ALBERT

Description: Background:Leukemia cutis (LC) occurs in 10-30% of AML cases and may be a marker of poor prognosis. However, outside of monocytic AML (FAB M4/M5), no clinical or genetic predictors of LC are known. Recently, a number of somatic molecular mutations have been described in AML. Using amplicon-based next-generation sequencing (NGS) of a panel of recurrent, hematologic malignancy-associated mutations, we sought to determine potential molecular markers associated with the development of LC. Methods: A cohort of non-M3 AML patients treated at the University of Pennsylvania was identified in which NGS had been performed on either leukemic blasts obtained during clinical care or from the institutional tissue bank.Average read depth for 33 hematologic malignancy-associated genes was approximately 3000X, minimal depth was 250x, and reporting frequency cutoff for variants was 5%. Mutations were reported as pathogenic or variants of uncertain significance (VUS, further sub-classified internally as likely disease associated, VUS, or likely benign) based on the University’s Center for Personalized Diagnostics (CPD) review of publically available data; only pathogenic or likely disease-associated mutations were included in this analysis. A database maintained by dermatopathology was reviewed to identify cases of leukemia cutis at any time during the disease course. Independent dermatopathology review was obtained for indeterminate cases. Association between presence of each of the 3 most common molecular mutations (FLT3-ITD, DNMT3A, and NPM1) and development of LC was assessed by logistic regression, with adjustment for FAB M4/M5, as appropriate. The association between presence of a molecular mutation in different functional classes (tumor suppressors, activated signaling, chromatin modifiers, transcription factors, splicing machinery) and the development of LC was also assessed. Results:279 adult patients with AML with known molecular genotype were identified. Molecular profile was determined from AML diagnosis in (243, 88%) with the remainder undergoing assessment after prior therapy (relapsed or refractory). 56% were male with median age of 60 years (range 18-87) and median WBC count at diagnosis of 22 K/uL (range 0.4 -388 K/uL; 17% ≥100K/uL). The majority of patients had intermediate cytogenetic risk (12% favorable, 59% intermediate, 23% unfavorable, 6% unknown) and 41% of patients had FAB M4/M5 AML (9% unknown). The three most common mutations were NPM1 (29%), DNMT3A (25%), and FLT3-ITD (23%). NPM1mutations were enriched in patients with FAB M4/M5 AML (41% vs 23%, p=0.003). Leukemia cutis was present in 26 (9%) of patients. NPM1 mutant status was present in 14 of 26 cases of leukemia cutis (OR 3.17, 95% CI 1.40-7.20, p=0.006). No association was detected for LC and the presence of mutant FLT3-ITD (OR 1.27, p=0.613), mutant DNMT3A (OR 1.7, p=0.224), or a mutation in any functional class of AML mutations (all p-values NS). The impact of NPM1 mutant status remained significant after adjustment for association with M4/M5 AML (OR 3.91, p=0.005). As the histologic subtype of AML might modify the association between NPM1 mutations and leukemia cutis, we next examined the impact of NPM1 mutant status on patients with FAB M4/M5 AML and non-M4/M5 AML. Among patients with M4/M5 AML, 10/12 (80%) patients with LC were NPM1 mutant compared to 32/91 (35%) without LC suggesting that the presence of mutated NPM1 was significantly associated with the development of LC (OR 9.22, p=0.006). Among patients with non-M4/M5 AML, 3/9 (33%) of patients with leukemia cutis were NPM1 mutant compared to 32/142 (22.5%) without LC indicating no association in the non-M4/M5 subgroup (OR 1.72, p=0.461). Interestingly, M4/M5 AML was not associated with LC in the NPM1 WT cohort (OR 0.65, p=0.6). Conclusion: Using NGS, we identify a novel association between NPM1 mutation status and the presence of leukemia cutis, particularly within monocytic AML. Confirmation of these observations in a larger dataset is planned. Our data suggest potential cellular effects of NPM1 mutation affecting homing of leukemic blasts to skin and support the World Health Organization’s provisional classification of NPM1-mutated AML as a distinct biologic entity. Disclosures No relevant conflicts of interest to declare.

