Al‐Kali, Aref

Abstract Background Chronic myelomonocytic leukemia (CMML) is a clonal hematologic disorder that was classified by the World Health Organization (WHO) as a myelodysplastic/ myeloproliferative overlap disease. Cytogenetic abnormalities have a significant prognostic role in many hematologic neoplasms, but their prognostic value in CMML has been debatable. Recently, monosomal karyotype (MK) has been reported to be a marker of poor prognosis in patients with myelodysplastic syndromes (MDS) and primary myelofibrosis, but its value in CMML is unknown. Aim To study MK effect on clinical outcome for patients diagnosed with CMML Method A retrospective study of all cases diagnosed with CMML at Mayo Clinic Rochester between 1994 to 2011 was performed. Only pts with complete cytogenetic analysis at presentation to our institution were included. MK was defined as the presence of ≥ 2 autosomal monosomies or one autosomal monosomy with at least one structural abnormality (Breems et al, JCO 2008). CK was defined as the presence of at least 3 chromosomal abnormalities. Appropriate IRB approval was obtained in accordance with Helsinki declaration. Comparison between groups’ medians was done using Wilcoxon test, while survival estimates were calculated using Kaplan-Meier curves using JMP V9. Results A total of 262 pts diagnosed with CMML had available cytogenetic data at diagnosis. Median age was 72 years, 176 (67%) were male. Median hemoglobin 10.5 g/dL, white blood cells (wbc) 12 x109/L, platelet 89 x109/L, peripheral blood (PB) blast 0, and bone marrow (BM) blast 4%. CMML2 was seen in 9% while 47% were proliferative (wbc >13). Leukemic transformation was documented in 34 pts (13%). Median overall survival was 513 days. Cytogenetic (CG) analysis was diploid in 167 pts (64%). Trisomy 8 was the most frequent cytogenetic abnormality at 8% (22), followed by complex karyotype (CK) 5% (14), then -7 at 4% (10) and MK 3% (7, six of which were also CK). Comparing pts with diploid CG to other categories indicates: to abnormal CG pts had lower wbc (0.001), PB blasts (p<0.0001), and BM blasts (p=0.0001); to CK pts had lower PB blasts (p=0.003) and higher platelets (p=0.03); to -7 pts had lower wbc (p=0.005), PB blast (p=0.0004), BM blasts (p=0.03) and higher platelets (p=0.03); to +8 pts had lower PB blast (p=0.02) and BM blasts (p= 0.01); no difference was noted when compared to MK. Median OS was statistically significantly worse in MK+ vs MK- (24 vs 527 days, p= 0.002), but not in other comparisons: -7 vs others (250 vs 527 days, p=0.2), CK+ vs CK- (256 vs 527 days, p=0.05), diploid vs others (570 vs 365 days, p=0.1), +8 vs others (312 vs 527 days, p=0.1). Pts with MK+ only or MK+CK+ did worse than CK+ only or other groups (4, 63, 304, 527 days, respectively, p<0.0001). On a multivariate analysis, MK+ (in addition to platelet, BM blast, hemoglobin, and wbc) did have an impact on OS (p=0.0004), while CK+, -7, +8, diploid CG, age, PB blast did not. Conclusion Cytogenetic abnormalities were not frequent findings in pts diagnosed with CMML (36%), but did affect wbc, PB and BM blasts. The most common cytogenetic abnormality was +8 while MK was present at 3% (less than published data in MDS). Only MK predicted statistically significant shorter mOS between all other cytogenetic categories on both univariate and multivariate analysis. This finding needs to be validated by larger cohorts of pts due to its rare occurrence in CMML. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 460 Background: SF3B1 mutations were recently reported to occur in myelodysplastic syndromes (MDS), especially in the presence of ring sideroblasts (RS) (Papaemmanuil et al. Leukemia Research 2011, Volume 35, Supplement 1, page S18). We sought to accurately define the interaction between SF3B1 mutations, bone marrow morphology, karyotype and prognosis in MDS with ≥15% RS (MDS-RS). Methods: Mayo Clinic databases and cell banks were queried to identify patients with MDS and ≥15% RS (MDS-RS). All study patients were required to have undergone bone marrow examination and cytogenetic evaluation at diagnosis. Pathology slides, including iron stains, were centrally re-reviewed to accurately quantify bone marrow RS percentage and confirm World Health Organization (WHO) morphologic categories. Detailed analysis of clinical and cytogenetic parameters was performed to risk stratify patients according to the revised International Prognostic Scoring System (IPSS-R) (Greenberg et al. Leukemia Research 2011, Volume 35, Supplement 1, page S6). All patients were annotated for their mutational status involving JAK2, MPL and IDH. PCR sequencing was used to identify SF3B1 mutations. Results I: Baseline patient information: The study is currently ongoing; to date, results are availab1e in 88 patients (median age 72 years, 69% males) including 36 (41%) patients with refractory anemia with RS (RARS), 36 (41%) with refractory cytopenia with multilineage dysplasia and ≥15% RS (RCMD-RS), 11 (12%) with refractory anemia with excess blasts (RAEB)-1 and ≥15% RS (RAEB1-RS) and 5 (6%) with RAEB2-RS. Median (range) values were 9.1 g/dL (5.8–15.7) for hemoglobin, 4.1 × 109/L (1.2–35.2) for leukocytes and 164 × 109/L (6–585) for platelets. IPSS-R risk categories were 20% very good, 49% good, 11% intermediate, 3% poor and 16% very poor. Karyotype was normal in 60%, other very good/good risk 16%, intermediate-risk 2%, and poor/very poor in 22%; 14% had monosomal karyotype (MK). Six (7%), four (5%) and zero (0%) patients displayed IDH, JAK2 or MPL mutations. Red cell transfusion need was documented in 27 (31%) patients. Results II: Prevalence and distribution of SF3B1 mutations and clinical correlates: SF3B1 mutations (all heterozygous) were detected in 40 (∼46%) of all 88 