Abstract: In the current phase 1 study, the combination of brentuximab vedotin, an antibody‐drug conjugate targeting CD30, and re‐induction chemotherapy (mitoxantrone, etoposide, and cytarabine) was found to be safe for patients with CD30‐expressing relapsed/refractory acute myeloid leukemia. The results suggest that CD30 may be a target of further exploration in this patient population.

Abstract: Mutations in genes encoding isocitrate dehydrogenase 1/2 (IDH 1/2) enzymes result in increased 2-hydroxyguterate (2-HG) levels, which may provide a non-invasive marker of disease in IDH-mutant AML. The purpose of this study was to characterize patients with IDH-mutant AML by assessing presenting features, concurrent mutations, and 2-HG levels. From 7-2011 through 6-2014, we identified 170 consecutive patients with newly diagnosed AML and measured 2-HG by liquid chromatography-tandem mass spectrometry in serum, urine, marrow aspirate, and marrow pellet samples. All patients had IDH1 R132, IDH2 R140 and R172 testing; 169/170 had hotspot mutational profiling for AKT1, APC, BRAF, CTNNB1, EGFR, ERBB2, KIT, KRAS, MAP2K1,NOTCH1, NRAS, PIK3CA, P53, and PTEN. We assessed FLT3 (168/170), NPM1 (168/170), CEBPA (100/170) mutational status as routine clinical care; 2 patients had BCR/ABL alterations, and 6 were JAK2 positive (of 36 tested). IDH1/2-mutant were compared to wildtype (WT) patients using a Wilcoxon rank sum test, Fisher's exact test, or Kruskal Wallis test, as appropriate. The group was 54% male; 83% white, 2.4% black, 2.4% Asian, and 6.5% Hispanic. 12 patients had APL. IDH mutations included IDH1 R132C (n=10), IDH2 R172 (n=7), and IDH2 140Q (n=22). Other mutations included NPM1 (20.8%), FLT3-ITD (17.3%), FLT3-TKD (6.6%), NRAS (18.4%), TP53 (3%), KRAS (6.5%), and KIT (1.2%). CEBPA mutations occurred in 13 of 100 patients. IDH mutations (n=39) more frequently co-occurred with normal cytogenetics and NPM1 mutations, vs IDH-WT, consistent with prior reports (Table 1). No patients with favorable cytogenetics harbored an IDH1/2 mutation. Significantly higher 2-HG levels were detected among those with IDH1/2 mutations compared to IDH WT, in the serum (p 〈 0.0001), urine (p 〈 0.0001), marrow aspirate (p 〈 0.0001) and marrow pellet (p 〈 0.0001). Overall, elevated 2-HG levels were present regardless of type of IDH mutation. Serum and marrow pellet 2-HG levels were elevated ( 〉 1000 ng/mL in serum and 〉 1000ng/2x10^6 cells in marrow pellet) in 30/38 and 24/29 IDH-mutant patients, respectively, compared to 1/129 and 5/117 IDH WT patients. All but 2 IDH-mutant patients displayed either or both