Description: Key Points Serum 2HG analysis by LC-MS can accurately identify patients with AML with and without IDH mutations. Oncometabolite testing of serum 2HG is indicated as a diagnostic, prognostic, and therapeutic monitoring tool in AML.

Description: Introduction: Venous thromboembolism (VTE) is a significant adverse event in adults receiving pegaspargase (PEG) for acute lymphoblastic leukemia (ALL). PEG increases VTE risk by depletion of antithrombin III (AT). Heparin requires adequate AT for anticoagulation. Younger adults with T-cell ALL receiving prednisone may be particularly at risk. Retrospective series (most with L-asparaginase) suggest AT supplementation may decrease VTE, however prospective data in adults beyond induction is limited while the optimal dose of AT remains undefined and varies across series. We reviewed adults at our institution who received PEG for ALL to assess the incidence of VTE within our AT supplementation practice. Laboratory and cost data for AT repletion were also analyzed. Methods: Adults who received PEG for ALL between 11/2015 and 7/2018 were retrospectively identified. Institutional recommendations were to supplement AT if serum AT 〈 60% following PEG for at least the first 2 courses (induction/consolidation). AT levels were assessed twice weekly until normalized. AT supplementation following additional cycles was recommended for all patients receiving therapeutic anticoagulation. Pharmacists calculated the AT dose using a repletion factor of 80-120%, rounded to the nearest vial. After VTE, patients received therapeutic enoxaparin throughout all remaining PEG doses, with enoxaparin held only if platelets 〈 50,000/mcL or for procedures. After 3/2018, all patients receiving PEG also received enoxaparin prophylaxis when platelets 〉30,000/mcL. A retrospective analysis was done to assess the incidence of VTE. Secondary endpoints included an assessment of VTE risk factors, ability to achieve therapeutic AT levels with supplementation and to characterize drug therapy costs with AT supplementation. Results: Thirty-one patients (30 newly diagnosed, 1 in relapse) with ALL received ≥ 1 dose of PEG followed by AT supplementation. Seventeen of 31 patients were adolescent/young adults (AYA) and 13/31 had T cell ALL. Additional patient characteristics are summarized in table 1. The incidence of VTE was 19%, with 7 VTEs identified in 6 patients. Two patients developed CNS thrombosis (1 fatal), 1 had a pulmonary embolism, and the remainder were upper extremity VTE. Six of 7 VTE occurred during the first two courses at a mean of 66 days (range 6-225) following the first PEG dose. Patients with VTE had a median platelet count of 118/mcL (range 34-377) and a mean AT nadir of 53% (36-98) within 72 hours of VTE. Two of 7 events occurred despite enoxaparin prophylaxis. Five of 6 (83%) patients with VTE had T-ALL; which was more common in the VTE vs. no-VTE group (p = 0.01). The incidence of VTE within the T-ALL group was 38%. Patients with VTE were all AYA and were younger than those without VTE (median 31 vs. 42 years, p = 0.06). Patients with VTE received a higher mean PEG dose than patients without VTE (4589 vs. 3504 units, p 〈 0.0001), reflective of the more aggressive dosing in the AYA regimen. Six of 7 VTEs occurred during a course containing prednisone (p = 0.08 vs. dexamethasone). AT nadirs during cycles with VTE were similar to cycles without VTE. No clinically significant bleeding occurred. Characteristics of patients with VTE are summarized in table 2. Overall the mean time to AT nadir was 11 days. Therapeutic AT (〉 60%) following supplementation occurred 56% of the time. Most AT doses (89%) were calculated with a correction factor of 80-89%. The probability of obtaining a therapeutic AT increased when a higher repletion factor (〉 90%) was used (76% vs. 52%, p = 0.06). Patients received a mean of 1.9 (0-6) doses of AT per PEG dose, and a mean of 5.9 (1-21) AT doses throughout treatment. The mean AT supplementation cost per PEG dose was $11,663 with 186 doses administered ($3.22/unit). Conclusions: VTE occurred in 19% of patients receiving AT supplementation following PEG, with 2/7 events involving the CNS. The risk of VTE was greatest in younger adults with T-ALL receiving concurrent prednisone and higher doses of PEG. AT levels were low at the time of VTE in most patients, however nadirs were similar compared to courses not complicated by VTE. Routine or augmented VTE prophylaxis and a higher AT repletion goal (〉 90%) may further limit VTE risk but given the cost and patient inconvenience, prospective evaluation is needed to confirm the benefit. Disclosures Frey: Servier Consultancy: Consultancy; Novartis: Consultancy. Perl:Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Arog: Consultancy; Astellas: Consultancy; NewLink Genetics: Membership on an entity's Board of Directors or advisory committees. Porter:Genentech: Other: Spouse employment; Novartis: Other: Advisory board, Patents & Royalties, Research Funding; Kite Pharma: Other: Advisory board.