study patients: 25 (63%) K700E, 6 (15%) K666N/Q/R, 3 (8%) E622D, 2 (5%) H662D/Q, 2 (5%) Y623C, 1 (3%) R625C, and 1 (3%) T663I. One patient each displayed both SF3B1K700E and IDH2R140Q or SF3B1K700E and JAK2V617F. SF3B1 mutational frequencies were 69% for RARS, 36% for RCMD-RS, 18% for RAEB1-RS and 0% for RAEB2-RS (p=0.0007). SF3B1 mutations clustered with normal (59%) and other very good/good risk (57%) karyotype and were infrequent in poor/very poor karyotype (5%; p=0.0004). Additional significant correlations were noted between SF3B1 mutations and lower IPSS-R risk category (p=0.0004), advanced age (p=0.006), higher platelet count (p=0.0003). Results II: SF3B1 mutations and prognostic relevance in MDS-RS: To date, 68 (∼77%) deaths and 10 (∼11%) leukemic transformations have been documented. Median follow-up for living patients was 82 months. Univariate survival analysis considering all 88 study patients identified the following as strongly significant risk factors: IPSS-R (p<0.0001), WHO morphologic categories (p<0.0001), cytogenetic risk categories (p<0.0001), and transfusion need (p=0.0003). In multivariable analysis, only IPSS-R and transfusion need remained significant. In univariate analysis, the presence of SF3B1 mutations was significantly associated with better overall (p=0.04) and leukemia-free (p=0.03) survival; however, in both instances, significance was completely accounted for by WHO morphologic risk categorization and the morphology-adjusted p values were 0.6 and 0.2, respectively. In other words, when RARS and RCMD were analyzed separately, there was no additional prognostic value from the presence or absence of SF3B1 mutations (Figures 1 and 2; p=0.67 and 0.44, respectively). Conclusions: SF3B1 mutations are prevalent in RARS and RCMD-RS but do not provide additional, WHO morphology-independent or IPSS-R-independent, prognostic information. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Treatment-related AML (t-AML) accounts for 10 to 20% of all AML cases and carries an especially poor prognosis (Kayser et al. 2011, Godley et al. 2008). Patients diagnosed with t-AML are likely to have abnormal cytogenetic profiles with chromosome changes that are predictive of an aggressive malignancy, poor response to therapy, and decreased overall survival(Smith et al. 2003). The simultaneous use of multiple chemotherapeutic agents of different classes makes it increasingly difficult to predict risk for developing t-AML and determining disease course. An updated analysis of predictive factors for t-AML is needed so clinicians can more accurately inform patients of their prognosis. The aim of this study was to classify t-AML according to primary malignancy, previous chemotherapy exposure, and cytogenetic profile. Methods: A retrospective chart review of patients that were diagnosed with AML at Mayo Clinic from 7/1/1990 to 5/13/2015 was performed following IRB approval. AML patients found to have a previous malignancy treated with chemotherapy were classified as t-AML. Chemotherapeutics were classified as alkylating agents, antimetabolites, anti-tubulin agents, and topoisomerase II inhibitors. Patients diagnosed with a myelodysplastic or myeloproliferative disorder prior to development of AML were excluded from this study. Previous chemotherapy exposures, duration of chemotherapy exposure, complete blood count, chromosome abnormalities, and survival data were collected for t-AML cases. Cytogenetic changes were classified as favorable, intermediate, and adverse according to the system used by Kayser et al. 2011. JMP 10.0 was used for statistical analysis. Results: Out of 584 patients, 64 patients (11%) had a primary malignancy that was treated with chemotherapy prior to being diagnosed with AML. The most common primary malignancies were breast cancer (31%), non-Hodgkin lymphoma (27%), colorectal cancer (8%), and Hodgkin lymphoma (8%). Laboratory findings showed median hemoglobin 9.6 g/dL (4.7-13.8), median white blood cells 3.2 x109 (0.6-126), median platelets 50x109 (3-320), median peripheral blood blasts of 8% (0-91), and median bone marrow blasts 38% (1-94). 95% of patients diagnosed with t-AML had been previously treated with an alkylating agent. Additional exposure to an anti-metabolite trended towards a more adverse cytogenetic profile (χ2=5.0, p=0.08) but there was not a statistically significant decrease in overall survival (KM analysis, p=0.31). The median overall survival for patients diagnosed with t-AML was 10.2 months compared to 19.2 months for patients with de-novo AML (KM analysis, p=0.04). Adverse cytogenetic profiles were associated with decreased survival (KM analysis, p <0.0001). However, there was no difference in overall survival between patients with t-AML that had intermediate cytogenetics and those with de-novo AML (KM analysis, p=0.36). None of the chemotherapy classes other than antimetabolites were associated with poor cytogenetics or survival when combined with an alkylating agent. Conclusion: Over half of all patients classified as having t-AML in this study received prior chemotherapy for breast cancer or non-Hodgkin lymphoma. Cytogenetic classification of t-AML into favorable, intermediate and adverse groups is useful in predicting disease course. Interestingly, t-AML patients with intermediate risk cytogenetics had similar overall survival to patients with de-novo AML. This suggests that the poor outcomes observed in patients with t-AML is predominantly due to the subset with adverse cytogenetics. Thus, cytogenetic analysis remains the best indicator of overall survival regardless of chemotherapy exposure. Additional work is needed to delineate the risk associated with the aforementioned chemotherapy classes. Disclosures Al-Kali: Celgene: Research Funding.

