Al‐Kali, Aref

Abstract Background In myelodysplastic syndromes (MDS), we have previously shown the adverse prognostic effect of ALC <1.2 x 10(9)/L (Nisha et al. Am J Hematol 2010;85:160). In the current larger study of 889 patients with MDS, we sought to validate and expand on our previous observations and also examine the effect of lymphocyte-to-monocyte ratio (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 ALC and absolute monocyte count (AMC) at time of referral was documented. The diagnosis of MDS and leukemic transformation (LT) was according to WHO criteria (Blood. 2009;114:937). Complete follow-up information was updated in January 2015. Comparison of laboratory and clinical features was made between patients with subnormal and normal ALC; patients with above normal ALC were considered separately. Overall and leukemia-free survivals of patients with normal ALC was compared to those with either subnormal ALC or, in order to validate our previous observation, with ALC <1.2 x 10(9)/L. 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), AMC 0.2 x 10(9)/L (0-1.7), platelet count 106 x 10(9)/L (2-1804), circulating blasts 0% (0-18) and bone marrow blasts 3% (0-19). Transfusion need was documented in 33% of patients and abnormal karyotype in 49%. Risk stratification by the revised international prognostic scoring system (IPSS-R) was very high in 10%, high in 16%, intermediate in 20%, low in 36% and very low in 16%. The median (range) ALC for the entire study population of 889 patients was 1.16 x 10(9)/L (0.02-8.9). The normal range of ALC at our institution was 0.9-2.9 x 10(9)/L; the number of patients with subnormal, normal and above normal ALC was 261 (29%), 598 (67%) and 30 (4%), respectively. In addition, 442 (50%) and 417 (47%) patients had ALC below 1.2 x 10(9)/L and ALC between 1.2 and the upper limit of normal, respectively. After a median follow-up of 27 months, 712 (80%) deaths and 116 (13%) leukemic transformations were documented. Comparison of patients stratified by absolute lymphocyte count Compared to patients with normal ALC, patients with subnormal ALC displayed lower hemoglobin (p=0.002), higher red blood cell transfusion need (p=0.0003), lower leukocyte count (p<0.0001), lower monocyte count (p=0.002) and lower platelet count (p<0.0001), whereas borderline association was also apparent for older age (p=0.06). In univariate analysis, survival was adversely affected by lower ALC, treated as a continuous variable (p=0.01). Similarly, when compared to patients with normal ALC, patients with subnormal ALC (p=0.001; HR 1.3, 95% CI 1.1-1.5) and those with ALC <1.2 x 10(9)/L (p=0.0002; HR 1.3, 95% CI 1.2-1.6) experienced significantly shortened survival. There was no difference in survival between patients with above normal ALC and those with either subnormal (p=0.58) or normal (p=0.41) ALC; accordingly, patients with above normal ALC were excluded from subsequent analysis. In multivariable analysis, the adverse effect of subnormal ALC was shown to be independent of age, gender, anemia, thrombocytopenia, neutropenia , circulating blast percentage, bone marrow blast percentage or cytogenetic risk stratification by and IPSS; the same held true for ALC <1.2 x 10(9)/L. The association with IPSS-R was of borderline significance for both ALC <1.2 x 10(9)/L (p=0.06) and subnormal ALC (p=0.1). The adverse effect of ALC was most apparent in patients with very low or low risk disease per IPSS-R (p=0.0007 for subnormal ALC and 0.0003 for ALC <1.2 x 10(9)/L), compared to those with higher risk status (p=0.67 and 0.7, respectively). Neither subnormal ALC (p=0.4) nor ALC <1.2 x 10(9)/L (p=0.1) affected leukemia free survival. Analysis using LMR in place of ALC showed similar but not necessarily superior results. Conclusions Compared to those with normal ALC, MDS patients with either subnormal ALC or with ALC below 1.2 x 10(9)/L experienced shorter overall, but not leukemia-free, survival; this adverse effect was most apparent in lower risk patients and was independent of most of the currently established risk factors for survival in MDS. The observations from the current study suggest the possible therapeutic value of augmenting host immunity in lower risk MDS. Disclosures Al-Kali: Onconova Therapeutics, Inc.: Research Funding; Celgene: Research Funding.