an elevated marrow pellet or serum 2-HG. Patients with IDH2 R172 mutations had lower marrow 2HG levels compared to those with R140Q mutations (Figure 1, p=0.0434). The WBC and blast count was lower among IDH2 R172-mutant compared to R140Q- or IDH1 R132C-mutant patients (p= 0.0134 and p=0.0039, respectively); there was no significant difference in serum 2HG levels. All three canonical IDH1/2 mutations have higher 2HG levels compared to IDH WT. IDH2 R172 mutated AML may present with lower WBC counts and peripheral blast percentage compared to IDH1 R132C and IDH2 R140Q mutant AML. Urine and serum 2HG levels effectively identify patients with mutant IDH1/2, of particular relevance given targeted therapies for these mutations. Table 1. Characteristics of IDH1/2-mutant and WT AML patients. IDH1/2 Mutated IDH1/2 WT p-value Age, y (median, range) 67 (41-86) 65 (20-87) 0.4718 AML History (n, %) De Novo 28 (72%) 82 (63%) 0.6336 Therapy-related 4 (10%) 15 (11%) MDS 2 (5%) 17 (13%) Cytogenetic Risk (n, %) Favorable 0 23 (18%) 0.0006 Intermediate 30 (81%) 71 (55%) Normal 25 (68%) 44 (34%) Poor 7 (19%) 34 (27%) Concurrent Mutations (n, %) NPM1 15 (38%) 20 (16%) 0.0033 FLT3-ITD 3 (8%) 26 (20%) 0.0907 FLT3-TKD 2 (5%) 9 (7%) 1.000 CEBPA Heterozygous Homozygous 3 (14%) 0 8 (10%) 2 (3%) 0.8118 NRAS 9 (23%) 22 (17%) 0.4788 KRAS 0 11 (8%) 0.0700 KIT 1 (3%) 1 (1%) 0.4093 P53 1 (3%) 4 (3%) 1.000 Table 2. WBC and 2-HG levels by IDH mutation (median, range). BQL, below quantitative limit. IDH1 R132C N= 10 IDH2 R172 N=7 IDH2 R140Q N=22 IDH WT N=131 WBC count 10.1 [1.8-333.2] 1.6 [0.7-3.2] 5.9 [0.9-122.8] 6.3 [0.4-315.4] Peripheral blast % 33.0 [0-98] 1.0 [0-9.8] 18.2 [2-91] 15 [0-94] Marrow aspirate 2-HG (ng/mL) 20,900 [1330-93500] (n=7) 4300 [2230-26000] (n=6) 30800 [BQL-311000] (n=19) BQL [BQL-22000] (n=116) Serum 2-HG (ng/mL) 1807 [101-66207] (n=9) 1102 [287-2908] (n=7) 1464 [365.1-11696] (n=22) 86.9 [BQL-1224] (n=128) Urine 2-HG (ng/mL) 33850 [7260-282000] (n=10) 7430 [2460-63700] (n=7) 11300 [2070-177000] (n=20) 3140 [BQL-53200] (n=125) Marrow pellet 2-HG (ng/2*10^6 cells) 13680 [193-172,800] (n=7) 7480 [1056-79600] (n=5) 5560 [564-96400] (n=17) 65 [BQL-4040] (n=116) Figure 1 Figure 1. Disclosures Brunner: NIH T32 CA 71345-18: Research Funding. Attar:Agios: Employment. Yen:Agios: Employment. Yang:Agios Pharmaceuticals: Employment, Stockholder Other. Straley:Agios: Employment. Agresta:Agios Pharmaceuticals: Employment, Stockholder Other. Stone:Agios: Consultancy. Fathi:Millennium: Research Funding; Seattle Genetics: Advisory Board, Advisory Board Other; Agios: Advisory Board, Advisory Board Other.

