ALBERT

Description: Abstract 44 CALGB (now part of the Alliance for Clinical Trials in Oncology) performed a non-randomized phase II study testing one year (yr) of investigational maintenance therapy with decitabine for newly diagnosed adult AML patients (pts) 1 × 109/L, platelets 〉75 × 109/L, and be within 90 days after day 1 of the final consolidation. Decitabine 20mg/m2 was given IV over 1 hour for 4–5 days, every 6 weeks, for 8 cycles. 546 pts enrolled with a median age of 48 yrs (range, 17–60) and median presenting white blood count (WBC) of 12.6 × 109/L (range, 0.3–380 × 109/L). 75% achieved CR (412/546). Reasons for CR pts not receiving maintenance were mainly early relapse, alloHCT in 1st CR, inadequate count recovery, and patient refusal (Blum et al. ASH 2011). 33% of CR pts (134/412) received investigational maintenance. Of these, 46 (34%) were favorable risk; among the remaining 88 pts, 73 were consolidated with autoHCT, and 15 received HiDAC-based consolidation. The median time from initial study registration to initiation of maintenance therapy was 6.3 months. Pts receiving decitabine had a median age of 45 yrs (range, 18–60) and presenting WBC of 13.5 × 109/L (range, 0.4–221 × 109/L). Treatment with decitabine maintenance was feasible and reasonably well tolerated; the primary toxicity was myelosuppression. Preplanned dose reduction criteria for neutropenia were met after the first 20 pts had been treated. After this early timepoint, all subsequent pts who had been consolidated with autoHCT received only 4 days of decitabine per cycle (HiDAC consolidated pts continued to receive 5 days per cycle). The median number of cycles of decitabine received was 7 (range, 1–8); 46% of pts (62/134) received all 8 cycles, and 75% completed at least 4 cycles. Reasons for discontinuation of decitabine before completing 8 cycles included relapse (28%, 38/134), pt refusal (13%), adverse events (4%), and others. In this selected cohort of pts who received post-CR maintenance with decitabine, 1-yr and 3-yr overall survival (OS) were 96% and 66%; 1-yr and 3-yr disease-free survival (DFS) were 80% and 53%. 1-yr “failure-free survival” calculated from the time of registration to decitabine was 68% (70% for favorable risk, 68% for others). These results are similar to the outcomes for comparable pts enrolled on our prior CALGB study 19808 who received identical chemotherapy for induction and consolidation and then were randomized to observation or maintenance with interleukin-2 (3-yr OS 61% and 68%, 3-yr DFS 45% and 56%, for observation and IL-2 respectively). Post-consolidation maintenance with decitabine appears to provide only modest, if any, benefit overall. Correlative studies for CALGB 10503 are ongoing, including investigations into the impact of decitabine in unique molecular and cytogenetic subsets of disease, the prognostic/predictive value of aberrant methylation and other molecular markers, and assessment of minimal residual disease. Supported by CA33601 and CA128377. Disclosures: No relevant conflicts of interest to declare.

