Abstract: Background: FLT3 mutations, found in ~30% of patients with AML, and are associated with a poor prognosis. HM43239 is a novel FLT3 inhibitor that potently inhibits not only FLT3 mutants, including ITD and TKD mutants and FLT3 wild type but also spleen tyrosine kinase (SYK). Its dual inhibition of both FLT3 and SYK may activity in AML. In preclinical studies, HM43239 showed more potent activity than Gilteritinib in FLT3-WT/ITD heterozygous MOLM-13/-14 AML cell models. Furthermore, HM43239 showed potent antileukemia activity in xenograft models of FLT3-ITD/F691L cell lines harboring double mutations of ITD/TKD, without any body weight loss or significant toxicity. These results indicate that HM43239 may be useful in the treatment of AML patients with FLT3-ITD and/or -TKD mutation, including patients with gilteritinib resistant mutations such as F691L. Herein, we present a clinical trial design to assess the potential clinical activity and safety of HM43239 in patients with AML. This phase I/II clinical trial (NCT03850574) is in clinical development in the United States and Korea to access the overall safety and efficacy of HM43239 in AML. Trial Design: This is an ongoing, open-label, multicenter, first in human phase I/II trial enrolling adult FLT3 mutated and FLT3 wild-type patients with AML who have relapsed or refractory disease after at least one prior line of therapy, what can include prior FLT3 inhibitors such as gilteritinib, midostaurin. Patients are treated with HM43239 once daily (QD) in 28-day cycles, except for the first 30-day cycle, which includes a single PK sampling period. This trial comprises two parts: dose-escalation (Part A) and dose expansion (Part B). During dose escalation, the study follows an accelerated titration design, with around 50% dose increments and 1 patient per dose level. Accelerated titration will continue until 1 patient experiences dose-limiting toxicity (DLT) or moderate toxicity (MT), drug-related grade 2 adverse event (except for hematologic toxicities), at any dose level, after which, a 3 + 3 dose-escalation design will be used. If a patient achieves a clinical response at any dose level in the escalation cohort, an expansion cohort will be open at that dose level. Based on the evaluation of DLTs and composite complete remissions (CRc) from the dose-escalation cohorts, additional subjects may be recruited in the expansion cohort at each dose level selected for expansion. If no CRc is achieved in 6 subjects or less than 2 composite CRs are achieved in 12 subjects who complete 2 treatment cycles that dose level will stop further enrollment. Subjects with FLT3 wild-type will be enrolled to both escalation and expansion cohorts, however, at least 10 subjects with FLT3 mutations (ITD or activating point mutations such as D835Y, D835V, I836) should be enrolled to each dose level selected for expansion (including the subjects from the dose-escalation cohort). Blood samples are collected for pharmacokinetics (PK) & pharmacodynamics (PD) evaluation and for exploratory biomarker analysis in both cohorts. A 2-parameter Bayesian logistic regression will be used to model the dose-toxicity relationship on DLT in dose-escalation and expansion parts and the estimated DLT rate will be provided as a supportive reference for dose-escalation procedure and safety monitoring. The primary endpoint is the assessment of safety, tolerability and PK to determine the recommended phase 2 dose (RP2D). Secondary endpoints include best response rate, duration of response, event free survival, overall survival, cumulative incidence of relapse. PK-PD relationships and PD evaluated by plasma inhibitory assay are exploratory endpoints. The trial was initiated in Jan 2019 and patients have been evaluated since May 2019. Dose level 1 (20 mg) and 2 (40mg) were completed without any DLTs. In Dose level 3 (80mg), one patient experienced MT, the design was changed from accelerated titration design to 3+3 design. Three patients (one FLT3 mutated) were enrolled, including an ongoing FLT3 wild-type patient (currently in cycle 5) with relapsed AML post-stem cell transplant who had prior chemotherapy and achieved CRi and maintains 0% marrow blasts. The enrollment to next dose level 4 (120mg) initiated in June 2020 and subjects have been enrolled. This study is currently recruiting patients at multiple sites in the Republic of Korea and the USA. Clinical trial information: NCT03850574. Disclosures Daver: Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Research Funding; Servier: Research Funding; Genentech: Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novimmune: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trovagene: Research Funding; Fate Therapeutics: Research Funding; ImmunoGen: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Trillium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Syndax: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lee:Hanmi: Research Funding. Jung:Hanmi: Research Funding. Soo:Hanmi: Research Funding. Arellano:Cephalon Oncology: Research Funding; Hanmi: Research Funding; Gilead Sciences, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees. Jonas:LP Therapeutics: Research Funding; Pfizer: Research Funding; Pharmacyclics: Research Funding; Sigma Tau: Research Funding; Celgene: Consultancy, Research Funding; AbbVie: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Amgen: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; GlycoMimetics: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Genentech/Roche: Research Funding; Hanmi: Research Funding; Incyte: Research Funding; Jazz: Consultancy, Research Funding; Takeda: Consultancy; Tolero: Consultancy; Treadwell: Consultancy; Forty Seven: Research Funding; Accelerated Medical Diagnostics: Research Funding; AROG: Research Funding; Daiichi Sankyo: Research Funding; F. Hoffmann-La Roche: Research Funding; Forma: Research Funding. Yoon:Hanmi: Current Employment. Jung:Hanmi: Current Employment. Noh:Hanmi: Current Employment. Bae:Hanmi: Current Employment. Kim:Hanmi: Current Employment.

