19]IPSS-RVery low50(15)Low128(38)Intermediate59(18)High60(18)Very high36(11) DisclosuresNo relevant conflicts of interest to declare.

NPM1+/FLT3- Patients with Acute Myeloid Leukemia (AML) Have Excellent Clinical Outcome Independent of Age When Treated with Cytotoxic Chemotherapy: Mayo Clinic Experience

Background:Molecular profiling has revolutionized the field of hematology, and in particular myeloid neoplasms. NPM1+/FLT3- mutational status has been shown to have a favorable prognostic impact in patients with acute myeloid leukemia (AML). However, little is known about its interaction with age.Methods:We retrospectively analyzed the overall survival (OS) in newly diagnosed AML patients, whose FLT3 and NPM1 data were available, and were treated with cytotoxic chemotherapy at our institution between 2003 and 2013. Patients 18 to 60 years of age were categorized as adult, and those above 60 years were classified as elderly. Each of the elderly or adult groups were further divided according to the presence or absence of combined NPM1+/FLT3- mutational status. Estimated probabilities of overall survival were calculated using the Kaplan-Meier method, with the log-rank test to compare groups. Demographics and continuous variables were compared using the Wilcoxon rank sum test. Appropriate IRB approval was obtained.Results:Out of 835 patients with AML, 86 patients with both known FLT3/NPM1 mutation status and receiving induction chemotherapy were found. NPM1+/FLT3- mutational status was present in 11 elderly (median age 68 yr, hemoglobin (Hb) 8.7 g/dL, white blood cells (WBC) 9.6 x109/L, platelets (PLT) 100 x109/L, peripheral blood blasts percentage (PB%) 31), and in 11 adult patients (median age 49 years, Hb 9.1 g/dL, WBC 14 x109/L, PLT 67 x109/L, and PB% 21). Twenty-eight elderly patients (median age 66 yr, Hb 9.4 g/dl, WBC 15.7 x109/L, PLT 66 x109/L, and PB% 33), and 36 adult patients (median age 49 years, Hb 9.1 g/dL, WBC 14 x109/L, PLT 67 x109/L, and PB% 21) were carrying genotypes other than NPM1+/FlT3-. There was no statistical significant difference in the median age, Hb, WBC, PLT, and PB% at the time of diagnosis. Out of 86 patients, 79 had intermediate, 6 had adverse, and 1 had favorable cytogenetic risk. All elderly and adult patients with NPM1+/FLT3- genotype had intermediate risk cytogenetics.When treated with cytotoxic chemotherapy, elderly patients with NPM1+/FLT3- genotype demonstrated a significantly better overall survival compared to elderly patients without this genotypes (p=0.015), and interestingly also to adult AML carrying other genotypes (p=0.028). Surprisingly, there was not an improved survival in adults with NPM1+/FLT3- genotype compared to adults carrying other genotypes (p=0.14), but this may have been related to the small numbers in each group. No significant difference in the overall survival was observed between elderly and adult patients who were carrying NPM1+/FLT3- mutational status (p=0.4). The estimated 5-year survival rates for elderly with and without NPM1+/FLT3- status were 71% vs. 14%, and for adults with and without this genotype were 49% vs. 19%, respectively.Conclusion:Age does not have an impact on the OS in AML patients with NPM1+/FLT3- mutational status, arguing strongly for intense chemotherapy in this group. Elderly AML patients with NPM1+/FLT3- genotype have a superior OS compared to both adult and elderly patients carrying other genotypes, when treated with cytotoxic chemotherapy. Further validation in large prospective studies is warranted. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Plasmapheresis Is an Effective Approach Preventing Clinically Significant Tumor Lysis Syndrome during Induction Therapy in AML Patients with Hyperleukocytosis

