Erba, Harry Paul

BACKGROUND: Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR) has been the standard therapy for younger patients with CLL. FCR therapy is particularly effective in patients with immunoglobulin heavy chain variable region (IGHV) mutated CLL. Approximately half of IGHV mutated patients are progression free 8 years after FCR therapy. At the ASH 2018 meeting, we reported the initial results of the ECOG 1912 (E1912) trial, a phase 3 trial comparing the FCR regimen to the combination of ibrutinib and rituximab (IR) for previously untreated CLL patients age 70 or younger who required therapy. With median follow-up of approximately 34 months, the trial demonstrated both a progression-free survival (PFS) and an overall survival (OS) benefit relative to FCR. On sub-set analysis by IGHV mutation status, the difference in PFS was statistically significant for IGHV unmutated patients but, with current follow-up, not IGHV mutated patients. Here, we present updated results for PFS in the E1912 trial. METHODS: As previously reported, eligible patients were treatment-naive individuals with CLL age 70 or younger. Patients with deletion 17p- were excluded from participating in the E1912 trial given their known poor response to FCR therapy. Patients were randomly assigned in a two-to-one ratio to receive ibrutinib (420 mg/day until disease progression or unacceptable toxicity) and rituximab (50 mg/m2 on day 1 of cycle 2, 325 mg/m2 on day 2 of cycle 2, and then 500 mg/m2 on day 1 of cycles 3-7) or six courses of intravenous fludarabine (25 mg/m2 days 1-3), cyclophosphamide (250 mg/m2 days 1-3) and rituximab (50 mg/m2 on day 1 of cycle 1, 325 mg/m2 on day 2 of cycle 1, and then 500 mg/m2 on day 1 of cycles 2-6) every 28-days. Adverse events (AEs) were graded according to the NCI Common Toxicity Criteria (version 4). Dose adjustments for cytopenias were based on the IWCLL CLL Working Group grading scale. The primary endpoint of the trial was PFS with OS a secondary endpoint. Analysis was by intention to treat. RESULTS: With median follow-up of 45 months, 257 (73%) of 354 patients randomized to IR remain on ibrutinib. With extended follow-up, grade 3 and above treatment-related AEs were observed in 70% of IR and 80% of FCR treated patients (OR=0.56; 95% CI 0.34 - 0.90; p=0.013). Among IR-treated patients, the median time on treatment is currently 43 months (range=0.2-61). Among the 95 patients who have discontinued ibrutinib, the reason for discontinuation was progression or death in 23 (7% of patients who started IR; 24% of those who discontinued treatment), AE or complication in 48 (14% of patients who started IR; 51% of those who discontinued treatment), and withdrawal of consent or other reasons in 24 (7% of patients who started IR; 25% of those who discontinued treatment). On multivariable Cox regression adjusting for Timed Up and Go test score, Cumulative Illness Rating Scale (CIRS) score, age, gender, ECOG performance status, creatinine clearance, and baseline anemia/thrombocytopenia, only CIRS score (range 0 - 14) predicted discontinuation of ibrutinib for a reason other than progression or death (HR=1.13 per unit increase; 95% CI 1.03 - 1.23; p=0.009). Among the 72 patients who discontinued ibrutinib for a reason other than progression or death, the median time on ibrutinib was 15.1 months (range 0.2-58.2 months). The median time from ibrutinib discontinuation to disease progression or death was 23 months. With current follow-up, we observed 110 PFS events. The hazard ratio (HR) for PFS favored IR over FCR (HR=0.39; 95% CI 0.26-0.57; p<0.0001). Updated analysis of OS will be presented. On sub-group analysis by IGHV mutation status, IR was superior to FCR for IGHV unmutated patients (HR=0.28; 95% CI 0.17-0.48; p<0.0001). With current follow-up the difference is not significant in IGHV mutated patients (HR=0.42; 95% CI 0.16-1.16; p=0.086). Kaplan-Meier estimates for PFS are shown in Figure 1. CONCLUSIONS: Although less than 7% of ibrutinib treated patients progressed while on therapy, roughly 1 in 5 patients have discontinued ibrutinib for a reason other than progression or death. The only parameter significantly associated with discontinuation for a reason other than progression was increased baseline CIRS score. With extended follow-up, the combination of ibrutinib and rituximab continues to provide superior PFS compared to FCR for younger patients with previously untreated CLL. Disclosures Shanafelt: Pharmacyclics: Research Funding; Patent: Patents & Royalties: US14/292,075 on green tea extract epigallocatechin gallate in combination with chemotherapy for chronic lymphocytic leukemia; Polyphenon E International: Research Funding; Merck: Research Funding; Abbvie: Research Funding; Genentech: Research Funding; Celgene: Research Funding; Glaxo-SmithKline: Research Funding; Hospira: Research Funding; Cephalon: Research Funding. Kay:MorphoSys: Other: Data Safety Monitoring Board; Infinity Pharmaceuticals: Other: DSMB; Celgene: Other: Data Safety Monitoring Board; Agios: Other: DSMB. O'Brien:Janssen: Consultancy, Honoraria; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Astellas: Consultancy; Aptose Biosciences, Inc: Consultancy; Amgen: Consultancy; Alexion: Consultancy; Acerta: Research Funding; Eisai: Consultancy; Gilead: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Verastem: Consultancy; Celgene: Consultancy; Sunesis: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Vaniam Group LLC: Consultancy; Regeneron: Research Funding; Kite: Research Funding. Barrientos:AbbVie: Consultancy, Research Funding; AstraZeneca: Consultancy; Genentech: Consultancy; Bayer: Consultancy; Gilead: Consultancy; Janssen: Honoraria; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Sandoz: Consultancy; Oncternal Therapeutics: Research Funding. Coutre:Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Gilead: Research Funding; BeiGene: Other: Travel, Accommodations, Expenses & Data Safety Monitoring Committee; Genentech: Consultancy. Barr:Pharmacyclics LLC, an AbbVie company: Consultancy, Research Funding; Gilead: Consultancy; Verastem: Consultancy; Genentech: Consultancy; Seattle Genetics: Consultancy; Merck: Consultancy; Celgene: Consultancy; Janssen: Consultancy; AbbVie: Consultancy; Astra Zeneca: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding. Cashen:Celgene: Other: Speaker's Bureau; Seattle Genetics: Other: Speaker's Bureau; Novartis: Other: Speaker's Bureau. Mato:AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Celgene: Consultancy; Johnson & Johnson: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; LOXO: Consultancy, Research Funding; DTRM Biopharma: Research Funding; Genentech: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Gilead: Research Funding; Acerta: Consultancy; Janssen: Consultancy. Erba:Amgen: Consultancy; MacroGenics: Consultancy, Other: Lecture fees, Research Funding; MacroGenics: Consultancy, Other: Lecture fees, Research Funding; Novartis: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; ImmunoGen: Consultancy, Research Funding; Astellas Pharma: Consultancy; Astellas Pharma: Consultancy; Amgen: Consultancy; GlycoMimetics: Consultancy, Other: Chair, data and safety monitoring board, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Celgene: Consultancy, Other: chair, AML Registry Scientific Steering Committee, Speakers Bureau; ImmunoGen: Consultancy, Research Funding; AbbVie: Consultancy, Other: Chair, IRC for phase III studies, Research Funding; GlycoMimetics: Consultancy, Other: Chair, data and safety monitoring board, Research Funding; Covance: Other: Fees for serving as chair on an independent review board for AbbVie Phase III studies; Covance: Other: Fees for serving as chair on an independent review board for AbbVie Phase III studies; AbbVie: Consultancy, Other: Chair, IRC for phase III studies, Research Funding; Celgene: Consultancy, Other: chair, AML Registry Scientific Steering Committee, Speakers Bureau; Pfizer: Consultancy; Pfizer: Consultancy; Seattle Genetics: Consultancy; Seattle Genetics: Consultancy; Daiichi Sankyo: Consultancy, Research Funding. Stone:Arog Pharmaceuticals: Consultancy, Honoraria, Research Funding; Otsuka-Astex Pharmaceuticals: Consultancy; Fujifilm: Consultancy; AstraZeneca: Consultancy; Celator Pharmaceuticals: Consultancy; Abbvie: Consultancy, Research Funding; Ono Pharmaceutical-Theradex Oncology: Consultancy; Cornerstone Pharmaceuticals: Consultancy; Daiichi Sankyo: Consultancy; Takeda: Other: Fees for serving on a data and safety monitoring board ; Orsenix: Consultancy; MacroGenics: Consultancy; Jazz Pharmaceuticals: Consultancy; Agios: Consultancy, Research Funding; Stemline Therapeutics: Consultancy; Pfizer: Consultancy; Celgene: Consultancy, Other: Fees for serving on a steering committee, and fees for serving on a data and safety monitoring board; Novartis: Consultancy, Research Funding; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees; Argenx: Other: Fees for serving on a data and safety monitoring board ; Roche: Consultancy. Tallman:Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees.

