Larson, Richard A.

Abstract Dasatinib with corticosteroid yields high complete remission (CR) rates in Ph+ ALL with minimal induction death. Optimal post-remission therapy is not known. We report a prospective study evaluating dasatinib/dexamethasone induction then consolidation with reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT), autologous HCT (autoHCT), or chemotherapy alone (chemo), followed by dasatinib-based maintenance. Methods: We conducted a phase II, 3-arm, non-randomized trial (NCT01256398, Support: U10CA180821, U10CA180882, U10CA180861, U24CA196171) at 17 US centers with primary objectives to determine 3-year overall survival (OS) and disease-free survival (DFS) of adults ≥18 years (yrs) old with untreated Ph+ ALL treated with dasatinib/dexamethasone induction, CNS prophylaxis with systemic and intrathecal methotrexate, consolidation with alloHCT, autoHCT, or chemo, then dasatinib maintenance. Induction (Course I) used dasatinib 140 mg orally daily and dexamethasone 10 mg/m2/day orally or IV days 1-7. If ≤20% lymphoblasts in marrow at Day 15, Course II continued dasatinib with 7 days of dexamethasone. If >20% lymphoblasts, patients (pts) also received vincristine and daunorubicin. Pts not in CR/CRi received a second induction (Course III) with dasatinib, cyclophosphamide, vincristine, daunorubicin, and dexamethasone. CNS prophylaxis (Course IV) used dasatinib, IV vincristine and IV, oral, and intrathecal methotrexate. Course V consisted of HCT or chemo. Pts 18-70 yrs old underwent RIC alloHCT if they had a HLA-matched donor; otherwise they underwent autoHCT. AlloHCT conditioning used fludarabine 30 mg/m2/day IV day -7 through -3, alemtuzumab 20 mg/day IV day -7 through -3, and melphalan 140 mg/m2 IV once on day -2. GVHD prophylaxis with tacrolimus began day -2. Pts undergoing autoHCT received etoposide 10 mg/kg/day (age >65, 5 mg/kg/day) CIV for 4 days and cytarabine 2 g/m2 (age >65, 1 g/m2) IV every 12 hours for 8 doses then G-CSF for mobilization. AutoHCT conditioning was melphalan 100 mg/m2/day IV on days -2 and -1. Pts >70 yrs old or unable to undergo HCT received etoposide/cytarabine alone. Dasatinib maintenance (Course VI) began day 30 of Course V and continued for 12 months and until 2 consecutive negative BCR-ABL1 RT-PCR assays 3 months apart or relapse. BCR-ABL1 isoform and ABL1 kinase domain (KD) mutation determination were done locally. Results: From 12/15/2010 to 11/14/2014, 64 eligible pts enrolled. Median age was 60 yrs (22-87); median WBC 23.2 x 103/μl (0.3-454). The dominant BCR-ABL1 isoform was p190 in 59%, p210 in 17%, and not reported in 23%. The CR rate was 97% with no induction deaths. Fifty-five pts completed CNS prophylaxis (Course IV). Twenty pts underwent protocol-specified alloHCT, 7 autoHCT, and 9 chemo. Nine pts underwent off-study alloHCT and 5 skipped Course V. Dasatinib maintenance was tolerable with 72%, 80%, and 80% receiving >50% of planned maintenance doses in alloHCT, autoHCT, and chemo arms, respectively. With a median follow up of 48 months (37-78) for survivors, 3-yr OS and DFS were 55% (median OS 45 months) and 43% (median DFS 30 months), respectively. For pts undergoing consolidation with protocol-specified alloHCT, autoHCT, or chemo, 3-yr OS was 75%, 71%, and 55% respectively with median OS not reached (NR) for all groups. DFS at 3-yrs was 55%, 43%, and 46% respectively. Median DFS for alloHCT was 42 months vs 15 months for autoHCT and 34 months for chemo (Log-Rank P=0.4). Outcomes were similar with inclusion of off-study alloHCT and chemo patients skipping Course V. Relative to p190 BCR-ABL1 isoform, p210 was associated with shorter median OS (NR vs 16 months, P=0.04) and median DFS (35 months vs 10 months, P<0.0001). Three-year DFS was 9% with p210. Relapse occurred in 23 pts with 5 CNS relapses reported, one isolated. Relapse occurred in 25% of alloHCT, 43% of autoHCT, and 37% of chemo pts. T315I mutation in ABL1 KD was detected in 6 of 8 marrow relapses (75%). One isolated CNS relapse had no ABL1 KD mutations. Conclusions: Dasatinib and dexamethasone followed by alloHCT, autoHCT, or chemo yield similar 3-yr survival comparable to approaches using intensive induction chemotherapy. Pts with the p210 BCR-ABL1 isoform had dismal outcomes and may benefit from alternate approaches. T315I mutation was the major cause of relapse and should be addressed in future studies. Disclosures Wieduwilt: Amgen: Research Funding; Reata Pharmaceuticals: Equity Ownership; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Leadiant: Research Funding; Shire: Research Funding; Merck: Research Funding. Uy:GlycoMimetics: Consultancy; Curis: Consultancy. Powell:Rafael Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Kolitz:Magellan Health: Consultancy, Honoraria. Liedtke:Caelum: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen/Onyx: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; celgene: Research Funding; Genentech/Roche: Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BlueBirdBio: Research Funding. Stock:Jazz Pharmaceuticals: Consultancy. Devine:Kiadis Pharma: Consultancy. Larson:BristolMyers Squibb: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding.