Abstract Background: Myelodysplastic syndromes (MDS) are rare hematological neoplasms that are more typically seen in elderly patients. Young patients (< 50 years old) have been reported to comprise between 3-6% in the Surveillance, Epidemiology and End Results (SEER) (Ma X et al, Cancer 2007; Rollison R et al, Blood 2008) with a better overall survival (OS). We hereby report the characteristics of young MDS patients with long survival follow-up. Methods: A total of 1012 MDS patients' data from Oct 1993 to Dec 2015 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our institution. Patients youngers than 50 years old (yMDS) were included as cohort 1, while the rest was included as control group (cohort 2). Prognostic factors were analyzed by univariate and multivariate analyses. Survival estimates were calculated using Kaplan-Meier curves and univariate and multivariate analyses was based on log-rank testing using JMP software version 10. Results: Characteristics: We identified 68 (7%) yMDS patients with a median age of 42 years (range, 18-49). Female gender was more common in yMDS (43% vs 31%, p= 0.05). Upon comparison between cohort 1 and 2, only platelets were significantly lower in yMDS (61 vs 102, p <0.0001), but not white blood cells, hemoglobin or degree of marrow fibrosis. MDS subtyping according to World Health Organization 2016 showed single lineage dysplasia in 15% vs 2%, multilineage dysplasia 24% vs 36% , ring sideroblasts 9% vs 15%, isolated del (5q) 1% vs 3%, excess blasts 44% vs 31%, and unclassifiable in 6% vs 5%. As expected, therapy related MDS (t-MDS) was more frequent in yMDS (33% vs 17%, p= 0.005). Transformation to acute myeloid leukemia (AML) was also more frequent in yMDS (28 % vs 11%, p= 0.0004). Compared to cohort 2, yMDS IPSS-R scores were very high, high, intermediate, low, and very low in 24% vs 13%, 29% vs 16%, 21% vs 20%, 19% vs 35%, and 7% vs 17%, respectively. Allogenic hematopoietic cell transplantation (HCT) was more frequent in yMDS (42% vs 4%, p< 0.0001). Survival outcome: Median OS was longer for cohort 1 vs cohort 2 but did not reach statistical significance (43 vs 21 months, p= 0.1). Median progression free survival (PFS) was shorter for cohort 1 vs cohort 2 but did not reach statistical significance (8 vs 12 months, p= 0.3). Median OS for cohort 1 based on R-IPSS was 44, 105, 40, 18, and 12 months for very low, low, intermediate, high and high risk groups, respectively (p= 0.09). Median OS was shorter in t-MDS vs de novo MDS in cohort 1 (13 vs 47 months, p = 0.04). Young patients who had transformed to AML had a worse median OS (18 vs 93 months, p=0.001). On multivariate analysis neither t-MDS nor R-IPSS had a statistically significant impact on OS. Conclusions: MDS is rarely diagnosed under the age of 50. IPSS-R was less powerful in detecting differences between its risk groups for this patient population, although more than half of the patients with yMDS had either high or very high risk. Among this cohort of yMDS patients, there was a significantly higher proportion with therapy-related myeloid neoplasms compared to older patients (one third of patients), with subsequent higher rates of transformation to AML and higher allogeneic HCT. In our study, we did not find an improved OS for yMDS patients compared to older patients. Disclosures Al-Kali: Celgene: Research Funding; Onconova Therapeutics, Inc.: Research Funding.

Abstract Background: Approximately 1,000 acute promyelocytic leukemia (APL) patients are diagnosed in the US annually. APL has the highest cure and early mortality rates of all acute leukemias. The availability of all trans-retinoic acid (ATRA) in 1995 and arsenic trioxide in 2000 has further improved the overall survival (OS). However, whether there is uniform improvement in OS across demographic subgroups and if sooner time-to-treatment (TTT) reduces early mortality are unknown. We used the National Cancer Data Base (NCDB), a nationwide oncology registry covering 70% of the US cancer population to answer these questions. Methods: We identified patients with APL diagnosed from 1998-2011 using ICD-O-3 code 9866. Survival functions were estimated using the Kaplan-Meier method and 30-day mortality was estimated as 1-survival at 30 days. We compared OS according to demographic subgroups (gender, age [18-40, 41-64, and >65 years], race [White, Black, Native American, Asian/Pacific Islander, and other], and ethnicity) across years of diagnosis (Period [P] 1: 1998-2001, P2: 2002-2006, and P3: 2007-2011). For 30-day mortality, we compared the rates according to demographic subgroups and time periods and determined the effect of TTT (days from APL diagnosis to ATRA and/or chemotherapy). For this analysis we included only patients treated within 30 days of diagnosis and those diagnosed from 2003 to 2011. TTT was grouped as 0, 1, 2, or >3 days. We used mixed-effects logistic regression model to obtain odds ratio comparing treatment delays. Our model accounted for multiple subjects per facility with a random intercept and was adjusted for gender, Charlson-Deyo score, and year of diagnosis. Results: Characteristics: There were 8,084 APL patients in our study. The median age at diagnosis was 51 (24% were older than 65) years and 50% were females. White race (85%) was the most common, followed by black (11%) and Asian (3%). Twelve percent were Hispanic in origin. Slightly more patients (54.8%) were treated in academic centers. Thirty seven percent had either Medicaid or Medicare insurance. OS: Race had no impact on OS, although Asians had a trend towards improved OS (P=0.06). Both females and young age affected OS favorably (P <0.0001). In general, OS improved over the three time periods (P=0.002). Across Periods 1-3, we observed significant improvement in OS among the males (P=0.03), 18-40 (P=0.035) and 41-64 (P=0.005) age groups, Whites (P=0.012), and non-Spanish/Hispanics (P=0.002), but not among their counterparts. 