Abstract: Background: The combination of carfilzomib with immunomodulatory drugs (IMiDs) and dexamethasone is active in multiple myeloma (MM). Carfilzomib, thalidomide, and dexamethasone (KTd) has been studied in upfront MM treatment but has not been studied in the setting of relapsed/refractory myeloma (RRMM). The ALLG MM018/ AMN002 is an open-label phase II study of KTd in patients with RRMM. This study was conducted across 16 sites across Australia, New-Zealand, Singapore, South Korea and Taiwan. Method: Patients with RRMM with 1-3 prior lines of treatment were given carfilzomib [K: 20mg/m2 IV cycle 1 days 1 and 2, 56mg/m2 (36mg/m2 for patients age ≥75 years) from cycle 1 day 8 onwards], thalidomide (T: 100mg po nocte) and dexamethasone [dex: 40mg (20mg for patients age ≥75 years) po weekly] , in a 28-day cycle. After 12 cycles, T was omitted, and K was given on days 1,2,15,16 and dex days 1,15 every 28-day cycles for a further six cycles. The primary endpoint was PFS. Secondary endpoints were ORR, overall survival, adverse events, and quality of life (QoL). The study had an 80% power to detect a ≥70% PFS at 6.5 months compared to historical ≤50% PFS at 6.5 months expected with Td (Kropff, M. et al. Haematologica 2012), at a significance level of 0.05. Results: This study has completed accrual. Eighty-three patients [median age of 66 years (42-85)] were enrolled with a median follow up of 15.9 (0.9-26) months. ORR rates were 86.4% (≥VGPR 70.2%). Median PFS was 20m (95% CI 15.9-26m). PFS at 6.5 months was 76.2% (95% CI 73.6-84.9%). Median OS has not been reached, and was 75% at 20 months. The most common grade ≥3/4 AEs were peripheral neuropathy (16%), upper respiratory tract infections (12%), dyspnoea (14%), and hypertension (10%). Grade ≥3/4 cardiac AEs occurred in 6%. The median carfilzomib dose that was delivered was 70.7% (32.8-92.6%) of the target dose. Thus far, 41% of patients have completed the intended 18 cycles of treatment. 21% of patients ceased therapy early. The most common reason for early treatment cessation was disease progression (30%) and adverse events (15%). Fifteen patients (18%) have died, 11 were due to MM, two from infection, one from an ischaemic cardiac event, and one from a traffic accident. QoL, as measured by the EQ-5D-5L instrument, remained stable throughout treatment. Conclusion: The ALLG MM018/AMN 002 study has met its primary endpoint. The KTd schedule as outlined in this study is efficacious in patients with RRMM, resulting in a prolonged PFS and a safety profile in line with previous reports for each of carfilzomib and thalidomide. KTd is an active option in jurisdictions where the cost of other IMiDs prohibits regulatory funding. Comparisons of efficacy and adverse events between the Caucasian and Asian populations will be presented at the meeting. Disclosures Quach: Celgene: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Glaxo Kline Smith: Consultancy, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Janssen Cilag: Consultancy, Honoraria; Sanofi: Consultancy, Research Funding. Harrison:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; F. Hoffmann-La Roche: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria; CRISPR Therapeutics: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: wrt panobinostat; Haemalogix: Consultancy. Augustson:Roche: Other: Support of parent study and funding of editorial support. Campbell:Amgen, Novartis, Roche, Janssen, Celgene (BMS): Research Funding; AstraZeneca, Janssen, Roche, Amgen, CSL Behring, Novartis: Consultancy. Soo:Hanmi: Research Funding. Durie:Amgen, Celgene, Johnson & Johnson, and Takeda: Consultancy.

