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Background Patients diagnosed with acute myeloid leukemia with a FLT3 mutation (FLT3+ AML) have historically had poor outcomes. While the addition of the FLT3 inhibitors to induction therapy has been shown to improve survival outcomes in FLT3+ AML, interactions and overlapping toxicities between FLT3 inhibitors and standard of care medications used during induction therapy (e.g. azole antifungals, anthracyclines) and logistical barriers have complicated their use. To avoid these concerns, our institution has opted to defer initiation of midostaurin until after completion of induction therapy. However, to our knowledge no study confirming the effectiveness of this strategy for real world FLT3 inhibitor use has been published. Methods We performed a single center, propensity-score matched, retrospective cohort study characterizing efficacy and safety of our strategy for use of FLT3 inhibitors in the treatment of FLT3+ AML. The primary outcome was median event-free survival (EFS), while secondary endpoints included median overall survival (OS), overall response rate (ORR), 30-day mortality, duration of neutropenia, duration of thrombocytopenia, consolidation cycle delays, documented infections, and all-cause hospital readmission. Results A total of 83 FLT3+ AML patients treated with intensive induction therapy were included in the study, of whom 48 were propensity-score matched and analyzed. Baseline characteristics were similar between the patients who received a FLT3 inhibitor after induction therapy and the historical control arm. Median EFS was not significantly different but compared favorably between the FLT3 inhibitor cohort and historical controls (not reached vs 8 months, p = 0.343) with 18-month EFS of 54% and 43% for the two cohorts, respectively. Similarly, no significant differences were noted with regard to median OS (not reached vs 28.7 months, p = 0.752), ORR (79.2% vs 79.2%), or safety outcomes between groups. Conclusion Compared to historical controls, addition of a FLT3 inhibitor to intensive chemotherapy post-induction may improve EFS or OS in a real world patient cohort with longer follow-up and a larger sample size. The omission of midostaurin in induction allowed for the use of an azole antifungal and the intensification of anthracycline dose may have contributed to high remission rates in both groups.

Liposomal daunorubicin/cytarabine (CPX-351) gained FDA approval for secondary AML after demonstrating improved outcomes over daunorubicin and cytarabine (7 + 3). A number of study limitations prompted a comparison of safety/efficacy of CPX-351 against regimens containing a purine analogue and high-dose cytarabine (HIDAC). This retrospective study compared complete response rates with/without count recovery (CR/CRi) between HIDAC-based regimens and CPX-351 in 169 patients with newly diagnosed sAML. The CR/CRi rate was 62.7% in the HIDAC-based therapy arm vs. 47.9% in the CPX-351 arm (

The use of tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL fusion protein have dramatically changed the clinical management and outcomes for patients with chronic myelogenous leukemia (CML)...

The diagnosis of pure erythroid leukemia (PEL) can be challenging. Prompt identification of CD45+, CD34‐, CD71+, CD117+, and E‐cadherin+ erythroblasts is important. The differential diagnosis is broad and includes megaloblastic anemia.

Internal tandem duplications and tyrosine kinase mutations in the fms-like tyrosine kinase 3 (FLT3) receptor can occur in acute myeloid leukemia (AML) and portend a poor prognosis. Midostaurin, a multikinase inhibitor that targets FLT3, demonstrated a survival benefit in FLT3-mutated AML in combination with front-line chemotherapy. Despite this advancement, the use of FLT3 inhibitors in clinical practice is complicated by significant drug-drug interactions and uncertainty about optimal timing, duration, and sequencing of therapy. As monotherapy, the utility of FLT3 inhibitors was initially limited by incomplete and transient clinical responses and the development of acquired resistance. This led to the development of more potent and selective FLT3 inhibitors designed to overcome common resistance mechanisms. One of these second generation FLT3 inhibitors, gilteritinib, is now FDA-approved for the treatment of relapsed or refractory AML. Now that multiple FLT3 inhibitors are commercially available, it is important to further delineate the role of these agents in the AML population. This review aims to provide a comprehensive overview of the role of FLT3 inhibitors in AML and apply the current literature to clinical practice.

Conventional karyotyping is essential standard practice in the initial evaluation of myelodysplastic syndrome (MDS) and is the most impactful single component of the Revised International Prognostic Scoring System (IPSS-R). While single nucleotide polymorphism array (SNP-A) has demonstrated the ability to detect chromosomal defects with greater sensitivity than conventional karyotype, widespread adoption is limited by the unknown additional prognostic impact of SNP-A analysis. Here, we investigate the significance of additional SNP-A abnormalities in the setting of MDS and demonstrate differences in survival of patients with additional abnormalities, even those initially characterized as relatively lower risk either by cytogenetic score or IPSS-R. Our findings identify specific abnormalities, particularly KMT2A partial tandem duplication, that are invisible to conventional karyotype and potentially contribute to the poor prognosis of MDS patients. Furthermore, these results demonstrate the added value of SNP-A analysis in identifying patients who may benefit from more aggressive therapy, particularly those who would otherwise be classified into lower risk categories.

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. Recent advances have resulted in an expansion of treatment options for AML, especially concerning targeted therapies and low-intensity regimens. This portion of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AML focuses on the management of AML and provides recommendations on the workup, diagnostic evaluation and treatment options for younger (age

The availability of Erwinia Asparaginase has been limited across the world due to manufacturing shortages or for some countries due to the high acquisition cost, putting patients at risk for inferior outcomes. This manuscript provides guidance on how to manage hypersensitivity reactions and utilize therapeutic drug monitoring (TDM) to conserve and limit Erwinia use. The clinical and financial impact of a multidisciplinary committee are also discussed. Faced with a global Erwinia shortage, a multidisciplinary asparaginase allergy committee was created to review all hypersensitivity reactions to asparaginase therapy, staff education was performed on the management of asparaginase hypersensitivity reactions, an institution-wide premedication policy was mandated, and standardized guidelines were created for TDM. This multidisciplinary approach reduced the PEG-asparaginase to Erwinia switch rate from 21% (35 of 163) to 7% (10 of 134) (

Myelodysplastic syndromes (MDS) are a heterogeneous category of myeloid neoplasms that represent the most common class of acquired bone marrow failure syndromes in adults. MDS is typically associated with a hypoproliferative macrocytic anemia, but atypical findings on initial diagnostic evaluations can raise concern for a distinct pathophysiological process and lead to the investigation of alternative etiologies. Here, we report a case of MDS with a concomitant hypoproliferative microcytic and hypochromic anemia that led to the identification of acquired hemoglobin H due to a novel somatic ATRX mutation.

Secondary AML is associated with a disproportionately poor prognosis, consistently shown to exhibit inferior response rates, event-free survival, and overall survival in comparison with de novo AML. Secondary AML may arise from the evolution of an antecedent hematologic disorder, or it may arise as a complication of prior cytotoxic chemotherapy or radiation therapy in the case of therapy-related AML. Because of the high frequency of poor-risk cytogenetics and high-risk molecular features, such as alterations in TP53, leukemic clones are often inherently chemoresistant. Standard of care induction had long remained conventional 7 + 3 until its reformulation as CPX-351, recently FDA approved specifically for secondary AML. However, recent data also suggests relatively favorable outcomes with regimens based on high-dose cytarabine or hypomethylating agents. With several investigational agents being studied, the therapeutic landscape becomes even more complex, and the treatment approach involves patient-specific, disease-specific, and therapy-specific considerations.

Background Current literature has demonstrated the utility of the MRSA nasal screen as a de-escalation tool to decrease unnecessary anti-MRSA antibiotic therapy. However, data on the applicability of this test in patients with hematologic malignancy is lacking. Methods This is a single-center, retrospective cohort study of patients with acute myeloid leukemia (AML) with or without history of hematopoietic cell transplant (HCT), with pneumonia and MRSA nasal screening with respiratory cultures obtained. The primary outcome was to determine the negative predictive value (NPV) of the MRSA nasal screen for MRSA pneumonia. Secondary outcomes included sensitivity, specificity, positive predictive value (PPV) of the MRSA nasal screen and prevalence of MRSA pneumonia. Results Of 98 patients with AML and pneumonia, the prevalence of MRSA pneumonia was 4.1% with confirmed positive MRSA respiratory cultures observed in 4 patient cases. In patients with confirmed MRSA pneumonia, 3 had positive MRSA nasal screens while 1 had a false negative result, possibly due to a long lag time (21 days) between MRSA nasal screen and pneumonia diagnosis. Overall, the MRSA nasal screen demonstrated 75% sensitivity and 100% specificity, with a PPV of 100% and a NPV of 98.9%. Conclusions Given the low prevalence, empiric use of anti-MRSA therapy in those AML and HCT patients with pneumonia may not be warranted in clinically stable patients. For patients in whom empiric anti-MRSA antibiotics are initiated, nasal screening for MRSA may be utilized to de-escalate anti-MRSA antibiotics in patients with AML with or without HCT.