30-day mortality rate: Age above 65 years was associated with highest 30-day mortality (33%). Similarly male gender had statistically significant higher 30-day mortality (shown in the Figure). There was no statistically significant difference among Periods 1-3. As expected, untreated patients had an increased risk of death versus treated (HR=1.9, confidence interval 1.7-2.1). TTT: A third (33.5%) of the patients was treated within two days of APL diagnosis. TTT was not independently associated with lower 30-day mortality rate (shown in the Table). Presence of disseminated intravascular coagulopathy (DIC) data was not available to analyze. Conclusions: From 1998-2011, the OS of APL continued to improve but not uniformly across demographic subgroups. In contrast, the 30-day mortality did not improve in the same time period. Both Age above 65 and male gender predicted worse 30-day mortality and OS. Our study did not find a favorable association between shorter TTT and lower 30-day mortality rate. Our study was not able to study these findings among different risk groups. Disclosures Al-Kali: Celgene: Research Funding. Tibes:TetraLogic Pharmaceuticals: Research Funding.

Abstract Background: The results of the primary endpoint of the E2906 North American Intergroup phase 3 trial - demonstrating significantly inferior OS after single agent clofarabine versus standard intensive daunorubicin & cytarabine induction and consolidation - strongly support the use of intensive therapy for patients age ≥60 years with newly-diagnosed AML who are fit for treatment. This result was achieved despite similar CR rates (including CRi - CR with incomplete blood count recovery) and similar early (30- & 60-day) induction mortality between study arms, raising the question as to the importance of achieving CR as an endpoint. Therefore, we performed a follow-up analysis to address the factors that contribute to early mortality, the necessity for 2nd induction cycle to achieve CR, and to assess the survival impact of the quality of remission. Methods: E2906 design, study population and results for the primary objective were reported previously (ASH 2015, abstr. #217a). We performed this updated analysis to evaluate clinical risk factors for early mortality and re-induction, and to assess the impact of response quality on OS. Univariate comparisons were made with Fisher's exact test (category) and t-test (continuous variable), and logistic regression models were used to examine risk factors associated with early mortality, and with requiring a 2nd cycle of induction therapy. We performed a landmark analysis (beginning Day 60 after initiation of therapy) to determine the impact of response quality (CR/CRi, morphologic leukemia-free-state (MLFS), and treatment failure - i.e. residual/refractory AML) on OS. Survival comparisons were performed with log-rank test. Results: A total of n=727 patients were registered to E2906, the median age is 68 years (range 60-86) and the median follow-up of surviving patients is now 18.3 months. Adjusting for treatment, cytogenetic risk group, FAB subtype, WBC count, and secondary AML, increasing age (p=0.06) and performance status (PS) >1 (p=0.05) were associated with 30-day mortality and only PS >1 (p=0.06) with 60-day mortality. Treatment arm (p=0.003), adverse cytogenetic risk group (p=0.02), increasing age (p=0.03) and baseline WBC <10K (p=0.03) were each independently associated with higher risk of receiving 2nd cycle induction, but there was no difference in CR/CRi (44.2% vs. 42.2%, p=0.58) or in median OS (13.8 versus 12.0 months, p=0.11) for those receiving 1 vs. 2 induction cycles, respectively. We next performed a landmark analysis (day 60, n=608 evaluable patients) to evaluate OS in relation to the quality of response (Table). We observed an advantage in achieving CR and CR/CRi, although the benefit of CRi diminished greatly after 12 months, and OS after MLFS appeared more similar to treatment failure (Figure, p<0.001). The relative adverse impact of CRi and MLFS (vs. CR) was most pronounced for patients treated with clofarabine, where median OS was shorter for those achieving CRi (12.2m vs. 22.6m standard therapy, p=0.007) and MLFS (6.6m vs. 13.4m standard therapy, p=0.15). Conclusion: This follow-up analysis confirms the importance of CR regardless of the number of cycles of induction therapy required to achieve remission, and identifies risk factors associated with early mortality and with requiring re-induction. At longer follow-up the OS after CRi appears to be inferior to true CR, particularly after clofarabine. We hypothesize that this may be due to higher rates of minimal residual disease in CRi, and studies to determine this are being performed. MLFS is not associated with a better overall survival than frank treatment failure (i.e. residual disease) and therefore its value as a response category is uncertain. These results highlight the role of standard intensive remission induction therapy with the intent of achieving CR, which remains the standard of care for fit older adults. Table. Table. Figure 1. Figure 1. Disclosures Foran: karyopharm: Honoraria; novartis: Honoraria; medscape: Honoraria; Millennium Pharmaceuticals, Inc.: Research Funding; pfizer: Honoraria; boehringer ingelheim: Research Funding; agios: Research Funding; Cellerant: Research Funding. Melnick:Janssen: Research Funding. Altman:Novartis: Honoraria; BMS: Honoraria; Janssen: Honoraria; Syros: Honoraria. Al-Kali:Novartis: Research Funding; Celgene: Research Funding.