Abstract: Abstract 2072 Poster Board II-49 Backgrounds Currently, there are many efforts to design risk-adapted strategies in newly diagnosed acute promyelocytic leukemia (APL) by modulating treatment intensity and those seem to be an efficient approach to minimize treatment-related morbidity and mortality (TRM) while maintain the potential in cure for each relapse-risk group. We had postulated that maintaining of Ara-C during induction therapy might have acceptable toxicities yet obtaining good CR in newly diagnosed APL, and idarubicin alone during consolidation periods might have excellent LFS and OS with low relapse rate. Patients and Methods Eighty six patients with newly diagnosed APL were enrolled in the “multicenter AML-2000 trial” after informed consents were obtained during the period of January 2000 to July 2007. For remission induction therapy, patients received oral ATRA (45mg/m2/d, maintained until CR) combined with idarubicin (12mg/m2/d, D1-D3) plus Ara-C (100mg/m2/d, D1-D7). After CR achievement, patients received 3 monthly consolidation courses consisting of idarubicin (12mg/m2/d, D1-D3) alone and maintenance therapy with ATRA (45mg/m2/d, D1-D15, every 2 month) alone had continued for 2 years. Total patients were divided into low-risk, intermediate-risk and high-risk groups according to a predictive model for relapse risk (Sanz score) based on pretreatment WBC and platelet count and the treatment outcomes were compared in the different risk groups. Results The median age of our cohort was 40 years old (range; 6-80) and median follow-up was 27 months (range; 1-90). The distribution of patients in the 3 risk groups was as follows ; 28 (32.6%) patients in low-risk, 40 (46.5%) in intermediate-risk and 18 (20.9%) in high-risk. Overall, CR was achieved in 78 (90.7%) of 86 patients. The CR rate according risk groups was 96.4% in low-risk, 87.5% in intermediate-risk, and 88.9% in high-risk group and there was no significant statistical difference among the different risk groups. During induction therapy, 48 (55.8%) patients experienced grade 3-4 treatment-related toxicity (TRT), mostly fever and infection (38.8% of all patients) and 6 (7.0%) patients died of treatment-related complications. During 3 consolidation courses, 25 (29.1%) of 78 patients experienced grade 3-4 TRT in 1st course, 27 (36.0%) of 75 patients in 2nd course, and 14 (28.0%) of 50 patients in 3rd course. Overall, 3 (3.5%) patients died of treatment-related complications in CR. The incidence of TRT and treatment-related mortality (TRM) during induction or consolidation therapy showed no significant statistical difference among the different risk groups. The relapse occurred in 6 (7.0%) patients; 2 cases in intermediate-risk and 4 cases in high-risk. However, none had relapsed in low risk group, 5 patients of relapsed patients relapsed during consolidation courses and only one patient, however, relapsed during maintenance therapy. The overall survival (OS) and leukemia-free survival (LFS) rate at 7 years in all of patients was 76.7% and 83.5%, respectively. The OS rate at 7 years was 92.9% in low-risk, 78.6% in intermediate-risk and 53.6% in high-risk group (P:0.04) and the LFS rate at 7 years was 96.4%, 83.4% and 62.2% respectively, showing the significant difference between 3 different risk groups (P:0.046). Conclusions This study indicates that our protocol composed of induction therapy with “3+7” chemotherapy plus ATRA followed by consolidations with three courses of idarubicin alone and maintenance therapy with ATRA alone yields a high CR rate and low relapse rate but minimal acceptable toxicities. Despite of adding Ara-C during induction therapy, we did not find much significant toxicities but having good CR rates, and despite of not adding any additional low/intermediate dose chemotherapies(ie, 6MP), we were able to observe significantly high relapse rate in low and intermediate risk group with excellent LFS and OS. Meanwhile, in high-risk group, the relapse rate was significantly higher than other risk groups and most of the relapses occurred in the middle of consolidation courses. This data suggests that our consolidation therapy composed of anthracycline alone may be not enough to minimize risk of relapse in high-risk group in contrast with the low and intermediate-risk groups. More intensive consolidation therapy combined with other effective, but get tolerable chemotherapies or hematopoietic stem cell transplantation in first CR or the combination of arsenic trioxide or others in front-line therapy should be considered in the patients with high-risk of relapse. Disclosures: No relevant conflicts of interest to declare.