Background Acute leukemia with mixed-phenotype blasts is associated with poor outcomes. There are no standard treatment regimens. Due to disease heterogeneity, controversy exists over whether an AML-based, ALL-based, or a combined (hybrid) AML/ALL-based regimen is most appropriate. Materials and Methods We conducted a single-center, retrospective case series review of patients with acute leukemia with mixed phenotype blasts as described by the European Group for Immunological Characterization of Leukemia (EGIL) or the 2008 WHO classification. Patients were treated from November 2014 and December 2019 with the combination chemotherapy regimen FLAG-idarubicin-vincristine-prednisone with or without rituximab. Outcomes included induction response, time to transplant, time to relapse, overall survival, time to neutrophil or platelet recovery, infection, and duration of hospitalization. Results The median age was 68 years (range 21−77). Six patients (87.5 %) had unfavorable/complex cytogenetics. All patients achieved a complete remission (CR) or complete remission with incomplete hematologic recovery (CRi). Estimated 1-year overall survival was 85.7 %. There were no deaths during induction, with a 22 day median duration of hospitalization for induction. Conclusion The combination of FLAG, idarubicin, vincristine, and prednisone (FLAG-VIPR) demonstrated favorable induction responses in a disease state with historically poor outcomes and should be studied in a prospective clinical trial.

Fibroblast growth factor 23 (FGF23)–induced hypophosphatemia is a rare paraneoplastic syndrome of phosphate wasting that, if unrecognized, may cause tumor-induced osteomalacia. It is classically associated with benign mesenchymal tumors but occasionally has been found in patients with other malignancies. Hypophosphatemia has been associated with acute leukemia but has not previously been reported to be due to inappropriate FGF23 secretion. Here, we describe FGF23-induced severe hypophosphatemia and renal phosphate wasting associated with a mixed-phenotype Philadelphia chromosome-like acute leukemia in a previously healthy 22-year-old man. He was found to have low serum 1,25-dihydroxyvitamin D and extremely high FGF23 levels, as well as inappropriate urinary phosphorus excretion. The hypophosphatemia improved with calcitriol and oral phosphate treatment but normalized only during chemotherapy-induced ablation of the blasts. FGF23 levels declined with a reduction in peripheral blast counts. Using real-time reverse transcription polymerase chain reaction, we found that the leukemia cells were the source of FGF23. To our knowledge, this is the first description of FGF23-induced hypophosphatemia associated with acute leukemia. We recommend that the FGF23 paraneoplastic syndrome be considered as a possible etiology of hypophosphatemia in patients with acute leukemia., A young man with refractory mixed-phenotype Philadelphia chromosome-like acute leukemia was found to have phosphaturic hypophosphatemia associated with expression of FGF23 by his leukemia cells.

The 5-year overall survival (OS) in patients ≥ 60 years old with acute myeloid leukemia (AML) remains

Background Relapsed/refractory acute myeloid leukemia (AML) confers a poor prognosis, and there is no single standard of care first-line salvage regimen. FLAG (fludarabine, cytarabine, and granulocyte colony-stimulating factor) is a common salvage regimen with a favorable toxicity and efficacy profile in poor-risk AML. Materials and Methods We conducted a single-center, retrospective analysis of first relapse/primary refractory patients with AML that received salvage chemotherapy from January 2009 to July 2019. We propensity-score matched patients 1:1 (based on age at diagnosis, cytogenetic risk group, Charlson comorbidity index, de novo vs. secondary AML, and whether or not they received an allogeneic stem cell transplant in first complete remission) into 2 groups, FLAG (Group 1) or non-FLAG (Group 2) as first-line salvage regimen, with 66 patients in each group. The primary endpoint was overall response rate (complete response and complete response with incomplete hematologic recovery). Results The median patient age was 59 years (range, 19-80 years). Patients treated with FLAG had a higher overall response rate (complete response/complete response with incomplete hematologic recovery) (71.2% vs. 50.0%; odds ratio, 2.47; 95% confidence interval [CI], 1.21-5.08; P = .013), longer event-free survival (8.9 vs. 2.1 months; hazard ratio [HR], 0.58; 95% CI, 0.39-0.86; P = .005), and longer overall survival (14.2 vs. 5.9 months; HR, 0.62; 95% CI, 0.41-0.93; P = .019). Patients who received FLAG had a shorter median duration of neutropenia (22 vs. 34 days; HR, 0.43; 95% CI, 0.29-0.64; P Conclusion This analysis supports the FLAG regimen as an effective and well-tolerated salvage therapy for patients with relapsed/refractory AML.

Asparaginase remains a cornerstone of ALL therapy and is one of the key contributing factors to improved outcomes in adolescent and young adult (AYA) patients treated on pediatric protocols. Asparagine depletion has been associated with improved outcomes in ALL patients; this has led to an increased emphasis on optimizing asparagine depletion in ALL patients of all ages. To ensure adequate asparagine depletion, the use of therapeutic drug monitoring of asparaginase therapy holds much promise, yet remains underutilized in practice. Data regarding asparaginase activity level monitoring and associated outcomes are reviewed, and an evidence-based asparaginase activity level monitoring algorithm is presented. Finally, unique management strategies for key asparaginase toxicities in ALL patients are discussed, as well as a discussion of novel asparaginase formulations on the horizon.

Asparaginase is commonly de-emphasized/omitted in adult acute lymphoblastic leukemia regimens due to poor tolerability, including hepatotoxicity (HTX). Adult patients (n = 100) given induction therapy containing pegylated asparaginase (PEG) from January 2008 to February 2016 were evaluated for HTX. Sixteen patients met criteria for HTX (direct bilirubin >3 g/dL). A multivariable model identified body surface area >2m2 (OR 7.40; 95% CI: 1.73–31.61, p = .007), albumin

Acute myeloid leukemia (AML) is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths due to leukemias in the United States. Recent advances have resulted in an expansion of treatment options for AML, especially concerning targeted therapies and low-intensity regimens. This portion of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AML focuses on the management of AML and provides recommendations on the workup, diagnostic evaluation and treatment options for younger (age

Objectives The incidence of Clostridium difficile infection (CDI) in adults with malignancy is 7%-14% compared with 1%-2% in the general hospitalized population. Despite the increased incidence of CDI in this population, a major concern is the propensity of CDI to recur, leading to delays in therapy impacting outcomes. We conducted a retrospective case-control study to identify risk factors for recurrent CDI (rCDI) and to determine the impact of rCDI on adult patients with a haematological malignancy. Methods Adult haematology patients with CDI from June 2010 to December 2014 were divided into two groups: rCDI and non-rCDI. Multivariable models using logistic regression were constructed to identify risk factors for rCDI. Results A total of 100 patients in our study yielded a 41% recurrence rate. CDI impacted chemotherapy significantly more in the rCDI group (53.7% versus 11.9%, P

Central nervous system (CNS) relapse in acute myeloid leukemia (AML) confers a poor prognosis. Despite the identification of risk factors for CNS relapse (e.g. hyperleukocytosis), there is no standard practice for CNS relapse risk reduction with intrathecal (IT) chemotherapy in patients. We compared outcomes of 50 patients who did not receive IT chemotherapy with 18 patients who did receive IT chemotherapy with a hyperleukocytosis at diagnosis (defined as white blood cell count ≥100,000 cells/mcL). There were three occurrences of CNS relapse, all within patients who did not receive prophylaxis. There was no difference in the incidence of CNS relapse between the patient cohorts (

Introduction Acute myeloid leukemia (AML) is a heterogeneous clonal hematopoietic neoplasm. The cytogenetic changes associated with AML affect the response rate and survival and are one of the most important independent prognostic factors. AML with inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM accounts for 1% to 2% of all forms of AML and has been associated with a younger age at diagnosis, a poor response to standard induction chemotherapy, and very poor long-term prognosis. Patients and Methods We performed a single-center, retrospective cohort study comparing the outcomes with hypomethylating agent (HMA) plus lenalidomide to those with standard intensive induction therapies for newly diagnosed and relapsed/refractory AML with inv(3). Results Of the 15 patients, 4 (26.7%) had received lenalidomide and HMA as primary therapy. The overall response rate (ORR) was 100% for the 4 patients who had received lenalidomide with HMA as first-line induction therapy. The ORR was 27.3% (3 of 11) for the patients who had received other induction regimens (P = .0256). The duration of response for first induction therapy was an average of 7.4 months after lenalidomide plus an HMA and a mean of 1.5 months after induction with other chemotherapy regimen (P = .057). The ORR for induction and reinduction therapy was also assessed, with an ORR of 21.4% (6 of 28) for alternative chemotherapy regimens and an ORR of 75% (6 of 8) for induction and reinduction with lenalidomide plus HMA (P = .0046). Conclusions The high ORR and reasonable duration of response could allow for potentially curative allogeneic hematopoietic cell transplantation for these patients with high-risk AML. Our initial data suggest that lenalidomide plus HMA is a promising approach for patients with AML with inv(3).