Abstract 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. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Abstract Background: Tyrosine kinase inhibitors (TKI) are associated with marked improvements in molecular response and survival compared with previous therapies for patients with chronic myelogenous leukemia (CML) in chronic phase (CP). We previously reported efficacy and safety of TKI at 12-month follow-up (Firwana et. al.JCO. 2014; 32(15_suppl): 7054). Here, we summarize the evidence of TKI efficacy and safety of TKI, comparing them directly and in-directly, in the mature follow-up for patients with newly diagnosed CP-CML. Methods: We included randomized controlled trials (RCTs) evaluating TKI in adults with newly diagnosed CP-CML. TKI (imatinib, dasatinib and nilotinib) were included if used as an initial treatment. Studies on bosutinib were excluded as it is only approved in the US for the treatment of CP-CML after failure of initial therapy. Studies that included patients with accelerated- or blast-phase CML, intolerant or resistant patients to first-line treatment, those on IFN-α, older agents or stem cell transplantation were excluded. Main outcomes are efficacy, represented by major molecular response (MMR, ≤ 0.1% BCR-ABLIS) and deeper molecular responses (MR4.5, ≤ 0.0032%IS), survival, represented by overall survival (OS) and progression free survival (PFS), and safety represented by medication discontinuation rate due to adverse events. Latest period of reporting outcome data were considered. As available trials provides direct comparison with imatinib, with no head-to-head trials to compare other TKI, we conducted a mixed treatment comparison (MTC) analysis which pools evidence from direct and indirect comparisons to facilitate simultaneous inference regarding all treatments. Bayesian mixed-treatment comparison method was used to rank TKI in terms of effectiveness. Results: Four landmark trials reported in 15 published articles and conference abstracts were identified involving 1647 patients with CP-CML. Follow-up times ranged from 3 months to 6 years. Table-1 depicts the results of MTC for imatinib, dasatinib and nilotinib. MTC analysis demonstrated superiority of both nilotinib and dasatinib over imatinib in terms of efficacy and safety. Nilotinib ranked first in efficacy with better improvement in MMR and MR4.5 at 48-month follow-up despite its different regimens, followed by dasatinib. Dasatinib has the highest medication discontinuation rate due to adverse events or drug-related toxicity. Among TKI, nilotinib was found to have the best survival profile; however, it was statistically nonsignificant. Conclusion: Both nilotinib and dasatinib are associated with significantly better efficacy and safety profiles compared to imatinib. At 48-month follow-up period, nilotinib ranked first to achieve MMR and MR4.5, with lower discontinuation rate due to adverse events. This analysis shows that new generation TKI are not only showing faster response, but also maintaining a more potent one through longer follow up period. It is important to note out that MTC is not a substitute for well conducted RCTs investigating direct comparisons. Table-1: Results of mixed treatment comparison for imatinib, dasatinib and nilotinib using fixed-effect Bayesian method. Comparison Mean risk difference (95% CrI) compared to from reference standard (Imatinib) Rank* MMR MR 4.5 PFS OS Discontinuation due to adverse events 48 months 48 months 36 months 48 months 48 months Imatinib Reference Reference Reference Reference Reference 4 Dasatinib 0.62 (0.26 to 1.01) 0.32 (-0.05 to 0.69) 0.21 (-0.43 to 0.85) 0.17 (-0.49 to 0.83) 0.59 (-0.05 to 1.25) 3 Nilotinib 300 0.92 (0.56 to 1.28) 0.81 (0.45 to 1.18) 1.02 (0.24 to 1.86) 0.19 (-0.51 to 0.89) -0.11 (-0.66 to 0.43) 1 Nilotinib 400 0.76 (0.41 to 1.12) 0.68 (0.31 to 1.05) 0.05 (-0.57 to 0.65) 0.81 (0.01 to 1.67) 0.30 (-0.20 to 0.81) 2 *Reported rank is valid for all outcomes, except for PFS and OS, where Nilotinib 400 ranks #1 and Nilotinib 300 ranks #2. Also, for rate of medication discontinuation due to adverse events, Dasatinib has the highest rate for discontinuation, followed by Nilotinib, both doses. Abbreviations: CrI, credible intervals; MMR, major molecular response, BCR-ABLIS ≤ 0.1%; MR4, deeper molecular responses, BCR-ABLIS ≤ 0.0032%; PFS, progression free survival; OS, overall survival. Disclosures No relevant conflicts of interest to declare.