Description: Background: Donor grafts with more naive T cells and plasmacytoid dendritic cells were associated with improved overall survival after unrelated donor bone marrow, but not peripheral blood stem cell (PBSC) transplants (Waller, E JCO 2014). Here we present results on influence of innate and adaptive immune subsets in G-CSF mobilized allografts on incidence of acute GVHD (aGVHD) and chronic GVHD (cGVHD) in 238 patients (pts). Methods: We analyzed the absolute numbers and percentages of T, NK, NKT and B cells along with an extensive immunophenotypic characterization of their activation status in consecutive PBSC allografts obtained from sibling and unrelated donors between 2010 - 2014 and studied their association with the incidence of aGVHD and cGVHD. Wilcoxon rank sum tests were used to screen differential marker expression between those who did vs. did not develop aGVHD and similarly for cGVHD. Significant markers were evaluated in the multivariable (m.v.) setting along with known prognostic factors, including: recipient age, related vs. unrelated donor, female donor vs. not, Anti-thymocyte globulin (ATG) use (yes vs. no), and Reduced-intensity conditioning (RIC) vs. not. Cutpoints for markers were generated using recursive partitioning algorithms and evaluated in m.v. models. Results: Of the 238 alloSCT pts evaluated, most (71%) had unrelated donors, 64% received ATG, where most pts with unrelated donors received ATG (83%), and 78% received RIC. The incidence of aGVHD and cGVHD was 58% and 38% respectively. A total of 107 pts had grade II-IV aGVHD reported (71 II, 28 III, 8 IV), and 92 of 192 evaluable for cGVHD (at least 100 days of f/u) had reported cGVHD. Median follow-up in living pts was 21 months (range: 1.4 to 41.1 months). Table 1 shows dichotomized markers most influential on aGVHD. Higher absolute numbers of T cells, activated T cells, CD8+ cells, CD8+ cells expressing IL-7 receptor and CD27 were associated with higher incidence of aGVHD. Higher number of Stage 4 NK cells expressing stem cell factor receptor, and T-regs were associated with a lower incidence of aGVHD. Similar analyses were done for cGVHD (Table 2). Higher absolute numbers of activated T lymphocytes, activated B lymphocytes, KIR expressing CD3+ cells, CD8+ lymphocytes and activated NK cells were associated with higher incidence of cGVHD. When the percent of these makers in relation to total lymphocytes was evaluated regarding association with aGVHD, higher percent of T-regs (OR: 0.204, p=0.0018), effector memory T cells (OR: 0.45, p=0.024) and NKG2D positive NK cells (OR: 0.38, p=0.0008) conferred protection from aGVHD . Similar analysis for cGVHD showed higher percent of naïve CD4+ T cells conferred protection from cGVHD (OR: 0.44; p=0.0062) while higher percent of CD8+ cells (OR: 3.93; p=0.0032) and activated NK cells (OR: 2.08; p=0.024) was associated with cGVHD. Conclusions: These results show a protective role of donor T-regs, CD4+ T cells and Stage 4 NK cells from aGVHD. Additionally, higher content of activated T cells, CD8+ cells and B lymphocytes are associated with higher incidence of cGVHD. Higher content of activated NK cells seems to protect from aGVHD, but not from cGVHD. Updated results including multivariable analyses will be presented. These findings showing the influence of specific subsets in the allograft on aGVHD and cGVHD may provide opportunities for therapeutic interventions for graft engineering or pharmacologic methods for targeting specific immune subsets to decrease incidence of aGVHD and cGVHD. Table 1 Univariate model results for aGVHD with dichotomized markers using cutpoints: Marker Absolute OR p-value CD3+/CD5616- (T lymphocytes) 3.07 0.0013 CD3+/HLA DR+ (Activated T lymphocytes) 3.26 0.012 CD8+/CD45RA- (CD 8+ lymphocytes) 2.56 0.012 CD8+/CD27+ (Effector Memory CD8 cells) 3.25 0.0082 CD8+/CD127+ ( CD8 cells expressing IL-7 receptor) 2.92 0.073 CD4+/CD25+/CD127-(T regs) 0.43 0.057 CD3-/CD16-/CD56+/CD117+ (Stage 4 NK cells expressing Stem cell factor receptor) 0.12 0.0007 Table 2 Univariate model results for cGVHD with dichotomized markers using cutpoints: Marker Absolute OR p-value CD3+/HLA DR+ (Activated T lymphocytes) 4.41