Background Despite fungal prophylaxis, invasive mold infections (IMIs) are a significant cause of morbidity and mortality in patients with acute myeloid leukemia (AML) receiving remission induction chemotherapy. The choice of antifungal prophylaxis agent remains controversial, especially in the era of novel targeted therapies. We conducted a retrospective case–control study to determine the incidence of fungal infections and to identify risk factors associated with IMI. Methods Adult patients with AML receiving anti-Aspergillus prophylaxis were included to determine the incidence of IMI per 1000 prophylaxis-days. Patients without and with IMI were matched 2:1 based on the day of IMI diagnosis, and multivariable models using logistic regression were constructed to identify risk factors for IMI. Results Of the 162 included patients, 28 patients had a possible (n = 22), probable, or proven (n = 6) diagnosis of IMI. The incidence of proven or probable IMI per 1000 prophylaxis-days was not statistically different between anti-Aspergillus azoles and micafungin (1.6 vs 5.4, P = .11). The duration of prophylaxis with each agent did not predict IMI occurrence on regression analysis. Older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.004–1.081; P = .03) and relapsed/refractory AML diagnosis (OR, 4.44; 95% CI, 1.56–12.64; P = .003) were associated with IMI on multivariable analysis. Conclusions In cases that preclude use of anti-Aspergillus azoles for prophylaxis, micafungin 100 mg once daily may be considered; however, in older patients and those with relapsed/refractory disease, diligent monitoring for IMI is required, irrespective of the agent used for antifungal prophylaxis., The risk for proven or probable breakthrough invasive mold infections (IMI) in acute myeloid leukemia (AML) patients undergoing induction chemotherapy was not different between patients receiving micafungin or anti-aspergillus azoles. Older patients and those with relapsed or refractory AML were at the highest risk of breakthrough IMI.

Key Points This is the first report of successful treatment of therapy-resistant leptomeningeal T-PLL with intrathecal alemtuzumab. Intrathecal alemtuzumab is a potentially safe and efficacious therapeutic alternative for treatment of leptomeningeal T-PLL.

High dose cytarabine (HIDAC) consolidation has demonstrated a survival benefit in patients with acute myeloid leukemia (AML). The increasing prevalence of obesity and the toxicity risk with this therapy renders important the quantification of potential risks with weight-based dosing in this patient population. The American Society of Clinical Oncology published recommendations on chemotherapy dosing in obese patients, but patients with leukemia were excluded from analysis. This was a retrospective comparison of safety and efficacy outcomes in obese and non-obese patients with AML who received HIDAC consolidation. Thirty-nine (41.9 %) patients received dose adjusted HIDAC in cycle 1. Nine of the 40 patients in the obese group received HIDAC dose-adjusted for obesity. The combined incidence of cycle delays, febrile neutropenia, or documented infection was 41.5 % in non-obese patients compared to 57.5 % in obese patients (p = 0.127). The median overall survival (OS) and event free survival (EFS) were not reached in both cohorts. The estimated 36-month overall survival was 76.4 % (95 % CI 0.623-0.905) in non-obese patients, compared to 66.1 % (95 % CI 0.472-0.85) in obese patients. There were no significant differences in safety or efficacy outcomes for obese versus non-obese patients who received HIDAC consolidation. For class III obesity, baseline dose-adjustments were more common.

Pediatric high-grade glioma (HGG, WHO Grade III and IV) is a devastating brain tumor with a median survival of less than two years. PDGFRA is frequently mutated/ amplified in pediatric HGG, but the significance of this finding has not been fully characterized. We hypothesize that alterations of PDGFRA will promote distinct prognostic and treatment implications in pediatric HGG. In order to characterize the impact of PDGFR pathway alterations, we integrated genomic data from pediatric HGG patients (n=290) from multiple pediatric datasets and sequencing platforms. Integration of multiple human datasets showed that PDGFRA mutation, but not amplification, was associated with older age in pediatric HGG (P=

Acute myeloid leukemia is a hematologic malignancy characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow, and other tissues. Prognosis is poor with 5-year survival rates ranging from 5–65% depending on demographic and clinical features. Outcomes are worse for patients that have an antecedent myeloproliferative neoplasm that evolves to acute myeloid leukemia, with a survival rate of 15 mg/dL).

Systemic mastocytosis (SM) is characterized by a clonal proliferation of aberrant mast cells within extracutaneous sites. In a subset of SM cases, a second associated hematologic non-mast cell disease (AHNMD) is also present, usually of myeloid origin. Polymerase chain reaction and targeted fluorescence in situ hybridization studies have provided evidence that, in at least some cases, the aberrant mast cells are related clonally to the neoplastic cells of the AHNMD. In this work, a single nucleotide polymorphism microarray (SNP-A) was used to characterize the cytogenetics of the aberrant mast cells from a patient with acute myeloid leukemia and concomitant mast cell leukemia associated with a KIT D816A mutation. The results demonstrate the presence of shared cytogenetic abnormalities between the mast cells and myeloid blasts, as well as additional abnormalities within mast cells (copy-neutral loss of heterozygosity) not detectable by routine karyotypic analysis. To our knowledge, this work represents the first application of SNP-A whole-genome scanning to the detection of shared cytogenetic abnormalities between the two components of a case of SM-AHNMD. The findings provide additional evidence of a frequent clonal link between aberrant mast cells and cells of myeloid AHNMDs, and also highlight the importance of direct sequencing for identifying uncommon activating KIT mutations.

Multiple BCR-ABL tyrosine kinase inhibitors (TKIs) are available for the treatment of chronic myeloid leukemia in chronic phase (CML-CP), and several baseline and on-treatment predictive factors have been identified that can be used to help guide TKI selection for individual patients. In particular, early molecular response (EMR; BCR-ABL ≤10% on the International Scale at 3 months) has become an accepted benchmark for evaluating whether patients with CML-CP are responding optimally to frontline TKI therapy. Failure to achieve EMR is considered an inadequate initial response according to the National Comprehensive Cancer Network guidelines and a warning response according to the European LeukemiaNet recommendations. Here we review data supporting the importance of achieving EMR for improving patients' long-term outcomes and discuss key considerations for selecting a frontline TKI in light of these data. Because a higher proportion of patients achieve EMR with second-generation TKIs such as nilotinib and dasatinib than with imatinib, these TKIs may be preferable for many patients, particularly those with known negative prognostic factors at baseline. We also discuss other considerations for frontline TKI choice, including toxicities, cost-effectiveness, and the emerging goals of deep molecular response and treatment-free remission.

7510 Background: CPX-351 (Vyxeos; daunorubicin and cytarabine liposome for injection), a dual-drug liposomal encapsulation of cytarabine [C] and daunorubicin [D], is approved by the FDA and EMA for the treatment of adults with newly diagnosed therapy-related AML or AML with myelodysplasia-related changes. Primary analysis of the pivotal phase 3 study (NCT01696084) that formed the basis for these approvals evaluated patients (pts) aged 60-75 y with newly diagnosed high-risk/secondary AML and found that CPX-351 significantly improved median overall survival (OS) vs conventional 7+3, with a comparable safety profile. Here, we report the prospectively planned final 5-y follow-up results from this phase 3 study. Methods: Pts were randomized 1:1 to receive ≤2 induction cycles of CPX-351 (100 units/m2 [C 100 mg/m2 + D 44 mg/m2] as a 90-min infusion on Days 1, 3, 5 [2nd induction: Days 1, 3]) or 7+3 (C 100 mg/m2/d continuously for 7 d + D 60 mg/m2 on Days 1-3 [2nd induction: 5+2]). Pts achieving complete remission (CR) or CR with incomplete platelet or neutrophil recovery could receive up to 2 consolidation cycles. Pts could receive a hematopoietic cell transplant (HCT) at the physician’s discretion. Pts were followed until death or up to 5 y following randomization. Results: In total, 309 pts were randomized to CPX-351 (n = 153) or 7+3 (n = 156). The survival rate at 5 y was higher for CPX-351 vs 7+3 (18% vs 8%; Table). Among pts who died, the most common primary cause of death was progressive leukemia in both arms (CPX-351: 56%; 7+3: 53%). After a median follow-up of 60.65 mo, improved median OS with CPX-351 vs 7+3 was maintained: 9.33 vs 5.95 mo; Kaplan-Meier (KM) OS curves plateaued at ~30 mo. HCT was received by 53 (35%) vs 39 (25%) pts after CPX-351 vs 7+3; among these pts, the survival rate at 5 y was higher for CPX-351 vs 7+3 (52% vs 23%), and median OS landmarked from the HCT date was not reached for CPX-351 vs 10.25 mo for 7+3 (Table). Conclusions: After 5 y of follow-up, improved OS was maintained in this phase 3 study, supporting that CPX-351 has the ability to produce or contribute to long-term remission and survival in older pts with newly diagnosed high-risk/secondary AML. Clinical trial information: NCT01696084 . [Table: see text]