Abstract Introduction: Patients with RR-AML, particularly older adults, have dismal outcomes and limited therapy options. Given low response rates and high toxicity with salvage intensive chemotherapy, and frequent ineligibility for allogeneic stem cell transplantation (alloSCT), many patients are treated with HMAs. Robust data regarding use of HMAs in AML predominates in the frontline setting, while their use in RR-AML has limited supportive data. Here wesought to analyze theoutcomes and their predictors in patients with RR-AML treated with HMAs. Methods:We collected data, spanning a period from 2006 to 2016, from 7 centers in the United States and 4 centers in Europe regarding patients treated with HMAs for RR-AML. Responses were defined by International Working Group criteria. Kaplan-Meier methods estimated overall survival (OS) from initiation of HMAs to death or end of follow-up. Multivariable logistic regression models estimated odds for response, and multivariable Cox Proportional Hazard (CPH) models estimated hazards ratios (HR) for OS. Covariates considered included HMA received, age at diagnosis (in years), AML classification at diagnosis (AML with myelodysplasia-related changes [AML-MRC], therapy-related [t]-AML), disease status (relapsed vs. refractory), number of therapy lines prior to HMA (1 vs. 2 vs. >=3), duration of first complete remission (CR1), white blood cell count, peripheral blood blast percentage, bone marrow (BM) cellularity (<=20% vs. > 20%), BM blast percentage (<=20% vs. >20%), cytogenetic risk group, and the presence of complex or chromosome 7 abnormalities. Results: Of 514 patients, 217 patients (42.2%) had refractory and 297 (58%) had relapsed AML. By end of study, 415 patients (88.5%) had died. Median follow-up for living patients was 11.6 months.Median age at diagnosis was 64 years (range [R], 16-92). AML-MRC was diagnosed in 29.0% while 8.2% had t-AML. Median number of prior therapies was 2 (R, 1-7), with 48.3% receiving 1 prior line, 30.2% receiving 2 prior lines, and 21.5% receiving >=3 prior lines. Prior alloSCT was performed in 21.2%. Only 1.9% had good risk (core binding factor) karyotype, while 56.2% had intermediate risk karyotype, and 41.9% had poor risk karyotype. Azacitidine was used in 45.8% and decitabine in 54.2%; median number of azacitidine cycles was 4 (Interquartile range [IQR], 2-6) compared to 2 for decitabine (IQR, 1-4, p <0.001). Best response to HMAs was CR in 11.7% (95%CI, 9%-14%), CRi in 6.4% (95%CI, 4.3%-8.8%), hematologic improvement (HI) in 8% (95%CI, 5.7%-10.5%), stable disease (SD) in 9.8% (95%CI, 7.2%-12.5%), while 64.1% (95%CI, 57.7%-66.2%) had progressive disease (PD). Median OS from HMA initiation for all patients was 6.9 months (IQR, 3.0-13.3). There was a significant difference in OS based on best response achieved [Figure 1]. Unadjusted OS showed an insignificant trend for worsening with increasing number of prior lines of therapy [Figure 2A]. In unadjusted analyses, there was no difference in OS based on HMA received in all patients [Figure 2B] or the subset who received only 1 prior line of therapy (median OS: Azacitidine vs. decitabine 8.4 vs 7.3 months, p=0.88). Following HMA therapy, the median number of subsequent therapies was 0 (R, 0-6), and only 12.8% underwent alloSCT. In multivariate CPH models, HMA used was not significantly associated with OS (HR=0.80, 95%CI, 0.42-1.51, p=0.49), while increasing age, and presence of complex cytogenetics and chromosome 7 abnormalities were significantly associated with risk of death [Table 1]. In multivariable logistic regression models, HMA used was not associated with achieving CR+CRi (Odds ratio=0.56, p=0.32). Conclusions: In this largest reported cohort of patients with RR-AML treated with HMAs, we found that HMAs are often used as alast line of therapy, with a minority of patients receiving subsequent treatment. Nonetheless, the minority of patients who achieve CR (11.7%) with HMA therapy had a median OS of 25.6 months. Therefore, use of HMAs for management of RR-AML is a reasonable intervention in the absence of clinical trial options. There appears to be no difference in OS or probability of achieving CR+CRi based on HMA used. Ongoing analyses in this dataset include further evaluations of predictors, including genetic mutations, and the development of prediction tools for clinical outcomes with HMA therapy. Figure 1. Figure 1. Disclosures Podoltsev: Ariad: Consultancy, Honoraria; Incyte: Consultancy, Honoraria. Ritchie:Novartis: Honoraria; Incyte: Speakers Bureau; Arian: Speakers Bureau; Pfizer: Honoraria; Celgene: Speakers Bureau. Sekeres:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Komrokji:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Speakers Bureau. Al-Kali:Onconova Therapeutics, Inc.: Research Funding; Celgene: Research Funding. Santini:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Onconova: Consultancy; Amgen: Consultancy; Astex: Consultancy. Roboz:Cellectis: Research Funding; Agios, Amgen, Amphivena, Astex, AstraZeneca, Boehringer Ingelheim, Celator, Celgene, Genoptix, Janssen, Juno, MEI Pharma, MedImmune, Novartis, Onconova, Pfizer, Roche/Genentech, Sunesis, Teva: Consultancy. Fenaux:Celgene, Janssen,Novartis, Astex, Teva: Honoraria, Research Funding. Prebet:celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Gore:celgene: Consultancy, Honoraria. Zeidan:Ariad: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Celgene: Consultancy, Honoraria.