Description: BACKGROUND: Effective and well tolerated treatment options for patients with relapsed acute myelogenous leukemia (AML) are limited. Birinapant is a small molecule, peptidomimetic of second mitochondrial-derived activator of caspases (SMAC) that selectively targets Inhibitor of Apotosis proteins (IAPs) resulting in tumor cell apoptosis and inactivation of NF-kB. SMAC mimetics represent a novel class of anti-tumor agents and birinapant has been explored as a single agent and in combination with chemotherapy in trials in solid tumors. Based on pre-clinical response observed in a mouse model with AML, we developed an investigator initiated Phase I clinical trial using single agent birinapant in pts with relapsed AML and high risk myelodysplastic syndrome (MDS). METHODS: Eligible pts were 〉18 years old with non-M3 relapsed or refractory AML or high risk MDS refractory to a hypomethylating agent. A standard 3+3 dose escalation was planned using single agent birinapant at increasing dose levels and frequency. Subjects who did not complete at least one cycle of therapy (4 wks) or experience a dose limiting toxicity (DLT) were replaced. The primary endpoint was safety and determination a maximum tolerated dose (MTD). Secondary endpoints included pharmacokinetic (PK) and pharmacodynamics (PD) analysis as well as disease response. RESULTS: From 12/2011 to 05/2014, 20 subjects were enrolled at the Hospital of the University of Pennsylvania and received at least one dose of study drug, 1 had MDS, 19 had AML (9 with antecedent MDS). The median age was 75 (range 36 to 80). The median number of prior treatments was 2 (range 1 to 5) and 11 patients required hydroxyurea during study treatment. No other concurrent chemotherapy was permitted. Several dose levels were tested varying the dose (17mg/m2, 22mg/m2 and 26mg/m2) and frequency (weekly, twice weekly (BIW) and 3 times weekly (TIW)) for 3 out of 4 wk cycles. Evaluable subjects have stayed on study drug for

Description: Introduction: Gilteritinib is a novel, potent, highly-selective oral fms-like tyrosine kinase 3 (FLT3)/AXL inhibitor. Once-daily single-agent gilteritinib doses of ≥80 mg/day elicited antileukemic responses in FLT3 mutation-positive (FLT3mut+) subjects with relapsed/refractory AML (Perl AE, et al. Lancet Oncol. 2017). We examined the safety/tolerability and antitumor activity of gilteritinib plus front-line intensive chemotherapy in newly diagnosed AML patients. Methods: This ongoing open-label, dose-escalation/expansion phase 1 study (NCT02236013) assesses the safety/tolerability and antitumor effects of gilteritinib combined with 7+3 induction and high-dose cytarabine consolidation, and as single-agent maintenance therapy in subjects aged ≥18 years with newly diagnosed AML (excluding core-binding factor translocations). Dose escalation followed a 3+3 design; successive cohorts of 3-6 subjects received 40, 80, 120, or 200 mg/day gilteritinib. Subjects received ≤2 cycles of a 7+3 induction regimen (cytarabine 100 mg/m2/day, Days 1-7 plus idarubicin 12 mg/m2/day, Days 1-3 [dose-escalation and dose-expansion cohorts], and once-daily gilteritinib on Days 4-17 [Schedule 1]). After completion of the dose-expansion cohort using Schedule 1, a new cohort of patients were enrolled. In this cohort of six patients, gilteritinib administration was changed to Days 8-21 (Schedule 2) in preparation for phase 3 studies and daunorubicin 90 mg/m2/day, administered on Days 1-3, was used as an alternative anthracycline to idarubicin. During consolidation, subjects received cytarabine (1.5 g/m2 every 12 hours, Days 1, 3, and 5) and once-daily gilteritinib (Days 1-14) at the induction dose for ≤3 cycles. Subjects in the dose-expansion cohort received gilteritinib at the recommended expansion dose established during dose escalation. Transplantation was allowed for responding subjects. After consolidation or transplantation with stable engraftment, subjects received maintenance therapy with once-daily gilteritinib (28-day cycles; ≤26 cycles). Results: As of July 2, 2018, 62 subjects have been enrolled; 60 are included in the safety analysis set. Most subjects were male (66.7%; median age, 59.5 years [range, 23-77]) and 32 (53.3%) had FLT3 mutations (FLT3-ITD, n=23). During dose-escalation, two subjects in the 40 mg/day cohort who had received gilteritinib on Days 1-14 experienced dose-limiting toxicities (DLTs; neutropenia, thrombocytopenia, decreased ejection fraction). After the