Treatment of acute myeloid leukemia (AML) among the elderly is challenging because of intolerance of intensive therapy and therapy-resistant biology. Hypomethylating agents (HMAs) are commonly used, with suboptimal outcomes. Vadastuximab talirine is a CD33-directed antibody conjugated to pyrrolobenzodiazepine (PBD) dimers. Preclinically, HMAs followed by vadastuximab talirine produced upregulated CD33 expression, increased DNA incorporation by PBD, and enhanced cytotoxicity. A combination cohort in a phase 1 study (NCT01902329) assessed safety, tolerability, and activity of vadastuximab talirine with HMAs. Those eligible had Eastern Cooperative Oncology Group status 0 to 1 and previously untreated CD33-positive AML, and declined intensive therapy. Vadastuximab talirine was administered intravenously at 10 μg/kg on last day of HMA (azacitidine or decitabine) infusion in 4-week cycles. Among 53 patients treated, the median age was 75 years. Patients had adverse (38%) or intermediate (62%) cytogenetic risk. Median treatment duration was 19.3 weeks. No dose-limiting toxicities were reported. The majority of adverse events were a result of myelosuppression, with some causing therapy delays. Thirty- and 60-day mortality rates were 2% and 8%, respectively. The composite remission rate (complete remission [CR] and CR with incomplete blood count recovery) was 70%. Fifty-one percent of remissions were minimal residual disease-negative by flow cytometry. Similarly high remission rates were observed in patients with secondary AML, aged at least 75 years, and with adverse cytogenetic risk. Median relapse-free survival and overall survival were 7.7 and 11.3 months, respectively. Compared with historical data for HMA monotherapy, the combination of vadastuximab talirine with HMAs produced a high remission rate, but was accompanied by increased hematologic toxicity.

Purpose CPX-351 is a dual-drug liposomal encapsulation of cytarabine and daunorubicin that delivers a synergistic 5:1 drug ratio into leukemia cells to a greater extent than normal bone marrow cells. Prior clinical studies demonstrated a sustained drug ratio and exposure in vivo and prolonged survival versus standard-of-care cytarabine plus daunorubicin chemotherapy (7+3 regimen) in older patients with newly diagnosed secondary acute myeloid leukemia (sAML). Patients and Methods In this open-label, randomized, phase III trial, 309 patients age 60 to 75 years with newly diagnosed high-risk/sAML received one to two induction cycles of CPX-351 or 7+3 followed by consolidation therapy with a similar regimen. The primary end point was overall survival. Results CPX-351 significantly improved median overall survival versus 7+3 (9.56 v 5.95 months; hazard ratio, 0.69; 95% CI, 0.52 to 0.90; one-sided P = .003). Overall remission rate was also significantly higher with CPX-351 versus 7+3 (47.7% v 33.3%; two-sided P = .016). Improved outcomes were observed across age-groups and AML subtypes. The incidences of nonhematologic adverse events were comparable between arms, despite a longer treatment phase and prolonged time to neutrophil and platelet count recovery with CPX-351. Early mortality rates with CPX-351 and 7+3 were 5.9% and 10.6% (two-sided P = .149) through day 30 and 13.7% and 21.2% (two-sided P = .097) through day 60. Conclusion CPX-351 treatment is associated with significantly longer survival compared with conventional 7+3 in older adults with newly diagnosed sAML. The safety profile of CPX-351 was similar to that of conventional 7+3 therapy.

Patients with secondary acute myeloid leukemia (sAML) have poor outcomes, with CR/CRi rates of 25-35% with standard 7 + 3 induction chemotherapy, while single center non-comparative analyses suggest promising outcomes with FLAG. We conducted a single-center, retrospective cohort study assessing outcomes in treatment-naïve patients with sAML treated with fludarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (FLAG, n = 40) compared with 7 + 3 (n = 66). Median patient age was 63 years (range: 27-82) in the FLAG group and 60 years (range: 21-76) in the 7 + 3 group (P = 0.968). Patients treated with FLAG achieved higher overall response rates (CR + CRi + MLFS) compared to 7 + 3 (70% vs. 48%, P = 0.043). FLAG was well tolerated, with only one induction death (30-day mortality rate, 3% vs. 8%, P = 0.405) and no cases of cerebellar toxicity. Duration of neutropenia was significantly shorter with FLAG (median 16 vs. 23 days, P 0.001). Half of the FLAG-treated patients proceeded to consolidative therapy compared with only 27% of those who received 7 + 3 (P = 0.022). Overall survival was comparable between groups (8.5 mos, FLAG vs. 9.1 mos, 7 + 3; P = 0.798). Thus, FLAG may represent a low-cost treatment strategy in sAML that produces higher response rates and promising survival outcomes with minimal treatment-related toxicity. Further studies are required to prospectively compare FLAG to the newly FDA-approved CPX-351 in sAML.

Vadastuximab talirine (SGN-CD33A, 33A) is an antibody-drug conjugate consisting of pyrrolobenzodiazepine dimers linked to a monoclonal antibody targeting CD33, which is expressed in the majority of acute myeloid leukemia (AML) patients. This phase 1 study evaluated the safety, pharmacokinetics, and preliminary activity of vadastuximab talirine and determined the recommended monotherapy dose in patients with relapsed or refractory AML. Additional expansion cohorts tested vadastuximab talirine in specific subpopulations of relapsed AML, and in a cohort of older, treatment-naive patients. Patients received vadastuximab talirine IV on day 1 (5-60 µg/kg) or on days 1 and 4 (20 µg/kg) of 21-day cycles. A total of 131 patients (median age, 73 years [range, 26-89 years]) had intermediate I-II (48%) or adverse (34%) risk by European LeukemiaNet classification; 50% of patients had underlying myelodysplasia. Two dose-limiting toxicities (grade 2 pulmonary embolism and grade 4 hypocellular marrow) occurred during dose finding. Most adverse events (AEs) were consistent with myelosuppression; nonhematologic AEs included fatigue, nausea, and diarrhea. The 30-day mortality was 8%. At the recommended monotherapy dose of 40 µg/kg, the complete remission + CRi rate was 28% (5 of 18 patients); 50% of patients who responded achieved minimal residual disease negativity. In patients across dose levels who achieved CR or CRi, the median time to full count recovery was 6.4 weeks for neutrophils (≥1000/µL) and 10.6 weeks for platelets (≥100 × 109/L). Vadastuximab talirine demonstrates activity and a tolerable safety profile as a single agent in patients with AML. The recommended monotherapy dose of vadastuximab talirine is 40 µg/kg. This trial was registered at www.clinicaltrials.gov as # NCT01902329.