Abstract Background: Induction therapy with daunorubicin (Dauno) & cytarabine (Ara-C) [DA] has been the standard of care for eligible older adults (age ≥ 60 years) with newly diagnosed acute myeloid leukemia (AML) for over 2 decades. Single agent Clofarabine (CLO) induction & consolidation (Consol.) therapy has demonstrated important clinical activity in this age group in large phase II studies. Lower induction mortality (IM) & similar reported complete remission rate (CR) & overall survival (OS), as well as notable activity in those with higher risk disease features [including unfavorable cytogenetics, therapy-related AML (t-AML) & prior antecedent hematologic disorder (AHD)] raises the possibility that a non-Ara-C-based regimen could achieve similar or superior OS with lower toxicity. Methods: We performed a randomized United States Intergroup Phase III trial of single agent CLO [30mg/m2 x 5 days induction; 20 mg/m2 re-induction (if indicated) & 2 cycles Consol.] vs. standard DA therapy [Dauno 60mg/m2 D1-3 & Ara-C 100mg/m2 D1-7 induction x 1-2 cycles; 2 cycles Consol. with Ara-C (1.5g/m2 Q12hrs D1-6 age 60-69; once daily if age 70+)] in patients (pts) age ≥ 60 yrs with newly diagnosed AML. Patients with serum creatinine >1.0 (or GFR <60 mL/min) and those with AML-M3 and ECOG performance status >3 (PS>2 if age 70+ yrs) were excluded. Randomization was stratified by age (60-69 vs. 70+), t-AML, & AHD. Pts with HLA-matched donor were eligible for allogeneic transplantation (AlloHCT) after induction, and those completing Consol. were eligible for randomization #2 (R#2) to maintenance decitabine [20mg/m2 x 3D, monthly x 1 year] versus observation. With a target accrual of 747, E2906 was powered to determine non-inferiority [and possible superiority] of CLO vs. standard DA, and primary endpoint was OS. A weighted statistical analysis was performed to account for confounding impact of R#2. AlloHCT patients were censored at transplant in this analysis. Responses & cytogenetics were confirmed centrally and OS & CR rates were monitored by an independent Data Safety Monitoring Committee (DSMC) at pre-specified time points. Results: As of Feb 23, 2015, 727 pts were randomized. Median age was 68 years (range 60-86); 57% were male, and 38% were age ≥70 yrs. Treatment arms are well balanced for all baselineclinical & AML characteristics, & 30% had unfavorable cytogenetics. Of 659 with complete treatment information reported, 30.4% on DA vs. 40.1% on CLO received 2 cycles of induction (p=0.006). Median follow-up of surviving patients is 7.6 months. Table 1. shows early treatment results (CR, toxicity) for the 686 pts randomized as of Dec 23, 2014 (2 months prior to study end, & excluding 90 with ongoing response evaluation). DA CLO p-value CR/CRi 43.8% 42.8% p=0.87 30-day mortality 8.5% 7.9% p=0.89 60-day mortality 14.9% 13.1% p=0.58 Gr 4-5 Non-Heme Tox.Induction 27% 19% p=0.02 Gr 4-5 Non-Heme Tox.Consol. 20% 7% p=0.001 374 pts have died (174, DA; 200, CLO) & significantly inferior OS was observed for CLO vs. DA [Hazard Ratio (HR) 1.41 (95% CI 1.12-1.78)] (Fig. 1). Planned subgroup analyses were performed (Table 2) demonstrating significant differences in OS after CLO for patients age 60-69 yrs, without AHD, & with intermediate risk cytogenetics; but not for those with Unfav. Cytogen. (Fig. 2) or t-AML. Based on the primary weighted analysis, DSMC recommended suspension of new accrual to E2906 on Feb 23, 2015 & all active patients on CLO were transitioned to DA Arm. Table 2.NHR CLO/Standard (95% CI)*Weighted OS7271.41 (1.12-1.78)Unweighted OS7271.23 (1.00-1.50)Age 60-694491.48 (1.10-1.99)Age 70+2781.34 (0.93-1.93)Intermed. Risk Cytogen.3781.77 (1.27-2.47)Unfav. Risk Cytogen.2160.96 (0.65-1.43)No AHD6041.46 (1.13-1.89)AHD1231.22 (0.74-2.00)De novo AML6271.52 (1.18-1.96)Therapy-related AML1000.94 (0.54-1.61) Conclusions: Despite similar CR & IM, OS after single agent CLO is inferior to standard DA therapy for pts age ≥60 years with newly diagnosed AML who are fit for intensive therapy, and DA remains the standard of care. However no difference in OS was observed after CLO in some pre-specified high risk AML subgroups. R#2 & AlloHCT arms continue in E2906 for pts already enrolled. Embedded prospective minimal residual disease study at CR is being performed to identify pts at higher risk after CLO & DA. Figure 1. Weighted Kaplan-Meier Curves for OS Figure 1. Weighted Kaplan-Meier Curves for OS Figure 2. Unfavorable Cytogenetics OS by Therapy Figure 2. Unfavorable Cytogenetics OS by Therapy Disclosures Off Label Use: Use of clofarabine in AML, and maintenance therapy with decitabine in AML. Claxton:Medimmune: Research Funding; BMS: Consultancy; Astellas: Research Funding; Cyclacel: Research Funding; Merck: Research Funding; Ambit: Research Funding. Levine:Loxo Oncology: Membership on an entity's Board of Directors or advisory committees; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees; Foundation Medicine: Consultancy. Altman:Seattle Genetics: Consultancy; BMS: Consultancy; Spectrum: Consultancy; Astellas: Consultancy; Ariad: Consultancy; Novartis: Consultancy. Al-Kali:Novartis: Research Funding.