Abstract Background: Overall survival (OS) remains the definitive primary efficacy endpoint to evaluate previously untreated acute myeloid leukemia (AML) therapies, but it requires prolonged follow-up. An earlier endpoint assessed post-treatment would expedite clinical trial conduct and accelerate patient access to effective new therapies. Our objective was to formally evaluate event-free survival (EFS) as a surrogate endpoint for OS in untreated AML. Methods: Individual patient data were analyzed from 2,475 patients (pts) from 4 multicenter, randomized controlled phase III trials of active treatment in previously untreated AML using anthracycline and cytarabine induction chemotherapy as the concurrent control (CALGB 10201, n=506, enrollment period 2003-2006, age 60-88 years (y); CALGB 10603, n=717, enrollment period 2008-2015, age 18-60 y, FLT3-mutated pts only; SWOG 0106, n=595, enrollment period 2004-2009, age 18-60 y; ECOG-ACRIN 1900, n=657, enrollment period 2002-2008, age 17-60 y). Individual patient-level surrogacy examines the association between the individual patients' EFS and OS time after adjusting for treatment effect, and was assessed using the copula bivariate survival model (Kendall's tau). Trial-level surrogacy measures how precisely the treatment effect on OS can be predicted on the basis of observed treatment effect on EFS, and was evaluated using both linear regression (R2WLS) weighted by trial size and Copula bivariate (R2Copula) models. Pre-specified criteria for surrogacy required either R2WLS or R2Copula ≥0.80, neither below 0.7, with either lower bound 95% Confidence Interval (CI) >0.60. Sensitivity analyses were conducted using different EFS definitions (Table 1). Results: With a median follow-up of 50.2 months for the 896 patients still alive, the median OS and EFS across all four trials were 20.9 months (95% CI: 19.0-22.7) and 5.6 months (95% CI: 4.5-6.4), respectively. Trial-level surrogacy for EFS was strong (R2WLS=0.79; R2Copula=0.89), indicating a high correlation of treatment effect between EFS and OS. At the individual patient-level, however, EFS showed weak association with OS (tau= 0.52), compared to the strength of trial-level surrogacy. The discrepancy between patient-level EFS and OS was greatest among patients who did not achieve a CR, followed by those who achieved a CR but relapsed (Figure 1). Sensitivity analysis on alternative EFS definitions showed that the trial-level surrogacy was similar, but individual patient-level surrogacy varied across different EFS definitions (Table 1). This is consistent with what we previously reported (ASH 2016): EFS estimates differed considerably based on the definition of induction failure (IF) in a single arm setting, but this had minimal impact on the estimation of the treatment effect using EFS in randomized trials. In addition, when considering only relapse and death as events (definition 4), both individual patient- and trial-level correlations were high. Conclusions: Correlation between EFS and OS was impacted by patients not achieving CR during induction. Despite the lack of patient-level correlation, a strong correlation between hazard ratios for treatment effects was observed between EFS and OS on the trial level. Hence, it remains debatable whether EFS represents a clinical benefit in itself for patient with untreated AML considering the strong correlation in treatment effects. Further validation is needed due to the small number of trials included and the heterogeneity across trials. Acknowledgment: We gratefully acknowledge the important contributions of the late Dr. Stephen H. Petersdorf, SWOG S0106 Study Chair. Support: U10CA180821, U10CA180882, U10CA180794, U10CA180820, U10CA180888; Clinicaltrials.gov Identifiers: NCT00085124 (10201), NCT00651261 (10603), NCT01253070 (11001), NCT00085709 (SWOG S0106), and NCT00049517 (ECOG-ACRIN E1900) Disclosures Uy: Curis: Consultancy; GlycoMimetics: Consultancy. Larson:Pfizer: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding.

Abstract Abstract 924 Background: Therapy-related myeloid neoplasia (t-MN), including myelodysplastic syndrome and acute myeloid leukemia, has been reported at a higher frequency with chlorambucil + fludarabine as compared to fludarabine alone, but has not been rigorously studied in the context of cyclophosphamide as an alkylator agent. The intergroup prospective randomized Phase 3 trial, E2997, compared FC with F alone as initial therapy for patients (pt) with chronic lymphocytic leukemia (CLL). FC therapy led to higher complete and overall response rates and longer progression-free survival at the initial analysis (Flinn et al JCO 2007). One rationale for combining F with C is that F can inhibit repair of DNA damage induced by C. FC did cause more myelosuppression that could lead to more long-term effects on myeloid hematopoietic function, including t-MN. Methods: E2997 enrolled 278 pts, 141 on FC and 137 on F. These cases were assessed for t-MN by required reporting of these events. Baseline genetic and molecular features of CLL were available through a companion lab correlative trial for 235 pts, 122 on FC and 113 on F. Results: With median follow-up of 6.4 yrs, there have been 13 (4.7%) reported cases of t-MN, 9 after FC and 4 after F. By cumulative incidence methodology, adjusting for the competing risk of death, the rates of t-MN at 7 yr are 8.2% after FC and 4.6% after F (p=0.18 by the Gray test). Median age at study entry of the t-MN pts was 60 (range 45–80) yrs vs 61 (range 33–86) yrs among those not reported to have t-MN. Median time from initial therapy to diagnosis of t-MN was 5 (range 0.7–8) yrs and did not differ between FC and F. Ten of 13 affected pts received 6 chemotherapy cycles. Additional therapy prior to occurrence of t-MN was given to only 2 of 9 FC pts, in contrast to 3 of 4 F pts. Thus, t-MN occurred in only 1 pt treated with F and no further therapy vs 7 who received FC and no further therapy. Ten of 12 pts with available cytogenetics at diagnosis of t-MN had an abnormality of chromosome 5 and/or 7, common to alkylating agent-induced t-MN, usually (n=8) with complex karyotype. Of the 9 pts with t-MN after FC, all 7 with available CLL data had lower risk IgVH mutated disease, in contrast to 1 of 4 with t-MN after F and 44% in the entire cohort. Conclusion: Our analysis suggests that a higher incidence of t-MN has occurred after FC than after F. t-MN after FC occurred most often without additional therapy and in IgVH mutated CLL which is associated with more favorable outcome. The increased incidence of t-MN after FC in this study, usually in the absence of additional treatment, suggests that FC is more leukemogenic than F. This finding emphasizes a need for longer follow-up of toxicity and survival before concluding that FC is preferable to F as the chemotherapy backbone for initial therapy of both low and high risk CLL. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Potent inhibitors of BCR-ABL1have improved remission results and altered post-remission therapy for Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Dasatinib plus dexamethasone followed by hematopoietic cell transplantation (HCT) promises high response rates, reduced toxicity, and durable remissions. Methods: We conducted a Phase II trial at 17 U.S. centers with the primary objective being to estimate the 3-year overall survival and disease-free survival of patients with Ph+ ALL treated with dasatinib and dexamethasone for remission induction and intensification, central nervous system (CNS) prophylaxis, consolidation with reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or etoposide and cytarabine, and dasatinib-based maintenance. Eligible patients had untreated Ph+ ALL, were ≥18 years old, and had normal cardiac function. Induction (Course I) used dasatinib 140 mg oral daily and dexamethasone 10 mg/m2/day oral or intravenous (IV) days 1-7. For patients with ≤20% blasts in the Course I, Day 15 bone marrow biopsy, intensification (course II) continued daily dasatinib with another 7 days of dexamethasone. Those with >20% lymphoblasts also received vincristine (VCR) and daunorubicin (DNR). Patients (n=3) not in CR/CRi after Course II received a second induction (Course III) with dasatinib, cyclophosphamide, VCR, DNR, and dexamethasone. After Course II or III, CNS prophylaxis (Course IV) consisted of IV VCR and IV, oral, and intrathecal methotrexate (MTX). Dasatinib was restarted at serum [MTX] <0.05 microM. Course V consisted of HCT or chemotherapy. Patients aged 18-70 years with an HLA-matched donor underwent RIC allogeneic HCT; otherwise they underwent autologous HCT. Allogeneic HCT conditioning used fludarabine 30 mg/m2/day IV day -7 through -3, alemtuzumab 20 mg/day IV day -7 through -3, and melphalan 140 mg/m2 once on day -2. GVHD prophylaxis with tacrolimus began day -2. Patients undergoing autologous HCT received etoposide 10 mg/kg/day (age >65 years, 5 mg/kg/day) continuous IV for 4 days and cytarabine 2 g/m2 (age >65 years, 1 g/m2) IV every 12 hours for 8 doses (EA) then G-CSF for mobilization. Autologous HCT conditioning used melphalan 100 mg/m2/day on days -2 and -1. Patients >70 years or unable to undergo HCT received EA alone. Dasatinib maintenance (Course VI) began on day 30 of Course V and continued for 12 months and until 2 consecutively negative bone marrow BCR-ABL1RT-PCR assays 3 months apart or until relapse. Dasatinib levels were measured on day 15 of induction. Results: Sixty-six patients enrolled from 12/15/2010 to 11/14/2014; 65 received dasatinib and are evaluable. Median age was 60 years (22-87); 49% were male. Median presenting WBC count was 23.1 x 103/ul (0.3-453.6). No deaths occurred during induction or intensification. CR or CRi occurred 31 patients (48%) by Day 15 of induction and in 62 patients overall (95%; CR 86%). Median dasatinib levels in serum and CSF on Day 15 of induction were 30.3 ng/mL (<3-308) and 0.29 ng/mL (<0.2-1.37), respectively suggesting approximately 1% of plasma dasatinib penetrates into the CSF, less than the unbound fraction (6%). Fifty-four patients started Course IV, 38 Course V, and 37 Course VI. Fourteen patients continue on protocol therapy. Of 38 patients receiving Course V, 22 had allogeneic HCT, 6 had autologous HCT, and 10 had EA chemotherapy. Median age of allogeneic HCT recipients was 61 years (31-69). Robust autologous stem cell mobilization was observed [median CD34+ cell count, 90 x 106/kg (31-166, n=6)]. Dasatinib maintenance was feasible after allogeneic HCT, autologous HCT, and chemotherapy alone with no missed doses in 59%, 83%, and 63% of cycles, respectively. Ten patients have relapsed with one isolated CNS relapse. No relapses have occurred after allogeneic HCT with 3 relapses after autologous HCT and one after Course V EA alone. Median follow up for survivors is 22.8 months (longest, 51 months). There have been 23 deaths: 5 treatment-related (4 after allogeneic HCT, 1 after course V EA), 16 disease-related and 2 unrelated. Conclusions: Dasatinib with dexamethasone yields CR rates comparable to those reported with tyrosine kinase inhibitors combined with conventional chemotherapy. Post-remission therapy with reduced-intensity allogeneic HCT, autologous HCT, or chemotherapy followed by dasatinib maintenance is feasible. Survival follow up is maturing. Disclosures Stock: Sigma-Tau: Honoraria, Research Funding; Royalties for a chapter in Up to Date: Patents & Royalties; ADC Therapeutics: Honoraria; Amgen: Honoraria; Gilead Sciences: Honoraria. Beumer:Bristol-Myers Squibb: Research Funding. Stone:Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Juno Therapeutics: Consultancy; Karyopharm: Consultancy; Sunesis Pharmaceuticals: Consultancy; Agios: Consultancy; Amgen: Consultancy; Celator: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Jansen: Consultancy; Merck: Consultancy; ONO: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Xenetic Biosciences: Consultancy. Larson:Bristol-Myers Squibb: Consultancy; Astellas: Consultancy, Research Funding.