Abstract: Cytogenetics is still being considered the most powerful single prognostic factor, which is useful to determine the types of post-remission therapy in AML, though various molecular markers are available for predicting the prognosis of AML patients. Most phase III studies have failed to demonstrate a clear advantage of allografting over chemotherapy in terms of overall survival because of significant risk of transplant-related mortality. Optimal post-remission therapies in terms of frequencies (number of treatment) or intensities are not decided yet. In this study, since 2000, we investigated that outcomes of post-remission therapies(high-dose cytarabine (HDAC) vs autologous stem cell transplantation (AutoSCT) vs allogeneic stem cell transplantation from sibling or unrelated donors (AlloSCT)) based on cytogenetic risk (GPG, Good prognosis group; IPG, Intermediate prognosis group; PPG, Poor prognosis group by MRC definition) on the AML patients who achieved complete remission after induction chemotherapy. The aims of this prospective intention to treat analysis was to compare the CR, recovery kinetics, DFS and OS in the different prognostic groups. Three plus seven (idarubicin 12mg/m2, D1–D3; cytarabine 100mg/m2, D1–D7) were given to de novo AML, secondary AML and therapy-related AML. Then, HDAC or AutoSCT was given after intermediate dose (8gm/m2) of cytarabine to the patients with GPG. Three times of post-remission therapy including HDAC, or AutoSCT followed by two times of post-remission therapy were given to IPG or PPG. If HLA-identical sibling was available, then AlloSCT underwent after 1st post-remission therapy. Since January, 2000, 506 patients(18 centers) were enrolled up to December, 2007. Among them, 92.3% was de novo AML, and GPG, IPG and PPG were, 23.1%, 62.1% and 14.8% respectively. Over all complete remission rate after 1st induction was 79.0% and CR rate in GPG, IPG, PPG were 92.0%, 81.0% and 43.9% respectively(P & lt;0.001) in 476 patients who were eligible to this study. In Good Prognosis Group (GPG), survivals were not different between different treatment groups (5 year LFS: HDAC 34.2%, AutoSCT 63.5%, AlloSCT 54.8%, p=0.270; 5 year OS: HDAC 54.5%, AutoSCT 62.5%, AlloSCT 53.3%, p=0.676). However, beneficial effect of AlloSCT in post-remission therapy therapy was observed by multivariate analysis in terms of LFS compared to HDAC (HR of relapse for HDAC 3.198 compared to AlloSCT, p=0.045). Outcomes of HDAC group were inferior in GPG in terms of OS and LFS compared to other studies. This results may be due to low cumulative dose of Ara C, because patients of HDAC group in GPG treated just 1 cycle of IDAC before HDAC therapy. In addition, in our cohort, majority (80%) of GPG have t(8;21), which are known as having inferior survival results, compared to inv(16) group. In Intermediate Prognosis Group (IPG), survivals were not different among different types of treatment (5 year LFS: HDAC 31.1%, AutoSCT 42.4%, AlloSCT 55.0%, p=0.131; 5 year OS: HDAC 39.2%, AutoSCT 42.5%, AlloSCT 46.5%, p=0.491). AlloSCT group showed a trend of being superior to other therapeutic modalities in terms of LFS (p=0.07). AutoSCT group showed a trend of being superior to other therapeutic modalities in OS by multivariate analysis (HR of death for AutoSCT 0.539 compared to AlloSCT, p=0.085). In Poor Prognosis Group (PPG), though data showed slightly beneficial effect of AlloSCT in AML therapy, however, there were no significant statistical differences on OS/LFS in 3 types of consolidation therapy modalities (4 year LFS: HDAC 48.3%, AutoSCT 0%, AlloSCT 39.1%, p=0.379; 4 year OS: HDAC 21.4%, AutoSCT 33.3%, AlloSCT 56.1%, p=0.638). Based on this trial, Allo- or Auto-SCT over HDAC may have beneficial effects in some subgroup with high risk and young age, among the patients with good and intermediate cytogenetic risk. In GPG, “sufficient cumulative dose” of Ara C seems to be necessary to have a good outcome. However, GPG seems to be heterogenous group in terms of biology having poor prognosis when one has additional CG abnormalities on top of t(8;21) or inv(16), which ones need to investigate further. While finding more effective anti-AML molecules/monoclonal Ab’s are necessary, good therapeutic rationales in terms of choosing AlloSCT vs AutoSCT vs HDAC should be established. Same time, identifying for better cellular and molecular prognostic factors over cytogenetics are still relevant for designing “effective therapies, but minimal toxicities”.