Abstract: Introduction: Treatment of acute myeloid leukemia (AML) has remained largely unchanged for several decades despite the emergence of new agents. Long-term survival for patients aged 〉 60 years is less than 10% (median survival 10.5 months). Targeting the proteasome in treating AML is attractive, since leukemia stem cells have demonstrated sensitivity to proteasome inhibition, perhaps through down regulation of nuclear NF-KB (Guzman, Blood 2001). Preclinical studies in leukemia cell lines revealed synergistic cytotoxicity when bortezomib, a proteasome inhibitor, was combined with the standard agents daunorubicin and cytarabine. We have shown that adding bortezomib to standard treatment in AML results in a high remission rate, although neurotoxicity was noted among treated patients, 12% grade 3 sensory (Attar, …, Amrein, et al. Clin Cancer Res 2008, Attar, … Amrein, J Clin Oncol 2012). The next generation proteasome inhibitor, ixazomib, which is less frequently associated with neurotoxicity, was therefore selected for combination with conventional chemotherapy in this phase I trial. The primary objective was to determine the maximum tolerated dose (MTD) in the combination, initially in induction, and then in combination with consolidation in a subsequent portion of the overall study. We report here the results of the induction portion of the study, which has been completed. Methods: Adults 〉 60 years of age with newly diagnosed AML were screened for eligibility. Patients with secondary AML were eligible, including those with prior hypomethylating agent therapy for myelodysplastic syndromes (MDS). We excluded those with promyelocytic leukemia. The induction treatment consisted of the following: cytarabine 100 mg/m2/day by continuous IV infusion, Days 1-7; daunorubicin 60 mg/m2/day IV, Days 1, 2, 3; ixazomib orally at the cohort dose, Days 2, 5, 9, and 12 A standard 3 + 3 patient cohort dose escalation design was used to determine whether the dose of ixazomib could be safely escalated in 3 cohorts (1.5 mg/day, 2.3 mg/day, 3.0 mg/day), initially in induction and subsequently in consolidation. The dose of 3.0 mg/day was the maximum planned for this study. The determined MTD of ixazomib in the first portion of the trial would be used during induction in the second portion, which seeks to test dose escalation of ixazomib during consolidation. Secondary objectives included rate of complete remission and disease-free survival. Results: Fourteen patients have been analyzed for toxicity and activity during the induction portion of the study. There were 4 (28%) patients with either secondary AML or treatment related AML, 9 (64%) were male, and the median age was 67 years (range 62-80 years). There have been no grade 5 toxicities due to study drug. Three patients died early due to leukemia, 2 of which were replaced for assessment of the MTD. Nearly all the grade 3 and 4 toxicities were hematologic (Table). There was 1 DLT (grade 3 thrombocytopenia) indicated at the highest dose level. There has been no neurotoxicity with ixazomib to date. Among the 14 patients, there have been 10 complete remissions (CR's) and 1 CRi for a remission rate of 79%. Conclusions: The highest dose level planned for this portion of the trial, 3.0 mg of ixazomib, was reached with 1 DLT and is the recommended dose for induction in the next portion of this study, which will seek to determine a safe ixazomib dose in combination with conventional consolidation therapy. That no neurotoxicity was encountered was reassuring, and the remission rate in this older adult population is favorable. Table. Table. Disclosures Amrein: Takeda: Research Funding. Attar:Agios: Employment, Equity Ownership. Brunner:Takeda: Research Funding; Novartis: Research Funding; Celgene: Consultancy, Research Funding. Fathi:Celgene: Consultancy, Honoraria, Research Funding; Boston Biomedical: Consultancy, Honoraria; Astellas: Honoraria; Agios: Honoraria, Research Funding; Jazz: Honoraria; Seattle Genetics: Consultancy, Honoraria; Takeda: Consultancy, Honoraria.