Abstract Background: Midostaurin (M) is a multi-targeted small molecule FLT3 inhibitor which has single agent activity in both internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutant FLT3 AML. The objective of this global rand phase III trial was to determine if the addition of M to ind and consol therapy followed by one year of maint would improve overall survival (OS) compared to standard chemotherapy in younger adults with activating FLT3 muts. Methods: Between May 2008 and October 2011, 3279 previously untreated AML pts age 18-60 (exclusive of acute promyelocytic leukemia) in 225 sites/17 countries were screened for FLT3 muts at one of 7 academic labs (subject to extensive assay cross-validation). Hydroxyurea was allowed for up to 5 d prior to beginning ind therapy while awaiting results of mut testing. Pts were rand for the duration of therapy to M or P stratified by FLT3 mut subtype (TKD v ITD high allelic mut fraction (>0.7) vs low mut fraction (0.05-0.7). Ind therapy consisted of D 60 mg/m2 IV d1-3 and C 200 mg/m2 d1-7 CIV plus M or P (50 mg po bid, d 8-22). Re-treatment with a second blinded course was allowed if residual AML was noted on a d 21 marrow exam. Pts achieving complete remission (CR) received 4 cycles of C 3g/m2 over 3h q 12h on days 1, 3, and 5 plus M or P (50 mg po bid, d 8-22) followed by a year of maint therapy with M or P (50 mg po bid). Transplantation (SCT) was allowed. With a sample size of 717 pts, the trial was powered to detect an improvement from 16.3 (P) to 20.9 (M) months in median OS (HR = 0.78) using a one-sided alpha of 0.025 and power of 84%. The final analysis was to occur after 509 deaths, but given the slow rate of events (359 deaths by April 2015), the trial was amended to change the timing of the OS analysis, and promote event free survival (EFS, defined as the earliest of death, relapse, or no CR within 61 d of the start of ind) as a key secondary endpoint. The critical value for this primary analysis is set at 0.02286 (1-sided) accounting for the alpha spent at the interim analysis (0.5%). Support: U10CA180821, U10CA180882, CA31946, Novartis Results: 717 pts (341 FLT3 ITD-Low, 214 FLT3 ITD-High; 162 FLT3 TKD) were rand to either M (n=360) or P (n=357). There were no significant differences between the arms in age (median, 48y), race, FLT3 subtype, or baseline CBC except for gender (M, 48.2% male; P, 40.6% male; p=.04). All pts are off active treatment, with a median follow-up of 57 months for surviving pts. No statistically significant differences were observed in the overall rate of grade 3 or higher hematologic or non-hematologic adverse events (AEs) between M and P (regardless of attribution). A total of 37 grade 5 AEs were reported (M, 5.3%; P, 5.0%; p=1.0). No differences in treatment-related grade 5 AEs were observed (M, 3.1%; P, 2.5%; p=0.82). CR rate is 59% (M) and 54% (P) (p=0.18). The HRs comparing M to P for OS is 0.77 (one-sided p = 0.007; Figure 1), and for EFS is 0.80 (one-sided p = 0.004; Figure 2). 402/717 (57%) pts received an allogeneic SCT (M, 58%; P, 54%) at any time; 177/717 (25%) in CR1 (M, 27%; P, 22%). Median time to allogeneic SCT was similar on each arm (M, 5.0 months; P, 4.6; p=0.23). Secondary analyses for OS and EFS censoring at the time of SCT provided similar results (Table). The benefit of M was consistent across all FLT3 subgroups for both EFS and OS (Figure 3). Conclusions: The C10603 trial demonstrated that a prospective trial in a pre-therapy genetically defined subgroup of AML pts was feasible and that the addition of the multi-kinase inhibitor M to standard chemotherapy and for one year of maint therapy significantly improved EFS and OS (in both uncensored and censored for transplant analyses) in pts whose blasts had a TKD or ITD (low or high FLT3 mut burden). These findings may lead to improved outcomes through the use of M as a component of therapy in younger adults with mutant FLT3 AML. Table.ArmMedian, mos (95% CI)p-value 15-year Event rate% (95% CI)HR2(95% CI)OSM74.7 (31.5, * )0.00750.8 (45.4-55.9)0.77 (0.63, 0.95)P26.0 (18.5, 46.5)43.1 (37.6-48.4)OS, SCT censoredM* (*,*)0.04762.6 (54.6-69.7)0.77 (0.56,1.05)P* (36.9, *)54.9 (46.2-62.8)EFSM8.0 (5.3, 10.6)0.004426.7 (22.2-31.5)0.80 (0.67, 0.95)P3.0 (1.9, 5.8)19.1 (15.1-23.6)EFS, SCT censoredM8.2 (5.5, 10.7)0.02524.2 (18.9-29.8)0.84 (0.70, 1.0020)P3.0 (1.9, 5.8)21.8 (16.8-27.3)1Stratified on FLT3 subtype; one-sided, log-rank p-value.2Cox model stratified on FLT3 subtype.*= not attained Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Stone: Celgene: Consultancy; Sunesis: Consultancy, Other: DSMB for clinical trial; Novartis: Research Funding; Amgen: Consultancy; Agios: Consultancy; Roche/Genetech: Consultancy; Merck: Consultancy; Pfizer: Consultancy; AROG: Consultancy; Celator: Consultancy; Juno: Consultancy; Abbvie: Consultancy; Karyopharm: Consultancy. Off Label Use: midostaurin- FLT 3 inhibitor. Thiede:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AgenDix GmBH: Equity Ownership. Niederwieser:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Medeiros:Celgene: Honoraria, Research Funding; Agios Pharmaceuticals: Honoraria. Schlenk:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Research Funding; Arog: Honoraria, Research Funding; Teva: Honoraria, Research Funding; Boehringer-Ingelheim: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Research Funding. Larson:Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Ariad: Consultancy, Research Funding; Pfizer: Consultancy.