Introduction. Most studies have found that hyperleukocytosis (HL >100*109/l) is a poor prognostic factor in acute myeloid leukemia (AML). It is diagnosed in 5-13 % of cases and is more common in AML with monocytes’ differentiation (M4, M5), as well as in cases with poor prognostic molecular markers, such as FLT3-ITD and others.According to the literature the early (during the first week) mortality in AML due to HL may reach 90%. The main cause of death are leukostasis, leading to neurological symptoms, respiratory distress syndrome (RDS) with lung lesions, disseminated intravascular coagulation (DIC) syndrome with the development life-threatening bleedings and massive tumor lysis syndrome during induction therapy.Aim. National Research Center for Hematology (NRCH) has initiated a prospective clinical study aiming to develop a feasible clinical approach preventing severe tumor lysis syndrome during induction in AML patients with initial WBC >100*109/l by using serial plasmapheresis (PA).Patients and Methods. From Jan 2010 till June 2014, 92 patients with de novo AML were treated in the NRCH according to AML-10 protocol (ClinicalTrials.gov Identifier: NCT01587430). Initial white blood cell (WBC) count more than 100x109/l was detected in 18 patients (19,5%): median age - 38 y (17-56yy), M/F - 10/8, WBC - 130x109/l (100-408x109/l), LDH -1765 µ/l (720-6653). 2 patients were in the favorable, 13 – in the intermediate, 2 - in the poor cytogenetic risk group. 83,3% (15/18) patients had hepatosplenomegaly and lymphadenopathy, 38.8 % (7/18) - gingival hyperplasia, 16,6 % (3/18) - neuroleukemia, 16,6% (3/18) - skin leukemids. All patients had infectious complications at diagnosis.Lung infiltrates due to leukostasis were revealed - in 77,8% (14/18), including 5 patients (27,8%) with RDS; neurological symptoms (headache, blurred consciousness) - in 33,3% (6/18), DIC syndrome - in 8/18 (44,4%) with 1 intracranial hemorrhage.All patients received allopurinole 600 mg/day. PA procedures were started during cytoreductive therapy (hydroxyurea 10 mg/kg/day 1-2 days) sometimes with leukapheresis (LA) and were continued within 1 or 2 days of conventional 7+3 (ARA-C 100 mg/m2 bid iv 1-7 d, DNR 60 mg/m2 x 3d) 2 hours after short (30 min) ARA-C infusion. DNR was applied on days 3 to 5 or 5 to 7, thus PA did not interfere with its pharmacokinetic properties. All patients concomitantly have got intensive hydrating (3-4 l) and diuretic therapy with electrolytes and albumin support.Results: Cytoreductive therapy with hydroxyurea was used for a median 2 days (1-7 dd). Half of the patients (9/18) have got 1-2 procedures of LA (median 2). Median 2 (1-4) procedures of PA were performed in 17/18 patients. The volume of removed plasma for 1 PA procedure was 1200 ml (900-1500 ml), the volume of compensation was – plasma 1100 ml (500-1600 ml) +/- 20% albumin 50-150,0 and 0,9% NaCl 500-1000,0.Median WBC count after cytoreductive therapy at the 1st day of 7+3 was 60x109/l (5,6-124x109/l). DNR was administered on days 5-7 in 16 and on days 3-5 - in 2 patients. No severe cytolysis with the development of multiple organ failure was observed. Only 1 patient with massive extramedullary involvement has developed just laboratory signs of acute renal failure without stopping the urinary function. Less than third of the patients (5/18) developed the transient signs of volemic overload within the first days of chemotherapy treated successfully with diuretics and plasmapheresis.CR after the 1st induction was achieved in 50% of (9/18) patients. Additional 7 patients achieved CR after the 2nd induction, resulting in 89% overall CR rate. Only 1 patient (5,5%) died with severe infectious complications during aplasia. Allogeneic bone marrow transplantation was performed in 8 of 16 CR patients. The median OS and DFS was 28 and 23 months, 3-years OS and DFS was 32% and 35% respectively.Conclusions. Our small study brought us to a conclusion that serial PA procedures during cytoreductive phase and the first days of 7+3 may prevent the development of tumor lysis syndrome and its complications. This clinical approach is feasible, easy to perform and decreases early mortality. DisclosuresNo relevant conflicts of interest to declare.

Leukocyte Count Defines Patients on Risk for Thrombotic Complications with Well Controlled Essential Thrombocythemia- Data from a Patient- Registry

There is compelling evidence that white blood cell (WBC) counts impact the risk of thrombosis in patients with myeloproliferative neoplasms (MPN) (Barbui Blood 2013). Moreover, recent publications disclosed significant differences regarding certain disease characteristics and the course of disease in WHO 2008 (Tefferi Blood 2007) classified essential thrombocythemia (ET) and prefibrotic primary myelofibrosis (PMF) (Kvasnicka Am J Hematol 2008; Barbui JCO 2011; Buxhofer-Ausch Am J Hematol 2012). Hence, patients cohorts classified prior to WHO 2008 may likely consist of a mix of patients with ET and prefibrotic PMF.We aimed to reproduce the influence of WBC counts on the thrombotic risk in patients under real-life conditions. Therefore we assessed data of 825 Austrian patients from a patient registry for anagrelide in ET that was initiated 2001 in Austria due to an official authorities demand and is now being maintained in several Central European countries.Efficacy of treatment was assessed by investigating the course of platelet counts and event free survival relating to the first minor or major thrombotic event. WBC counts from the first available time points were correlated with the first thrombotic event. The cut off for the WBC subgroup analysis was set at 8,5 G/l. Statistical analysis was performed using the open-source R statistical software package, version 3.0.2. Non-parametric two-sided 95% confidence intervals for medians were calculated. Survival probabilities were assessed by applying the Kaplan-Meier method. For the comparison of time to event between the leukocyte- specific subgroups the log-rank test was used.Median Follow up of the study cohort is 3,07 years. Platelet count at start of anagrelide was median 777 G/l (95% CI 757-803). After 12, 24 and 36 months patients presented with median platelet counts of 473, 457 and 438 G/l, respectively. Median WBC count at start of therapy was 9 G/l (95% CI 8,7-9,3) and after 12, 24 and 36 months 8,5 G/l, 9,2 G/l and 8,7G/l, respectively. Incidence of thrombotic events per 100 patient- years was 5,14 for all events and 1,65 for major events only. 102 patients experienced at least one minor or major thrombotic event (major events n=36). Median time to the first minor or major thrombotic event was 1,27 years. Probability of event free survival at 1 year is 94,4% and at 3 years 87,6%. Patients with a baseline WBC count of higher than 8,5 G/l exhibit a significantly shorter probability of event free survival than patients below the cut off (p= 0,007 for all thrombotic events; p= 0,026 for major events only).This data proof the efficacy of anagrelide in lowering platelet counts and reducing significantly the risk of thrombotic events in patients with ET. The significantly shorter event free survival of patients with a WBC count above 8,5 G/l confirms earlier studies for the first time in a real-life setting. This result emphasizes the separation of true ET from prefibrotic PMF by using the WHO 2008 classification. Moreover, further investigations are needed to assess, whether a correlation of certain platelet and leukocyte counts modifies the risk of thrombotic events in MPN. DisclosuresSchloegl:AOP Orphan Pharmaceuticals AG: Research Funding.