PURPOSE: Patients with acute myeloid leukemia with high-risk cytogenetics in first complete remission (CR1) achieve better outcomes if they undergo allogeneic hematopoietic cell transplantation (HCT) compared with consolidation chemotherapy alone. However, only approximately 40% of such patients typically proceed to HCT. METHODS: We used a prospective organized approach to rapidly identify donors to improve the allogeneic HCT rate in adults with high-risk acute myeloid leukemia in CR1. Newly diagnosed patients had cytogenetics obtained at enrollment, and those with high-risk cytogenetics underwent expedited HLA typing and were encouraged to be referred for consultation with a transplantation team with the goal of conducting an allogeneic HCT in CR1. RESULTS: Of 738 eligible patients (median age, 49 years; range, 18-60 years of age), 159 (22%) had high-risk cytogenetics and 107 of these patients (67%) achieved CR1. Seventy (65%) of the high-risk patients underwent transplantation in CR1 ( P < .001 compared with the historical rate of 40%). Median time to HCT from CR1 was 77 days (range, 20-356 days). In landmark analysis, overall survival (OS) among patients who underwent transplantation was significantly better compared with that of patients who did not undergo transplantation (2-year OS, 48% v 35%, respectively [ P = .031]). Median relapse-free survival after transplantation in the high-risk cohort who underwent transplantation in CR1 (n = 70) was 11.5 months (range, 4-47 months), and median OS after transplantation was 14 months (range, 4-44 months). CONCLUSION: Early cytogenetic testing with an organized effort to identify a suitable allogeneic HCT donor led to a CR1 transplantation rate of 65% in the high-risk group, which, in turn, led to an improvement in OS when compared with the OS of patients who did not undergo transplantation.

Abstract Background: Adult acute myeloid leukemia (AML) patients with high-risk cytogenetics have a significantly worse survival compared to similarly treated intermediate- or favorable-risk patients. Although prior studies suggest better outcome in high-risk AML patients in first complete remission (CR1) who undergo allogeneic hematopoietic cell transplantation (HCT) compared with consolidation chemotherapy, only 40% of patients proceed to HCT. The lack of a matched sibling donor (available in about 33%) should not be a barrier to HCT since alternative donors are available for the large majority of high-risk AMLpatients and recent data suggest outcomes after allogeneic HCT from fully matched unrelated donors are similar to those following matched related donor transplantation. We sought to determine if a prospective organized effort could rapidly identify alternative donors to improve the historical 40% allogeneic HCT rate in high-risk CR1 AML patients ≤ age 61. Secondly, we hypothesized that transplanting significantly more adults with high-risk AML in CR1 would lead to an improved outcome compared with the historical relapse-free survival (RFS) of 22%. Patients and Methods: Adult patients between ages 18 and 60 years with untreated AML were randomized to receive induction therapy with standard cytarabine plus daunorubicin (7+3; n=261), idarubicin with high-dose cytarabine (IA; n=261), or IA with vorinostat (IA+V; n=216). Conventional cytogenetics were obtained at time of enrollment and used to determine risk classification by standard criteria. All patients with high-risk cytogenetics underwent expedited HLA-typing. High-risk patientswere encouraged tobe referred for consultation with a transplant team with the goal of conducting an allogeneic HCT in CR1. Results: Of 738 eligible patients (median age, 49 years; range, 18-60), 159 (22%) had high-risk cytogenetics, of whom 60 (38%), 61 (38%), and 38 (24%) received induction with 7+3, IA, or IA+V, respectively. A total of 107 of the 159 high-risk patients achieved CR/CRi (67%). HCT was performed in 317 of all 738 patients (43%) and 68 (64%) of the high-risk patients received a transplant in CR1 (p<0.001 compared to historical rate of 40%). Twenty-five (37%) had a matched related donor, 31 (45%) had a matched unrelated donor, 3 (4%) had a mismatched related donor, 8 (12%) had a mismatched unrelated donor, and 1 (1%) received an umbilical cord blood transplant. Sixty-six high-risk patients transplanted in CR/CRi have detailed data. Median time to HCT from CR1 was 76 days (range, 20-365). Fifty-seven patients (86%) received a myeloablative regimen and 9 (14%) reduced-intensity conditioning. Reasons for 39 high-risk CR1 patients not receiving a transplant in CR1 were: co-morbidities (n=1), death (n=6), no insurance (n=1), no donor (n=1), physician decision (n=3), patient decision (n=3), relapse (n=6), other (n=10), or unknown (n=8). The 2-year RFS estimate in the entire high-risk cohort is 32%, significantly higher than the 22% historical rate (p=0.05). Median RFS in the high-risk CR1 cohort (n=107) was 10 months [range, 1-32* (censored) months]. RFS and OS were similar among HCT patients using matched related [1 year estimates: 40% (95% CI 27%, 74%) and 56% (37%, 74%), respectively] and matched unrelated [1 year estimates: 52% (37%, 75%) and 56% (37%, 74%), respectively] donors in CR1. The HR (reference = unrelated) for RFS was 0.67 (0.32, 1.37) and for OS was 0.88 (0.41, 1.90). Median overall survival (OS) among all patients in the high-risk cohort (n=159) was 12 months [range, 1-33* (censored) months] and was 18 months [range 3-33* (censored) months] for those transplanted in CR1 (Fig. 1). Conclusions: In newly diagnosed adults with AML age 18-60, early cytogenetic testing with an organized effort to identify a suitable allogeneic HCT donorled to a CR1 transplant rate of 64% in the high-risk group, which in turn led to a significant improvement in RFS over historical controls. Better outcomes in poor prognosis AML patients may be achieved simply by rapidly finding unrelated donors and performing allogeneic HCT in CR1 as soon as possible. Clinical Trials Registry: NCT #0180233; Support: NIH/NCI grants: CA180888, CA180819, CA18020, CA180821, CA180863, CA077202; CCSRI #021039 Figure 1 Overall Survival (OS) among all patients in the high-risk cohort, all high-risk patients achieving CR1, and in those high-risk patients transplanted in CR1. Figure 1. Overall Survival (OS) among all patients in the high-risk cohort, all high-risk patients achieving CR1, and in those high-risk patients transplanted in CR1. Disclosures Othus: Glycomimetics: Consultancy; Celgene: Consultancy. Radich:Novartis: Consultancy, Other: laboratory contract; ARIAD: Consultancy; Pfizer: Consultancy; TwinStrand: Consultancy; Bristol-MyersSquibb: Consultancy. Strickland:Alexion Pharmaceuticals: Consultancy; Ambit: Consultancy; Baxalta: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding; CTI Biopharma: Consultancy; Daiichi Sankyo: Consultancy; Sunesis Pharmaceuticals: Consultancy, Research