Abstract Background: Myelodysplastic syndrome (MDS) is a heterogeneous disease characterized by cytopenias and a propensity to progress into acute myeloid leukemia in a subset of patients. Clinical trials which led to FDA approval of hypomethylating agents (HMAs) stratified patient's risk status per the IPSS. In 2008, WHO further categorized patients into different groups and the IPSS was revised into the IPSS-R. Therefore, there is a paucity of data regarding the response rates and clinical outcomes of HMA therapy when stratified per WHO subtype and IPSS-R. Goal: We carried this review to assess whether WHO subtypes or IPSS-R had a differential response with corresponding impact on survival. Methods: After IRB approval, all MDS pts who received hypomethylating agents (HMA) (azacitidine or decitabine) with available response data (2000-2014) were included. Clinical characteristics were obtained retrospectively. IPSS-R (Greenberg 2012) was used for risk stratification. Response assessment was based on IWGR 2006 criteria. Statistical comparisons were performed with the χ2 test for categorical variables and the Wilcoxon test for continuous variables. Survival analysis was based on the Kaplan-Meier method and log rank test. For all analyses, P ≤ 0.05 was considered statistically significant. Results: We identified 823 pt in our MDS database; among those that received HMA therapy 70 patients (pts) had evaluable response data. The median age at diagnosis was 67 years (31-85) and 49 (70%) were males. MDS subtypes per WHO 2008 classification were 31(44%) RAEB1/2, 26(37%) RCMD, 10(14%) MDS-U, 2(3%) RARS, and 1(1%) MDS 5q. Fifteen (33%) patients had secondary MDS. 23(32%) developed AML, and median time to leukemic transformation was 14 months (7.8-21). Median time to start HMA was 2.7 months (0-77). Median follow up from initial diagnosis was 20 months (3-118) at which time 22(31%) deaths were documented. A. Patient characteristics: Prior to HMA therapy median laboratory values included; Hemoglobin 9.6 g/dL (6.6-14.8), ANC 1.1 x1010 (0.01-16), Platelet 66 x1010 (4-937), peripheral blast % 0 (0-18), and bone marrow blast % 5 (0-17). IPSS-R for our cohort was as the following, 15(27%) Very high, 14(25%) high, 10(18%) intermediate 12(21%) low, and 5(9%) very low risk. B. HMA Response rates based on WHO subtype: We observed no significant difference in response (p = 0.6) when comparing response rate among different groups. Response rates per WHO subtype were as follows: i. RAEB: 7 (22%) pts achieved CR/Marrow CR, 1(3%) had HI/PR, 17(55%), and 6(20%) had stable disease (SD) and progressive disease (PD), respectively. ii. RCMD: 2 (8%) pts achieved CR/Marrow CR, 4(16%) had HI/PR, 12(46%), and 8(30%) had SD and PD, respectively. iii. MDS-U: 1 (10%) pt achieved CR/Marrow CR, 1(10%) had HI/PR, 6(60%), and 2(20%) had SD and PD, respectively. iv. MDS 5q/RARS: 1(33%) had SD, and the remaining three pts had PD. C. HMA Response rates based on IPSS-R: i. Very low: 1(20%) had HI/PR, 3(60%), and 1(20%) had SD. ii. Low: 2(17%) pts achieved CR/Marrow CR, 3(25%) had HI/PR, 4(33%), and 3(25%) had SD and PD, respectively. iii. Intermediate: 2 (20%) pts achieved CR/Marrow CR, 5(50%), and 3(30%) had SD and PD, respectively. iv. High: 2(14%) pts achieved CR/Marrow CR, 2(14%) had HI/PR, 7(50%), and 3(21%) had SD and PD, respectively. v. Very high: 1(7%) pts achieved CR/Marrow CR, 9(60%), and 5(33%) had SD and PD, respectively. Comparing responses among IPSS-R risk stratification groups, was not statistically significant (p = 0.49). We did not observe a difference in response rate when we further classified pts into low risk (very low, low & intermediate), and high risk (high, very high) (p = 0.27). D. Response effect on Survival: Overall survival was not statistically different among responders (CR/Marrow CR/HI &PR) and non-responder (SD & PD); 22.3 vs 14.7 months respectively (p = 0.21) (Figure1). Conclusion: Using contemporary MDS risk stratification and WHO classification was not predictive of response to hypomethylating agents. Responders did not seem to benefit from prolongation of survival. Given the small sample size in this cohort, this should be further explored in larger groups to identify if there are any potential subgroups that would benefit more from such therapy. Figure 1. Figure 1. Disclosures Al-Kali: Celgene: Research Funding.