Abstract: 6606 Background: Mutations in isocitrate dehydrogenase (IDH1 and IDH2) occur in 10-20% of AML patients and result in production of 2-hydroxyglutarate (2-HG). We hypothesize that serial 2-HG quantification may be used to monitor response and predict relapse in patients with AML. Methods: We are conducting a prospective study at MGH and DFCI to (1) assess changes in serum and urine 2-HG levels during treatment in patients with newly diagnosed AML, (2) compare 2-HG levels in serum, urine, and bone marrow and, (3) serially compare 2-HG levels with IDH1/2mutant allele burden. In those with elevated serum 2-HG (≥1000ng/ml), 2-HG is monitored serially or at relapse. Results: To date, 20 patients have been enrolled, 5 (25%) of whom had elevated baseline serum 2-HG. All 5 were found to have IDH1/2 mutations. The serum 2-HG for these patients was significantly higher than for those who were IDH-wt (median 1933 vs 87ng/mL; p 〈 0.001). Urine 2-HG was also higher in IDH-mutant patients (median 30500 vs 4230ng/mL; p 〈 0.021), as was bone marrow 2-HG (median 9870 vs 309ng/mL; p 〈 0.005). Serum 2-HG levels strongly correlated with that in urine (R 2 0.987). Serum 2-HG decreased in all IDH mutant patients on therapy, but more rapidly in those receiving induction chemotherapy (Table), all of whom achieved remission, than those receiving hypomethylatingagents. Conclusions: Patients with IDH-mutant AML have markedly elevated serum and urine 2-HG. 2-HG levels decreased with therapy and there is a strong correlation between serum and urine 2-HG. Data on the sensitivity of serial 2-HG monitoring as well as comparison with mutant IDH1/2allele burden will be presented. This data suggests that serial 2-HG quantification may be a valuable non-invasive biomarker in this genetically defined subset of AML. [Table: see text]

Abstract: Mutations of genes encoding isocitrate dehydrogenase (IDH1 and IDH2) have been recently described in acute myeloid leukemia (AML). Serum and myeloblast samples from patients with IDH-mutant AML contain high levels of the metabolite 2-hydroxyglutarate (2-HG), a product of the altered IDH protein. In this prospective study, we sought to determine whether 2-HG can potentially serve as a noninvasive biomarker of disease burden through serial measurements in patients receiving conventional therapy for newly diagnosed AML. Our data demonstrate that serum, urine, marrow aspirate, and myeloblast 2-HG levels are significantly higher in IDH-mutant patients, with a correlation between baseline serum and urine 2-HG levels. Serum and urine 2-HG, along with IDH1/2-mutant allele burden in marrow, decreased with response to treatment. 2-HG decrease was more rapid with induction chemotherapy compared with DNA-methyltransferase inhibitor therapy. Our data suggest that serum or urine 2-HG may serve as noninvasive biomarkers of disease activity for IDH-mutant AML.

Abstract: The aurora kinases play an essential role in regulating mitosis and cell division. Over-expression of aurora kinases A and B has been associated with poor-risk features in acute myeloid leukemia (AML). Preclinical studies suggest that small molecule aurora kinase inhibitors have activity in AML cell lines. Alisertib (MLN8237), a novel Aurora-A kinase inhibitor, has been generally well tolerated in early clinical trials of hematological malignancies, including AML. This study sought to evaluate tolerability of alisertib combined with standard “7+3” induction chemotherapy for AML. In this phase I, 3+3 cohort dose-escalation study, alisertib was administered with standard 7+3 induction for newly diagnosed AML. Those with acute promyelocytic leukemia or with AML and core-binding factor alterations were excluded. All patients received 7+3 induction (continuous infusion cytarabine 200mg/m2 x 7 days and intravenous idarubicin 12mg/m2 x 3 days), after which on day 8, alisertib was administered twice daily (BID) for 7 days. Dose escalation occurred via three cohorts (10mg BID, 20mg BID, 30mg BID). All underwent a mid-induction bone marrow biopsy, following the course of alisertib, to assess for residual disease, which if present, was to be treated with 5+2 re-induction (cytarabine 200mg/m2 x 5 days, idarubicin 12mg/m2 x 2 days) without alisertib. Following induction, up to four cycles of consolidation were allowed, using cytarabine (3g/m2 BID days 1,3,5 for those aged 〈 60 and 2g/m2 daily days 1-5 for those aged ≥60) followed