Funding; Abbvie: Research Funding; Astellas Pharma: Research Funding; Celator: Research Funding; Cyclacel: Research Funding; GlaxoSmithKline: Research Funding; Karyopharm Therapeutica: Research Funding; Sanofi: Research Funding. Savoie:AbbVie: Consultancy; Lundbeck: Consultancy; BMS: Consultancy, Honoraria; Velgene: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Novartis: Consultancy, Honoraria; Jazz: Consultancy. Sekeres:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Stone:Amgen: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Xenetic Biosciences: Consultancy; Jansen: Consultancy; Pfizer: Consultancy; ONO: Consultancy; Juno Therapeutics: Consultancy; Merck: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Sunesis Pharmaceuticals: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy; Novartis: Consultancy; Celator: Consultancy; Karyopharm: Consultancy. Erba:Seattle Genetics: Consultancy, Research Funding; Pfizer: Consultancy; Jannsen: Consultancy, Research Funding; Juno: Research Funding; Celator: Research Funding; Ariad: Consultancy; Agios: Research Funding; Amgen: Consultancy, Research Funding; Novartis: Consultancy, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Research Funding; Incyte: Consultancy, DSMB, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Gylcomimetics: Other: DSMB; Sunesis: Consultancy; Daiichi Sankyo: Consultancy; Astellas: Research Funding.

Background: Less-fit patients with acute myeloid leukemia (AML) or high-risk myelodysplasia (MDS) age 60 years and older constitute the majority of patients with AML/MDS but are not well represented in clinical trials. DNA-methyltransferase inhibitor (HMA) monotherapy (e.g. azacitidine or decitabine) is usual. Overall response rates (ORR) are low; improvement in overall survival relative to supportive care alone is modest, highlighting the critical need for efficient identification of effective novel therapies. Blocking programed cell death protein-1 (PD-1) signaling with nivolumab may increase the sensitivity of AML cells to azacitidine and improve outcomes and is the focus of one arm of the S1612 trial. Signaling through PD-1 contributes to tumor immune evasion and growth in AML [Chen, Cancer Biol Ther 2008]. Increased expression of PD-1 (~40% of AML), is associated with poor HMA response [Ørskov, Oncotarget 2015]. A single center azacitidine/nivolumab non-randomized phase II study in relapsed/refractory AML reported ORR of 33% (23/70), including 22% complete remission/complete remission with incomplete hematologic recovery [Daver, Cancer Discovery 2018]. About 25% of the patients developed grade 2-4 immune toxicities; nivolumab immune-related adverse events led to treatment discontinuation in nearly 1 in 7 patients. Study Design and Methods:The S1612 trial [NCT03092674] is a platform randomized phase II/III clinical trial with a common azacitidine control arm (CA) and two currently active experimental arms (EA). Therapy is intended for community setting: azacitidine/nivolumab; and azacitidine/midostaurin. The innovative design utilizes a phase II go/no-go decision comparing each EA with the CA independently when there are 100 pts/arm and 104 deaths on the EA and CA combined. EAs will proceed to phase III if the null hypothesis (HR=1) is rejected in favor of the EA (15% one-sided alpha). When the two currently active EAs complete phase II accrual, a third EA (decitabine/cytarabine) will open. The CA stays open the entire length of the trial and only concurrently randomized patients will be compared across arms. If an EA proceeds to phase III, 200 additional patients (300 total patients) will be accrued. Phase III analysis occurs 1.5 years after accrual or at 414 deaths (in the respective EA and CA), whichever comes first. The phase III tests the null hypothesis with 4.5% two-sided alpha and 83% power for each EA to detect an improvement in median OS from 10.4 to 15.6 months. Eligible pts are age ≥60 years, newly diagnosed AML with ≥ 20% blasts or myelodysplastic syndrome with excess blasts-2 (MDS-EB-2); deemed by the treating physician unfit for standard cytotoxic chemotherapy; and no prior HMA permitted. Trial in Progress Issues:Between December 2017 and October 2018, 113 patients were screened and 78 randomized to study treatment (median/range age: 75/61-86 years; median/range performance status 1/0-3). Two concerns challenged this trial: 1) required administration of 7-day azacitidine at the enrolling sites created a burden for this population and 2) an early excess grade 5 toxicity signal in the azacitidine/nivolumab arm compared with the control arm. Without a control comparison, this safety signal likely would have been missed. Strategies to address these concerns were developed by the study team. Discussion with the sponsor and US Food and Drug Administration (FDA) focused on allowance of standard-of-care protocol-directed azacitidine administration in the patient's primary care doctor's office rather than at the oncology center. Because of the toxicity concern, the trial was placed on partial clinical hold for further evaluation and possible nivolumab-arm eligibility changes, along with new surveillance and pre-emptive action including prompt steroid initiation for suspected immune-related toxicities. The S1612 trial highlights special concerns when enrolling vulnerable populations onto leukemia clinical trials, and the importance of collaborative strategies including with the FDA to preserve clinical trial integrity for patient benefit. It also demonstrates the efficiency this novel platform design has for therapeutic investigation and, importantly, very early identification of serious toxicity. Updates on accrual and resolution and of these issues will be presented. Disclosures Hay: Kite: Research Funding; Gilead: Research Funding; AbbVie: Research Funding; Janssen: Research Funding; MorphoSys: Research Funding; Seattle Genetics: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Roche: Research Funding; Novartis: Research Funding. Assouline:Janssen: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Speakers Bureau; Abbvie: Consultancy, Honoraria. Walter:Pfizer: Consultancy, Research Funding; Race Oncology: Consultancy; New Link Genetics: Consultancy; Agios: Consultancy; Amphivena Therapeutics: Consultancy, Equity Ownership; Seattle Genetics: Research Funding; Aptevo Therapeutics: Consultancy, Research Funding; Argenx BVBA: Consultancy; Astellas: Consultancy; BioLineRx: Consultancy; BiVictriX: Consultancy; Boehringer Ingelheim: Consultancy; Boston Biomedical: Consultancy; Covagen: Consultancy; Daiichi Sankyo: Consultancy; Jazz Pharmaceuticals: Consultancy; Kite Pharma: Consultancy; Amgen: Consultancy. Foran:Agios: Honoraria, Research Funding. Radich:TwinStrand Biosciences: Research Funding; Novartis: Other: RNA Sequencing. Othus:Celgene: Other: Data Safety and Monitoring Committee; Glycomimetics: Other: Data Safety and