Abstract Abstract 230 The prognosis for patients (pts) with acute myeloid leukemia (AML) who are aged 60 years or older at the time of initial diagnosis is poor. Even for pts achieving a first complete remission (CR1), prospects for long-term survival are poor due to the very high risk of relapse. Conventional myeloablative conditioning followed by allogeneic blood or marrow transplantation is associated with significantly less relapse compared with conventional chemotherapy when performed in younger pts with AML in CR1. However, the toxicity of this approach in older pts is prohibitive. A reduced intensity conditioning (RIC) regimen may mitigate the risk of early toxicity and while early results in older AML pts have been encouraging and suggest disease free survival (DFS) rates above 30% at 3 yrs (Farag et al, Biol Blood Marrow Transplant 2011), most data are retrospective and pts have not been treated uniformly. We therefore sought to determine the effectiveness of a uniform RIC regimen given to older pts with AML in CR1 on a prospective multi-center phase II trial conducted by the Alliance (formerly Cancer and Leukemia Group B (CALGB)) and the Blood and Marrow Transplant Clinical Trials Network (BMT CTN). The study, activated in 2004, was initially limited to recipients of a matched related donor (MRD) graft but was amended in 2006 to include matched unrelated donor grafts (URD). The primary endpoint of the study was 2-year DFS. We hypothesized that DFS at 2-years would exceed 20% and powered the study to detect a 2-year DFS probability of 35% for URD recipients. We focused the primary analysis on URD recipients since the majority of older pts require an URD graft. Eligible pts were from 60–74 years old inclusive, had AML in CR1 following induction chemotherapy, availability of a 6/6 MRD or 8/8 URD, and absence of significant end-organ damage prior to transplantation. Adverse events (AE) were initially recorded according to NCI-CTCAE v3.0, amended to v4.0 in 10/2010. Accrual was completed in 12/2011. 132 pts were registered at 21 centers and 123 transplanted (MRD (47%); URD (53%). All donor grafts were mobilized and collected following G-CSF (PBSC). The median age of pts was 65 (range 60–74) and 76 pts (62%) were male. At diagnosis, 67% had an intermediate risk karyotype, 20% adverse risk, <1% favorable, and in 11% data were missing. More than 90% achieved CR following standard “7+3” based induction. CR1 was achieved after 1 (59%) or 2 (41%) induction cycles. Consolidation therapy was administered for one (50%) or two (24%) cycles and 17% received no consolidation with data missing in 9%. All but the initial 8 MRD recipients (who received fludarabine and busulfan alone) were conditioned with the same regimen containing fludarabine (30mg/m2/day × 5), busulfan (6.4mg/kg IV total dose), and antithymocyte globulin (ATG; thymoglobulin) (7.5mg/kg total dose). Only one case of primary graft failure was reported. With a median follow-up of 3.3 yrs, the results in the 123 transplanted pts are depicted below: Event Cumulative incidence at 100 days* or 2yrs† 95% CI Acute GVHD 2-4 9.4%* 4.1–15% Acute GVHD 3-4 3.4%* 1.2–6.7% Chronic GVHD 26%† 17–34% Relapse 47%† 37–57% Treatment related mortality (TRM) 14%† 7.2–21% Event Probability at 2 yrs 95% CI DFS 39% 30–50% DFS URD only 38% 26–55% Overall survival (all pts) 46% 36–57% The rates of both acute and chronic GVHD as well as TRM were relatively low. There were 81 grade 3–5 non-hematologic AE recorded, including 7 grade 5 (4 infections, 1 each cardiac, pulmonary, and second malignancy). Relapse was the most common cause of death. In conclusion, the results of this first prospective US cooperative group trial conducted in a homogeneously treated group of older AML patients in CR1 demonstrate the feasibility and effectiveness of RIC allografting using MRD or URD PBSC grafts. DFS appears better following a RIC allograft compared to results achieved historically after conventional therapies, warranting prospective comparison in pts with contemporary cytogenetic and molecular disease characterization. Future research should also focus on preventing disease relapse after RIC allografting in this population. Disclosures: Devine: Sanofi: Honoraria, Research Funding. Off Label Use: Antithymocyte globulin for GVHD prophylaxis is included in the abstract. Vij:Millennium: Speakers Bureau. Shea:Otsuka: Research Funding.

Abstract Background SGI-110 is a second generation HMA formulated as a dinucleotide of decitabine (DAC) and deoxyguanosine. The compound is delivered as a small volume, pharmaceutically stable subcutaneous (SQ) injection which allows longer half-life and more extended DAC exposure than DAC intravenous infusion. This pharmacokinetic profile offers the potential for improved biological and clinical activity and safety over currently available HMAs (Kantarjian et al. ASH, 2012). Methods A randomized Phase 1-2 first-in-human PK/PD-guided, dose-escalation study was conducted in patients with relapsed or refractory intermediate or high-risk MDS or AML. Patients were initially randomized to one of two SQ regimens - Dailyx5 or Weeklyx3, for 28-day courses. Subsequently, a Twice Weeklyx3 regimen (Monday, Thursday) was added for evaluation based on emerging LINE-1 demethylation data from the Weeklyx3 regimen. Results 93 patients (74 AML, 19 MDS) were treated in the dose escalation phase: 44, 34, and 15 patients were treated in the Dailyx5, Weeklyx3, and the Twice Weeklyx3 regimens, respectively. Across the three regimens, median age was 70 years (range, 29–86), 68% male, and 87% had ECOG PS of 0-1. The median number of prior regimens was 3 (range, 1–9) and 68% of patients had prior HMA treatment (59% AML, and 100% MDS). Of the 74 AML patients treated, 31 (42%) had secondary AML including antecedent MDS. Patients received a median of 2 courses of SGI-110 (range, 1-20). LINE-1 demethylation data at the 2 highest dose levels which were well tolerated and evaluated for all 3 regimens (60 and 90 mg/m2) are shown in the figure below. The