gilteritinib induction schedule change, no more DLTs occurred at this dose. Two subjects in the 200 mg/day cohort experienced DLTs (neutropenia, neutropenic enterocolitis). The maximum tolerated dose and the recommended expansion dose were established at 120 mg/day. Grade ≥3 adverse events (AEs) in ≥10% of patients were febrile neutropenia (63.3%), thrombocytopenia (18.3%), decreased platelet count (16.7%), neutropenia (15.0%), bacteremia (10.0%), sepsis (10.0%), and decreased white blood cell count (10.0%). Serious drug-related AEs in 〉1 subject were febrile neutropenia (n=9), small intestinal obstruction, lung infection, sepsis, and decreased ejection fraction (all n=2). The end-of-treatment investigator-reported rate of composite complete remission (CRc) for response evaluable FLT3mut+ subjects receiving gilteritinib 120 mg on Schedule 1 (n=17) was 100%. The CRc rate in FLT3mut+ subjects receiving Schedule 2 induction with daunorubicin was also 100% (Table). Enrollment in the Schedule 2 cohort receiving idarubicin is ongoing; the two subjects in this cohort have not been assessed for response. Among subjects who received ≥80 mg/day gilteritinib (n=47), CRc rates for FLT3mut+ subjects were 88.9% (n=24/27). Median overall survival has not been reached. Median disease-free survival was 297 days (95% CI: 112, not reached). Assessment of minimum residual disease in FLT3-ITD patients using a next-generation sequencing-based assay is ongoing; results will be available at the time of presentation. Conclusions: Gilteritinib can be safely combined with intensive chemotherapy, and given as single-agent maintenance therapy in subjects with newly diagnosed AML. Treatment was well tolerated. High response rates were observed in FLT3mut+ subjects after treatment with either idarubicin or daunorubicin in combination with two different gilteritinib administration schedules. Disclosures Pratz: Millenium/Takeda: Research Funding; AbbVie: Consultancy, Research Funding; Agios: Research Funding; Astellas: Consultancy, Research Funding; Boston Scientific: Consultancy. Altman:Astellas Pharma: Other; Agios: Other: Payment to the institution to conduct the trial ; Epizyme: Other: payment to the institution to conduct clinical trial work; BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: payment to the institution to conduct clinical trial work; Cyclacel: Other: payment to the institution to conduct clinical trial work; Celator: Other: payment to the institution to conduct clinical trial work; Ariad: Other: payment to the institution to conduct clinical trial work; Bayer: Other: payment to the institution to conduct clinical trial work; Genetech: Other: Payment to the institution to conduct clinical trial work; FujiFilm: Other: payment to the institution to conduct clinical trial work; Incyte: Other: payment to the institution to conduct clinical trial work; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: payment to the institution to conduct clinical trial work; Boeringer Ingelheim: Other: payment to the institution to conduct clinical trial work; Syros: Membership on an entity's Board of Directors or advisory committees; GSK: Other: payment to the institution to conduct clinical trial work; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Immune Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Cruz:Takeda: Speakers Bureau. Jurcic:Kura Oncology: Research Funding; Forma Therapeutics: Research Funding; Celgene: Research Funding; Daiichi-Sankyo: Research Funding; Incyte: Consultancy; Actinium Pharmaceuticals, Inc: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Syros Pharmaceuticals: Research Funding; Genetech: Research Funding; AbbVie: Consultancy, Research Funding; Astellas: Research Funding. Lin:Jazz Pharmaceuticals: Honoraria. Perl:AbbVie: Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Arog: Consultancy; NewLink Genetics: Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy. Podoltsev:Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas Pharma: Research Funding; LAM Therapeutics: Research Funding; Astex Pharmaceuticals: Research Funding; Genentech: Research Funding; Boehringer Ingelheim: Research Funding; Sunesis Pharmaceuticals: Research Funding; Daiichi Snakyo: Research Funding; Celator: Research Funding; Celgene: Research Funding; Pfizer: Research Funding. Schiller:bluebird bio: Research Funding; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding. Liu:Astellas Pharma: Employment. Bahceci:Astellas Pharma: Employment.