A Comprehensive Assessment of Phase 1 Clinical Trials in Acute Myeloid Leukemia

Introduction: There have been minimal therapeutic advancements in the management of acute myeloid leukemia (AML) over the past 3 decades. Although approximately 70% of younger AML patients will achieve a complete remission (CR) with standard induction chemotherapy regimens, overall outcomes are dismal. It is unclear why drug development has been particularly hindered in AML when compared to other hematologic malignancies and cancers.Methods: A retrospective analysis was performed on 65 phase 1 clinical trials supported by the Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) from 1984-2009. A total of 711 adult AML patients were enrolled in these studies. The primary objectives were to assess overall response rates ([ORR]: CR + partial remission) and treatment-related mortality (all causes of 60-day mortality) over time. Clinical characteristics and outcomes were summarized by study date, grouped as: 1) 1984-1990, 2) 1991-1995, 3) 1996-2000, 4) 2001-2005, 5) 2006-2009. Two multivariable logistic regression modeling approaches were used to estimate the ORR and treatment-related mortality rates with A) a comparison of subgroups with 1984-1990 as the reference group, and B) time as a continuous variable.Results: The number of AML patients enrolling on phase 1 clinical trials increased substantially over time (1984-1990: n=61, 2006-2009: n=256). The clinical characteristics resembled a high-risk, relapsed/refractory patient population: median age = 60 years, median # of prior therapies = 4 (63% had ≥3 prior therapies), and median white blood cell count = 3,600/mm3. The proportion of patients ≥60 years increased from the earliest subgroup (1984-1990: 18%) to the most recent (2006-2009: 64%). Additionally, there was a relative increase in the proportion of patients without any prior therapies over time from 1984-1990 (13%) to 2006-2009 (24%). Figure 1 demonstrates the ORR and treatment-related mortality for each subgroup. The ORR for the entire cohort was 15%. ORR was significantly improved in the most recent subgroup (2006-2009: ORR=23%) when compared with the earliest subgroup (1984-1990: ORR=9%), p=0.05. Additionally, there was a small but significant improvement in ORR and 60-day mortality rates with each increasing year, odds ratio (OR)=1.04, p=0.03, OR=0.96, p=0.008, respectively.Discussion: Our analysis of CTEP-sponsored phase 1 clinical trials demonstrates a relative upsurge of AML patients being enrolled in phase 1 studies over the last 26 years. ORRs and 60-day mortality rates appear to be modestly improving over time, which may be due to the relative increase of treatment-naïve patients enrolling in phase 1 studies. To our knowledge, this is the largest compilation of phase 1 clinical trials reported for AML. Continued enrollment of AML patients on early-phase clinical trials at all stages of disease, including those with newly diagnosed AML with poor-risk features, is vital for drug development and improvement in therapeutic outcomes. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Pediatric Acute Megakaryoblastic Leukemia without Down Syndrome: A Retrospective Study by the International Berlin-Frankfurt-Munster Study Group (I-BFMSG)

Acute megakaryoblastic leukemia (AMKL) comprises up to 10% of childhood acute myeloid leukemia (AML) cases. However, no large-scale studies have comprehensively evaluated the clinical characteristics and outcomes of patients with AMKL. We performed a large-scale international retrospective study of pediatric patients (diagnosed at age ≤18 years) with de novoAMKL without Down syndrome treated from 1989 to 2009.The study included 490 patients with AMKL, which comprises 7.9% of the pediatric AML patients treated by 19 members of the I-BFMSG. At diagnosis, the median age of patients was 1.5 years (range, 0.0–16.5 years), median white blood cell count was 12.0×109/L (range, 0.6–188.0×109/L), 23 (4.7%) patients showed central nervous system involvement, and both sexes were equally represented. Complete remission (CR) was achieved in 417 (85.1%) patients, and 5-year event-free (EFS) and overall survival (OS) rates were 43.7%±2.7% and 49.0%±2.7%, respectively. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) was performed in 206 (42.0%) patients. The 5-year disease-free survival and OS rates for patients who received allo-HSCT in first CR (n=112, 56.3%±5.2%, and 57.7%±5.2%, respectively) and for those who did not receive transplantation in first CR (n=298, 50.2%±3.6% and 55.2%±3.5%) were not significantly different (P=0.12 and P=0.57).Complete cytogenetic data were available for 372 (75.9%) patients: diploid (n=49, 13.2%), hypodiploid (n=18, 4.8%), pseudodiploid (n=119, 32.0%), 47–50 chromosomes (n=142, 38.2%), and >50 chromosomes (n=44, 11.8%). Chromosome gain occurred in 195 (52.4%) patients: +21 was the most common (n=106, 28.5%), followed by +19 (n=93, 25.0%), and +8 (n=77, 20.7%). Losses occurred in 65 cases (17.5%), in the decreasing order of –7 (n=13, 3.5%), –9 (n=9, 2.4%), –13, and –15 (n=7 each, 1.9%). Structural chromosomal aberrations were observed in 278 (74.7%) patients, most commonly t(1;22) (n=51, 13.7%) and 11q23 rearrangements (n=38, 10.2%) with t(9;11) in 21 patients. Other abnormalities included 7p (n=43, 11.6%) and 13q (n=31, 8.3%; 16 with deletions) breakpoints. Patients with t(1;22) were significantly younger at diagnosis (P<0.001; median 0.6 years, range 0.0–6.3 years) and more often female (P=0.05; 64.7%) while those with –7 were significantly older (P=0.006; median 4.2 years, range 0.4–15.0 years) than those with other cytogenetic subgroups.Multiple regression analysis for EFS and OS with clinical and cytogenetic features showed that treatment period (1989–1999 vs. 2000–2009), normal cytogenetics, –7, t(9;11), 13q-, and –15 were associated with significantly worse outcomes than those for other subgroups, whereas abnormalities in 7p were associated with better outcomes (Table). Patients with –13 and 9p abnormalities other than t(9;11) had a poorer EFS and OS, respectively. Patients with +21 or t(1;22) did not show a significant difference in survival rates.This international study on the largest cohort of AMKL patients analyzed to date shows heterogeneity in cytogenetic findings and identifies some subgroups with a particularly dismal outcome. The advent of newer methods to evaluate genetic lesions can help identify therapeutic targets for improving the outcome in this subgroup of patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