Description: GTI-2040 is a 20-mer antisense to the R2 component of RNR mRNA. RNR is required for the conversion of ribonucleotides to deoxyribonucleotides, a crucial step during DNA synthesis and repair. Cytarabine (AraC) is a cytotoxic agent that is converted into AraC triphosphate (Ara-CTP) and is the backbone of several regimens in AML. Ara-CTP competes with deoxycytidine for DNA incorporation. We hypothesize that RNR downregulation by GTI-2040 results in decrease of levels of deoxycytidine thereby leading to a preferential DNA incorporation of ARA-CTP and increase in its cytotoxic activity. To test this hypothesis we undertook a CTEP-sponsored Phase I dose-escalation study of GTI-2040 plus HiDAC in patients (pts) with relapsed or refractory AML. Pts were stratified in 2 cohorts according to age. Cohort I (18–59 yrs) received escalating doses of GTI-2040 (dose level 1: 3.5 mg/m2/d) by continuous IV infusion (CIVI) on d 1–6 combined with escalating doses of cytarabine IV over 2 hrs q12 hrs on d 2, 4, and 6 (dose level 1: 2500 mg/m2/dose). Cohort II (≥60 yrs) received GTI CIVI on d 1–6 and cytarabine IV over 4 hrs on d 2 to 6 (dose level 1: 1500 mg/m2/d). To date, 30 pts were enrolled. Pts received median of 1 prior regimen (range 1–3). Cohort I included 8 pts with relapsed and 6 with refractory disease; 7 had intermediate risk cytogenetics (CyG) and 7 adverse CyG; 6 received prior HiDAC. Cohort II included 10 pts with relapsed and 6 with refractory disease; 8 pts had intermediate risk CyG and 8 high risk CyG; 5 pts received prior HiDAC. Toxicities were comparable to HiDAC therapy alone. Grade 3/4 non-hematologic toxicities included fatigue, fevers, anorexia, pneumonitis, and catheter related infections; a grade 3 reversible cerebellar toxicity (n=1) was observed at level 1/cohort I. An ELISA-based assay with a limit of quantification of 50 pMol was used to determine GTI2040 plasma and intracellular (IC) concentrations. Dose-dependent increase in plasma steady state concentration (Css) and area under the curve (AUC) of GTI2040 was observed in both cohorts, although higher AUC and longer t1/2 were demonstrated in the younger pts compared to the older ones. In cohort I, disease responses were seen at all dose levels Five of 14 pts achieved complete remission (CR) and one achieve incomplete CR (CRi; i.e., no marrow disease and incomplete blood count recovery). In cohort II, no disease response was observed. Median IC GTI2040 concentration in BM mononuclear cells at 120 hours following start of antisense infusion was higher in younger (i.e., 175 nM) than in older (i.e., 75 nM) pts. A median decrease in R2 protein levels of 50% (range 50–90%) detected by immunoblotting was noted in 5/9 and 5/10 pts in cohort I and II, respectively. In cohort I CR pts (n=4) had a median 50% decrease and non-responders (n=9) had a median 200% increase in R2 levels. In cohort II changes in R2 levels did not predict disease response. In summary, combination of GTI-2040/HiDAC is feasible. PK/PD studies demonstrate achievable plasma and IC levels of the antisense and target downregulation. Disease response was observed only with the dose/schedule administered to younger pts. Dose escalation in this group continues to establish a recommended dose for Phase II trials. [NCI U01 CA 76576-05].

Description: Use of a novel, pharmacokinetically derived schedule of flavopiridol given as a 30 minute (min) intravenous bolus (IVB) followed by 4 hour (hr) infusion (CIVI) resulted in marked improvement in efficacy in refractory chronic lymphocytic leukemia (CLL) compared with earlier studies using other schedules (Byrd, Blood 2007). We modified and intensified the Byrd hybrid IVB/CIVI regimen for single-agent flavopiridol administration in adult acute leukemias to determine the maximum tolerable dose. Using this schedule, 23 patients (pts) have been enrolled in this phase I study of flavopiridol by IVB/CIVI on days 1, 2, and 3. Prophylactic antidiarrheals (loperamide, cholestyramine) were aggressively used. Tumor lysis syndrome (TLS) precautions were utilized in all cases. Dose escalation was as follows (IVB/CIVI dose in mg/m2): 20/30 (n=3), 30/35 (n=7), 30/50 (n=3), 40/60 (n=8), and 50/75 (n=2). Pts had relapsed/refractory AML (n=19) or ALL (n=4) and were 23–78 yrs old (median age 62 yrs). The dose limiting toxicity was secretory diarrhea (Grade 3), occurring in both pts treated at the 50/75 level. Clinically significant diarrhea (