Description: Introduction: FLT3-ITD mutations are among the most common molecular abnormalities in AML, occurring in ≈ 25% of pts. These driver mutations are associated with high leukemic burden and poor prognosis, eg, high risk of relapse, decreased response to salvage therapy, and shorter overall survival (OS). Pts with R/R FLT3-ITD AML have a worse prognosis and represent a population with high unmet medical need. Q is a once-daily, oral, highly potent and selective FLT3i shown in phase 2 trials to have promising single-agent antileukemic activity and a manageable safety profile. QuANTUM-R was the first global, phase 3, randomized controlled trial (NCT02039726) to show that an FLT3i prolonged OS compared with salvage chemotherapy (SC) in pts with R/R FLT3-ITD AML. Final efficacy and safety data from this pivotal phase 3 trial are reported. Methods: Pts aged ≥ 18 years with FLT3-ITD AML refractory to or relapsed (duration of first remission ≤ 6 mo) after standard AML therapy, w/wo hematopoietic stem cell transplant (HSCT) were randomized 2:1 to receive Q (60 mg [30-mg lead-in]) or 1 of 3 preselected investigator's choice (IC) SC: low-dose cytarabine (LoDAC); mitoxantrone, etoposide, and intermediate-dose cytarabine (MEC); or fludarabine, cytarabine, and granulocyte-colony stimulating factor (G-CSF) with idarubicin (FLAG-IDA). Up to 2 cycles of MEC or FLAG-IDA were permitted; Q and LoDAC were given until lack of benefit, unacceptable toxicity, or HSCT. Prior therapy with midostaurin was allowed, but all other FLT3i were not. Pts receiving HSCT in the Q arm could resume Q after HSCT. Primary and secondary endpoints were OS and event-free survival (EFS), respectively. Sensitivity analyses for OS and EFS were conducted: (1) using the per-protocol set (randomized and treated patients without major protocol deviations), (2) censoring at HSCT, (3) censoring at the use of other postbaseline FLT3i (for OS only). Predefined subgroup analyses of OS were also performed. Exploratory endpoints included response rates, duration of CRc, and transplant rate. Results: 367 pts were randomized; 245 to Q and 122 to IC SC (LoDAC, n=29; MEC, n=40; FLAG-IDA, n=53). Four pts randomized to Q and 28 pts randomized to SC did not receive therapy. Median follow-up was 23.5 mo. Six pts were still on initial Q treatment at data cutoff vs 0 in the SC arm. Treatment groups were well balanced for baseline characteristics, including age, response to prior therapy, transplant history, and FLT3-ITD allelic burden. OS hazard ratio (HR) of Q relative to SC was 0.76 (95% CI, 0.58-0.98; stratified log-rank test, 1-sided P=0.0177). Median OS was 6.2 (95% CI, 5.3-7.2) vs 4.7 (95% CI, 4.0-5.5) mo, with an estimated 12-mo OS probability of 27% vs 20% in Q and SC arms, respectively. EFS HR was 0.90 (95% CI, 0.70-1.16; stratified log-rank test, 1-sided P=0.1071); median EFS was 6.0 (95% CI, 0.1-8.3) vs 3.7 (95% CI, 0.4-5.9) wk, respectively. Sensitivity analyses of OS and EFS all supported benefit of quizartinib compared with SC, as did OS analyses across subgroups, including varying allelic ratio, prior