Allogeneic hematopoietic cell transplantation (HCT) has been increasingly used in the setting of FMS-like tyrosine kinase-3 (FLT3)-mutated AML. However, its role in conferring durable relapse-free intervals remains in question. Herein we sought to investigate FLT3 mutational status on transplant outcomes. We conducted a retrospective cohort study of 262 consecutive AML patients who underwent first-time allogeneic HCT (2008-2014), of whom 171 had undergone FLT3-ITD (internal tandem duplication) mutational testing. FLT3-mutated AML was associated with nearly twice the relapse risk (RR) compared with those without FLT3 mutation 3 years post-HCT (63% vs 37%, P

Latent HIV infection of long-lived cells is a barrier to viral clearance. Hematopoietic stem and progenitor cells are a heterogeneous population of cells, some of which are long-lived. CXCR4-tropic HIVs infect a broad range of HSPC subtypes, including hematopoietic stem cells, which are multi-potent and long-lived. However, CCR5-tropic HIV infection is limited to more differentiated progenitor cells with life spans that are less well understood. Consistent with emerging data that restricted progenitor cells can be long-lived, we detected persistent HIV in restricted HSPC populations from optimally treated people. Further, genotypic and phenotypic analysis of amplified env alleles from donor samples indicated that both CXCR4- and CCR5-tropic viruses persisted in HSPCs. RNA profiling confirmed expression of HIV receptor RNA in a pattern that was consistent with in vitro and in vivo results. In addition, we characterized a CD4high HSPC sub-population that was preferentially targeted by a variety of CXCR4- and CCR5-tropic HIVs in vitro. Finally, we present strong evidence that HIV proviral genomes of both tropisms can be transmitted to CD4-negative daughter cells of multiple lineages in vivo. In some cases, the transmitted proviral genomes contained signature deletions that inactivated the virus, eliminating the possibility that coincidental infection explains the results. These data support a model in which both stem and non-stem cell progenitors serve as persistent reservoirs for CXCR4- and CCR5-tropic HIV proviral genomes that can be passed to daughter cells., Author summary People who are effectively treated with antiretroviral medication harbor persistent forms of HIV that are integrated into the cellular genome. While HIV is cytopathic to most cells, transcriptionally silent, latent forms do not express toxic HIV gene products and can survive in the host for years. When conditions change, the latent virus can be activated to reinitiate infection. Because of the capacity for virus to spread, cure of HIV will require that we identify and eradicate all cells harboring functional HIV provirus. CD4+ T cells are abundant and easily identified as harboring proviral genomes. However, rare cell types that express HIV receptors, such as bone marrow hematopoietic progenitor and stem cells can also be infected by the virus potentially serving as barriers to cure strategies. We found that HIV can infect and persist in progenitor sub-types that were previously thought to be short lived, which expands the types of cells that can support reservoir formation. In addition, we found that HIV can spread by proliferation and cellular differentiation without the need for viral gene expression and virion production that could reveal the infection to the immune system. A deeper understanding of viral reservoirs is critically important for developing strategies that will succeed in viral eradication.

Leukemic myeloblasts expressing E-selectin ligand (E-sel ligand) adhere to E-selectin on bone marrow endothelium resulting in environment-mediated drug resistance (EMDR). Uproleselan, a potent E-selectin inhibitor, disrupts the adhesion of AML cells in the bone marrow, re-sensitizing blasts to the cytotoxic effects of chemotherapy. Retrospective data demonstrated that E-sel ligand expression in AML patients is higher in relapsed disease compared to newly diagnosed AML, is more commonly seen in biologically adverse risk patients, and is present on leukemic stem cells (Chien et al ASH 2018). Preliminary data from a phase 1-2 trial of uproleselan combined with mitoxantrone, etoposide, cytarabine (MEC) chemotherapy in R/R AML demonstrated enhanced survival in patients with E-sel ligand expression on AML cells of > 10% compared to lower levels (DeAngelo et al ASH 2018). In order to more fully understand the relationship of E-sel ligand to the activity of uproleselan, we examined the clinical variables of patients with both high (> 10%) and low E-sel ligand levels in comparison to the total population of patients treated on the phase 1-2 trial. Uproleselan, combined with MEC chemotherapy was studied in 66 patients with relapsed and/or refractory AML. The expression level of E-sel ligand on the surface of AML cells (blasts/leukemic stem cells (LSCs)) in the bone marrow was measured by a flow cytometric assay using the HECA 452 antibody that recognizes a functional trisaccharide domain shared by sialyl Lea and sialyl Lex and known to bind to E-selectin. Data on E-sel ligand was available in 36 patients at study entry in the phase 1-2 study and E-sel ligand was detectable on blasts in all patients. E-sel ligand on LSCs was demonstrated at levels ≥ 10% in 22 patients (61%) and at levels < 10 % in 14 patients (39%). Overall, the clinical characteristics confirmed a highly resistant population of R/R AML patients (see table) with 79% categorized as either poor risk by the European Prognostic Index (EPI) for first salvage therapy or ≥ second salvage, with an expected 1 year survival of less than 20% (Breems et al JCO 2005, Giles et al Cancer 2005). Although the sample size was small (n=36), substantially more patients with high E-sel ligand had achieved an initial remission and were in relapse (68%) whereas low E-sel ligand patients were more likely to be primary refractory (57%) (p=0.17). Patients with high E-sel ligand were more likely to have adverse ELN risk disease (55%) compared to low E-sel ligand patients (28%) (p=0.053). These data are consistent with previous findings demonstrating that higher E-sel ligand expression contributes to clinical chemotherapy resistance, particularly increasing the risk of relapse, whereas alternative resistance mechanisms may more commonly contribute to primary resistance. Importantly, the 45% response rate and 12.7 months median overall survival (OS) in the high E-sel ligand patients suggests that E-selectin inhibition by uproleselan contributed to their significantly improved outcomes when compared to the historically dismal outcomes with standard of care alone in these poor risk R/R AML patients. Table. Disclosures DeAngelo: Incyte Corporation: Consultancy; Celgene Corporation: Consultancy; Pfizer, Inc.: Consultancy; GlycoMimetics: Research Funding; AbbVie, Inc.: Research Funding; Takeda Pharmaceuticals: Consultancy; Shire: Consultancy; Amgen: Consultancy; Blue Print Medicines: Consultancy, Research Funding; Jazz Pharmaceuticals, Inc.: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding. Jonas:AbbVie, Accelerated Medical Diagnostics, AROG, Celgene, Daiichi Sankyo, Esanex, Forma, Genentech/Roche, GlycoMimetics, Incyte, LP Therapeutics, Pharmacyclics: Research Funding; AbbVie, Amgen, Celgene, GlycoMimetics, Jazz, Pharmacyclics, Tolero: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie, Amgen, GlycoMimetics: Other: Travel expenses. Liesveld:Abbvie: Membership on an entity's Board of Directors or advisory committees; Onconova: Other: Data safety monitoring board. Advani:Pfizer: Honoraria, Research Funding; Glycomimetics: Consultancy, Research Funding; Amgen: Research Funding; Kite Pharmaceuticals: Consultancy; Abbvie: Research Funding; Macrogenics: Research Funding. Marlton:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees. O'Dwyer:Onkimmune: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics Inc: Research Funding; BMS: Research Funding. Fogler:GlycoMimetics Inc: Employment, Equity Ownership. Magnani:GlycoMimetics Inc: Employment, Equity Ownership. Chen:GlycoMimetics: Employment. Feldman:GlycoMimetics Inc: Employment. Thackray:GlycoMimetics Inc: Employment. Becker:AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding; Accordant Health Services/Caremark: Consultancy; The France Foundation: Honoraria.

Summary: Long-lived reservoirs of persistent HIV are a major barrier to a cure. CD4+ hematopoietic stem and progenitor cells (HSPCs) have the capacity for lifelong survival, self-renewal, and the generation of daughter cells. Recent evidence shows that they are also susceptible to HIV infection in vitro and in vivo. Whether HSPCs harbor infectious virus or contribute to plasma virus (PV) is unknown. Here, we provide strong evidence that clusters of identical proviruses from HSPCs and their likely progeny often match residual PV. A higher proportion of these sequences match residual PV than proviral genomes from bone marrow and peripheral blood mononuclear cells that are observed only once. Furthermore, an analysis of near-full-length genomes isolated from HSPCs provides evidence that HSPCs harbor functional HIV proviral genomes that often match residual PV. These results support the conclusion that HIV-infected HSPCs form a distinct and functionally significant reservoir of persistent HIV in infected people. : HIV causes an infection that persists even when optimal therapy is used. Zaikos et al. provide evidence that HIV-infected progenitor cells from the bone marrow can amplify virus through normal cellular growth pathways in some treated people. Keywords: HIV, latency, reservoir, virus, persistence, clonal, hematopoietic, human, defective, infectious

This study evaluated the impact of antibacterial prophylaxis with levofloxacin in relapsed/refractory acute myeloid leukemia (AML) patients. This was a retrospective, single-center, cohort study. Adult patients with relapsed/refractory AML admitted for reinduction chemotherapy between November 1, 2006 and June 15, 2015 were screened for inclusion. A protocol initiating levofloxacin prophylaxis was implemented on December 1, 2013. Patients receiving hypomethylating agents (decitabine/azacitidine) were not administered antibacterial prophylaxis and thus not included in this analysis. Patients receiving broad spectrum antibiotics on day 1 of reinduction chemotherapy or receiving another antibacterial agent for prophylaxis were also excluded. Ninety-seven patients were included in the control group (no prophylaxis), while 48 patients received levofloxacin prophylaxis. Patients in the prophylaxis group received levofloxacin 500 mg once daily on day 1 of chemotherapy and continued until neutrophil recovery (or hospital discharge or death). There was a reduction in the rate of bacteremia in the prophylaxis group (37.5 %) compared to the control group (53.6 %, p = 0.0789), largely due to a reduction in gram-negative bacteremia (2.1 vs. 21.6 % respectively, p = 0.001). No difference was found between prophylaxis and the control groups in the incidence of neutropenic fever, incidence of multidrug resistance, length of hospital or ICU stay, or mortality. Levofloxacin prophylaxis reduced the rate of infections overall in adult patients with relapsed/refractory AML, without increasing rates of multidrug-resistant organisms.