Monitoring Committee. Erba:Astellas Pharma: Consultancy; Amgen: Consultancy; Amgen: Consultancy; ImmunoGen: Consultancy, Research Funding; Novartis: Consultancy, Research Funding, Speakers Bureau; MacroGenics: Consultancy, Other: Lecture fees, Research Funding; Pfizer: Consultancy; Pfizer: Consultancy; ImmunoGen: Consultancy, Research Funding; Covance: Other: Fees for serving as chair on an independent review board for AbbVie Phase III studies; Astellas Pharma: Consultancy; Covance: Other: Fees for serving as chair on an independent review board for AbbVie Phase III studies; MacroGenics: Consultancy, Other: Lecture fees, Research Funding; AbbVie: Consultancy, Other: Chair, IRC for phase III studies, Research Funding; AbbVie: Consultancy, Other: Chair, IRC for phase III studies, Research Funding; Seattle Genetics: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy, Other: chair, AML Registry Scientific Steering Committee, Speakers Bureau; Celgene: Consultancy, Other: chair, AML Registry Scientific Steering Committee, Speakers Bureau; Daiichi Sankyo: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; GlycoMimetics: Consultancy, Other: Chair, data and safety monitoring board, Research Funding; GlycoMimetics: Consultancy, Other: Chair, data and safety monitoring board, Research Funding; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau. Michaelis:Pfizer: Equity Ownership, Research Funding; Incyte: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; TG Therapeutics: Consultancy, Research Funding; JAZZ: Other: Data Safety Monitoring Board, uncompensated, Research Funding; BMS: Research Funding; Bioline: Research Funding; ASTEX: Research Funding; Janssen: Research Funding; Millenium: Research Funding; Macrogeneics: Research Funding. OffLabel Disclosure: Off label experimental combination therapies in newly diagnosed AML/MDS will be discussed, including nivolumab and azacitidine.

Abstract Introduction: The most effective initial therapy for older adults with CLL has not yet been established due to the lack of comparison of chemoimmunotherapy (CIT) and targeted therapy with the Bruton's Tyrosine Kinase (BTK) inhibitor ibrutinib. CIT has been the gold standard since studies showing that addition of CD20 antibody to chemotherapy prolongs survival. Bendamustine plus rituximab (BR) is one standard, more aggressive CIT regimen for patients (pts) age 65 or older. While ibrutinib has been FDA approved for untreated CLL since 2016, it has only been compared to chlorambucil, which is relatively ineffective, and never before to aggressive CIT. Additionally, the benefit of the addition of rituximab to ibrutinib in this setting has not been prospectively studied in a phase 3 trial. As part of a randomized phase 3 trial, the Alliance sought to answer these important clinical questions. Pts and Methods: Alliance A041202 is a multicenter NCI National Clinical Trials Network phase 3 study comparing BR (Arm 1) with ibrutinib (Arm 2) and the combination of ibrutinib plus rituximab (Arm 3) to determine whether ibrutinib-containing regimens are superior to CIT in terms of PFS. Additionally, this study sought to determine if adding rituximab to ibrutinib would prolong PFS over ibrutinib alone. At time of progression, pts on Arm 1 could cross over to Arm 2. Eligible pts were those age ≥ 65 years with previously untreated, symptomatic CLL. Pts had a CrCl ≥ 40 mL/min, bilirubin ≤ 1.5 x ULN, and no significant life-limiting intercurrent illness or need for warfarin treatment. Pts were stratified based upon Rai stage, Zap-70 methylation performed centrally, and del(17)(p13.1) or del(11)(q22.3) by local interphase cytogenetics and were randomized 1:1:1 to each arm. With 166 pts per arm, the trial was powered to detect an improvement in 2-year PFS from 61% in Arm 1 to 75% in Arms 2 or 3 (HR=0.586) using two one-sided log-rank tests with type I error rate of 2.5% and 90% power. The Alliance Data and Safety Monitoring Board approved the data release after meeting the protocol-defined efficacy threshold at a planned interim analysis with a one-sided critical value of 0.001538. These data were locked July 2, 2018; updated results will be presented at the meeting. Results: Between 12/9/2013 and 5/16/2016, 547 pts were registered and randomized (Arms 1: 183, 2: 182, and 3: 182). Median age was 71 years and 67% of pts were men. High-risk Rai stage (stage III/IV) was seen in 54%, unmethylated Zap-70 in 53%, and del(17p) or del(11q) by local FISH in 28%. Local vs centralized FISH was performed for del(11q) and del(17p) with agreement between local and central results in 94% (Kappa=0.80) and 97% (Kappa=0.76) of pts, respectively. 525 (96%) pts were eligible and included in the primary PFS analysis (Arms 1: 176, 2: 178, and 3: 171). With median follow-up of 32 months (mo), median PFS was 41 mo in Arm 1 and has not been reached in Arms 2 or 3 (HR comparing Arm 2 to 1 is 0.40 with one-sided p&lt;0.0001; HR comparing Arm 3 to 1 is 0.41 with one-sided p&lt;0.0001; HR comparing Arm 3 to 2 is 1.01 with one-sided p=0.48). 2-year PFS estimates were 74%, 87% in 2, and 88% in Arms 1, 2, and 3 respectively. At this time, there are no significant differences in overall survival (OS) among arms (p=0.87), median OS has not been reached for any arm, and 2-year OS estimates were 95%, 90%, and 94% in Arms 1, 2, and 3, respectively. Adverse events (AEs) were compared among arms using Fisher's exact tests. Grade 3+ treatment-emergent AEs were seen in 428 of 537 evaluable pts with 61%, 41%, and 38% of pts experiencing Grade 3+ heme AEs (p&lt;0.0001) and 60%, 72%, and 71% of pts experiencing Grade 3+ non-heme AEs (p=0.03) in Arms 1, 2, and 3 respectively. Grade 5 AEs were seen in 5 (2.8%), 14 (7.8%), and 14 (7.7%) pts (p=0.07). Unexplained or unwitnessed death over the entire observation period was seen in 2 (1.1%), 7 (3.9%), and 4 (2.2%) pts (p=0.24) in Arms 1, 2, and 3 respectively. Conclusions: This international phase 3 trial demonstrates that ibrutinib produces superior PFS to standard CIT in older pts with CLL and justifies it as a standard of care treatment for pts age 65 and older. The addition of rituximab does not prolong PFS with ibrutinib. While ibrutinib represents a major therapeutic advance, toxicities and also cost justify future efforts to reduce the need for long-term continuous treatment. Support: K23CA178183, R01CA183444, U10CA180821, U10CA180882, U24CA196171, Clinicaltrials.gov identifier: NCT01886872 Figure. Figure. Disclosures Ding: Merck: Research Funding. Bartlett:Astra Zeneca: Research Funding; ImaginAB: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Bristol-Meyers Squibb: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Affimed: Research Funding; Janssen: Research Funding; Novartis: Research Funding; Merck & Co: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Immune Design: Research Funding; Forty Seven: Research Funding; Novartis: Research