HSCT, AML risk score, and response to prior therapy (Tables 1 and 2, Figure). CRc was 48% (95% CI, 42%-55%) and 27% (95% CI, 19%-36%) in Q and SC arms (nominal P=0.0001), respectively. Duration of CRc was 12.1 (95% CI, 10.4-27.1) vs 5.0 (95% CI, 3.3-12.6) wk. Transplant rate was 32% and 12% in Q and SC arms (nominal P500 ms (grade 3) by central laboratory was 3% in the Q arm; no grade 4 QTcF occurred. Q-treated pts post-HSCT had a similar AE profile to those overall. Conclusions: This report confirms the survival benefit observed with single-agent Q compared with SC in pts with R/R FLT3-ITD AML and the favorable Q safety profile, providing evidence of meaningful clinical benefit in pts who have few options. These results are paradigm changing in the R/R FLT3-ITD AML treatment setting. Disclosures Cortes: Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Astellas Pharma: Consultancy, Research Funding; Arog: Research Funding. Khaled:Juno: Other: Travel Funding; Daiichi: Consultancy; Alexion: Consultancy, Speakers Bureau. Perl:Arog: Consultancy; Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy; NewLink Genetics: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Ganguly:Amgen: Consultancy; Janssen: Consultancy; Daiichi Sankyo: Research Funding; Seattle Genetics: Speakers Bureau. Russell:Daiichi Sankyo: Consultancy; Jazz Pharma: Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau. Kramer:Daiichi Sankyo: Consultancy; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Research Funding. Dombret:Daiichi Sankyo: Honoraria; Roche/Genentech: Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Ariad: Honoraria, Research Funding; Novartis: Honoraria; Celgene: Consultancy, Honoraria; Jazz Pharma: Honoraria, Research Funding; Agios: Honoraria; Sunesis: Honoraria; Karyopharm: Honoraria; Kite Pharma: Honoraria, Research Funding; Menarini: Honoraria; Astellas: Honoraria; Janssen: Honoraria; Servier: Honoraria; Seattle Genetics: Honoraria. Jonas:Accelerated Medical Diagnostics: Research Funding; Incyte: Research Funding; Esanex: Research Funding; LP Therapeutics: Research Funding; AbbVie: Consultancy, Research Funding; Daiichi Sankyo: Research Funding; Kalobios: Research Funding; Pharmacyclics: Research Funding; Celgene: Consultancy, Research Funding; Genentech/Roche: Research Funding; Glycomimetics: Research Funding; Tolero: Consultancy; Amgen: Consultancy; Forma: Research Funding. Leung:Novartis: Speakers Bureau; Daiichi: Research Funding. Mehta:Daiichi Sankyo: Honoraria. Montesinos:Daiichi Sankyo: Consultancy, Speakers Bureau; Novartis: Research Funding, Speakers Bureau. Radsak:Novartis: Consultancy, Honoraria; Jazz Pharmaceuticals: Other: Travel grant; TEVA: Consultancy; Daiichi Sankyo: Honoraria, Other: Travel grant; Gilead: Other: Travel grant; Celgene: Honoraria, Other: Travel grant; Takeda: Consultancy. Arunachalam:Daiichi Sankyo: Employment. Holmes:Daiichi Sankyo: Employment. Kobayashi:Daiichi Sankyo: Employment. Namuyinga:Daiichi Sankyo: Employment. Ge:Daiichi Sankyo: Employment. Yver:Daiichi Sankyo: Employment. Zhang:Daiichi Sankyo: Employment.