Description: Background: Midostaurin (M) is a multi-targeted small molecule FLT3 inhibitor which has single agent activity in both internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutant FLT3 AML. The objective of this global rand phase III trial was to determine if the addition of M to ind and consol therapy followed by one year of maint would improve overall survival (OS) compared to standard chemotherapy in younger adults with activating FLT3 muts. Methods: Between May 2008 and October 2011, 3279 previously untreated AML pts age 18-60 (exclusive of acute promyelocytic leukemia) in 225 sites/17 countries were screened for FLT3 muts at one of 7 academic labs (subject to extensive assay cross-validation). Hydroxyurea was allowed for up to 5 d prior to beginning ind therapy while awaiting results of mut testing. Pts were rand for the duration of therapy to M or P stratified by FLT3 mut subtype (TKD v ITD high allelic mut fraction (〉0.7) vs low mut fraction (0.05-0.7). Ind therapy consisted of D 60 mg/m2 IV d1-3 and C 200 mg/m2 d1-7 CIV plus M or P (50 mg po bid, d 8-22). Re-treatment with a second blinded course was allowed if residual AML was noted on a d 21 marrow exam. Pts achieving complete remission (CR) received 4 cycles of C 3g/m2 over 3h q 12h on days 1, 3, and 5 plus M or P (50 mg po bid, d 8-22) followed by a year of maint therapy with M or P (50 mg po bid). Transplantation (SCT) was allowed. With a sample size of 717 pts, the trial was powered to detect an improvement from 16.3 (P) to 20.9 (M) months in median OS (HR = 0.78) using a one-sided alpha of 0.025 and power of 84%. The final analysis was to occur after 509 deaths, but given the slow rate of events (359 deaths by April 2015), the trial was amended to change the timing of the OS analysis, and promote event free survival (EFS, defined as the earliest of death, relapse, or no CR within 61 d of the start of ind) as a key secondary endpoint. The critical value for this primary analysis is set at 0.02286 (1-sided) accounting for the alpha spent at the interim analysis (0.5%). Support: U10CA180821, U10CA180882, CA31946, Novartis Results: 717 pts (341 FLT3 ITD-Low, 214 FLT3 ITD-High; 162 FLT3 TKD) were rand to either M (n=360) or P (n=357). There were no significant differences between the arms in age (median, 48y), race, FLT3 subtype, or baseline CBC except for gender (M, 48.2% male; P, 40.6% male; p=.04). All pts are off active treatment, with a median follow-up of 57 months for surviving pts. No statistically significant differences were observed in the overall rate of grade 3 or higher hematologic or non-hematologic adverse events (AEs) between M and P (regardless of attribution). A total of 37 grade 5 AEs were reported (M, 5.3%; P, 5.0%; p=1.0). No differences in treatment-related grade 5 AEs were observed (M, 3.1%; P, 2.5%; p=0.82). CR rate is 59% (M) and 54% (P) (p=0.18). The HRs comparing M to P for OS is 0.77 (one-sided p = 0.007; Figure 1), and for EFS is 0.80 (one-sided p = 0.004; Figure 2). 402/717 (57%) pts received an allogeneic SCT (M, 58%; P, 54%) at any time; 177/717 (25%) in CR1 (M, 27%; P, 22%). Median time to allogeneic SCT was similar on each arm (M, 5.0 months; P, 4.6; p=0.23). Secondary analyses for OS and EFS censoring at the time of SCT provided similar results (Table). The benefit of M was consistent across all FLT3 subgroups for both EFS and OS (Figure 3). Conclusions: The C10603 trial demonstrated that a prospective trial in a pre-therapy genetically defined subgroup of AML pts was feasible and that the addition of the multi-kinase inhibitor M to standard chemotherapy and for one year of maint therapy significantly improved EFS and OS (in both uncensored and censored for transplant analyses) in pts whose blasts had a TKD or ITD (low or high FLT3 mut burden). These findings may lead to improved outcomes through the use of M as a component of therapy in younger adults with mutant FLT3 AML. Table.ArmMedian, mos (95% CI)p-value 15-year Event rate% (95% CI)HR2(95% CI)OSM74.7 (31.5, * )0.00750.8 (45.4-55.9)0.77 (0.63, 0.95)P26.0 (18.5, 46.5)43.1 (37.6-48.4)OS, SCT censoredM* (*,*)0.04762.6 (54.6-69.7)0.77 (0.56,1.05)P* (36.9, *)54.9 (46.2-62.8)EFSM8.0 (5.3, 10.6)0.004426.7 (22.2-31.5)0.80 (0.67, 0.95)P3.0 (1.9, 5.8)19.1 (15.1-23.6)EFS, SCT censoredM8.2 (5.5, 10.7)0.02524.2 (18.9-29.8)0.84 (0.70, 1.0020)P3.0 (1.9, 5.8)21.8 (16.8-27.3)1Stratified on FLT3 subtype; one-sided, log-rank p-value.2Cox model stratified on FLT3 subtype.