Funding; Millennium: Research Funding. Brander:BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Barr:AbbVie, Gilead: Consultancy. Parikh:Gilead: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. Coutre:Celgene: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria, Research Funding; Gilead: Research Funding; Beigene: Consultancy; AbbVie: Consultancy, Research Funding. Lozanski:Novartis: Research Funding; BI: Research Funding; Genentech: Research Funding; Stem Line: Research Funding; Coulter: Research Funding; Beckman: Research Funding. Larson:Ariad/Takeda: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Erba:Amgen: Research Funding; Juno: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; MacroGenics: Consultancy; Juno: Research Funding; Janssen: Research Funding; Seattle Genetics: Consultancy, Research Funding; Janssen: Research Funding; Juno: Research Funding; Agios: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Incyte: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Novartis: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Incyte: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Celgene: Consultancy, Speakers Bureau; Janssen: Research Funding; Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Astellas: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; MacroGenics: Consultancy; Daiichi Sankyo: Consultancy, Research Funding; Pfizer: Consultancy, Other: grant; Astellas: Research Funding; Juno: Research Funding; Janssen: Research Funding; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Agios: Consultancy, Speakers Bureau; Astellas: Research Funding; Agios: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Pfizer: Consultancy, Other: grant; Pfizer: Consultancy, Other: grant; Astellas: Research Funding; Amgen: Research Funding; Agios: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Pfizer: Consultancy, Other: grant; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Celgene: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee. Owen:Janssen: Honoraria, Research Funding; Celgene: Research Funding; AstraZeneca: Honoraria, Research Funding; Pharmacyclics: Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; AbbVie: Research Funding; Merck: Honoraria; Teva: Honoraria. Abramson:Bayer: Consultancy; Novartis: Consultancy; Merck: Consultancy; Karyopharm: Consultancy; Seattle Genetics: Consultancy; Verastem: Consultancy; Humanigen: Consultancy; Juno Therapeutics: Consultancy; Gilead: Consultancy; Celgene: Consultancy; Amgen: Consultancy.

Abstract Introduction: The preferred post-remission therapy for older patients (pts) with AML remains uncertain. We compared outcomes for older AML pts in CR1 receiving HCT reported to the CIBMTR to older AML pts achieving CR1 on National Clinical Trials Network induction and non-HCT consolidation therapy (CT) trials. Methods: This study focused on pts 60-75 years of age treated between 2004 to 2013. CT pts (n=211) underwent induction and consolidation on Alliance for Clinical Trials in Oncology, ECOG-ACRIN or SWOG clinical trials for initial therapy for newly diagnosed AML; the CIBMTR provided data for HCT pts (n=431). CT patients received at least one cycle of CT on study and were excluded if HCT occurred at any time. Time to event started at CR1 and pts entered at CT or HCT, respectively, using left-truncation to account for differential entry times. Results: For the CT cohort, first consolidation included standard therapy (e.g., cytarabine or a hypomethylating agent) and additional study drug (e.g., bortezomib, dasatinib, sorafenib, and Zosuquidar, gemtuzumab) or tipifarnib alone. Among HCT pts, the donor was a HLA-matched sibling or unrelated donor (URD) in 66% and the others were partially HLA-matched/mismatched URD (10%) or cord blood (24%). HCT pts were younger and more frequently had high-risk AML (high WBC, secondary AML and unfavorable cytogenetics) (Table). The median time from CR1 to HCT and CT was 3.2 and 0.5 months, respectively. Allogeneic HCT showed worse overall survival (OS) (HR=1.52, p=0.02) prior to 9 months and better OS thereafter (HR= 0.53, p <0.0001) relative to CT (figure 1A). Treatment-related mortality (TRM) was worse after HCT in the first 9 months (HR=2.8, CI: 1.5 -5.2, p=.0009), while relapse was less frequent beyond 9 months after treatment (HR = 0.42, CI: 0.29 to 0.61, p<.0001). Despite higher early TRM, HCT recipients went on to manifest superior OS [5 year OS: HCT 29% (24-34%), CT 13.8% (9 -22%)] (Figure 1A). The benefit of HCT for survival after 9 months was more prominent in those with unfavorable cytogenetics (Figure 1B). Multivariate analysis for OS showed no statistically significant effect of age or performance status, while unfavorable cytogenetics were detrimental (HR=1.74, p<.0001). Conclusions. Allogeneic HCT led to heightened early risks from TRM, but resulted in superior long-term survival in older AML pts receiving HCT relative to CT by reducing relapse. Efforts to attenuate early TRM after allogeneic HCT may further improve HCT outcomes for older pts. Disclosures Ustun: novartis: Speakers Bureau. Attar:Agios: Employment, Equity Ownership. Larson:Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Ariad/Takeda: Consultancy, Research Funding. Roboz:Roche/Genentech: Consultancy; Eisai: Consultancy; Cellectis: Research Funding; Aphivena Therapeutics: Consultancy; Sandoz: Consultancy; Janssen Pharmaceuticals: Consultancy; Otsuka: Consultancy; Jazz Pharmaceuticals: Consultancy; Sandoz: Consultancy; AbbVie: Consultancy; Celltrion: Consultancy; Cellectis: Research Funding; Eisai: Consultancy; Astex Pharmaceuticals: Consultancy; Argenx: Consultancy; Pfizer: Consultancy; Celgene Corporation: Consultancy; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy; Bayer: Consultancy; Bayer: Consultancy; Roche/Genentech: Consultancy; Orsenix: Consultancy; Astex Pharmaceuticals: Consultancy; Celgene Corporation: Consultancy; Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Janssen Pharmaceuticals: Consultancy; Otsuka: Consultancy; Orsenix: Consultancy; Daiichi Sankyo: Consultancy; Celltrion: Consultancy; Novartis: Consultancy; Aphivena Therapeutics: Consultancy; Argenx: Consultancy; AbbVie: Consultancy. Uy:GlycoMimetics: Consultancy; Curis: Consultancy. Stone:Fujifilm: Consultancy; Ono: Consultancy; Orsenix: Consultancy; Otsuka: Consultancy; Agios: Consultancy, Research Funding; AbbVie: Consultancy; Argenx: Other: Data and Safety Monitoring Board; Celgene: Consultancy, Other: Data and Safety Monitoring Board, Steering Committee; Arog: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Jazz: Consultancy; Astellas: Consultancy; Merck: Consultancy; Pfizer: Consultancy; Sumitomo: Consultancy; Amgen: Consultancy; Cornerstone: Consultancy. Foran:Agios: Research Funding; Xencor, Inc.: Research Funding. Weisdorf:Seattle Genetics: Consultancy; Equillium: Consultancy; FATE: Consultancy; SL Behring: Consultancy; Pharmacyclics: Consultancy.