Abstract Background The impact of cytomegalovirus (CMV) infection on the risk of relapse after Hematopoietic Cell Transplantation (HCT) remains controversial, with some studies demonstrating lower risk (Green et al, Blood 2013), while others demonstrating no impact (Schmidt-Hieber et al, Blood 2013), or lower relapse risk only in myeloablative (MA) (Manjappa et al, BBMT, 2014) or in reduced intensity conditioning (RIC) (Cichocki et al, ASH 2014) HCT. Furthermore, the majority of studies have used antigenemia for CMV monitoring, while there is limited data with the use of Quantitative Nucleic Acid Testing (QNAT). Aim To determine the impact of CMV infection, as detected by QNAT, on transplant-related outcomes for patients with acute myeloid leukemia (AML), stratified by MA or RIC HCT. Methods After IRB approval, consecutive adults with AML who underwent allogenic HCT from HLA-matched peripheral blood (PB) grafts at our institution between 2006 and 2014 were retrospectively reviewed. All grafts were T-cell replete. Early CMV infection was defined as any positive CMV result by PCR assay during the first 100 days post HCT. Relapse incidence (RI), non-relapse mortality (NRM), disease-free survival (DFS), and overall survival (OS) were compared between patients with and without CMV infection, and stratified according to MA or RIC. DFS and OS were estimated using the Kaplan-Meier method, and compared with log-rank test. Cumulative incidence of relapse and NRM were analyzed as competing events, using Gray's test. Multivariable analyses adjusting for patient's age, disease status at transplant, cytogenetic risk, and ABO incompatibility were performed using Cox's proportional hazards regression, and the Fine and Gray approach. Results A total of 190 consecutive patients, including 94 (49%) MA and 96 (51%) RIC HCT were analyzed. Patients, disease, and transplant characteristics are shown in table 1. Of the 94 MA HCT (median age 45 y, 50% male), 66 (70%) received total body irradiation. After a median follow up of 18 m, 36 (38%) CMV infection, 16 (17%) relapses, 22 (23%) NRM and 35 (37%) deaths occurred in the MA group. Median time to CMV infection and to relapse in this group was 38 (range 8-241) and 140 (29-1690) days, respectively. Among the recipients of MA HCT, patients with early CMV infection showed no difference in the RI (figure 1), but had a significant trend towards higher NRM and significantly lower DFS and OS in both univariate and multivariable analysis (figure 2) (P values shown in table 2). Among 96 RIC HCT (median age 59 y, 56% male), fludarabine plus melphalan was used in 62 (65%) and fludarabine plus busulfan in 34 (35%) patients. In this group, early CMV infection occurred in 33 (34%), relapse in 25 (26%), NRM in 25 (26%), and deaths in 46 (48%) patients after a median follow up of 21 m (1-91 m). Among the recipients of RIC HCT, median time to CMV infection and to relapse was 40 (17-175) and 291 (19-1971) days, respectively. In the RIC group, early CMV infection was associated with a significant trend towards lower RI (figure 1) and higher NRM in both univariable and multivariable analysis, but no difference in DFS and OS (figure 2). Conclusion Our study of a large homogenous group of AML patients who underwent a uniform HLA-matched PB HCT demonstrates a significantly lower risk of relapse associated with early CMV infection detected by QNAT following RIC, but not MA HCT. Early CMV infection in MA HCT is associated with higher NRM and therefore inferior survival, whereas in the RIC HCT, there is no impact on survival as the benefit of lower relapse is offset by the higher NRM. Table 1. Patients, disease and transplant characteristics according to CMV infection All Patients Patients with CMV Viremia Patients without CMV Viremia P value Patients, no (%) 190 (100) 69 (36) 121 (64) - Median age, y (range) 54 (18-72) 54 (26-70) 54 (18-72) 0.75 Male Patients, no (%) 104 (55) 30 (43) 74 (61) 0.02 D/R CMV Serostatus, no (%) <0.0001 -/- 29 (15) 1 (1) 28 (23) +/+ 64 (34) 35 (51) 29 (24) +/- 13 (7) 1 (1) 12 (10) -/+ 84 (44) 32 (47) 52 (43) Conditioning 0.65 MA 96 (51) 33 (48) 63 (52) RIC 94 (49) 36 (52) 58 (48) Disease status at Transplant 0.96 CR1 129 (68) 46 (67) 83 (69) CR2 34 (18) 13 (19) 21 (17) Other 27 (14) 10 (14) 17 (14) Cytogenetic 0.65 Favorable 8 (4) 2 (3) 6 (5) Intermediate 130 (68) 46 (67) 84 (69) Unfavorable 52 (28) 21 (30) 31 (26) Disclosures Al-Kali: Novartis: Research Funding.