Abstract: Abstract 4902 Introduction Cytogenetics and fluorescent-in situ hybridization (FISH) are important outcome predictors in multiple myeloma (MM). There were only few small studies that investigated prognostic implication of FISH and/or conventional karyotyping in Korean MM patients. We investigated the incidences and prognostic significances of chromosomal abnormalities detected by FISH and/or conventional karyotyping among Korean MM patients. Patients and Methods We collected data of patients from Korean Myeloma Registry and performed retrospective analysis. We compared the survival of patients with chromosomal abnormalities and other clinical findings. Results From 2000 to 2009, total of 801 newly diagnosed myeloma patients were enrolled in this study. Median age of patients was 62 years. Median overall survival was 82 months, and median follow up of time was 92 months. Among the patients who had conventional karyotype analysis, 17.1% were complex karyotype, followed by del13q (7.4%), hyperdiploidy (7.6%), hypodiploidy (3.0%), and t(11;14) (3.9%). Among the patients who had FISH analysis, 22.8% were del 13q, followed by t(11;14) (18.2%), t(4;14) (13.7%), del17p (11.8%) and t(14;16) (5.9%). Univariate analyses revealed that complex karyotype (p 〈 0.01), hypodiploidy (p=0.01), del13q (p 〈 0.01) by conventional karyotyping, and t(4;14) (p=0.04) by FISH negatively impacted the overall survival. Other genomic aberrations did not affect the overall survival. Clinical parameters that impact on overall survival were percentage of plasma cells in bone marrow, serum beta2-microglobulin, creatinine, low hemoglobin, and low albumin levels. On multivariate analysis, percentage of plasma cells in bone marrow (p 〈 0.01) and low serum albumin level (p 〈 0.01) were independent risk factors for overall survival. Conclusions Our results showed that complex karyotype, hypodiploidy, t(4;14), and del13q by FISH and/or conventional karyotyping were negative prognostic factors for overall survival in univariate analyses. On multivariate analysis, low serum albumin level and percentage of plasma cells in bone marrow were independent risk factors for overall survival. In future, prospective trial with laboratory standardization is warranted for more reliable results from FISH and/or conventional karyotyping in MM patients. Disclosures Suh: Janssen Korea: Research Funding.