Introduction: SY-1425 (tamibarotene) is an orally available, synthetic retinoid in Phase 2 development for non-APL AML and MDS patients (pts) positive for the RARA and/or IRF8 biomarkers of RARA pathway activation (McKeown et al, Cancer Discovery, 2017). Biomarker-selected pts treated with SY-1425 single agent showed myeloid differentiation, improved blood counts and reduced bone marrow blasts, and treatment was generally well tolerated with manageable and/or reversible side effects (Jurcic et al, ASH 2017). SY-1425 showed evidence of combination activity in preclinical models. Synergy was observed with HMAs, with DNA damage and apoptosis in vitro, and in an AML PDX model the combination of SY-1425 and azacitidine (Aza) demonstrated increased tumor reduction, deeper, more durable responses and improved survival relative to Aza or SY-1425 alone (McKeown et al, ASH 2016). SY-1425 induced CD38 expression in preclinical models and the combination with daratumumab (Dara), a CD38 targeting antibody indicated for multiple myeloma (MM), induced immune-mediated cell death ex vivo (Austgen et al, AACR 2017). SY-1425 also increased CD38 expression in bone marrow blasts in AML/MDS pts (Jurcic et al, ASH 2017). These data support the ongoing investigation of the efficacy and safety of SY-1425 in non-APL AML and MDS pts, in combination with Aza or Dara (NCT02807558). Methods: Biomarker positive (Bm+), unfit pts with newly-diagnosed (ND) AML received SY-1425 + Aza. The SY-1425 + Aza combination arm was recently expanded to include biomarker negative pts. Bm+ pts with relapsed/refractory (R/R) AML or R/R higher-risk MDS received SY-1425 + Dara. All enrolled pts received SY-1425 at 6 mg/m2/day PO with twice daily dosing. Aza (75 mg/m2 IV/SC) and Dara (16 mg/kg IV) were dosed as approved in MDS and MM, respectively. Objectives included characterization of activity by overall response rate (per IWG), duration of response, event-free, relapse-free and overall survival, hematologic improvement, and assessment of safety. For pts treated with SY-1425 + Dara, the kinetics and magnitude of CD38 increases were evaluated on peripheral blasts using a centralized assay. Results: With 10 ND AML pts currently enrolled to receive SY-1425 + Aza, 6 were Bm+. Data through 9 July 2018 were available for 5 Bm+ pts, 4 (80%) male and median age 76 years (64-83). Pts were reported to have poor (3 pts) and intermediate (2 pts) ELN genetic risk. Median time on treatment was 25.4 weeks (9.7-42.1). Early clinical responses at 4 weeks (C2D1) were reported in 4 of 5 pts. Best responses were CR (1 pt), CRi (1 pt) and PRi (2 pts), defined as PR with incomplete blood count recovery. A 5th pt with ND AML developing from prior CMML with 2 distinct blast populations had stable disease (AML blasts), but with CR of CMML marrow blasts by flow at 8 weeks (C3D1). 2 pts remained on treatment, including 1 with CR at 9 months (C10D1). 3 pts discontinued due to PD/lack of efficacy (2 pts) and AE (1 pt). 10 Bm+ pts have enrolled to receive SY-1425 + Dara. Data were available for 4 pts (3 R/R AML and 1 R/R MDS), 4 (100%) female and median age 60 years (36-68). Pt risk was poor (2 pts) and intermediate (1 pt) per ELN for AML, and good (1 pt) per IPSS-R for MDS. Median time on treatment was 5.9 weeks (0.7-8.9). 1 of 3 evaluable pts achieved a PRi at 4 weeks (C2D1) but progressed at C3D1. Initial data demonstrate that 3 of 4 pts showed an increase in CD38 expression levels in peripheral AML blasts as early as 3 days following SY-1425 treatment, up to 2.6-fold by 1 week. All 4 pts discontinued treatment due to disease progression. AEs (most common, all causality) reported in >2 pts receiving SY-1425 combination treatment included febrile neutropenia (44%), and hypertriglyceridemia, pruritus, abdominal pain and peripheral edema (33% each). Overall, AEs, including AEs ≥ grade 3 and SAEs, were consistent with those of single agent SY-1425, Aza or Dara. Conclusion: SY-1425 in combination with Aza in non-APL AML shows preliminary evidence of clinical activity with early objective responses observed. CD38 expression increased in 3 of 4 pts with R/R AML or R/R MDS within 3 days of SY-1425 treatment and reduction in marrow blasts was observed in 1 pt treated with SY-1425 in combination with Dara. No new safety signals have been identified with either combination regimen. In summary, early data suggest SY-1425 in combination has clinical potential in pts with non-APL AML and MDS. Updated results will be presented. Disclosures Cook: Syros Pharmaceuticals: Consultancy. Liesveld:Abbvie: Honoraria; Onconova: Other: DSMB. Rizzieri:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Arog: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teva: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy. Stein:Novartis: Consultancy; Agios: Consultancy; Pfizer: Consultancy; Daiichi Sankyo: Consultancy; Celgene: Consultancy; Bayer: Consultancy. Roboz:Argenx: Consultancy; Jazz Pharmaceuticals: Consultancy; AbbVie: Consultancy; Astex Pharmaceuticals: Consultancy; Cellectis: Research Funding; Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Astex Pharmaceuticals: Consultancy; Cellectis: Research Funding; Sandoz: Consultancy; Bayer: Consultancy; Otsuka: Consultancy; Novartis: Consultancy; Daiichi Sankyo: Consultancy; Novartis: Consultancy; Eisai: Consultancy; Celgene Corporation: Consultancy; Celltrion: Consultancy; AbbVie: Consultancy; Roche/Genentech: Consultancy; Pfizer: Consultancy; Orsenix: Consultancy; Celgene Corporation: Consultancy; Roche/Genentech: Consultancy; Orsenix: Consultancy; Argenx: Consultancy; Janssen Pharmaceuticals: Consultancy; Eisai: Consultancy; Bayer: Consultancy; Celltrion: Consultancy; Aphivena Therapeutics: Consultancy; Aphivena Therapeutics: Consultancy; Janssen Pharmaceuticals: Consultancy; Jazz Pharmaceuticals: Consultancy; Otsuka: Consultancy; Sandoz: Consultancy. Sekeres:Opsona: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Opsona: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Jurcic:Actinium Pharmaceuticals, Inc: Research Funding; Daiichi-Sankyo: Research Funding; Forma Therapeutics: Research Funding; Syros Pharmaceuticals: Research Funding; AbbVie: Consultancy, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Kura Oncology: Research Funding; Genetech: Research Funding; Incyte: Consultancy; Celgene: Research Funding; Astellas: Research Funding. Raza:Kura Oncology: Research Funding; Geoptix: Speakers Bureau; Novartis: Speakers Bureau; Celgene: Research Funding; Janssen: Research Funding; Onconova: Research Funding, Speakers Bureau; Syros: Research Funding. Bixby:GlycoMimetics: Research Funding. Cortes:Pfizer: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Astellas Pharma: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Arog: Research Funding. Stephens:Syros Pharmaceuticals: Employment, Equity Ownership. Volkert:Syros Pharmaceuticals: Employment, Equity Ownership. Kang:Syros Pharmaceuticals: Employment, Equity Ownership. Di Tomaso:Syros Pharmaceuticals: Employment, Equity Ownership. Roth:Syros Pharmaceuticals: Employment, Equity Ownership.