Abstract Background: Acute erythroleukemia (AML-M6) is an aggressive myeloid leukemia, with poor outcomes (median survival < 12months). In 2008, the WHO further sub-classified this disease into two subgroups- erythroid leukemia and pure erythroid leukemia, based on the number of erythroblasts and myeloblasts. We carried out this study to evaluate differences in presenting features and outcomes between erythroid leukemia and pure erythroid leukemia. Methods: After due IRB approval, out of 923 AML, 43(4.6%) pts who met the 2008 WHO criteria for acute erythroleukemia (2000-2014) were identified, and clinical characteristics retrospectively reviewed. A diagnosis of erythroid leukemia (M6a) was considered if > 50% of the total nucleate BM cells were of erythroid lineage and > 20% of non-erythroid cells were myeloblasts. Pure erythroid leukemia (M6b) was diagnosed in pts who presented with > 80% of BM nucleate cells consisting of immature erythroid precursors. Cytogenetic risk stratification was based on NCCN AML guidelines. Statistical comparisons were performed with the χ2 test for categorical variables and the Wilcoxon test for continuous variables. Univariate and multivariate analyses were performed with the Cox logistical regression. Survival analysis was based on the Kaplan-Meier method and log rank test. For all analyses, P ≤ 0.05 was considered statistically significant. Results: The median age at diagnosis was 65 years (27-90) and 34(79%) were male. 30 (69%) had M6a and 13 (30%) had M6b. 27 (62%) had de novo AML M6, whereas 16 (37%) had secondary AML (9 underlying MDS and 7 therapy related).The median time to leukemic transformation for pts with underlying MDS was 8 months (2-83). Median follow up in our cohort was 7.2 months (2-157) at which time 13 (30%) deaths were documented. A. Patient characteristics: At time of diagnosis median laboratory values included; Hemoglobin 8.5 g/dL (4.6-11), WBC 2x109 (0.7-11.1), ANC 0.47x109 (0.01-4.07), Platelet 33x 109 (7-177), peripheral blast % 2 (0-35), and bone marrow blast % 11 (0-84). Cytogenetic information was available in 38 pts; of which 6(16%) were diploid, 21(55%) were complex/monosmal and 1(3%) was complex/non monosomal. Intermediate risk cytogenetic was observed in 15 pts (39%), and poor risk cytogenetic was identified in 23(61%). Comparing M6a and M6b, we observed that pts with M6a tend to have more leukopenia and neutropenia and higher marrow blast percentage compared to M6b (Table 1). None of the patients experienced extramedullary disease or CNS involvement. B. Outcome and prognostics: We did observe a trend towards worse survival in pts with M6b, 7 months vs 12.9 months with M6a (p= 0.08) (Figure 1). There was no difference in survival in acute erythroleukemia compared to other acute myeloid leukemias, 10.1 vs 14 months (p= 0.28), respectively (Figure 2). In univariate analysis, WBC, ANC, and cytogenetic risk impacted survival (Table 2), however only cytogenetic risks retained significance in the multivariate model; Intermediate risk HR 0.18 (0.05-0.51; p = 0.0009) and poor risk HR 5.4 (1.9-17.6; p = 0.0009). Conclusion: Acute Erythroid Leukemia is a rare leukemia with ~5% incidence in our cohort. We observed that regardless of the percentage of bone marrow erythroblasts and myeloblasts, survival in patients with Acute Erythroleukemia are predominantly impacted by cytogenetic risk stratification. This raises a question on the clinical relevance of the sub-categorization of acute erythroleukemia into erythroid leukemia and pure erythroid leukemia. Larger studies are needed to validate our results. Figure 1. Figure 1. Disclosures Al-Kali: Celgene: Research Funding.