Abstract The prognosis of elderly patients (pts) with acute lymphoblastic leukemia (ALL) remains poor, and novel therapeutic approaches are clearly needed. CD19 is expressed on the majority of precursor-B ALLs and represents an attractive therapeutic target. The anti-CD19 bi-specific engager antibody blinatumomab has demonstrated significant activity in both relapsed/refractory ALL and minimal residual disease (MRD) positive ALL. Therefore, we evaluated blinatumomab as a single agent in the upfront treatment of newly diagnosed elderly pts with Philadelphia chromosome (Ph) negative B-lineage ALL to determine response rates and overall survival (OS). Methods: Pts were treated at National Clinical Trial Network sites from June 2015 to September 2017. The primary objective of the study was to estimate 3-year OS. An IND was approved by the FDA and the protocol was approved by a central institutional review board. Eligibility: age > 65 years, newly diagnosed Ph negative B-lineage ALL with adequate organ function and no evidence of central nervous system (CNS) disease. Pts received blinatumomab for induction at standard dosing for 1-2 cycles until attainment of complete response (CR) or CR with incomplete count recovery (CRi) (defined below). Pts then received 3 cycles of blinatumomab post-remission therapy followed by 18 months of maintenance POMP (prednisone, vincristine, 6-mercaptopurine, methotrexate). A total of 8 doses of intrathecal methotrexate were administered as CNS prophylaxis. Cytogenetic risk was ascribed by NCCN 2018 criteria and bone marrow samples were analyzed for the presence of the Ph-like signature. MRD was assessed centrally by 8 color flow cytometry pre-treatment, on Day 35 of induction cycle 1, and on Day 35 of re-induction (if applicable). Response was assessed at the completion of 1-2 cycles of blinatumomab. CR was defined as < 5% marrow blasts with no evidence of extramedullary disease and recovery of counts [absolute neutrophil count (ANC) > 1000/uL, platelets >100,000/uL]. CRi was defined the same as CR but ANC < 1000/ uL and/ or platelets ≤ 100,000/ uL. OS was measured from day of registration on trial until the date of death. Disease-free survival (DFS) was measured from the date the pt achieved CR/ CRi until relapse or death. Toxicities were graded according to NCI CTCAE version 4.0. Results: Of 31 pts enrolled, 29 were eligible. The median age was 75 years (range 66 - 84), 22 (76%) were male, median baseline white blood count was 3.7 x 103/uL (range 0.3 - 7,100), and median bone marrow blast count percentage was 86.5% (range 30-100). Three pts received hydroxyurea or steroids prior to treatment initiation. Cytogenetic risk at diagnosis was: poor (34% of pts; n=10), standard (55% of pts; n=16), good (3% of pts; n=1) and unknown (7% of pts, n=2). Testing for the Ph-like signature is being completed. The most common Grade 3-5 non-hematologic toxicities related to treatment during induction were hyperglycemia (14%), dyspnea (10%), febrile neutropenia (10%), hypertension (10%), and lung infection (7%). One pt developed Grade 3 cytokine release syndrome and 1 developed Grade 3 neurotoxicity. No pts died during the first 28 days of treatment. The overall response rate (CR + CRi) was 66% (all CRs). Thirteen of the 19 responders have available MRD data post-treatment. Of these, 12 pts (92%) achieved MRD negativity, all at Cycle 1 Day 35. One pt required 2 cycles of blinatumomab to achieve CR. One pt proceeded to allogeneic hematopoietic stem cell transplant. The median follow-up time is 1 year and median duration on trial is 170 days (6 pts are still on maintenance therapy). OS estimated by Kaplan Meier at 6 months is 79% (95% CI 58%-90%) and at 1 year is 65% (95% CI 43%-80%). DFS estimated at 6 months is 68% (95% CI 43%-84%) and at 1 year is 56% (95% CI 31%-75%). No baseline features including CD19 expression (by percentage or mean-fluorescent intensity) or presence of a CD19 negative subpopulation were associated with response. Conclusions: Blinatumomab was well tolerated and effective in the treatment of newly diagnosed elderly patients with Ph negative B-lineage ALL. Further follow up will determine the durability of these responses. Disclosures Advani: Pfizer: Honoraria, Research Funding; Amgen: Research Funding; Novartis: Consultancy; Glycomimetics: Consultancy. Wieduwilt:Leadiant: Research Funding; Merck: Research Funding; Shire: Research Funding; Reata Pharmaceuticals: Equity Ownership; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding. Park:Adaptive Biotechnologies: Consultancy; Pfizer: Consultancy; AstraZeneca: Consultancy; Novartis: Consultancy; Kite Pharma: Consultancy; Juno Therapeutics: Consultancy, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shire: Consultancy. Stock:Jazz Pharmaceuticals: Consultancy. Erba:Immunogen: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Agios: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Amgen: Research Funding; Novartis: Consultancy, Speakers Bureau; Juno: Research Funding; Juno: Research Funding; Celgene: Consultancy, Speakers Bureau; Daiichi Sankyo: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Takeda/Millenium: Research Funding; Incyte: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Jazz: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Agios: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Amgen: Research Funding; Agios: Consultancy, Speakers Bureau; Astellas: Research Funding; MacroGenics: Consultancy; Takeda/Millenium: Research Funding; Seattle Genetics: Consultancy, Research Funding; MacroGenics: Consultancy; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Novartis: Consultancy, Speakers Bureau; Janssen: Research Funding; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Janssen: Research Funding; Jazz: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Amgen: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Pfizer: Consultancy, Other: grant; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Astellas: Research Funding; Pfizer: Consultancy, Other: grant; Celgene: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Incyte: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Pfizer: Consultancy, Other: grant; Incyte: Consultancy, Speakers Bureau; Juno: Research Funding; Jazz: Consultancy, Speakers Bureau; Pfizer: Consultancy, Other: grant; Astellas: Research Funding; Seattle Genetics: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Immunogen: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Juno: Research Funding; Jazz: Consultancy, Speakers Bureau.