Abstract: Abstract 4881 Introduction The Korean Multiple Myeloma Working Party (KMMWP) initiated a nationwide registration of myeloma patients via a web page designated the “Korean Myeloma Registry.” This registry includes demographic features, characteristics of disease, treatment outcomes, and survival status. Herein, we retrospectively reviewed data representing 3,209 Korean myeloma patients. Methods Members of the registry committee of the KMMWP designed the web-based registration site for the “Korean Myeloma Registry (www.myeloma.or.kr).” A total of 3,209 patients were registered from 39 hospitals. Each one of participated hospitals registered their patients who were diagnosed as MM between the years 1999 and 2009. The approximate duration of registration was from May 2005 until March 2009; following collection, the data was downloaded for analysis. Results The median age at diagnosis was 64 years (range, 20 – 93 years) with 84 patients ' 40 years of age; this included three patients 〈 30 years of age (ages 20, 28, and 29 years old). Poor performance status (ECOG grade 2-3), anemia (Hgb 〈 10 g/dL), hypoalbuminemia ( 〈 3.5 g/dL), and elevated serum β2 microglobulin ( 〉 5.5 mg/dL) were more frequently observed in the 〉 65 years of age group than in the groups '65 years of age. Thus, an advanced ISS stage was more common in patients older than 65 years. The most common idiotype of myeloma was IgG (46.0%, 1475/3209), followed by IgA type (18.6%). Non-secretory myeloma accounted for 4.4% of cases, with IgD, IgM, and IgE subtypes being very rare. However, patients ' 40 years of age demonstrated a tendency toward a higher incidence of the IgD type (7.1%, 6/84) and light chain disease (22.6%, 19/84) compared to the other age groups. Other characteristics, including the presence of extramedullary plasmacytoma, demonstrated a similar pattern among the groups. Chromosomal studies of bone marrow aspirates were performed in 1,943 patients with 499 patients (25.7%) demonstrating abnormalities. In 60.9% of patients (1,954/3,209), an objective response to induction treatment included complete response (CR), partial response (PR), and minimal response (MR) (Table 4); 463 patients demonstrated progressive disease (PD) during induction treatment. Response could not be evaluated in 300 patients (9.3%) due to early drop out, including follow-up loss and early death. Eight hundred four patients (25.1%) received SCT. The majority of patients (23.1%, 741 patients) received autologous SCT within one year of diagnosis; designated as “early transplantation.” Autologous SCT was performed in those patients who achieved an objective response following induction treatment. Sixty three patients (2.0%) underwent autologous SCT after relapse; designated as “delayed transplantation.” Five hundred eighty patients received single autologous SCT. Tandem autologous SCT was performed in 134 patients. Allogeneic SCT was performed for 63 patients following autologous SCT. The median OS was 50.13 months (95% confidence interval (CI) of 46.20 – 54.06 months). When OS was compared according to age strata, patients '40 years of age demonstrated a prolonged OS (median OS of 71.13 months) compared with patients 〉 65 years of age (median OS of 36.73 months, P 〈 0.001). When we compared the survival of patients who received novel agents such as bortezomib or thalidomide at any time during the course of their treatments with patients who did not receive novel agents, there was a significant difference of OS between two groups (median OS 42.23 versus 55.50 months, P 〈 0.001). Tandem autologous SCT produced a superior OS when compared with single autologous SCT. Furthermore, patients who underwent delayed SCT demonstrated a longer OS compared with early SCT (P = 0.017). Multivariate analysis found that age 〉 65 years, poor performance status, platelet count 〈 100,000/μL, serum albumin 〈 3.5 g/dL, serum creatinine ≥ 2.0 mg/dL, serum β2 microglobulin ≥ 3.5 mg/dL, the presence of extramedullary plasmacytoma, and the presence of chromosomal abnormalities were all found to be independent prognostic factors for OS. Conclusion In this study, we demonstrate improved survival of patients with multiple myeloma after the introduction of novel agents and autologous stem cell transplantation. Disclosures No relevant conflicts of interest to declare.

Abstract: Introduction: The myelodysplastic syndrome (MDS) is frequently associated with various chromosomal abnormalities. ‘5q− syndrome’ is low-risk MDS known as good responder of lenalidomide recently. However, the patients with other abnormalities in chromosome 5 showed quite different clinical features from those with ‘5q− syndrome’. The aim of this study was a retrospective evaluation for Korean MDS patients with abnormalities in chromosome 5 other than ‘5q− syndrome’. Materials and Methods: Among 456 patients with MDS diagnosed at 16 hospitals in Korea between 1996 and 2006, 370 with available cytogenetic data entered the study. Univariate and multivariate analysis were performed. Results: Ninety three patients (25.1%) showed abnormalities in chromosome 5 and the ‘5q− syndorme’ was only 10 patients (2.7%). Among the rest, 39 patients (10.5%) had various abnormalities other than 5q deletion such as translocation or 5 monosomy, 38 (10.3%) had complex abnormalities with 5q−, and 2 had mosaic pattern with normal chromosome. Four patients had isolated 5q− but blasts in marrow were over 5%. The deletion of 5q was interstitial but with a predominance for 5q13-33 deletions (34.8%). MDS patients with chromosome 5 abnormalities other than ‘5q− syndrome’ didn’t share the clinical features with ‘5q− syndrome’. There was no leukemic transformation in ‘5q− syndrome’ group, but 18 (21.7%) with other abnormalities in chromosome 5 finally transformed to acute leukemia. Five year overall survival was significantly inferior in non-’5q− syndrome’ patients than ‘5q− syndrome’ (14.3% vs. 79.6%, P=0.0115). Conclusions: Patients with isolated 5q− and excess blast ( 〉 5%), other abnormalities than isolated 5q−, or mosaic chromosome with isolated 5q− and normal chromosome didn’t share the clinical features such as lower rate of leukemic transformation and long survival.