Dailyx5 regimen demonstrated the most potent average LINE-1 demethylation, while the Twice Weeklyx3 achieved the most prolonged LINE-1 demethylation. The least potent demethylation was seen with the Weeklyx3 regimen. There was no additional demethylation at the 90 mg/m2 dose compared to 60 mg/m2in all 3 regimens. Responses were reported according to the IWG Criteria 2006 (MDS)/2003 (AML). Complete remissions were observed in 5 AML patients (2CRs, 1CRp, and 2CRi). Clinical responses (2 mCR and 3 HI-E, 1 HI-N, 1 HI-P) were observed in 6 MDS patients, all of whom had been previously treated with HMA. All AML responses and both mCR in MDS patients achieved ≥10% LINE-1 demethylation. Safety is reported based on Adverse Events (AEs) as graded by the CTCAE v4 criteria. Across regimens, the Twice Weeklyx3 demonstrated an increased number of related AEs compared to the other regimens. The most commonly reported related AEs ≥ 10% in the Dailyx5 regimen (injection site pain, thrombocytopenia, neutropenia, anemia, fatigue), Weeklyx3 regimen (injection site pain and diarrhea), and Twice Weeklyx3 regimen (injection site pain, injection site reaction, fatigue, dizziness, febrile neutropenia, neutropenia, anemia, and thrombocytopenia). Conclusions SQ SGI-110 is a potent HMA using all 3 regimens evaluated. The most potent hypomethylation was achieved with Dailyx5 dosing and the most prolonged hypomethylation was achieved using the Twice Weeklyx3 regimen. All 3 regimens were well tolerated. Clinical responses were observed in heavily pretreated patients, including those with prior HMA exposure. These results support the ongoing Phase 2 expansion study investigating the Dailyx5 dosing schedule in patients with MDS and AML who are either HMA treatment naïve or previously treated with HMAs. Disclosures: Roboz: Astex Pharmaceuticals, Inc.: Honoraria, Research Funding. Issa:Astex Pharmaceuticals Inc.: Honoraria, Research Funding. Rizzieri:Astex Pharmaceuticals, Inc.: Research Funding. Stock:Astex Pharmaceuticals, Inc.: Research Funding. O'Connell:Astex Pharmaceuticals, Inc.: Research Funding. Yee:Astex Pharmaceuticals, Inc.: Research Funding. Tibes:Astex Pharmaceuticals, Inc.: Research Funding. Griffiths:Astex Pharmaceuticals, Inc.: Research Funding. Walsh:Astex Pharmaceuticals, Inc.: Research Funding. Feldman:Astex Pharmaceuticals, Inc.: Research Funding. Ritchie:Astex Pharmaceuticals, Inc.: Research Funding. Rao:Astex Pharmaceuticals, Inc.: Research Funding. Larson:Astex Pharmaceuticals, Inc.: Research Funding. Garcia-Manero:Astex Pharmaceuticals, Inc.: Research Funding. Ravandi:Astex Pharmaceuticals, Inc.: Research Funding. Jabbour:Astex Pharmaceuticals, Inc.: Research Funding. Cortes:Astex Pharmaceuticals, Inc.: Research Funding. Schimmer:Astex Pharmaceuticals, Inc.: Research Funding. Mesa:Astex Pharmaceuticals, Inc.: Research Funding. Blum:Astex Pharmaceuticals, Inc.: Research Funding. Chung:Astex Pharmaceuticals Inc.: Research Funding. Naim:Astex Pharmaceuticals, Inc.: Employment. Taverna:Astex Pharmaceuticals Inc.: Employment. Hao:Astex Pharmaceuticals Inc.: Employment. Choy:Astex Pharmaceuticals, Inc.: Employment. Azab:Astex Pharmaceuticals Inc.: Employment. Kantarjian:Astex Pharmaceuticals, Inc.: Research Funding.

Abstract The ECOG-ACRIN Cancer Research Group Led Trial, E2902, was a randomized phase III North American Leukemia Intergroup trial of the Farnesyl Transferase Inhibitor , R115777(Tipifarnib), as maintenance therapy for acute myeloid leukemia (AML). Patients (pts) with AML in remission after requiring salvage therapy (primary induction failure or second or subsequent remission) or over the age of 60 in first remission were eligible. Pts were eligible if they were in a complete remission (CR) or complete remission without platelet recovery (CRp) as confirmed by bone marrow examination within 2 weeks prior to randomization. Consolidation or post remission therapy prior to enrollment was allowed but not required. Pts who had received an allogeneic transplant in this remission were ineligible. Adequate blood counts (absolute neutrophil count >= 1000/mm3 and platelet count >=50,000/mm3), and normal renal, and hepatic function were required within 2 weeks of randomization. Pts were randomized to either receive tipifarnib twice daily (BID) or to observation. Pts were stratified by remission ( CR1 vs > CR1) and whether or not they received consolidation therapy in the current remission. The main objective of this study was to compare disease free survival(DFS) in the two groups. Between August 2004 and December 2009, 144 pts were accrued to the study. The median age of the pts was 69 (range 28-86). Seventy-three pts (51%) were male and 135 pts (94%) were white. The majority of pts enrolled on the study (70%) were in first CR, and had post remission chemotherapy (56%) prior to randomization. Seventy-three pts were enrolled onto the treatment arm (Arm A) and 71 pts were enrolled onto the observation arm (Arm B). When the study was initially opened, pts on Arm A were treated with tipifarnib at a dose of 400 mg BID with dose reductions and interruptions defined per protocol for toxicity. After the first planned interim analysis, based on toxicity data, the ECOG Data Monitoring Committee recommended that the starting dose be decreased to 300 mg BID. While non-hematologic toxicity was acceptable, significant hematologic toxicity was seen in pts treated at an initial dose of either 400 mg or 300 mg BID. Of note, hematologic toxicity was also seen on the observation arm although less frequently than with both treatment doses. The primary endpoint of the study was analysis of DFS on an intent to treat basis. The median DFS for arms A and B are 8.87 months and 5.26 months respectively ( p=0.058, HR 0.760). When restricted to eligible patients only(n=134 ), the DFS for arms A and B are 10.81 vs 5.26 months, respectively ( p=0.019, HR 0.690). An unplanned subgroup analysis was performed by gender. The median DFS for male pts (n=73) is 5.36 vs 5.91 months for arms A and B respectively (p=0.868, HR 