Abstract Background Therapy-related myeloid neoplasm (tMN) includes t-myelodysplasia (tMDS) and t-acute myeloid leukemia (tAML) and are serious late effects of the treatment of cancer. Prognosis of tMN is poor, related to the increased frequency of adverse cytogenetics and other clinical features which predict poor response to conventional treatment. Over the last years, azacitidine (AZA) has become the standard of treatment for high risk MDS (Silverman, JCO 2002; Fenaux, Lancet Oncol 2009) and has shown efficacy in AML. AZA represents an interesting option for patients with tMN considering its safety profile and its efficacy in poor prognosis subgroups of apparently de novo MDS patients including those with monosomy 7. Most prospective trials of AZA have excluded patients with tMN. Most tMN data are retrospective or registry studies (Bally, Leuk Res 2013). This abstract presents the results of 47 t-MN patients prospectively enrolled as a specific cohort in the E1905 study. Methods E1905 study is a randomized phase 2 study from the North American Leukemia Intergroup (NCT00313586, Prebet , ASH 2010) testing 10 days of AZA (50mg/m2/d s.c.) vs. 10 days of AZA + the histone deacetylase inhibitor entinostat (4 mg/m2/d PO days 3 and day 10). 6 cycles of treatment were planned; responding patients could receive up to 24 cycles. MDS, CMML, and AML with myelodysplasia-related changes were included. Patients with tMN were subsequently accrued as a separate cohort after amendment of the protocol. Response was assessed using IWG 2000 criteria (Cheson et al, Blood 2000); the primary endpoint of the overall trial was achievement of a normal hemogram in 25% of treated patients in either treatment arm. Results A total of 47 patients were included. Median age was 70 years (39y-83y), 45% male, and 94% of patients had ECOG PS 0-1. 29 patients could be subclassified as t-MDS and 18 as t-AML. At inclusion, median peripheral blood counts were: neutrophils 1.0 G/l, Platelets 35 G/L, Hemoglobin 9.2 g/l, peripheral blood blasts 0%, marrow blasts 14.0%. 68% of patients were RBC transfusion dependent and 40% platelet transfusion dependent. As expected, the cytogenetic evaluation showed a high frequency of unfavorable risk cytogenetics (74%) as compared to normal or intermediate risk cytogenetics (26%). Baseline characteristics were not statistically different between the 2 arms. 24 patients were treated with AZA monotherapy and 23 with AZA+entinostat. The median number of administered cycles was 4 and was significantly higher in patients treated with AZA monotherapy (6 cycles vs.3 cycles, p=0.008). 8 patients in the combination arm and 1 patient in the AZA monotherapy arm died of infection or hemorrhage before cycle 3. In an intent to treat analysis, overall response rates (CR, PR, or trilineage Hematologic improvement) were 11/24 (46%) in AZA monotherapy (95% CI 26 – 67%) and 4/23 (17%) in the combination arm (95% CI 5 – 39%, p=0.06 comparing the two arms). Median overall survival in the two arms were 12.8 months and 5.7 months (p=0.008). Conclusions In this group of very high risk patients with therapy-related myeloid neoplasms, the use of the novel 50 * 10 schedule of azacitidine monotherapy appears effective, with response rates comparable to those for patients with de novo MDS/AML treated on the same protocol (74 pts, 40% with unfavorable cytogenetics, ORR=32%, median OS=18 months). Because there are no prospective data examining the approved dose schedule of AZA (75 mg/m2/day * 7 days), it is not clear if this surprisingly high response rate derives from the current extended schedule of lower dose AZA, or would be true with standard dose AZA as well. This high response may enable many of these patients to proceed to allogeneic stem cell transplant. Entinostat combined with azacitidine at the dose and schedule applied in E1905 does not appear to be effective and tolerable as compared to azacitidine alone. Disclosures: Prebet: CELGENE: Honoraria. Off Label Use: Use of azacitidine in acute myeloid leukemia. Gore:CELGENE: Equity Ownership, Research Funding.

Abstract Background: The few therapies available to treat higher-risk MDS and CMML have limited impact on outcome. We previously reported initial results of S1117, which compared overall response rates (ORRs) of azacitidine (AZA) monotherapy to AZA combined with the histone deacetylase inhibitor vorinostat (VOR), or the immunomodulator lenalidomide (LEN)( ASH 2014 LBA-5). We now report updated response data and overall survival (OS), subgroup analyses, impact of cytogenetics, and effect of treatment center volume/centers of excellence on outcome. Methods: This randomized, Phase II study (ClinTrials.gov # NCT01522976) enrolled higher-risk MDS (International Prognostic Scoring System (IPSS) Int-2 or High and/or bone marrow blasts ≥5%) and CMML adult patients (pts) with <20% blasts from 3/12-6/14 to receive AZA (75 mg/m2/d on d1-7 of a 28d cycle), AZA + LEN (10 mg/d on d1-21), or AZA + VOR (300 mg BID on d3-9). Pts continued treatment until treatment failure, defined as disease progression, relapse, significant or unresolved toxicity, or lack of response. Dose reductions occurred for grade ≥3 adverse events (per NCI CTCAE) or delayed count recovery. Cytogenetic risk groups were defined per IPSS-R. The primary endpoint was improvement in ORR, by intention to treat and reviewed centrally, of one of the combination arms vs. AZA per 2006 International Working Group MDS response criteria (complete response (CR) + partial response (PR) + hematologic improvement (HI)). OS was from study entry. MDS Centers of Excellence (MCE) were defined per MDS Foundation; center volume was defined as low (1-4 pts enrolled) or high (5-17 pts). Results: Of 277 pts, 92 received AZA, 93 AZA+LEN, and 92 AZA+VOR. Baseline characteristics, previously reported, were similar across arms. Pts received a median of 22 weeks of therapy and were followed for a median of 10 months (range: 0-30). Non-protocol defined dose modification and protocol discontinuation due to toxicity occurred more frequently in combination arms vs. AZA (p=.0014 and p=.018, respectively). Responses are now assessable in all pts (Table 1). ORR was statistically similar for combination arms vs. AZA, with a trend for longer response duration (p=.083) for combinations. Within HI, AZA+LEN pts had higher HI-n than AZA pts (16% vs. 5%, p=.031). ORR for CMML pts was significantly higher for LEN+AZA vs. AZA (63% vs. 29%, p=.04), with a trend for longer response duration for combinations (p=.06); no differences in ORR were seen for therapy-related MDS, IPSS subgroups, or transfusion-dependent pts. Allogeneic transplantation rates were similar. Median OS (Figure) for AZA:AZA+LEN:AZA+VOR was 15:18 (p=.38):17 (p=.17) months; p=.19 