*= not attained Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Stone: Celgene: Consultancy; Sunesis: Consultancy, Other: DSMB for clinical trial; Novartis: Research Funding; Amgen: Consultancy; Agios: Consultancy; Roche/Genetech: Consultancy; Merck: Consultancy; Pfizer: Consultancy; AROG: Consultancy; Celator: Consultancy; Juno: Consultancy; Abbvie: Consultancy; Karyopharm: Consultancy. Off Label Use: midostaurin- FLT 3 inhibitor. Thiede:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AgenDix GmBH: Equity Ownership. Niederwieser:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Medeiros:Celgene: Honoraria, Research Funding; Agios Pharmaceuticals: Honoraria. Schlenk:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Research Funding; Arog: Honoraria, Research Funding; Teva: Honoraria, Research Funding; Boehringer-Ingelheim: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Research Funding. Larson:Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Ariad: Consultancy, Research Funding; Pfizer: Consultancy.

Description: MLL (ALL-1) chimeric fusions and MLL partial tandem duplications (PTD) may have mechanistically distinct contributions to leukemogenesis. Acute myeloid leukemia (AML) blasts with the t(9;11)(p22; q23) express MLL-AF9 and MLL wild-type (WT) transcripts, while normal karyotype AML blasts with the MLLPTD/WT genotype express MLL PTD but not the MLL WT. Silencing of MLL WT in MLLPTD/WT blasts was reversed by DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors, and MLL WT induction was associated with selective sensitivity to cell death. Reduction of MLL PTD expression induced MLL WT and reduced blast colony-forming units, supporting opposing functions for MLL PTD and MLL WT whereby the MLL PTD contributes to the leukemic phenotype via a recessive gain-of-function. The coincident suppression of the MLL WT allele with the expression of the MLL PTD allele, along with the functional data presented here, supports the hypothesis that loss of WT MLL function via monoallelic repression contributes to the leukemic phenotype by the remaining mutant allele. These data from primary AML and the pharmacologic reversal of MLL WT silencing associated with a favorable alteration in the threshold for apoptosis suggest that these patients with poor prognosis may benefit from demethylating or histone deacetylase inhibitor therapy, or both.

Description: Tandutinib (MLN518/CT53518) is a novel quinazoline-based inhibitor of the type III receptor tyrosine kinases: FMS-like tyrosine kinase 3 (FLT3), platelet-derived growth factor receptor (PDGFR), and KIT. Because of the correlation between FLT3 internal tandem duplication (ITD) mutations and poor prognosis in acute myelogenous leukemia (AML), we conducted a phase 1 trial of tandutinib in 40 patients with either AML or high-risk myelodysplastic syndrome (MDS). Tandutinib was given orally in doses ranging from 50 mg to 700 mg twice daily The principal dose-limiting toxicity (DLT) of tandutinib was reversible generalized muscular weakness, fatigue, or both, occurring at doses of 525 mg and 700 mg twice daily. Tandutinib's pharmacokinetics were characterized by slow elimination, with achievement of steady-state plasma concentrations requiring greater than 1 week of dosing. Western blotting showed that tandutinib inhibited phosphorylation of FLT3 in circulating leukemic blasts. Eight patients had FLT3-ITD mutations; 5 of these were evaluable for assessment of tandutinib's antileukemic effect. Two of the 5 patients, treated at 525 mg and 700 mg twice daily, showed evidence of antileukemic activity, with decreases in both peripheral and bone marrow blasts. Tandutinib at the MTD (525 mg twice daily) should be evaluated more extensively in patients with AML with FLT3-ITD mutations to better define its antileukemic activity.