Abstract Background: Hypomethylating agents (HMA) such as 5-Azacitidine (Aza) have overall responses rate of ~35-50% in acute myeloid Leukemia (AML) and higher risk myelodysplastic syndrome (MDS) patients (pts). However, eventually all pts develop resistance on therapy. To improve upfront response rates and to address HMA failure, we performed genome-scale RNAi screens targeting genes on chromosomes 5 and 7, recurrent cytogenetic abnormalities in AML/MDS. These screens identified Hedgehog pathway (Hh) genes as potentially targetable vulnerabilities with Aza. Combination experiments with smoothened (SMO) inhibitors (SMO is a central activating gene within the Hh pathway) showed pre-clinical synergy. These and additional published data support the Hh pathway as a targetable vulnerability in AML, and provide a rational for a trial. Methods: A phase I/Ib protocol of the oral SMO inhibitor LDE225 (Sonidegib) in combination with Aza in untreated and relapsed/refractory (rel/ref) AML, chronic myelomonocytic leukemia (CMML), MDS, or MDS/myeloproliferative neoplasm overlap pts. Objectives of the phase I part are to determine safety, toxicity and MTD and for the phase Ib part to assess the preliminary overall efficacy. Sonidegib was started at dose level (DL) 0 at 400mg oral daily continuously and Aza at the approved doses (75mg/m2 x 7 days or days 5-2-2) with dose adjustment per label. A classical 3+3 design was used and DLT (CTCAE v4.0) defined as > grade 3 CPK elevation or hepatic or non-hematologic adverse events (AEs) lasting > 7 days or any grade 4 event, except for hematologic toxicities. DLT was assessed after 42 days when steady-state concentrations of Sonidegib were reached. Pharmacokinetic assessments were not performed for this study. Results: Patients and Dose Levels : Between 5/22/2014 and the data cut-off date (7/20/2015), 36 pts were enrolled. Median age was 72 y (range 52-85 y) and 64% were male. Most AML pts (23 of 24) had intermediate or unfavorable cytogenetics and most MDS/CMML pts were in the int.- to high-/very high-risk group (IPSS-R). Six pts were treated at DL-0 of Sonidegib 400mg/day and one DLT of CPK elevation was observed. Another patient had grade 4 neutropenia (which at the time was included in the DLT definition, later removed). Due to overall tolerance of the combination at DL 0 and investigator assessment, despite only 1/6 pts having a formal DLT, DL -1 at Sonidegib 200mg was explored at which 0/3 pts (1 pt non-evaluable) had DLT and the phase Ib portion was opened at DL -1. To date a total of 24 AML (13 newly dx, 11 rel/ref), 11 MDS/CMML (5 newly dx, 6 rel/ref ) and 1 myelofibrosis pt have been enrolled. Safety and Tolerability: An initial safety and efficacy assessment for 25 of the 29 pts treated on the phase Ib (n=26) + the MTD cohort of 200 mg (n=3) and for who at least 2 cycles of treatment follow up was available, showed that all pts experienced at least one grade-3 or 4 hematologic AE with a lower rate in the untreated vs. treated cohort. Other, non-hematologic grade-3 and 4 AEs respectively were seen in 24 and 28% of patients-most commonly hyponatremia and fatigue, known AEs for this drug class. Treatment delays occurred in 28% of pts and Aza or Sonidegib dose reductions in 16%. 23 (79%) pts are alive and 6 have died (21%), with one death while pt was actively treated but was deemed unrelated; 11 pts remain on study, with the remainder showing disease progression (n=3) or taken-off study for other reasons (n=3 each for AEs and did not want further treatment; n=4 other). Efficacy : As of 7/20/15 with a median treatment duration of 2 cycles, 2/5 untreated MDS/CMML pts achieved CR/CRi; 1 HMA rel/ref AML had CR; 1 untreated AML pt each had PR and MLFS. 90% of pts have not progressed. Updated results will be presented at the ASH 2015 meeting; by then all 29 pts will have completed a minimum of 4-6 cycles on study and full efficacy and AE result on all pts will be reported. To date the OS at 6 mo is 77% (95% CI: 44-97%) with a median PFS of 4 mo (range: 2-NR). Many pts in the untreated cohorts have just enrolled. Conclusion: Hh pathway inhibition with the clinically well tolerated SMO inhibitor Sonidegib in combination with Aza in MDS and AML pts is well tolerated with mostly hematologic AEs as expected with early signs of clinical activity in untreated and HMA-failure pts. Full efficacy results of 29 pts and updated safety data will be reported for this first combination trial of a SMO inhibitor in combination with a HMA in MDS and AML pts. Disclosures Mesa: Gilead: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Incyte Corporation: Research Funding; Genentech: Research Funding; Pfizer: Research Funding; Promedior: Research Funding; NS Pharma: Research Funding; CTI Biopharma: Research Funding. Al-Kali:Novartis: Research Funding.