for combination arms vs. AZA. Median OS after failure was 7:9 (p=.6):9 (p=.05) months; p=.15 for combination arms after failure vs. AZA. For pts on therapy >6 months, there was a trend (p=.08) for higher ORR for AZA+LEN vs. AZA, though response duration was similar; median OS was 18:21 (p=.44 vs. AZA):21 months (p=.45 vs. AZA). Cytogenetic risk category distribution and ORR was similar across arms. OS (compared to Very Good/Good) was worse for Poor (HR 2.07, p=.022) and Very poor (HR 4.41, p<.001), without significant modification by treatment arm (Table 2). Compared to pts without identified cytogenetic abnormalities (abn), ORR across arms was better for pts with Chr 5 abn (OR 2.38, p=.004); OS was better for normal (HR .42, p<.001) and worse for Chr 5 abn (HR 3.1, p<.001), -7 (HR 2.69, p<.001), and 17p (HR 2.61, p<.001). While small numbers prevented definitive conclusions for treatment arm effect, combinations trended towards improving OS in Normal and Chr 5 abn only. The outcome of all pts and pts on discrete study arms treated at MCE (n=75) or high volume (n=138) sites were similar to non-MCE or low-volume sites for ORR, non-protocol defined dose modifications, dose adjustment in first 4 cycles, time to off-protocol (HR 1.2, p=.21 and HR .94, p=.64), and OS (HR .81, p=.3 and HR .77, p=.12). Conclusions: In higher-risk MDS pts, ORR and OS was similar for AZA monotherapy compared to combination arms, while for CMML pts, ORR was significantly higher with AZA+LEN. For cytogenetic subgroups, OS was worse for Chr 5 abn, -7, and 17p, and may be improved by combinations in normal or Chr 5 abn. MCE or treatment at a high volume site did not impact these effects or outcomes. Figure 1. Responses Figure 1. Responses Figure 2. Cytogenetics Figure 2. Cytogenetics Figure 3. Figure 3. Disclosures Sekeres: Celgene Corporation: Membership on an entity's Board of Directors or advisory committees. List:Celgene Corporation: Honoraria, Research Funding. Odenike:Sunesis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Stone:Merck: Consultancy; Celgene: Consultancy. Gore:Celgene: Consultancy, Honoraria, Research Funding. Buckstein:Celgene: Honoraria, Research Funding. Fang:Affymetrix: Research Funding. Attar:Agios Pharmaceuticals: Employment. Erba:Ariad: Consultancy; Daiichi Sankyo: Consultancy; Sunesis: Consultancy; Pfizer: Consultancy; Novartis: Consultancy, Speakers Bureau; Pfizer: Consultancy; Incyte: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Jannsen (J&J): Other: Data Safety and Monitoring Committees ; Ariad: Consultancy; Celgene: Consultancy, Speakers Bureau; GlycoMimetics: Other: Data Safety and Monitoring Committees; Seattle Genetics: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Millennium/Takeda: Research Funding; Millennium/Takeda: Research Funding; Celator: Research Funding; Celator: Research Funding; Astellas: Research Funding; Astellas: Research Funding; Sunesis: Consultancy; Daiichi Sankyo: Consultancy; GlycoMimetics: Other: Data Safety and Monitoring Committees; Jannsen (J&J): Other: Data Safety and Monitoring Committees.

Abstract Abstract 4013 Background: In recent years, azacytidine (AZA) has become the standard of treatment for high risk myelodysplasia (MDS). The approved schedule of AZA uses a 75mg/m2/d s.c. regimen for 7 days based on the CALGB-9221 (Silverman, JCO 2002) and the AZA-001 studies (Fenaux, Lancet Oncol 2009). The clinical response rates after AZA have been extensively presented but there is only limited data on the rates of cytogenetic response (CyR). Based on the review of the literature, there are no specific cytogenetic data published on prospective trials. Methods: We based our analysis on a randomized phase 2 study from the US Leukemia Intergroup (E1905 study, NCT00313586) testing 10 days of AZA (50mg/m2/d s.c.) vs 10 days of AZA+ the histone deacetylase inhibitor entinostat (4 mg/m2/d PO days 3 and day 10). MDS, CMML, and AML with myelodysplasia-related changes were included. This analysis includes all patients with cytogenetic abnormalities (at baseline or acquired following treatment) with available cytogenetic follow-up (cycle 6). Of 150 patients, 70 demonstrated baseline cytogenetic abnormalities. To date, forty patients (27 MDS and 13 AML) were evaluable for both time points. Karyotypes were performed at local laboratories, and reviewed centrally (RPK and GH). Cytogenetic response was assessed using IWG 2000 (Cheson et al, Blood 2000) criteria. Results: The clinical response rate (CR+PR+ trilineage HI) according to IPSS cytogenetic risk stratification were of 20%, 33%, and 35% for favorable, intermediate and poor cytogenetic risk groups respectively (p=NS). Patients with Chr 7 abnormalities (i.e. -7 or -7q, n=18) had a response rate of 28% including 17% CR. Of patients with complete cytogenetic data, the rate of overall CyR was 52% (n=21): 22% (n=9) complete CyR, 30% (n=12) partial CyR. This represents a complete CyR of 13% and a partial CyR of 23% as a proportion of all treated patients with initial cytogenetic abnormalities (including those who did not receive six cycles of therapy). To date, confirmatory FISH analyses were available for 4 patients with CyR (2 CCyR and 2 PCyR). All four had complete clearance of their cytogenetic clone. Among the cytogenetic responders, 15 had MDS and 6 had AML (p=NS). CyR did not differ between the two treatment arms. CyR and clinical response were highly correlated (p<0.001): all patients with complete CyR and 7/10 partial CyR had a clinical CR. Only 3 patients (1 CCyR and 2 PCyR) had a CyR without associated clinical response. Among 8 patients with cytogenetic progression, 3 pts showed increased frequency of a known aberration and 5 showed new or additional aberration including 2 cases involving Chr7. 65 AZA-treated patients from AZA001 had comparable cytogenetic results available. Only 3 patients experienced complete CyR 4.6% with 33.8% partial CyR (n=22). In contrast, the reported rate of clinical response was similar in the two studies. Complete CyR were more frequent in the E1905 10 days AZA schedule compared to the 7 days AZA schedule (p=0.007). There was no difference in overall CyR between the two studies. Conclusions: Both the standard AZA schedule and the 10 day schedule administered on E1905 lead to high rates of cytogenetic response. The novel schedule explored in E1905 demonstrated a particularly high rate of complete CyR (22%) with complete clearance of abnormal clone by FISH in 4 tested patients. Further prospective comparison of different AZA schedules will be needed to confirm this higher rate of complete CyR and determine its clinical significance. Disclosures: Beach: Celgene: Employment. Gore:Celgene: Consultancy, Research Funding, stock options; Syndax: Consultancy.