Description: Introduction: Exportin-1 (XPO1), a nuclear transport protein critical for the export of tumor suppressor proteins (TSPs) and select mRNAs to the cytoplasm, is highly expressed in acute myeloid leukemia (AML) and correlates with poor survival. Selinexor, an oral, first-in-class, selective inhibitor of nuclear export, blocks XPO1 function. We previously reported that sequential treatment of AML blasts using the hypomethylating agent decitabine followed by selinexor exhibited strong anti-leukemic effects in vivo by inducing the expression of silenced TSPs that are kept in the nucleus by XPO1 inhibition (Ranganathan, Blood 2015). Methods: Based on these findings, a phase I dose-escalation study was initiated to evaluate the safety, feasibility, maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), and preliminary clinical activity of selinexor in combination with decitabine in poor-risk AML pts (NCT02093403). Adults with relapsed or refractory (R/R) AML and older (age ≥60) unfit pts with untreated AML were eligible. Pts received 10-day decitabine induction(s) at 20mg/m2 on days 1-10 for up to four 28-day cycles in combination with selinexor once daily, twice weekly beginning on day 11. Pts with

Description: Abstract 2065 Poster Board II-42 Background: Hypomethylating agents have significant clinical activity in myelodysplastic syndromes (MDS) and AML. In AML, we recently demonstrated a novel epigenetic mechanism of action for the proteasome inhibitor bortezomib (Liu, Blood 2008). Bortezomib induced hypomethylation of leukemic cells in vitro and in vivo via depletion of the Sp1/NF-kB transcriptional activation complex on the DNA methyltransferase 1 (DNMT1) gene promoter, which results in down-regulation of DNMT1 mRNA and enzyme, DNA hypomethylation and re-expression of otherwise hypermethylated target genes. Based on this preclinical work, we designed a phase I dose escalation study of 5-azacytidine (AZA) in combination with bortezomib in AML. Methods: Adults with relapsed or refractory AML by WHO criteria and preserved organ function with ECOG ≤2 were eligible. Previous decitabine or AZA was permitted. Patients received AZA at 75mg/m2 IV daily for days (d) 1-7. Bortezomib was gradually dose escalated–dose level 1 (DL 1): 0.7mg/m2 by IV push given immediately after AZA on d 2 and 5; DL 2: 0.7mg/m2 on d 2, 5, 9, and 12; DL 3: 1.0mg/m2 on d 2, 5, 9, and 12; and DL 4: 1.3mg/m2 on d 2, 5, 9, and 12. Cycles were repeated every 28 d, regardless of count recovery or response at least until 3 cycles were administered. Responses were graded by International Working Group criteria for AML (Cheson, JCO 2003). Bortezomib was discontinued after 3 cycles if no objective response of complete remission (CR), CR with incomplete count recovery (CRi), or partial remission (PR) was achieved, but AZA could be continued beyond this timepoint in the absence of disease progression. For responding patients, 12 or more cycles of therapy were permitted. Dose limiting toxicities (DLT) were assigned for cycle 1 of therapy. Given the high likelihood of infection in this population regardless of therapy, infection was not considered a DLT. Six additional patients were treated at the recommended phase 2 dose (RP2D). Results: 23 patients were enrolled with a median age of 65 years (range, 42-81) and had received a median of 2 prior inductions (range, 1-5). Median presenting WBC was 3,700/uL (500-59,100/uL); median BM blast was 26% (2-93%). 14 patients were refractory to last therapy received, including 4 with primary refractory AML. 9 patients had relapsed disease; all but 2 of these had prior CR duration