by alisertib, according to dose cohort, on days 6-12. After consolidation, alisertib maintenance was initiated, at cohort dose level, for days 1-7 of 21 day cycles, to be continued for 12 months or until disease progression. Those eligible for stem cell transplant (SCT), following induction and/or consolidation courses, were removed from study for this purpose. Currently, 14 patients are enrolled on study (n=3, 10mg BID; n=7, 20mg BID; n=4, 30mg BID). The median age was 62 (range 43-75); 9 (64%) were male, and all but 3 were Caucasian. One patient (7%) had therapy-related AML and six (43%) had underlying myelodysplasia. FLT3 mutations were detected in 3 (21%), NPM1 mutations in 2 (14%), CEBPA mutations in 2 (14%), and IDH1/IDH2 mutations in 4 patients (28.4%). One patient in cohort 2 died of sepsis, deemed unrelated to study drug, prior to completion of the toxicity assessment period and was replaced. Five patients have gone on to SCT. All patients received induction, 7 patients have undergone first consolidation, 3 a second consolidation, 2 a third consolidation, 1 a fourth consolidation, and 1 patient has started maintenance therapy. Alisertib has been well tolerated. All patients have experienced expected grade 4 toxicities of anemia, thrombocytopenia, and febrile neutropenia seen during the induction phase of treatment. At initial dose of 10mg BID, no dose-limited toxicities (DLTs) were encountered. In the 20mg BID cohort, one DLT was encountered, of delayed thrombocytopenia (G4 at day 40). The final cohort, at 30mg BID, is currently accruing (4 of 6 enrolled). No other DLTs have been detected, and other toxicities on study will be presented. The maximum tolerated dose (MTD) will be established upon completion of this cohort. To date, 11 of 12 (92%) evaluable patients have achieved remission following induction (8 cases of CR and 3 of CRp). During the course of the study, one patient has experienced relapse, and none have died. Thirteen of 14 evaluable patients had an ablated mid-induction marrow biopsy, with the remaining patient showing 6% blasts in a 20% cellular marrow at mid-induction. None of the patients have undergone re-induction with 5+2 at mid-induction. We anticipate that the study will be fully enrolled and closed to further accrual by the time of presentation. Alisertib, a novel aurora A kinase inhibitor, appears to be well tolerated in conjunction with standard induction chemotherapy in newly diagnosed AML. Currently, 13 of 14 treated patients have demonstrated marrow ablation at the mid-induction point of therapy, and none have required re-induction with 5+2. Eleven of 12 evaluable patients have achieved remission following induction. These results suggest that alisertib is well-tolerated and may hold promise as a therapeutic agent in AML, when combined with induction chemotherapy. Ongoing efforts seek to define the MTD and establish appropriate dosing for phase II studies. Disclosures Fathi: Millennium: Research Funding; Seattle Genetics: Advisory Board, Advisory Board Other; Agios: Advisory Board, Advisory Board Other. Attar:Agios: Employment.

Abstract: Introduction: Outcomes for acute myeloid leukemia (AML) among older patients has remained largely unchanged for decades. Long-term survival for patients aged & gt;60 years is poor (median survival 10.5 months). Targeting the proteasome in AML is attractive, since leukemia stem cells have demonstrated sensitivity to proteasome inhibition in preclinical models, perhaps through down regulation of nuclear NF-KB (Guzman, Blood 2001). AML cell lines are susceptible to synergistic cytotoxicity when bortezomib, a proteasome inhibitor, is combined with daunorubicin and cytarabine. We have shown that adding bortezomib to standard treatment in AML results in a high remission rate, although grade 2 sensory neurotoxicity was noted in approximately 12% of treated patients. A newer generation proteasome inhibitor, ixazomib, is less frequently associated with neurotoxicity, and, therefore, was selected for combination with conventional chemotherapy in this phase I trial. The primary objective of this study was to determine the maximum tolerated dose (MTD) of ixazomib in combination with conventional induction and consolidation chemotherapy for AML. Herein are the initial results of this trial. Methods: Adults & gt;60 years of age with newly diagnosed AML were screened for eligibility. Patients with secondary AML were