IKZF1 deletions in Pediatric Acute Myeloid Leukemia

IKAROS family zinc finger 1 (IKZF1) is a transcription factor involved in lymphoid differentiation that acts as a tumor suppressor. In B-cell precursor acute lymphoblastic leukemia (BCP-ALL) loss of IKZF1 is found in ~15% of the patients, is associated with the presence of BCR/ABL1 (t(9;22)(q34;q11)) and confers a poor clinical outcome. Recent studies suggest that IKZF1 is also involved in myeloid differentiation. The best indication that loss of IKZF1 may contribute to myeloid leukemogenesis are deletions of the short arm of chromosome 7 associated with myeloproliferative-preceded secondary acute myeloid leukemia (AML) in adults, where the commonly deleted region is mapped to the IKZF1 locus (Jager et al,Leukemia 2010).To investigate whether IKZF1 deletions play a role in pediatric AML we screened a representative well-characterized panel of 258 de novo pediatric AML samples with available gene expression data, obtained from the DCOG (The Hague, the Netherlands), the AML–Berliner-Frankfurt-Münster Study Group (Germany and Czech Republic), the Saint-Louis Hospital (Paris, France) and the Royal Hospital for Sick Children (Glasgow, UK) for deletions of the IKZF1 locus on chromosome 7p12.2 using multiplex ligation-dependent probe amplification (MLPA).Median age of the patients was 9.5 years (range 0.1-18.5 years), median white blood cell count was 46.7x109/L (range 1.2-483x109/L). All major cytogenetic subgroups were included and all patients had received intensive cytarabine-anthracycline based pediatric AML therapy. Of 11 patients with an IKZF1 deletion, 8 cases presented with monosomy 7, and 3 cases showed a focal deletion of IKZF1. These focal deletions included the complete IKZF1 gene (n=2) or exons 1-4 (n=1), leading to a loss of IKZF1 function. Focal deletions were confirmed by high-resolution array comparative genome hybridization (array-CGH). Patients with a focal deletion included a 1.5 year old boy diagnosed with AML with a fusion of MNX1/ETV6 who died from relapse; an 11.3 year old girl diagnosed with AML M5 who remains in continuous complete remission (CCR) after salvage therapy for relapse; and a 2.3 year old boy diagnosed with AML M5 in CCR. IKZF1 deleted cases (n=11) did not differ significantly from the other pediatric AML cases (n=247) with regards to age at diagnosis (median age 9.1 years compared to 9.5 years respectively, p=0.41); gender (females 55% versus 42%, p=0.41); or white blood cell count at diagnosis (median 30.2 x109/L versus 47.5 x109/L, p=0.24). No specific FAB morphology subtypes were related to IKZF1 deletions. IKZF1 deleted samples showed either none or various different additional somatic mutations, most frequently activating the RAS pathway with mutations in NRAS or PTPN11 (n=4,). In BCP-ALL IKZF1 deletions are associated with BCR/ABL1 fusions and to test if this was also true for IKZF1 deletions in AML we screened samples for the BCR/ABL1 fusion and all were negative. The 3-year pOS in IKZF1 deleted patients (n=11) was 70±14% versus 63±3% (p=0.82) in IKZF1 wild-type patients (n=231). The 3-year pEFS was 36±15% versus 46±3%, and the 3-year pCIR was 64±16% versus 36±3% (p=0.87 and p=0.09) respectively. Genes differentially expressed in monosomy 7 cases correlated significantly with gene expression changes in focal IKZF1 deleted cases when comparing significant differences to non-IKZF1-deleted cases (n=247). Genes showing increased expression in IKZF1 deleted samples included those involved in myeloid cell cycling and self-renewal, such as HEMGN, FHL2, FZD6, and SETBP1.In summary, we found focal IKZF1 deletions to be rare but recurrent events in pediatric AML. Gene expression patterns suggest that the loss of IKZF1 may be an important determinant in the biology of pediatric AML with monosomy 7. DisclosuresNo relevant conflicts of interest to declare.

ASXL1 Mutations in AML: Molecular Biomarker for Secondary AML?