Abstract Abstract 1476 Background: Monosomal Karyotype (MK) is defined as the presence of two or more autosomal monosomies or one autosomal monosomy and one structural abnormality. MK has been found to be an independent poor prognostic factor in myeloid diseases (Patnaik et al, Leukemia 2011, Haferlach et al, Blood 2012) even in the setting of allogeneic stem cell transplantation (Fang et al, Blood 2011). The prognostic relevance of MK in Acute Lymphoblastic Leukemia (ALL) is unknown. Absolute lymphocyte count (ALC) at diagnosis, on the other hand, has been shown to be prognostic in a variety of lymphoproliferative disorders (Porrata et al, Leukemia 2010). However, the prognosis of ALC at diagnosis in ALL is undetermined Methods: This is a retrospective analysis of the Mayo Clinic leukemia database (1998–2010). The study was approved by the Institutional Review Board. Outcomes analyzed included overall survival (OS), leukemia free survival (LFS) and relapse rate. Clinical characteristics, cytogenetics, therapy and outcomes of patients with Philadelphia negative ALL (Ph-negative ALL) were analyzed. Cytogenetics were classified as follows: standard risk [hyperdiploidy], intermediate risk [Normal, del(11q)-not MLL, del(6q), del(17p), del(9p), del(12p), del(13q), t(14q32), t(10;14), low hyperdiploidy, others], high risk [-7, del(7p), +8, MLL translocations, t(1;19), t(17;19), t(5;14)], and very high [t(4;11), t(8;14), complex (≥5 abnormalities), hypodiploidy, triploidy] (Pullarkat et, Blood 2008). Multivariate analysis was performed using Cox Regression Model. Results: Between 1998 and 2010, a total of 175 consecutive patients with ALL were identified. Of these, 112 (64%) had Ph-negative ALL. The median age was 39.5 (16–88) years and 74 were male (66%). The majority of cases were B-ALL (78 patients, 69%). At presentation, the median hemoglobin was 10 (4.1–18.5) g/dL, platelet count was 61 (3–523) ×10(9)/L, WBC was 7.2 (0.8–377) ×10(9)/L and ALC was 1.9 (0–69.0) ×10(9)/L. The ALC was > 1000 in 75 (71%) patients. Cytogenetics risk categories were as follows: standard risk in 5 (4.4%), intermediate risk in 70 (62.5%), high risk in 8 (7.1%) and very high risk in 29 (25.9%) patients. Twenty-two patients (20.9%) presented with extranodal disease (CNS disease in 13 patients, 11.6%). Six patients (5.4%) had prior exposure to chemotherapy. Treatment involved allogeneic stem cell transplantation (SCT) in 34 (30.4%) patients. The median OS for the whole cohort was 24 (0–206) months and LFS was 18 (0–193) months. Forty four patients (39.3%) relapsed after achieving initial remission with a median time to relapse of 15 (2–73) months In a univariate analysis, low platelet count at diagnosis, poor ECOG performance status (PS), and high or very high risk cytogenetics risk categories were associated with inferior OS. ALC at diagnosis did not impact OS or LFS. On a multivariate analysis, high/very high risk cytogenetics, low platelet counts and poor ECOG PS were independent predictors of inferior outcomes. Nineteen patients (16.9%) had a MK. Of these, 16 (84.2%) fell in the very high risk cytogenetics category regardless of MK status. Three patients (1.6%) presented with extramedullary disease and six (3.2%) underwent SCT. The median OS of these 19 patients was 15 (1–73) months. While MK was associated with inferior LFS and a trend towards worse OS, this was not significant on a multivariate model that included cytogenetic risk categories, thrombocytopenia and the ECOG PS. Conclusions: Our study demonstrates that cytogenetics risk stratification, thrombocytopenia and ECOG performance status are independent prognostic factors in ALL. MK and ALC at diagnosis had no prognostic significance. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: 'Myelodysplastic syndrome (MDS) with isolated del(5q),' as defined by the World Health Organization (WHO) criteria (SwederlowSH, et al, 2008) is a unique pathological entity with favorable outcomes. The 2016 revision to the classification expands this entity to include cases that have an additional cytogenetic abnormality, with the exception of monosomy 7 or del(7q) (Arber DA, et al, Blood 2016). The objective of our study was to evaluate the prognostic impact of an additional cytogenetic abnormality, other than monosomy 7 or del(7q), in patients with 'MDS with isolated del(5q)'. Methods: After due IRB approval, the Mayo Clinic MDS database (n=1067) was utilized for this study. All patients had bone marrow (BM) biopsies and cytogenetic studies performed at diagnosis. The International Society for Cytogenetic Nomenclature guidelines were used for cytogenetic nomenclature, while the 2008 and 2016 WHO criteria were used for morphological diagnosis. Results: Patient Characteristics: 72 patients (7.2%) met the 2016 WHO criteria for 'MDS with isolated del(5q)' of which 60% were female and median age was 74 years (28-90). In 61 (85%) cases del(5q) was the only cytogenetic abnormality, while in 11 (15%), del(5q) was present with an 'additional cytogenetic abnormality' (ACA). One additional case within the database had del(5q) accompanied with monosomy 7, which was not included in the analysis. Risk stratification by IPSS-R was as follows; 24 (29%) 'very low', 44 (64%) 'low' and 4 (6%) 'Intermediate' risk, with no patient classified as 'high' or 'very high' risk. At a median follow up of 43 months, 55 (76%) deaths and 5 (7%) leukemic transformations were documented. del(5q) versus del(5q) with an additional cytogenetic abnormality- phenotypic correlates: In the 'del(5q) with ACA' group, the additional abnormalities included trisomy 8 (n=4), del(20q) (n=3), der(9;18) (n=1), inv(3)(p25,q21)(n=1), -Y (n=1), and i(Xp) (n=1) (Table 1). There was no significant difference between the 'del(5q)' and 'del(5q) with ACA' groups in terms of age, gender, hemoglobin, platelet count, white cell count, absolute neutrophil count, bone marrow blast percentage or transfusion requirement. A greater proportion of the 'del(5q) with ACA' group (27%) had IPSS-R risk in the 'intermediate' category compared to the 'del(5q)' group (2%) (p=0.01). 18 of 42 cases diagnosed after 2004 (43%) were treated with lenalidomide, with no difference in the proportions treated between the two groups (p=1.00). del(5q) versus del(5q) with an additional cytogenetic abnormality- impact on overall survival (OS) and leukemia-free survival (LFS): The median survival of the cohort was 54 months. Survival was not significantly different between the 'del(5q)' group (median 55 months) and the 'del(5q) with ACA' group (median 38 months) (p=.75, Figure 1). This finding was consistent when analysis was restricted to patients in both groups treated with lenalidomide (p=0.29). The incidence of leukemic transformation in the del(5q) group was 5%, compared with 18% for the 'del(5q) with ACA' group (p=0.16), however there was no significant difference in LFS between the two groups (p=0.57). Conclusion : In our cohort of primary MDS patients meeting the 2016 WHO definition of 'MDS with isolated del(5q)', we confirm no significant survival difference between cases with del(5q) as the sole cytogenetic abnormality versus cases where del(5q) was accompanied by an additional cytogenetic abnormality. Table 1 Additional Cytogenetic Abnormalities with del(5q): Table 1. Additional Cytogenetic Abnormalities with del(5q): Figure 1 del(5q) vs del(5q) with an additional abnormality (ACA): Overall Survival Figure 1. del(5q) vs del(5q) with an additional abnormality (ACA): Overall Survival Disclosures Al-Kali: Onconova Therapeutics, Inc.: Research Funding; Celgene: Research Funding.