Background Binding of E-selectin (E-sel) to sialyl Lex on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Expression of the E-sel ligand (E-sel-L) is associated with increased relapse and poor survival. Uproleselan (GMI-1271), a novel E-sel antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity with improved survival in vivo. We added uproleselan to mitoxantrone, etoposide, cytarabine (MEC) chemotherapy for R/R AML patients (pts) and to cytarabine and idarubicin (7+3) induction for older, treatment naïve (TN) AML pts. Here we report on final outcomes and correlative studies. Methods A Phase (Ph) 1/2 trial evaluated safety and efficacy of escalating doses of upro (5-20 mg/kg) combined with MEC in pts with R/R AML. The recommended Ph 2 dose (RP2D) was 10 mg/kg. Ph 2 added pts ≥60 yrs with TN AML treated with upro and 7+3. Uproleselan was given 24 hrs prior, every 12 hrs during and 48 hrs post chemotherapy. Responders could receive consolidation therapy (1 cycle MEC or 1-3 cycles IDAC) with uproleselan. Baseline E-sel-L expression on AML blasts (CD45+,SSC) and leukemic stem cells (LSC, CD34+CD38-CD123+) in blood and bone marrow (BM) was assessed by flow cytometry, for percentage of blasts binding to E-sel-Fc chimeric protein and HECA452 (antibody to sialyl Lex). Post-induction measurable residual disease (MRD-/MRD+) was assessed locally. Results 91 pts were enrolled (Ph 1 R/R=19; Ph 2 R/R=47. TN=25). Median age in R/R pts was 59 yrs (26-84) with 22/66 (33%) primary refractory, 22 (33%) CR1 Median age in TN pts was 67 yrs (60-79). 48% had adverse risk (ELN) and 52% secondary AML (sAML). Uproleselan was well tolerated, with no increase in adverse events, no Grade 3/4 mucositis, and mortality 8% (30d) and 12% (60d). CR/CRi was 72% (all), and 69% (sAML). 5/9 (56%) evaluable pts were MRD-. 19/25 (76%) proceeded to further anti-leukemic therapy; 11 (44%) proceeded to SCT. Median (95% CI) EFS, OS, and remission duration were 9.2 m (3.0-12.6), 12.6 m (9.9-NR), and 10.4 m (7.1-17.8) respectively; 1-year OS was 52%. For sAML, median (95% CI) EFS and OS were 7.7 m (1.1-9.5) and 10.5m (4.4-NR), respectively. For TN/MRD-, 1-year OS was 60%. E-sel-L was detectable on BM blasts in all 24 evaluable pts: median expression 31% (2-92) of blasts. In a subset of MRD evaluable pts (N=8), E-sel-L expression was higher in those who were MRD+ (35% vs 8%). In BM blasts (Figure N=24), LSC expression of E-sel-L correlated with blast E-sel-L (R2=0.87, p Conclusion The addition of uproleselan to chemotherapy was well tolerated, with low oral mucositis rates, high remission rates, high MRD- and transplant rates, and promising survival outcomes in pts with R/R and TN AML. High E-sel-L expression is associated with improved remission and survival with uproleselan treatment in R/R AML. Phase III studies in pts with R/R and (older) TN AML are underway. Figure. Figure. Disclosures DeAngelo: Shire: Honoraria; Amgen: Consultancy; BMS: Consultancy; ARIAD: Consultancy, Research Funding; Blueprint Medicines: Honoraria, Research Funding; Takeda: Honoraria; Glycomimetics: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria; Amgen: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Glycomimetics: Research Funding; Blueprint Medicines: Honoraria, Research Funding; Pfizer Inc: Consultancy, Honoraria; Shire: Honoraria; BMS: Consultancy; Takeda: Honoraria; Incyte: Consultancy, Honoraria; Pfizer Inc: Consultancy, Honoraria; ARIAD: Consultancy, Research Funding. Jonas:Glycomimetics: Research Funding; Genentech/Roche: Research Funding; Celgene: Consultancy, Research Funding; Accelerated Medical Diagnostics: Research Funding; Daiichi Sankyo: Research Funding; Incyte: Research Funding; Esanex: Research Funding; Tolero: Consultancy; Kalobios: Research Funding; LP Therapeutics: Research Funding; Amgen: Consultancy; Pharmacyclics: Research Funding; Forma: Research Funding; AbbVie: Consultancy, Research Funding. Liesveld:Onconova: Other: DSMB; Abbvie: Honoraria. Bixby:GlycoMimetics: Research Funding. Advani:Glycomimetics: Consultancy; Novartis: Consultancy; Amgen: Research Funding; Pfizer: Honoraria, Research Funding. Marlton:GlycoMimetics: Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. O'Dwyer:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Onkimmune: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Glycomimetics: Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees. Fogler:GlycoMimetics: Employment, Equity Ownership. Wolfgang:GlycoMimetics: Employment, Equity Ownership. Magnani:GlycoMimetics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Thackray:GlycoMimetics: Employment, Equity Ownership. Becker:GlycoMimetics: Research Funding.

Background: CPX-351 (Vyxeos®) is a dual-drug liposomal encapsulation of cytarabine and daunorubicin at a synergistic ratio. In a large randomized, open-label, multicenter, phase 3 study (NCT01696084) of CPX-351 versus conventional cytarabine/daunorubicin chemotherapy (7+3 regimen) in patients (pts) aged 60-75 years with newly diagnosed, high-risk/secondary AML, CPX-351 significantly improved overall survival (OS) and remission rates (Lancet JE, et al. J Clin Oncol. 2018). CPX-351 was approved by the US FDA in 2017 for the treatment of adults with newly diagnosed therapy-related AML or AML-MRC and is currently under review by the EMA. The WHO 2016 AML-MRC designation applies to AML pts who meet any of the following criteria: 1) a history of myelodysplastic syndrome (MDS) or myelodysplastic/myeloproliferative neoplasm (MDS/MPN), 2) an MDS-related cytogenetic abnormality, or 3) multilineage dysplasia in >50% of ≥2 cell lineages in the absence of NPM1 or biallelic CEBPA mutations. Pts with AML-MRC typically face a poor prognosis, with inferior outcomes in response to standard induction chemotherapy. A subgroup analysis of the phase 3 study was performed to specifically compare the efficacy and safety of CPX-351 versus 7+3 in pts with AML-MRC. Methods: Pts enrolled in the phase 3 study who met the WHO 2008 AML-MRC classification were included in this subgroup analysis; however, pts with a history of MPN other than CMML or combined MDS/MPN and pts with only morphologic evidence of multilineage dysplasia were excluded from the phase 3 study. Pts were randomized 1:1 to receive up to 2 inductions with CPX-351 (100 units/m2 [cytarabine 100 mg/m2 + daunorubicin 44 mg/m2] on Days 1, 3, and 5 [2nd induction: Days 1 and 3]) or 7+3 (cytarabine 100 mg/m2/day continuously for 7 days [2nd induction: 5 days] + daunorubicin 60 mg/m2 on Days 1-3 [2nd induction: Days 1-2]). Pts achieving complete remission (CR) or CR with incomplete platelet or neutrophil recovery (CRi) could receive up to 2 consolidations with CPX-351 (65 units/m2 [cytarabine 65 mg/m2 + daunorubicin 29 mg/m2] on Days 1 and 3) or 5+2 (as in 2nd induction). Pts could receive hematopoietic cell transplantation (HCT) at the discretion of their treating physician. Results: The study enrolled 309 pts, 246 of whom met the criteria for AML-MRC (CPX-351: n = 123; 7+3: n = 123). Of these 246 pts, 59.0% had antecedent MDS, 9.3% had antecedent CMML, and 31.7% had de novo AML with MDS karyotype. Baseline characteristics were similar between treatment arms (median age 68 years; 64.6% male; 11.0% with ECOG status of 2). A second induction cycle was received by 33.3% of pts in the CPX-351 arm and 37.8% of pts in the 7+3 arm. Among pts with AML-MRC, CPX-351 was associated with a significant OS benefit versus 7+3 (median: 9.07 vs 5.95 months; HR = 0.70 [95% CI: 0.53-0.93]). CPX-351 was also associated with higher rates of CR+CRi (48.0% vs 32.5%; OR = 1.83 [95% CI: 1.09-3.09]), CR (37.4% vs 24.4%; OR = 1.80 [95% CI: 1.02-3.17]), and HCT (33.3% vs 24.4%; OR = 1.53 [95% CI: 0.86-2.74]). Among pts who received HCT, median OS was longer with CPX-351 versus 7+3 when calculated from the date of randomization (not reached vs 15.21 months; HR = 0.50 [95% CI: 0.26-0.99]) or date of HCT (not reached vs 10.68 months; HR = 0.48 [95% CI: 0.24-0.96]). Early mortality rates in the CPX-351 and 7+3 arms, respectively, were 4.9% and 8.9% at Day 30 and 13.8% and 20.3% at Day 60. The treatment-emergent adverse event (TEAE) profile of CPX-351 in pts with AML-MRC was consistent with the overall study population and generally comparable between treatment arms (Table). Two pts treated with CPX-351 and 1 treated with 7+3 discontinued treatment due to a TEAE (cardiac failure [CPX-351], cardiomyopathy [CPX-351], and ejection fraction decreased [7+3]). Grade 5 TEAEs occurred in 8.9% and 14.3% of pts treated with CPX-351 and 7+3, respectively; those occurring in >1 pt in a treatment arm included sepsis (2.4% and 0.8%), disease progression (1.6% and 3.4%), multi-organ failure (0.8% and 1.7%), and respiratory failure (0.8% and 1.7%). Conclusions: In this subgroup analysis, CPX-351 improved OS and remission rates compared with 7+3 in older adults with AML-MRC, while maintaining a similar safety profile. Importantly, CPX-351 is the first agent to be associated with prolonged OS compared with standard-of-care chemotherapy (7+3 regimen) in adults with newly diagnosed AML-MRC, which supported FDA approval in this population. Disclosures Ryan: AbbVie: Equity Ownership; University of Rochester: Patents & Royalties. Uy:Curis: Consultancy; GlycoMimetics: Consultancy. Cortes:Astellas Pharma: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Arog: Research Funding; Pfizer: Consultancy, Research Funding. Ritchie:Bristol-Myers Squibb: Research Funding; Incyte: Consultancy, Speakers Bureau; NS Pharma: Research Funding; Novartis: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Astellas Pharma: Research Funding; Celgene: Consultancy, Other: Travel, Accommodations, Expenses, Speakers Bureau; Pfizer: Consultancy, Research Funding; ARIAD Pharmaceuticals: Speakers Bureau. Stuart:Sunesis Pharmaceuticals: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Agios: Research Funding; Astellas: Research Funding; Bayer AG: Research Funding; Celator/Jazz Pharmaceuticals: Research Funding; Incyte: Research Funding. Strickland:Sunesis Pharmaceuticals: Consultancy, Research Funding; Tolero Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Baxalta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas Pharma: Consultancy. Bixby:GlycoMimetics: Research Funding. Kolitz:Magellan Health: Consultancy, Honoraria. Schiller:bluebird bio: Research Funding; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding. Wieduwilt:Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Shire: Research Funding; Reata Pharmaceuticals: Equity Ownership; Leadiant: Research Funding; Amgen: Research Funding; Merck: Research Funding. Ryan:Jazz Pharmaceuticals: Employment, Other: Stock and stock options. Chiarella:Celator/Jazz Pharmaceuticals: Employment, Equity Ownership. Louie:Celator/Jazz Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties.