Background: Additional sex combs like transcription factor 1 (ASXL1) is a member of the polycomb group protein. ASXL1 mutation has been implicated in myeloid malignancy transformation. It is hypothesized that mutated ASXL1 leads to the loss of polycomb repressive complex 2 (PRC2) mediated gene repression and subsequent transforming events. Recent studies identify ASXL1 mutation as a poor prognostic marker in patients (pts) with de novo acute myeloid leukemia (AML) who present with intermediate–risk cytogenetic lesions (Patel, NEJM 2012; Schnittger, Leukemia2013). To study the impact of ASXL1 mutations in an unselected AML population, we analyzed clinical and molecular characteristics of patients with untreated AML who express ASXL1 mutation at presentation.Methods: Using next generation sequencing, 254 adult patients with AML seen at the Hospital of the University of Pennsylvania were analyzed for mutations, including ASXL1, using a 33-gene hematologic malignancy panel. Clinical characteristics were obtained from retrospective chart review. Kaplan-Meier estimates were used to calculate overall survival (OS) from time of diagnosis. Living patients were censored at date last seen.Results: ASXL1 mutations were detected in 36/254 (14%) AML pts. There were 29 known pathologic mutations, 1 benign, 1 probable pathologic, and 9 variants of unknown clinical significance (VUS). In 6/36 (16.7%) pts, ASXL1 was the sole mutation identified. Of the 30 pts with additional mutations (Figure 1), 6/30 (20%) pts harbored 2 independent ASXL1 mutations. When the 27 patients with pathologic ASCL mutations were analyzed for co-mutations, TET2 (13/27, 48%) was the most frequent ASXL1 co-mutation. FLT3 (0/27, 0%) and NPM1 (1/27, 3.7%) were notable for their absence.Median age of pts at diagnosis was 69 years (range 23-80). Prior myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN) was noted in 9/36 (25%) and 11/36 (30.6%) pts, respectively. Four pts (11.1%) had received chemotherapy and/or radiation therapy for a prior non-myeloid neoplasm. Karyotype was normal in 18/36 (50%) pts, and 7 additional pts had intermediate cytogenetic lesions. There were 7 pts (19.4%) with unfavorable cytogenetics (complex karyotype (3 pts), 7q- (3 pts), and 5q- (1 pt)). Four pts (11.1%) had a favorable karyotype, with t(8;21) in 3 pts and t(15;17) in 1 pt.At presentation, median white blood cell count (WBC) was 6.4x103/uL (1.0 x -103). In pts whose AML transformed from prior MPN, median WBC was 50 X103/uL (3.3-140). Standard induction chemotherapy with an anthracycline and cytarabine was given to 17/36 (47%) pts. An additional 3/36 (8.3%) pts underwent induction therapy with clofarabine. Complete remission (CR) was documented in 14/20 (70%) evaluable pts. Of the remaining pts, 11 received a hypomethylating agent, and 5 received other therapies. Thirty-day treatment mortality for all 36 pts and for 27 pts with known ASXL1 pathologic mutation was 13.4% and 18.5% respectively. Kaplan-Meier estimate showed a median overall survival of 349 days (median follow up of 107 days (range 15-1570)). For the 27 pts with a pathologic ASXL1 mutation, the OS was 276 days (Figure 2, median follow up of 145 days (range 18-1570)).Conclusion: ASXL1 mutations in de novo AML with intermediate-risk cytogenetics is associated with poor clinical outcome in cooperative group trials. Strikingly we demonstrate in a single institution, retrospective analysis that 66.7% of pts who present with ASXL1 mutations in the setting of previously untreated AML had documented MDS, MPN and/or prior chemotherapy/radiation. Further studies are necessary to evaluate if ASXL1 mutation has independent prognostic significance in AML or if it is primarily a marker for secondary leukemia. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Improvement in Treatment Outcome and Identification of a New Prognostic Parameter in Down Syndrome Acute Myeloid Leukemia (DS-AML): Results of the Children’s Oncology Group (COG) Phase III AAML0431 Trial