eligible, including those with prior hypomethylating agent therapy for myelodysplastic syndromes (MDS). We excluded those with promyelocytic leukemia. There were 2 phases in this study. In the first phase (A), the induction treatment consisted of the following: cytarabine 100 mg/m2/day by continuous IV infusion, Days 1-7; daunorubicin 60 mg/m2/day IV, Days 1, 2, 3, and ixazomib was provided orally at the cohort dose, Days 2, 5, 9, and 12. Consolidaton or transplant was at the discretion of the treating physician in phase A. In the second phase (B), induction was the same as that with the determined MTD of ixazomib. All patients were to be treated with the following consolidation: cytarabine at 2 g/m2/day, days 1-5 with ixazomib on days 2, 5, 9, and 12 at the cohort dose for consolidation. A standard 3 + 3 patient cohort dose escalation design was used to determine whether the dose of ixazomib could be safely escalated in 3 cohorts (1.5 mg/day, 2.3 mg/day, 3.0 mg/day), initially in induction (phase A) and subsequently in consolidation (phase B). The determined MTD of ixazomib in the first portion (A) of the trial was used during induction in the second portion (B), which sought to determine the MTD for ixazomib during consolidation. Secondary objectives included rate of complete remission, disease-free survival, and overall survival (OS). Results: Thirty-six patients have been enrolled on study, and 28 have completed dose levels A-1 through A-3 and B1 through B-2. Full information on cohort B-3 has not yet been obtained, hence, this report covers the experience with the initial 28 patients, cohorts A-1 through B-2. There were 12 (43%) patients among the 28 with secondary AML, either with prior hematologic malignancy or therapy-related AML. Nineteen patients (68%) were male, and the median age was 68 years (range 61-80 years). There have been no grade 5 toxicities due to study drug. Three patients died early due to leukemia, 2 of which were replaced for assessment of the MTD. Nearly all the grade 3 and 4 toxicities were hematologic (Table). There was 1 DLT (grade 4 platelet count decrease extending beyond Day 42). There has been no grade 3 or 4 neurotoxicity with ixazomib to date. Among the 28 patients in the first 5 cohorts, 22 achieved complete remissions (CR) and 2 achieved CRi, for a composite remission rate (CCR) of 86%. Among the 12 patients with secondary AML 8 achieved CR and 2 achieved CRi, for a CCR of 83%. The median OS for the 28 patients has not been reached (graph). The 18-month OS estimate was 65% [90% CI, 50-85%]. Conclusions: The highest dose level (3 mg) of ixazomib planned for induction in this trial has been reached safely. For consolidation there have been no serious safety issues in the first 2 cohorts with a dose up to 2.3 mg, apart from 1 DLT in the form of delayed platelet count recovery. The recommended phase 2 dose of ixazomib for induction is 3 mg. Accrual to cohort B-3 is ongoing. Notably, to date, no grade 3 or 4 neurotoxicity has been encountered. The remission rate in this older adult population with the addition of ixazomib to standard chemotherapy appears favorable. Figure Disclosures Amrein: Amgen: Research Funding; AstraZeneca: Consultancy, Research Funding; Takeda: Research Funding. Attar:Aprea Therapeutics: Current Employment. Brunner:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Forty-Seven Inc: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Hobbs:Constellation: Honoraria, Research Funding; Novartis: Honoraria; Incyte: Research Funding; Merck: Research Funding; Bayer: Research Funding; Jazz: Honoraria; Celgene/BMS: Honoraria. Neuberg:Celgene: Research Funding; Madrigak Pharmaceuticals: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding. Fathi:Blueprint: Consultancy; Boston Biomedical: Consultancy; BMS/Celgene: Consultancy, Research Funding; Novartis: Consultancy; Kura Oncology: Consultancy; Trillium: Consultancy; Amgen: Consultancy; Seattle Genetics: Consultancy, Research Funding; Abbvie: Consultancy; Pfizer: Consultancy; Newlink Genetics: Consultancy; Forty Seven: Consultancy; Trovagene: Consultancy; Kite: Consultancy; Daiichi Sankyo: Consultancy; Astellas: Consultancy; Amphivena: Consultancy; PTC Therapeutics: Consultancy; Agios: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Jazz: Consultancy. OffLabel Disclosure: Ixazomib is FDA approved for multiple myeloma. We are using it in this trial for acute myeloid leukemia.