Abstract Background: Acute myeloid leukemia (AML) is an aggressive form of blood cancers with a wide range of response and relapse rates using standard chemotherapy regimen (commonly known as 7+3). Several genes (FLT3, IDH1, RAS) have been targeted using small molecule tyrosine kinase inhibitors with encouraging results. The stem cell receptor tyrosine kinase KIT is expressed more than 10% in the blasts in 95% of relapsed AML cases and mediates leukemic proliferation and has anti-apoptotic effects (Domen and Weissman 2000). AML with high KIT expression is associated with poorer outcome (Del Poeta, Venditti et al 2003). Goals: To study the efficacy and safety of combination 7+3 and nilotinib in patients (pts) with AML and KIT expression. Primary goal is to determine the complete response (CR) rate; while secondary goals include 2-year overall survival (OS) and disease free survival (DFS) in addition to safety of DATA regimen. Methods: A single arm, Phase II study, enrolled pts at Mayo Clinic (MN and AZ). Appropriate IRB was obtained and study was registered (NCT 01806571). Pts were enrolled if they were newly diagnosed with AML with KIT (CD117) expression of 20% or higher on myeloblasts by flow cytometry. KIT mutations were allowed if present. Nilotinib 300 mg twice daily was given on days 4-14 of induction and consolidation; and continuous daily maintenance therapy for up to 2 years. Cytarabine 100 mg/m2/day continuous IV x7 days plus daunorubicin 60 mg/m2 IV daily x3 days were used for induction , while consolidation used standard cytarabine 3 gm/m2 twice daily days 1, 3, 5 for a total of 4 cycles. This is a Simon 1-stage design with a safety analysis after enrolling 12 pts, and an interim analysis after enrolling 18 out of 43 pts. If 11 or fewer pts achieve complete remission, the regimen will be considered ineffective. Results: Eighteen pts have been enrolled between July 2013 and July 2015, 17 of which have baseline data. Median age was 58 years (range 24-65) with 76.5% being male. Median laboratory findings include hemoglobin of 9.3 gm/dL, platelets of 52 x109, and white blood count of 7.0 (0.5-125). Cytogenetics were normal in 41% of the pts. Favorable cytogenetics were seen in 2 pts (inv 16). FLT3 testing was done on 15 pts and was positive in 27%. KIT gene sequencing (exon 8, 9, 10, 11, 17) revealed no pathogenic mutation. Median number of cycles was 3 (range 1-7). Six pts had treatment delays, with 2/13 (15%) delays being due to non-hematologic toxicities. No delays or missed doses affected cytarabine and daunorubicin administration. Out of 15 pts evaluable for response, 12 (80%) achieved CR (or CR with incomplete platelet recovery). Six of the 12 pts (50%) who achieved remission needed a second induction on protocol. Two out of 15 did not respond (did not get re-induction on protocol). One pt died before disease assessment due to liver failure (G5, had only one dose of nilotinib and toxicity was attributed to daunorubicin). Of the 14 pts having at least 1 bone marrow biopsy, the overall CR rate was 86%. Five (33%) pts proceeded to allogeneic stem cell transplant, all are alive and none were able to initiate protocol nilotinib maintenance therapy. Only 2 out of 12 (17%) pts relapsed after achieving CR, one was secondary AML from myelodysplastic syndrome with complex karyotype and the other was therapy-related AML with t(9;11). Only 2 (11%) pts died at time of report. Thirteen pts were evaluated for adverse events (AE). Six pts had G4 non-hematological AEs. Five of 12 G4 AEs were related to infection, 2 were electrolyte imbalances, and 2 were heart failures. Most common G3 non-hematological AEs were febrile neutropenia (53%), hypophosphatemia (23%), hyperglycemia (23%), and hypertension (23%). In agreement with the favorable outcomes, the molecular target validation revealed that nilotinib treatment down-regulates the expression of KIT, Sp1, DNA methyltransferase (DNMT) 1, DNMT3a and DNMT3b. Conclusion: Combination daunorubicin and cytarabine with nilotinib (DATA) appears to be safe and effective. Interim results show an acceptable safety profile in the first 12 evaluable pts with most common AE being infection as expected. Thirty day mortality is acceptable (7%). DATA regimen has encouraging CR rates of 80% (intent to treat) and 86% in assessed pts, with half of the pts who achieved remission requiring 2 cycles of induction. Relapse rate seems to be low at 17%. We will continue accrual until all pts accrued for final results. Disclosures Al-Kali: Celgene: Research Funding. Off Label Use: This is a Phase II study of combination nilotinib to standard chemotherapy in patients diagnosed with AML.. Tibes:TetraLogic Pharmaceuticals: Research Funding.