Abstract: Abstract 1866 Background: In multiple myeloma (MM), the association between the response to induction before autologous stem cell transplantation (ASCT) and long-term outcome is less clear but the situation may change with the introduction of novel agents. We therefore assessed the clinical relevance of response of bortezomib induction treatment or post-ASCT response for patients who received bortezomib-combined induction chemotherapy followed by ASCT. Methods: We retrospectively assessed 183 MM patients who received bortezomib-containing induction therapy (BTZ-IT) followed by ASCT in 24 institutions throughout Korea between 2003 and 2010. Records of these patients were reviewed using the Korean Myeloma Registry database (www.myeloma.or.kr). Each institution was requested to reconfirm the data using additional case report forms. Patients who had overt MM based on International Myeloma Working Group diagnostic criteria were selected. Results: One-hundred seventy eight patients were eligible. Their median age was 56 years (range, 28–69 years) and 96 (53.9%) were male. Forty nine (27.5%) received bortezomib as front-line therapy and 129 (72.5%) as second-line treatment. All patients underwent ASCT and 22 (12.4%) were treated with tandem ASCT. Ninety-seven (54.5%) patients were treated with maintenance therapy after ASCT. After BTZ-IT, the response rates in this selected series of patients were 37.6% CR, 12.4% VGPR, 41.0% PR, 7.3% SD and 1.7% PD (Figure 1A, 1B, 1C); the corresponding post-ASCT rates were 69.2% CR, 14.0% VGPR, 11.0% PR, 2.9% SD and 2.9% PD. At a median follow-up of 46.6 months, the 3-year overall survival (OS) and event-free survival (EFS) rates were 70.0% and 31.9%, respectively. Multivariate analysis showed that factors independently predictive of OS and EFS included achievement of BTZ-IT response °Ã PR (P=0.025 and P=0.014, respectively) and the treatment with maintenance therapy (P=0.048 and P=0.001, respectively). Post-ASCT CR vs. °Â VGPR was also an independent prognostic factor for OS and EFS (P=0.0001 and P=0.002, respectively). Conclusion: At least PR to BTZ-IT and CR after ASCT were predictive of survival. These findings suggest that patients who responded to BTZ-IT may benefit from ASCT due to an enhanced quality of response. Maintenance therapy can also affect patient outcomes. Disclosures: No relevant conflicts of interest to declare.