Background: DS-AML patients (<4 years of age), have favorable outcomes compared to non-DS AML patients. However, DS patients experience significant treatment-related morbidity and mortality due to infectious and cardiac complications. Blast cells from DS-AML patients reportedly have increased sensitivity to cytarabine (araC) and daunorubicin, suggesting that optimization of drug dosing may improve outcomes and/or reduce toxicity.Objective: The main objectives of the AAML0431 study were to determine whether high-dose (HD)-araC) administered earlier during treatment could improve EFS rates, and whether EFS rates could be maintained despite reducing the cumulative daunorubicin dose and the number of intrathecal treatments. The study also aimed at determining the clinical significance of minimal residual disease (MRD) in this AML subgroup.Methods: AAML0431 consisted of 4 cycles of induction and 2 of consolidation therapy based on a backbone of the previous COG A2971 trial with several modifications including the use of HD-araC for Induction II rather than during Intensification therapy (fifth cycle of therapy), a 25% reduction in the cumulative daunorubicin dose and a decrease in the number of intrathecal treatments from 7 to 2. The recommended criteria for proceeding to each subsequent cycle of therapy was an absolute neutrophil count ≥1,000/µL and platelets ≥100,000/µL. MRD was measured by a multi-parameter flow cytometry assay capable of detecting 0.01% DS AML blasts.Results: Between March 2007 and December 2011, 205 children (106 females, 99 males) with DS or DS mosaicisim were enrolled. Of the 204 evaluable patients, 144 were classified as having AML and 60 myelodysplastic syndrome (MDS); median age at diagnosis was 1.57 years. Sixty two patients (40 AML, 28%; 22 MDS, 37%) had a prior diagnosis of the transient myeloproliferative disorder (TMD) and 6 had received chemotherapy for TMD. Congenital heart defects were present in 90 (44%) patients.Among AML patients, median white blood cell count (WBC) at diagnosis was 6.5 x 103/µL, peripheral blast percentage 7% and platelet count 34 x 103/µL; for MDS patients, these were 4.85. x 103/µL, 0% and 36.5 x 103/µL, respectively. No patient had CNS leukemia at diagnosis. Institutional reporting of morphology was megakaryocytic leukemia in 85 (42%) of cases.Event-free survival (EFS) from study entry for all eligible patients was 90% ± 4.4% at 3 years; overall survival (OS) was 92.7% ± 3.8% at 3 years, with equivalent results for MDS patients. There were 19 treatment failures: 2 induction failures, 14 relapses and 3 non-relapse deaths. MRD data on day 28 of Induction I was available in 149 patients. Three-year disease-free survival among patients who were MRD-negative (blasts <0.01%) after Induction I (93.5% ± 4.8%; n=125) was significantly higher than that of MRD-positive patients (70.6% ± 18.7%; n=24; log-rank P <.001). The OS at 3 years for the 16 patients with refractory/relapse leukemia was 30% ± 23.6%.There were a total of 1045 adverse events (AEs) classified as grade 3 or higher; 66% of these AEs were reported during the Induction II cycle. No life-threatening cardiac toxicities were reported and overall, only 7 cardiac AEs classified as ≥ Grade 3 were identified.Thirteen patients were electively taken off protocol therapy by request from the treating physician (n=6) or parents (n=7) (Induction I, 4; Induction II, 3; Induction IV, 2; Intensification I, 4), primarily due to experiencing significant toxicities. One patient taken off therapy after Induction II, relapsed and died and another had a non-relapse death after stopping therapy post-Induction I. The remaining patients were reported to be alive.The earlier use of HD-araC in AAML0431 resulted in improvements in EFS and OS compared to past COG studies, while a 25% reduction of the cumulative daunorubicin dose (compared to COG A2971) and limited intrathecal chemotherapy treatments did not adversely impact outcome. In addition, MRD analysis performed after Induction I was identified as a prognostic factor for DS-AML patients for the first time. MRD provides a prospective tool for risk stratification for future trials to identify patients who may benefit from a further reduction in therapy intensity (e.g., elimination of HD-araC), as well as identifying patients with resistant disease who require new treatment options (e.g. treatment intensification, new agents). DisclosuresNo relevant conflicts of interest to declare.

Leukapheresis in management of hyperleukocytosis in children's leukemias.

We describe 16 leukapheresis (LK) procedures performed in 7 children with different types of leukemia and hyperleukocytosis. We also provide an analysis of previously published experiences of pediatric LK. Median age and body weight of patients were 12.3 years (range, 0.2 to 16.7 y) and 49 kg (range, 5 to 61 kg). Immediate pre-first-LK median white blood cell count was 478×10/L (108×10/L to 988×10/L). All cytoreduction were performed on Cobe Spectra cell separator. Sixty-eight percent of procedures were performed with peripheral veins. Extracorporeal line had been primed with red blood cell for 31% of LK. The median decrease in white blood cell count after each LK was 33% (0% to 69%), and overall decrease after completion of LK procedures was 62% (11% to 94%). Only minor clinical adverse events and no metabolic complication were attributable to LK. No more clinical symptom of hyperleukocytosis was observed after completion of LK procedures. Our findings are consistent with reported results in other pediatric series: LK is a well-tolerated procedure that can be safely performed with an experienced pediatric team even on the smallest children.

Clinical efficacy of decitabine combined with modified CAG regimen for relapsed-refractory acute myeloid leukemia with AML1-ETO⁺

This study was aimed to investigate the clinical characteristics of relapsed-refractory acute myeloid leukemia (AML) with AML1-ETO⁺, and its therapeutic efficacy and side effects when decitabine combined with modified CAG regimen was used. Clinical data of 5 cases of AML with AML1-ETO⁺ from January 2013 to Agust 2013 were analyzed retrospectively. The analyzed data included age, sex, initial symptoms, peripheral blood and bone marrow characteristics. Meanwhile, the therapeutic effecacy and side effects of decitabine combined with modified CAG regimen were evaluated. The 5 patients were with median age of 35 (17-43) years. Among these 5 patients, 2 patients were relapsed and other 3 patients were relapsed-refractory patients, their median white blood cell count was 12.55 (7.8-66.55) × 10⁹/L, median platelets count was 44 (20-72) × 10⁹/L, median hemoglobin level was 110 (77-128) g/L, median lactate dehydrogenase level was 312.9 U/L (123.6-877.8) at the initial diagnosis. The results showed that after decitabine combined with modified CAG regimen was administered, 4 patients achieved complete remission, 1 patient did not achieve remission, the overall remission rate was 80% (4/5). The main side effects of this regimen was myelosuppression, these were no new lung infection and other serious complications, one case without complete remission treated with FLAG once again died of heart failure when being mobilized for transplantation. It is concluded that according to preliminary results of decitabine combined with modified CAG regimen for relapsed and refractory AML patients with AML1-ETO⁺ displays higher remission rate and lower side effects, which worthy to further explore for clinal application.