Abstract Background We have previously shown an independent adverse prognostic effect of lymphopenia (absolute lymphocyte count <1.2 x 10(9)/L) for survival in MDS (Jacobs et al. Am J Hematol 2010;85:160) whereas others have suggested a similar value from lymphocyte-to-monocyte ratio (LMR); patients with LMR ≥5 experienced shorter survival with median 67 vs. 126 months (Mushtaq et al. JCO May 20 Supp. 2016:7062). Whether or not "monocytopenia" also carries a prognostic value in MDS is currently unknown and was the main objective for the current study, which also addresses the prognostic value of LMR. Methods We retrospectively recruited 889 consecutive patients with primary MDS who were untreated at the time of referral to our institution and in whom absolute monocyte count (AMC) and absolute lymphocyte count (ALC) at time of referral were documented. The diagnosis of MDS and leukemic transformation (LT) was made according to WHO criteria (Blood. 2009;114:937). Complete follow-up information was updated in January 2015. For the purposes of the current study, monocytopenia was defined as AMC below the lower limit of the institutional normal range, which was 0.3 to 0.9 x 10(9)/L. Comparisons of survival and other clinical parameters were performed between i) patients with and without monocytopenia and ii) patients with and without LMR ≥5. Conventional methods were used for statistical analysis. Results Patient characteristics: Median (range) values for the 889 study patients (69% males) included: age 72 (18-98), hemoglobin 9.6 g/dL (5.4-15.7), leukocyte count 3.4 x 10(9)/L (0.4-35), platelet count 106 x 10(9)/L (2-1804), circulating blasts 0% (0-18), bone marrow blasts 3% (0-19) and absolute lymphocyte count (ALC) 1.2 x 10(9)/L (.02-8.9). Transfusion need was documented in 33% of patients and abnormal cytogenetics in 49%. Risk stratification by the revised international prognostic scoring system (IPSS-R) was very high in 11%, high in 16%, intermediate in 21%, low in 36% and very low in 16%. The median (range) AMC for the entire study population of 889 patients was 0.22 x 10(9)/L (0.0-1.8).The number of patients with subnormal AMC was 539 (61%). After a median follow-up of 27 months, 712 (80%) deaths and 116 (13%) leukemic transformations were documented. Comparison of patients stratified by absolute monocyte count and LMR Compared to patients with AMC >0.3 x 10(9)/L, MDS patients with monocytopenia displayed younger age (p<0.0001), lower hemoglobin (p=0.005), higher red blood cell transfusion need (p=0.03), lower leukocyte count (p<0.0001), lower platelet count (p<0.0001), lower absolute neutrophil count (p<0.0001), higher circulating (p=0.03) and bone marrow (p<0.0001) blasts, higher incidence of abnormal karyotype (p=0.03), and higher risk distribution in terms of both IPSS-R (p<0.0001) and cytogenetic risk stratification by IPSS-R (p=0.03). In univariate analysis, lower AMC was associated with inferior survival (p=0.002); significance was even more apparent when comparing patients with and without monocytopenia (p=0.0003; HR 1.3, 95% CI 1.1-1.5). Similarly, there was significant association between LMR and survival (p<0.0001) with patients with LMR ≥5 experiencing inferior survival (p=0.03; HR 1.2; 95% CI 1.02-1.4). In multivariable analysis, the adverse effect of monocytopenia was shown to be independent of age (p<0.0001), gender (p=0.0001), anemia (Hemoglobin <10 g/dL; p=0.002), thrombocytopenia (platelets <100 x 10(9)/L; p=0.01), neutropenia (absolute neutrophil count <0.8 x 10 (9)/L; p=0.005), subnormal ALC (p=0.0008), circulating blast percentage (p=0.002), cytogenetic risk stratification by IPSS-R (p=0.006) and LMR (p=0.02) or LMR ≥5 (p=0.002); however, significance was lost when risk stratification by IPSS-R was added to the multivariable analysis (p=0.7). In regards to LMR, it retained its significance (p=0.009) during multivariable analysis that included monocytopenia or subnormal ALC, as covariates; however, significance was lost in the context of IPSS-R (p=0.24 for LMR and 0.8 for LMR ≥5) Conclusions Monocytopenia in MDS clusters with adverse disease features and both monocytopenia and higher LMR were associated with poor survival. Despite the display of prognostic independence from each other and other risk factors considered individually, the survival impact of neither monocytopenia nor LMR was found to be independent of IPSS-R. Disclosures Al-Kali: Novartis: Research Funding; Celgene: Research Funding.