1.320) and 12.09 vs 3.91 months for female pts (n=71)(p=0.0002, HR=0.408) In a multivariate Cox proportional hazards model to adjust for baseline clinical variables, there is a significant interaction between treatment and gender. (Table 1) Similar results were noted for OS (Figure 1). ECOG ACRIN Trial E2902 evaluated the potential role of Tipifarnib ( R115777) in patients with AML in remission with a high risk of relapse. While the primary endpoint for improved DFS was not reached when evaluating all randomized pts, when restricted to eligible patients only, there is a statistically significant improvement in DFS seen. Moreover, an unplanned subgroup analysis by gender demonstrates an improvement in DFS and OS for females who were enrolled on the study which persists on multivariate analysis. Possible explanations include the use of flat dosing rather than BSA based dosing on this study. However futher evaluation of patient and disease characteristics, dosing and toxicity profiles of responders and nonresponders is needed. Given what appears to be a potentially clinically relevant benefit, further evaluation of this agent is warranted. Table 1. Multivariate Cox Proportional Hazards Model for DFS: All Randomized Patients Hazard Ratio (95% CI) P value Arm B vs A 2.559(1.547,4.236) 0.00025 Male vs Female 2.005(1.228,3.274) 0.00544 CR1 vs >CR1 0.447 (0.305,0.656) 0.00004 Figure 1. (A) DFS (B) OS in Female Patients Figure 1. (A) DFS (B) OS in Female Patients Disclosures Rowe: BioSight Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; BioLineRx Ltd.: Consultancy. Larson:Astellas: Consultancy, Research Funding.

Abstract Background Acute promyelocytic leukemia (APL) is commonly complicated by complex coagulopathy. The early use of all-trans retinoic acid (ATRA) appears to have reduced induction mortality; however, with modern regimens the risk of early hemorrhagic death remains at about 5-10% in clinical trials and up to 30% in population-based studies. Previously identified as markers of bleeding risk in this setting are: white blood cell count (WBC), peripheral blood blast count, platelet count, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT) and creatinine. Nonetheless, uncertainty remains as to which ones are independent predictors. Materials and Methods The database for study was from APL patients enrolled on three large clinical trials that used ATRA for induction: APML3 (single arm of ATRA + idarubicin ± prednisone), APML4 (single arm of ATRA + idarubicin + arsenic trioxide + prednisone) and ECOG 2491 (intergroup I0129, consisting of daunorubicin + cytarabine vs ATRA). Known determinants of bleeding were assessed at baseline and considered as potential predictors of hemorrhagic death in the first 30 days of induction. In univariate analysis, using Wilcoxon Rank Sum and Fisher’s exact test, we looked at the association of the parameters mentioned above with hemorrhagic death within 30 days of induction. Results A total of 619 patients were enrolled: ECOG 2491 (intergroup I0129) - 394, APML3 - 101, and APML4 -124. Among these, thirty (4.8%) deaths from bleeding during the first 30 days (early deaths, ED) following induction were recorded. Baseline characteristics of the patients are shown in Table 1 and Table 2. Initial coagulation parameters (PT, aPTT and fibrinogen) were not available for the ECOG trial. Parameters with significant differences between the ED cases and the remaining of the cohort included WBC (median: 7.4 vs 2.4 /Kmcl respectively, p<0.001), peripheral blood blast count (median: 1.0 vs 0.2 /Kmcl respectively, p=0.049) and platelet count (median: 20 vs 33 /Kmcl respectively, p=0.002). Conclusions In this large cohort of approximately 600 APL patients enrolled on 3 large clinical trials, higher WBC, peripheral blast count and lower platelet count emerged as univariate predictors of early hemorrhagic death. Surprisingly, age, PT, aPTT, fibrinogen and creatinine clearance did not differ between the patients who died from bleeding and the remaining of the cohort. Multivariate analysis will clarify the relative strength of the significant predictors in assessing ED, and will be available, along with coagulation parameters for ECOG, at the time of presentation. These data hopefully will allow us to build a clinical prediction rule to identify patients at the highest risk of early hemorrhagic death. Such a stratification tool could prove useful in future trials testing novel approaches to treat the coagulopathy associated with APL. : Abstract 948. Table 1 Baseline Characteristics of Patients, Continuous Variables Variable Total Death from Bleeding within 30 days No Yes N Median (IQR) N Median (IQR) N Median (IQR) p-value Age (years) 619 40.0 (26.0 - 54.0) 589 40.0 (26.0 - 54.0) 30 47.0 (26.0 - 63.0) 0.15 White Blood Cell Count (K/mcL) 611 2.5 (1.2 - 8.2) 582 2.4 (1.1 - 7.6) 29 7.4 (3.1 - 20.7) <0.001 Peripheral blood blast count (K/mcL) 581 0.2 (0.0 - 2.2) 552 0.2 (0.0 - 1.9) 29 1.0 (0.1 - 5.7) 0.049 Hemoglobin (g/dL) 615 9.3 (8.0 - 10.5) 585 9.3 (7.9 - 10.5) 30 9.4 (8.2 - 10.7) 0.75 Platelets (K/mcL) 615 31.0 (17.0 - 56.0) 585 33.0 (17.0 - 57.0) 30 20.0 (13.0 - 34.0) 0.002 Prothrombin time (s) 184 16.0 (13.3 - 18.2) 179 16.0 (13.3 - 18.1) 5 16.7 (16.5 - 144.3) 0.15 Activated partial thromboplastin time (s) 225 29.0 (26.0 - 32.0) 216 29.0 (26.0 - 32.0) 9 31.2 (29.0 - 38.0) 0.07 Fibrinogen (mg/dL) 217 1.8 (1.3 - 2.6) 208 1.8 (1.3 - 2.6) 9 2.3 (2.0 - 2.5) 0.36 Creatinine Clearance (mg/dL)* 225 389 (261.2 - 511.6) 216 392 (264.9 - 512.4) 9 262 (219.2 - 432.0) 0.15 *calculated using the Jelliffe formula : Table 2 Baseline Characteristics of Patients, Categorical Variables. Variable Total Death from Bleeding within 30 days No Yes N % N % N % p-value ECOG Performance Status 579 93.54 552 93.72 27 90.00 0.50 Good(0-2) Poor(3-4) 36 5.82 33 5.60 3 10.00 Missing 4 0.65 4 0.68 0 0 FAB Classification 248 40.06 239 40.58 9 30.00 >0.95 M3 M3v 67 10.82 65 11.04 2 6.67 Missing 304 49.11 285 48.39 19 63.33 Disclosures No relevant conflicts of interest to declare.