Abstract: Purpose According to our experience, ethnic difference in acute myeloid leukemia (AML) is considerable, especially between Caucasians and Asians. In this study, first we tried to identify genomic signature of Korean AML patients and investigat how these genomic signatures would correlate with clinical parameters. Additionally, we tried to compare genomic signatures of Korean AML patients with that of TCGA. Methods We identified specific single nucleotide variant (SNV)'s, small indels and copy number variation (CNV)'s using whole exome sequencing (WES) of acute myeloid leukemia (AML) samples from 103 patients. For detection of SNV's and small indels, we used in-house algorithm Adiscan (https//www.syntekabio.com). For detection of CNV's, we used CONTRA. Clinical parameters considered includes gender, age, bone marrow blast percentage, WBC count at diagnosis, French-American-British (FAB) classification, WHO classification, disease free survival (DFS), reception of allogeneic stem cell transplantation (ASCT) and overall survival (OS). We used TCGA data available on cBio portal. Results In the analysis, when clustering analysis was performed, gender did not have correlation with genetic signatures both in terms of SNV's, indels and CNV. For patient's age, genetic signature of middle-aged patients (age between 35-60) was rather diverse compared to the young patients (age 〈 35) and old patients (age 〉 60). From phenotypical perspective, M4 and M5 AML by FAB had common genetic signatures, which was in contrast to M2 and M3 disease. It is of note that M3 disease does have heterogeneous genetic signature. When the prognosis of AML patients were considered, patients with excellent prognosis (complete remission for more than 3 years) had rather homogenous genetic clustering, while patients with poor prognosis (relapse in 1 year) had very heterogeneous genetic clustering, which implicate complexity of disease relapse mechanism. Commonly mutated non-synonymous genes include TPMRSS13, IDH2, TTN, TNN, NXPE1, NRAS, FAT1, DNMT3A, ANO1, and ADAMTS15. Copy number changes were observed in genes including PTPRC, PTPRQ, NBR1, and WASL. TPMRSS mutation seemed to have prognostic value but further validation is necessary. Compared to TCGA, TMPRSS13 mutation and TNN mutation were unique SNVs found in Korean AML. On the other hand, frequency of IDH2, NRAS, and DNMT3A was considerably low in Korean AML patients. Conclusion Korean AML patients have their own genetic signature which is distinct to that of Caucasians, which supports ethnic difference of AML. TMPRSS13 and TNN mutation in Korean AML patients are noticeable. Figure 1 Commonly found SNV's found by WES in Korean AML patients and its relation with clinical parameters Figure 1. Commonly found SNV's found by WES in Korean AML patients and its relation with clinical parameters Figure 2 Commonly found CNV's found by WES in Korean AML patients and its relation with clinical parameters Figure 2. Commonly found CNV's found by WES in Korean AML patients and its relation with clinical parameters Disclosures No relevant conflicts of interest to declare.

Abstract: Background Acute promyelocytic leukemia (APL) has the best prognosis among acute myeloid leukemia (AML). However, a subset of APL patients is not cured with all-trans retinoic acid (ATRA) combined with anthracycline-based cytotoxic chemotherapy. Some mechanisms such as increased ATRA metabolism have been suggested to acquired resistance to ATRA. However genetic mechanism of ATRA resistance has not been characterized at all. Hence, in this study, we tried to reveal genetic alterations attributable to ATRA resistance. Methods First, we performed whole exome sequencing (WES) using DNA of three APL patients who showed resistance to ATRA based treatment. These included two patients who failed to achieve complete remission (CR) after induction chemotherapy, and one patient who experienced relapse after CR despite of consolidation treatment. DNA extracted from bone marrow at the time of diagnosis was used for analysis, while DNA extracted from saliva at the time of CR was used as germline control. Calling of single nucleotide variants (SNV) was performed using internal pipeline called Adiscan (http://www.syntekabio.com). Annotation was performed using Polyphen-2. SNV’s found by WES were validated by direct Sanger sequencing. The frequency of those validated SNV’s was defined in a separate APL cohort. Results We identified 34 somatic non-synonymous SNV’s in three patients. Polyphen-2 algorithm predicted 9 among 34 SNV’s to damage protein function. Sanger sequencing revealed 8 over 9 SNV’s to be validated. These validated SNV’s include RXRG M77R, N6AMT2 A78S, TXNDC15 D198E, B3GALTL A444T, RBBP8NL E182G, TNPO3 L173W, BHMT M185I and ADAMTS5 G85D. When these 8 SNV’s were genotyped in a separate cohort, none of these SNV’s was found in the APL cohort composed of 30 ATRA sensitive patients, suggesting these SNV’s would be truly related to ATRA resistance in APL. Especially, when a simulation using amber molecular dynamics was performed, we observed 1) Increase in hydrogen bonding, 2) Decreased helix folding structure, 3) Decreased energy state in RXRG mutant case. Conclusions WES identified eight SNV’s which were unique in ATRA resistant cases. Among those mutations, RXRG could be a promising nonsynonymous mutation that explains the genetic mechanism of ATRA resistance. Disclosures No relevant conflicts of interest to declare.