Abstract Background: Rigosertib (RIG) is a RAS-mimetic interacting with the RAS-binding domains of RAF kinases, preventing their binding to RAS and inhibiting the RAS-RAF-MEK pathway. Rigosertib also binds to the RAS-binding domains of Ral-GDS and PI3Ks (Athuluri-Divakar, et al, Cell 165:643, 2016). Mutations of RAS are involved in proliferative processes important in neoplastic transformation (Gil-Bazo, et.al, Cancer Biology and Therapy 17:719, 2016). As of May 2016, 557 patients with MDS or AML received IV (N=335) or oral (N=222) rigosertib. All IV rigosertib was administered as monotherapy. Oral rigosertib was administered as monotherapy (N=168) or in combination with injectable azacitidine (AZA; N=54). Safety results across this rigosertib development program have not been presented. Methods: We reviewed all treatment-emergent adverse events (TEAEs) among patients with MDS/AML treated with rigosertib IV monotherapy, rigosertib oral monotherapy, or in combination therapy, overall and by grade of severity, and serious TEAEs and TEAEs leading to discontinuation. Due to the unexpected observation of urinary AEs, including occasional gross hematuria, we analyzed urinary AEs in greater detail. Results: Rigosertib IV monotherapy: The most common TEAEs were fatigue (33%), nausea (33%), diarrhea (27%), constipation (25%), anaemia (24%) and pyrexia (24%). The most common ≥Grade 3 AEs were anaemia (21%), febrile neutropenia (13%), pneumonia (12%) and thrombocytopenia (11%). The most common serious AEs were febrile neutropenia (10%), pneumonia (9%), and sepsis (7%). The most common AEs leading to discontinuation of IV rigosertib were sepsis and pneumonia (3% each) (Table 1). Rigosertib oral monotherapy: The most common TEAEs were pollakiuria (increased urinary frequency) (35-%), fatigue (32%), diarrhoea (26%), dysuria (29%) and haematuria (24%). The most common ≥Grade 3 AEs were anaemia (17%), thrombocytopenia (5%), haematuria (4%) and urinary tract infection (4%). The most common serious AE was pneumonia (6%). The most common AEs leading to discontinuation of patients receiving oral rigosertib as monotherapy were (dysuria [8%], urinary tract pain [7%], haematuria [5%] and urinary frequency [5%] (Table 2). Rigosertib oral in combination with azacitidine (AZA): The most common TEAEs were nausea (41%), fatigue (39%), diarrhea (37%), constipation (37%) and dysuria (28%). The most common serious AEs were pneumonia (11%) and febrile neutropenia (7%). The most common AEs leading to discontinuation were AML (4%) and pneumonia (4%) (Table 3). In patients fully evaluable for gross hematuria the cause of bleeding was bladder inflammation. Urinary and plasma concentration of RIG were examined to assess dose relationship. According to the azacitidine package insert, the incidence of gross hematuria of any grade with single agent azacitidine is 6.3 % and Grade 3-4 of 2.3%. Evaluations performed of hematuria among 5 studies of oral rigosertib (4 monotherapy and 1 in combination with AZA) in patients with MDS/AML (Table 4). Conclusions: Rigosertib IV or oral formulations were generally well tolerated in clinical trials in over 500 patients with MDS/AML. Gastrointestinal AEs were most frequently reported with IV rigosertib and genitourinary AEs were seen more often with oral than IV dosing. The greater rate of urinary AEs in the oral than in the IV studies indicates a need for close monitoring of these patients and proactive risk management, such as adequate hydration, timing of administration of the second dose, and bladder emptying prior to sleep. Studies are being designed to optimize dosing and schedule to maximize efficacy and minimize hematuria of single agent oral rigosertib. A randomized trial of oral rigosertib/azacitidine versus azacitidine will be required to optimize the clinical benefit and safety in the management of higher-risk patients with MDS. Disclosures Fenaux: Celgene: Honoraria, Research Funding; Janssen: Research Funding; Novartis: Honoraria, Research Funding; Astex: Research Funding; Teva: Honoraria, Research Funding. Al-Kali:Celgene: Research Funding; Onconova Therapeutics, Inc.: Research Funding. Navada:Onconova Therapeutics, Inc.: Research Funding. Roboz:Agios, Amgen, Amphivena, Astex, AstraZeneca, Boehringer Ingelheim, Celator, Celgene, Genoptix, Janssen, Juno, MEI Pharma, MedImmune, Novartis, Onconova, Pfizer, Roche/Genentech, Sunesis, Teva: Consultancy; Cellectis: Research Funding. Santini:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Onconova: Consultancy; Amgen: Consultancy; Astex: Consultancy. Platzbecker:Onconova, Teva, Celgene, Janssen, Novartis, Amgen: Honoraria, Research Funding. Petrone:Onconova Therapeutics, Inc.: Employment. Brownstein:Onconova Therapeutics, Inc.: Consultancy. Zbyszewski:Onconova Therapeutics, Inc.: Employment. Maniar:Onconova Therapeutics, Inc.: Employment. Silverman:Onconova Therapeutics, Inc.: Patents & Royalties: Co-Patent holder for the combination of azacitidine and rigosertib, Research Funding.