Abstract CT307: Phase I/II study of vosaroxin and decitabine in older patients (pts) with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (MDS)

Abstract Background: Vosaroxin (formerly voreloxin), is a quinolone derived DNA topoisomerase II inhibitor, which is not a substrate for p53 or P-glycoprotein and has limited toxicity; it is currently under evaluation for the treatment of pts with AML and high-risk MDS. Methods: Pts were eligible if they had AML or high-risk MDS (defined as having ≥ 10% blasts in the bone marrow), were 60 years of age or older, and had adequate performance status (ECOG ≤ 2) and organ function. Pts younger than 60 who were unsuitable for standard chemotherapy were also eligible. The treatment regimen included vosaroxin 90 mg/m2 daily on days 1 and 4 with decitabine 20 mg/m2 daily for 5 days. Vosaroxin dose was reduced to 70 mg/m2 in consolidation cycles, which were repeated in approximately 4 to 5-week intervals for a total of up to 7 cycles. Dose adjustments and dose delays of one or both agents, were allowed based on toxicity. The primary endpoint was to determine the complete remission (CR) rate. Secondary endpoints were: CR duration, disease-free survival, overall survival, safety, and early mortality. Results: To date, 12 pts (9 AML, 3 high-risk MDS) with a median age of 71 years (range, 41-76) have been enrolled; 11 were older than 60 years. They included 6 (50%) pts with diploid cytogenetics, 4 (34%) with complex cytogenetic abnormalities including chromosome 5 and/or 7 abnormalities, and 2 (16%) with other miscellaneous abnormalities. 4 (34%) pts with AML had antecedent hematological disorders (AHD) including 1 (8%) with MDS, 1 (8%) with myeloproliferative neoplasm and 2 (17%) with MDS/MPN. Three pts with AHD had received prior therapy including 5-azacytidine (n=1), ruxolitinib + 5-azacytidine (n=1) and lenalidomide (n=1). RAS mutations were identified in 4 (34%) and IDH2 mutations in 2 (16%) pts. Median bone marrow blast %, median white blood cell, hemoglobin, &amp; platelet counts were 29% (11-73), 3.7 x 109/L (1.0-127.1), 9.5 g/dL (8.2-10.8), and 92 x 109/L (11-361), respectively. 9 pts were evaluable for response; 5 (42%) achieved CR, 1 (8%) CRp, and 2 (17%) CRi, for an overall response rate of 89%. 1 pt had no response after cycle 1 and is currently undergoing re-induction. Three are too early for response assessment. Pts have received a median of 2 (1-3) treatment cycles with median number of cycles to response being 1 (1-2) and median time to achieving response, 26 days (21-74 days). The median duration of CR/CRp/CRi is 53+ days (6-89+ days). One pt has proceeded to allogeneic stem cell transplant. No pts died during induction. One pt died on study on day 47 from sepsis and acute myocardial infarction. The regimen is well tolerated with the main grade ≥ 3 toxicity being mucositis in 3 (25%) pts. Conclusion: Combination of vosaroxin and decitabine is effective and well tolerated in older patients with AML and high-risk MDS. Enrollment is ongoing. Citation Format: Naval Daver, Hagop M. Kantarjian, Guillermo Garcia - Manero, Naveen Pemmaraju, Tapan Kadia, Courtney DiNardo, Nitin Jain, Gautum Borthakur, Jorge Cortes, Craig Adam, Farhad Ravandi. Phase I/II study of vosaroxin and decitabine in older patients (pts) with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (MDS). [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 CT307. doi:10.1158/1538-7445.AM2014-CT307

Clinical and genetics characteristics of patients with monosomal karyotype acute myeloid leukemia patients

To investigate the clinical and genetics characteristics of patients with monosomal karyotype acute myeloid leukemia (MK-AML). The karyotypes of 3743 patients with newly-diagnosed de novo AML were analyzed, which had identified 153 cases with MK-AML, for whom the clinical and genetics characteristics were analyzed. There were 2056 patients (54.9%) among all patients. A total of 153 patients fulfilling the criteria for MK-AML were identified, which comprised 93 males and 60 females, with a median age of 54. The median white blood cell count on presentation was 4.4×10 (9)/L. One hundred and forty-five cases (94.8%) have fulfilled the criteria for complex karyotype (≥ 3 chromosomal abnormalities). Although the monosomy could be found with all autosomes, chromosome 7 has been most frequently involved (38.56%, 59/153). MK-AML is a distinct cytogenetic subtype of AML. Monosomy 7 is frequently detected among MK-AML patients. The monosomal karyotype is common among elder patients with AML.