Abstract Background: Retrospective analyses have demonstrated significantly improved survival for AYA ALL patients (pts) aged 16-21 years (yrs) when treated on pediatric versus adult U.S. NCI Cooperative group regimens where 2-yr event-free survivals (EFS) have been only 35-40%. The purpose of C10403, a large prospective US intergroup trial, was to evaluate the feasibility and effectiveness [with EFS as a primary endpoint), of treating AYA ALL pts (ages 16-39 yrs) using the standard arm of the successful Children's Oncology Group regimen (COG AALL0232) . Methods: Newly diagnosed AYA patients with B-precursor (B-ALL) or T-precursor (T-ALL) ALL were eligible to enroll on C10403. Burkitt type and Ph+ ALL were excluded. The regimen was identical to the Capizzi methotrexate arm of COG AALL0232 (Larsen E. JCO 2011; 29 suppl:3) and consisted of four intensive courses: remission induction, remission consolidation, interim maintenance, delayed intensification, and prolonged maintenance therapy. Pts with M2 marrow response (>5% but < 25% lymphoblasts) after remission induction received an extended remission induction course of therapy. Events were defined as induction failure (M3 [³25% blasts] day 29 of induction or M2 day 43 of extended induction), death, relapse, or second malignancy. Key correlative science studies in a subset of the total accrued population included assessment of Minimal Residual Disease (MRD) using quantitative real-time PCR of clonal IgH or TCR gene rearrangements as well as Low Density Microarray (LDA) assays designed to detect a previously validated gene expression profile (Harvey, R; ASH 2013, abstract 826) which can prospectively identify ALL pts with Ph-like (BCR-ABL1-like) ALL. Results: 318 pts were enrolled on C10403 from 11/2007 to 8/2012; 22 withdrew prior to therapy. Of 296 evaluable pts, the median age at diagnosis was 24 yrs (range: 17 to 39): 25% were 17-20 yrs, 53% were 21-29 yrs, and 22% were 30-39 yrs. The majority had B-ALL (76%) and were male ( 61%). Approximately 25% were non-Caucasian and 15% were Hispanic or Latino. 32% of pts were obese (BMI³30). There were 5 (2%) treatment-related deaths during protocol therapy: liver failure (n=2, both during induction), infection (1 in induction, 1 in consolidation), and ventricular arrhythmia (1 in induction). Overall, treatment toxicities were similar to those reported in the standard arm of COG AALL0232, with an increased thrombosis and early hyperbilirubinemia for C10403 pts, as reported previously (Advani A, ASH 2013, abstract 303). To date, 70 deaths have been reported and 87 pts remain on protocol therapy. With a median follow-up of 28 months for surviving pts, 105 events have been observed. The median EFS overall is 59.4 months (95% CI: 38.4 to NR) and the 2-yr EFS rate overall is 66% (95% CI: 60 – 72%) [Fig 1a] with similar 2-yr EFS rates for B and T- ALL pts (65%, and 68%). The 2-yr OS rate is 78% (95% CI: 72 – 83%)[Fig 1b], which is similar for B (78%, 95% CI: 72 – 84%) and T-ALL, (80%, 95% CI: 70 – 91%). These results allow rejection of the null hypothesis of this Phase II trial that the true median EFS is, at most, 32 months. In multivariable analysis of presenting clinical features, age > 20 years and initial WBC count ³ 30k/microliter were significantly associated with worse EFS and OS. Presence of MRD at day 28 following initiation of induction therapy and presence of a Ph-like gene expression signature were significantly associated with both worse EFS and OS. Notably, absence of detectable MRD noted in 22/58 [38%] evaluable pts at day 28 of induction was associated with 100% EFS (p=0.0006). The Ph-like like signature was detected in 28% of pts tested on C10403 and the 2 yr EFS for these patients was only 52%, compared to 81% for those without Ph-like disease (p = 0.04). Conclusions: This large prospective US adult intergroup trial (C10403) for pts 16-39 years old employing an intensive pediatric regimen demonstrates a significant improvement (compared to historical controls) in AYA EFS and OS and validates this approach for treatment of AYA with ALL by adult hematologists. The improved clinical outcomes and the predictive value of the correlative studies in this trial lay the foundation for the design of future trials, where incorporation of novel agents to eradicate MRD, and/or use of tyrosine kinase inhibitors to target the frequently detected Ph-like ALL in AYA pts may further improve survival for young adults with ALL. Figure 1a Figure 1a. Figure 1b Figure 1b. Disclosures Stock: Sigma-Tau: Membership on an entity's Board of Directors or advisory committees, Research Funding. Advani:Sigma Tau: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees. Liedtke:Onyx: Membership on an entity's Board of Directors or advisory committees. Larson:Novartis: Consultancy, Research Funding.