Description: Introduction: In the phase 3 QuANTUM-R trial, once-daily, oral, highly potent and selective FLT3 inhibitor Q improved clinical benefits vs SC (median overall survival [mOS], 6.2 vs 4.7 mo [HR, 0.76 (95% CI, 0.58-0.98); P = .02]; composite complete remission [CRc], 48% vs 27%; median duration of CRc, 12.1 vs 5.0 wk) in 367 pts with R/R FLT3-ITD AML (Cortes et al. Lancet Oncol, 2019; NCT02039726). Prior to randomization, 25% (Q) and 23% (SC) of pts had 1 prior HSCT. An OS sensitivity analysis, with censoring at the time of any subsequent HSCT during QuANTUM-R, was supportive (mOS, 5.7 vs 4.6 mo [HR, 0.79 (95% CI, 0.59-1.05)]; P = .05). Post hoc analyses of characteristics and clinical outcomes in pts who underwent subsequent HSCT in QuANTUM-R are reported. Methods: Pts aged ≥ 18 y with FLT3-ITD R/R AML receiving Q (60 mg [30-mg lead-in]) or 1 of 3 prespecified high- or low-intensity SC regimens and underwent subsequent HSCT as part of the open-label, randomized QuANTUM-R trial were analyzed. Pts receiving HSCT in the Q arm could resume maintenance Q 30-100 days after HSCT. Decisions to proceed to HSCT and resume Q after HSCT were made per investigator discretion/institutional policies. Results: Of 367 randomized pts, 85 in the Q arm underwent any subsequent HSCT (allogenic HSCT [allo-HSCT], 84 [6 with and 78 w/o additional AML therapy]; autologous HSCT, 1) and 19 in the SC arm underwent any HSCT (5 with and 14 w/o additional AML therapy]). Median age (range) was lower in pts with any HSCT (Q, 49 [19-71] y; SC, 44 [23-67] y) vs pts w/o (Q, 58 [19-81] y; SC, 59 [18-78] y). Q + SC pooled data showed a longer mOS (95% CI) in 104 pts with any HSCT vs 263 w/o (12.2 [10.0-24.1] vs 4.4 [4.1-4.9] mo; P 〈 .0001; Fig 1); 1-year OS probabilities (95% CI) were 50% (40%-60%) vs 13% (9%-18%). Among pts preselected for high-intensity therapy (Q [n = 188] + SC [n = 93]), mOS in the pooled high-intensity group was 11.9 (10.0-24.0) mo with any HSCT vs 4.6 (4.1-5.4) mo w/o. Among pts preselected for low-intensity therapy, 13/57 in the Q arm and 0/29 in the SC arm underwent any HSCT; mOS in the pooled low-intensity group was 32.4 (6.2-NA) mo with any HSCT vs 4.1 (2.7-4.6) mo w/o. In pts with CRc (last recorded response prior to allo-HSCT), mean time (range) to allo-HSCT was 13.3 (5.9-26.9) wk with Q and 12.1 (6.3-28.6) wk with SC. Q + SC pooled data showed that mOS (95% CI) was longer in pts with a CRc prior to allo-HSCT vs pts w/o CRc (20.1 [11.7-NA] vs 8.8 [7.0-11.4] mo). Survival outcomes by treatment were similar regardless of study treatment, with longer mOS in pts with any HSCT vs pts w/o (Q, 11.9 [10.2-25.1] vs 4.5 [4.1-5.4] mo; SC, 12.7 [6.1-NA] vs 4.0 [2.7-5.0] mo); respective 1-year OS probabilities (95% CI) were 50% (39%-60%) vs 13% (8%-20%) and 51% (26%-70%) vs 12% (6%-21%). In the Q arm, mOS (95% CI) was longer in pts with a best response of CRc who resumed Q after allo-HSCT (27.1 [18.2-NA] mo) vs pts not resuming Q (5.4 [4.7-11.4] mo; Fig 2). In 48 pts (62%) in the Q arm resuming Q after allo-HSCT, median time (range) from allo-HSCT to Q resumption was 65 (30-106) d. Four pts (5%) in the Q arm died 〈 30 days after allo-HSCT. As of 2/22/2018, 46 of 78 pts in the Q arm (59%) and 9 of 14 pts in the SC arm (64%) with allo-HSCT w/o additional AML therapy died, primarily due to AML disease progression (Q, 31 [40%]; SC, 7 [50%]). The frequency of treatment-emergent adverse events (TEAEs) was mostly lower in pts resuming Q after allo-HSCT than in the overall Q population (Table 1); TEAEs of interest were similar. Long-term survivor data will be presented. Conclusions: Independent of HSCT, Q improved survival vs SC in pts with FLT3-ITD R/R AML in QuANTUM-R. Q + SC pooled analyses showed longer survival in pts with HSCT vs pts w/o and in pts with CRc prior to allo-HSCT. Importantly, survival post-HSCT was similar in the Q and SC arms, indicating that pts eligible for HSCT were appropriately transplanted, and the higher HSCT rate in the Q arm