Prevention of pin tract infection with iodine-supported titanium pins

BackgroundPin tract infection is one of the most common complications of external fixation. We developed techniques to coat titanium implant surfaces with iodine. This study clinically evaluated the infection-preventive effects and biological safety of iodine-coated external fixation pins. Patients and methodsIodine-supported pins were placed in 39 limbs of 38 patients. The mean age of the patients was 33.6 years. Twenty-six patients were men and 12 were women. In all patients, the iodine-coated pins were used to prevent infection. There were 476 pin insertion sites. Pin sites were classified according to the Checketts–Otterburn classification (grade 1–6). White blood cells (WBC) and C-reactive protein (CRP) were measured pre- and postoperatively in all patients. To confirm whether iodine from the implant affected physiological functions, thyroid hormone levels in the blood were monitored. The change in the amount of iodine deposited in the body over time was calculated by examining the removed pins. ResultsExternal fixation was used for a mean duration of 6 months. Grade 1 infection was found in 2.5 % of patients, and grade 2 infection in 1.1 %. There was no patient with an infection of grade 3 or higher. Median WBC levels were in the normal range, and median CRP levels returned to <0.3 mg/dl within 3 weeks after surgery. Abnormalities of thyroid gland function were not detected. The amount of iodine was maintained for a long time, with approximately 40 % remaining after 1 year. ConclusionsIodine-supported titanium pins were able to decrease the pin tract infection rate and had no impact on thyroid function. These results suggest that iodine-coated titanium pins are biologically safe and effective at preventing pin tract infections.

L-Asparginase Administration Reduces White Blood Cell Count and Prevents Tumor Lysis Syndrome in Children with Hyperleukocytic Acute Lymphoblastic Leukemia

Background: The management of hyperleukocytosis currently involves intensive supportive care for preventing tumor lysis syndrome (TLS)-associated metabolic abnormalities as well as cytoreduction procedures to reduce the white blood cell (WBC) count. These procedures are often equipment-intensive and may not be practised in developing countries with limited resources. Hence, it is not clear what would be the most effective strategy to manage hyperleukocytosis and prevent TLS. Procedure: All children ≤12 years, diagnosed with acute lymphoblastic leukemia (ALL) and hyperleukocytosis (WBC count >100 × 10⁹/l) were administered <smlcap>L</smlcap>-asparginase (<smlcap>L</smlcap>-asp, 6,000 U/m², i.m.) along with standard supportive care consisting of hydration, oral allopurinol administration and alkalization. The complete blood counts and biochemical parameters were monitored for 72 h. After 48 h, if the WBC count was >100 × 10⁹/l, a repeat dose of <smlcap>L</smlcap>-asp was administered. Results: Twenty-one children (9 boys and 12 girls) with hyperleukocytic ALL were treated with <smlcap>L</smlcap>-asp. The median age of the children was 5.3 years (range 2-11 years). The median initial WBC count was 249 × 10⁹/l (range 151-476 × 10⁹/l). Twenty children received only one dose of <smlcap>L</smlcap>-asp. The mean reduction in WBC count achieved by treatment was 15.7, 42.0, 61.0, 76.4, 85.5 and 90.8% at 12, 24, 36, 48, 60 and 72 h, respectively. None of the patients developed TLS. Conclusions: Chemical cytoreduction by administering <smlcap>L</smlcap>-asp is an effective means of managing hyperleukocytosis and preventing TLS.

Correlation of KIT expression with higher FLT3 mutations and impact on clinical outcome in patients newly diagnosed with acute myeloid leukemia (AML).

7067 Background: KIT (CD 117) is a transmembrane tyrosine kinase protein receptor encoded by the c-kit protooncogene. KIT mutations were described in AML and impart a prognostic impact on patients (pt) with core binding factor. However, its expression effect on clinical phenotype and outcome is unknown. Methods: A retrospective, single institution study of cases with AML at Mayo Clinic between 2003 - 2011 was performed. Pts with blasts KIT expression studied by flow cytometry at diagnosis were included. Appropriate IRB approval was obtained in accordance with the Helsinki declaration. Comparison between groups’ medians was done using Wilcoxon test, while survival estimates were calculated using Kaplan-Meier curves. Results: Out of 154 pts who had KIT analysis, KIT+ (>20% of blasts) was in 134 (87%). Median age is 62 year, with median white blood cell (WBC) 9 x109, Hemoglobin (Hgb) 9.3 g/dl, platelet (PLT) 56 x109, peripheral blood (PB) blast 10%, bone marrow (BM) blasts 56%. Cytogenetics (CG) was diploid in 55% pt. NCCN grouping for CG was favorable, intermediate and poor in 8%, 71%, 21%. FLT3 was mutated in 25%, NPM1 in 38% pts. CR was found in 105 (68%) pts; 77 relapsed. Median OS is 577 days. Group 1 (KIT-) had median age 62 year, Hgb 9.3 g/dl, PLT 82 x109, WBC 18 x109, PB blasts 34%, BM blasts 71%. CG was favorable, intermediate and poor in 8%, 58%, 33%. NPM1 and FLT3 were mutated in 50%, 0, respectively. CR was obtained in 75% with 55% suffering a relapse. Group 2 (KIT+) had median age 62 year, Hgb 9.4 g/dl, PLT 56 x109, WBC 9 x109, PB blasts 19%, BM blasts 55%. CG was favorable, intermediate and poor in 8%, 74%, 18%. NPM1 and FLT3 were mutated in 37% and 29%. CR was found in 67% with 51% relapsing. Upon comparison, mutated FLT3 was more frequent in group 2 vs 1 (p=0.002). Median OS was not statistically different between group 1 vs 2 (447 vs 592 days, p= 0.25). On multivariate analysis, only NCCN grouping (p=0.006) affected mOS but not age, WBC, PB/BM blasts, or KIT. Conclusions: KIT expression was prevalent in AML pts. We found for the first time that KIT- AML pts did not have mutated FLT3 (0%) but KIT expression did not impact clinical outcome. Additional prospective studies are needed to confirm our results.