was beneficial to pts. More pts treated with Q underwent HSCT, likely due to a higher rate and duration of CRc with Q vs SC and better overall fitness. In pts preselected for low-intensity SC at study entry, 13 were able to undergo HSCT after Q treatment. Resumption of Q after HSCT was associated with better survival outcomes and was tolerable. These data illustrate the value of using Q to target the FLT3-ITD mutation as a part of the overall treatment sequence in pts with FLT3-ITD R/R AML. Disclosures Ganguly: Seattle Genetics: Speakers Bureau; Janssen: Honoraria, Other: Advisory Board; Kite Pharma: Honoraria, Other: Advisory Board; Daiichi Sankyo: Research Funding. Cortes:Bristol-Myers Squibb: Consultancy, Research Funding; BiolineRx: Consultancy; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Astellas Pharma: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Sun Pharma: Research Funding; Immunogen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Forma Therapeutics: Consultancy, Honoraria, Research Funding; Biopath Holdings: Consultancy, Honoraria; Merus: Consultancy, Honoraria, Research Funding. Krämer:Daiichi-Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Bayer: Research Funding. Levis:Amgen: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Daiichi Sankyo Inc: Consultancy, Honoraria; Astellas: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Menarini: Consultancy, Honoraria; FUJIFILM: Consultancy, Research Funding. Martinelli:Daiichi Sankyo: Consultancy, Honoraria; Pfizer: Consultancy, Other: trial grant; Celgene: Consultancy, Honoraria, Other: trial grant; Janssen: Consultancy, Other: trial grant; Incyte: Consultancy, Other: trial grant; Amgen: Consultancy, Other: trial grant; Abbvie: Consultancy, Honoraria, Other: trial grant; Novartis: Consultancy, Other: trial grant; Roche: Consultancy, Other: trial grant; Ariad: Consultancy, Other: trial grant. Perl:Novartis: Honoraria, Other: Advisory board, Non-financial support included travel costs for advisory board meetings as well as a medical writing company that assisted with manuscript preparation/submission and slide deck assembly for academic meeting presentations of the data., Research Funding; Bayer: Research Funding; BioMed Valley Discoveries: Research Funding; FujiFilm: Research Funding; Takeda: Consultancy, Honoraria, Other: Non-financial support included travel costs for advisory board meetings.; Astellas: Consultancy, Honoraria, Other: Non-financial support included travel costs for advisory board meetings as well as a medical writing company that assisted with manuscript preparation/submission and slide deck assembly for academic meeting presentations of trial data., Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Other, Research Funding; Arog: Consultancy, Other: Non-financial support included travel costs for advisory board meetings.; AbbVie: Consultancy, Honoraria, Other: Non-financial support included travel costs for advisory board meetings.; Actinium Pharmaceuticals: Consultancy, Honoraria, Other: Clinical Advisory Board member, Research Funding; Agios: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Non-financial support included travel costs for advisory board meetings.; Jazz: Consultancy, Honoraria, Other: Non-financial support included travel costs for advisory board meetings.; NewLink Genetics: Consultancy, Honoraria, Other: Non-financial support included travel costs for advisory board meetings.. Russell:Astellas: Consultancy, Honoraria, Speakers Bureau; Pfizer Inc: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy, Honoraria, Speakers Bureau; DSI: Consultancy, Honoraria, Speakers Bureau. Arunachalam:Daiichi Sankyo: Employment. Gammon:Daiichi Sankyo: Consultancy. Lesegretain:Daiichi-Sankyo Inc.: Employment, Equity Ownership. Mires:Daiichi Sankyo: Employment. Namuyinga:Daiichi Sankyo: Employment. Zhang:Daiichi Sankyo: Employment. Khaled:Omeros: Consultancy; Daiichi Sankyo: Other: Travel support; Alexion: Consultancy, Speakers Bureau.