Background: Outcomes for the treatment of AML with conventional induction chemotherapy (eg, 7+3 cytarabine/daunorubicin regimen) are poor for older adults and those with high-risk/secondary AML. CPX-351 (Vyxeos®), a dual-drug liposomal encapsulation of cytarabine and daunorubicin in a synergistic ratio, was approved by the US FDA in 2017 for the treatment of adults with newly diagnosed, therapy-related AML or AML with myelodysplasia-related changes and is currently under review by the EMA. A large randomized, open-label, multicenter, phase 3 study (ClinicalTrials.gov #NCT01696084) evaluated the efficacy and safety of CPX-351 versus conventional 7+3 chemotherapy in adults aged 60-75 y with newly diagnosed, high-risk/secondary AML (Lancet JE, et al. J Clin Oncol. 2018). In this study, CPX-351 significantly improved median overall survival (OS; primary endpoint) versus 7+3 (9.56 vs 5.95 mo; HR = 0.69 [95% CI: 0.52-0.90]; 1-sided P = 0.003), as well as event-free survival (EFS; 2.53 vs 1.31 mo; HR = 0.74 [95% CI: 0.58-0.96]; 2-sided P = 0.021). CPX-351 was also associated with higher rates of complete remission (CR; 37.3% vs 25.6%; 2-sided P = 0.040) and CR or CR with incomplete platelet or neutrophil recovery (CR+CRi; 47.7% vs 33.3%; 2-sided P = 0.016) versus 7+3, which likely contributed to the higher rate of patients undergoing hematopoietic cell transplantation (HCT) with CPX-351 (34.0% vs 25.0%; 2-sided P = 0.098). HCT is a potentially curative therapy, and the higher rate of HCT observed in the CPX-351 arm could therefore have an impact on long-term survival outcomes. To better understand the contribution of HCT and treatment with CPX-351 versus 7+3 to survival, exploratory analyses using a time-dependent proportional hazards model were performed to evaluate survival in patients who underwent HCT and assess the impact of treatment with CPX-351 versus 7+3 on survival independent of HCT status. Methods: Patients were randomized 1:1 to receive up to 2 induction cycles with CPX-351 (100 units/m2 [cytarabine 100 mg/m2 + daunorubicin 44 mg/m2] on Days 1, 3, and 5 [2nd induction: Days 1 and 3]) or 7+3 (cytarabine 100 mg/m2/d continuously for 7 d [2nd induction: 5 d] + daunorubicin 60 mg/m2 on Days 1-3 [2nd induction: Days 1-2]). Patients achieving CR or CRi could receive up to 2 consolidations with CPX-351 (65 units/m2 [cytarabine 65 mg/m2 + daunorubicin 29 mg/m2] on Days 1 and 3) or 5+2 (as in 2nd induction). Patients could receive HCT at the discretion of the treating physician. Results: A total of 309 patients were enrolled in the study (CPX-351: n = 153; 7+3: n = 156), and baseline characteristics were balanced between arms. A total of 52 (34.0%) patients in the CPX-351 arm and 39 (25.0%) in the 7+3 arm underwent HCT; most were 60-69 y of age (CPX-351: 69.2%; 7+3: 84.6%), had ECOG performance status ≤1 (CPX-351: 92.3%; 7+3: 94.9%), and were in CR (CPX-351: 57.7%; 7+3: 48.7%) or CRi (CPX-351: 19.2%; 7+3: 12.8%). Median time to HCT from first study dose was similar with CPX-351 (114.5 d) and 7+3 (113.0 d). Similar to the primary endpoint analysis, median OS landmarked from the time of HCT was significantly improved with CPX-351 versus 7+3 (not reached vs 10.25 mo; HR = 0.46 [95% CI: 0.24-0.89]). Further, in the current exploratory analyses in which HCT was treated as a time-dependent covariate, the HRs remained strongly in favor of CPX-351 versus 7+3 for OS (HR = 0.71) and EFS (HR = 0.74), with the upper bounds of the 95% CIs below 1.0 (Table). These results suggest CPX-351 may be associated with prolonged OS and EFS that is independent of HCT. The adverse event profile of CPX-351 was generally consistent with the known safety profile of conventional 7+3. Grade 3-5 adverse events reported in ≥10% of patients in the CPX-351 or 7+3 cohorts included febrile neutropenia (68.0% vs 70.9%), pneumonia (19.6% vs 14.6%), and hypoxia (13.1% vs 15.2%). Early mortality rates with CPX-351 and 7+3, respectively, were 5.9% and 10.6% at Day 30 and 13.7% and 21.2% at Day 60. Conclusions: Treatment with CPX-351 was associated with significantly longer median OS and EFS, as well as a higher proportion of patients achieving remission and undergoing HCT, compared with conventional 7+3 chemotherapy in this population of older patients with newly diagnosed, high-risk/secondary AML. Further, while it is expected that HCT had a positive impact on survival in this study, exploratory analyses suggest that CPX-351 produced positive OS and EFS outcomes independent of HCT. Disclosures Lin: Jazz Pharmaceuticals: Honoraria. Cortes:Novartis: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Astellas Pharma: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Arog: Research Funding. Ritchie:NS Pharma: Research Funding; Bristol-Myers Squibb: Research Funding; Incyte: Consultancy, Speakers Bureau; Novartis: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; ARIAD Pharmaceuticals: Speakers Bureau; Astellas Pharma: Research Funding; Celgene: Consultancy, Other: Travel, Accommodations, Expenses, Speakers Bureau; Pfizer: Consultancy, Research Funding. Stuart:Sunesis Pharmaceuticals: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Agios: Research Funding; Astellas: Research Funding; Bayer AG: Research Funding; Celator/Jazz Pharmaceuticals: Research Funding; Incyte: Research Funding. Strickland:Tolero Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Baxalta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas Pharma: Consultancy; Sunesis Pharmaceuticals: Consultancy, Research Funding. Bixby:GlycoMimetics: Research Funding. Kolitz:Magellan Health: Consultancy, Honoraria. Schiller:bluebird bio: Research Funding; Astellas Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding. Wieduwilt:Leadiant: Research Funding; Reata Pharmaceuticals: Equity Ownership; Merck: Research Funding; Shire: Research Funding; Amgen: Research Funding; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees. Ryan:University of Rochester: Patents & Royalties; AbbVie: Equity Ownership. Ryan:Jazz Pharmaceuticals: Employment, Other: Stock and stock options. Chiarella:Celator/Jazz Pharmaceuticals: Employment, Equity Ownership. Louie:Jazz Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties. Uy:GlycoMimetics: Consultancy; Curis: Consultancy.

HIV causes a chronic infection characterized by depletion of CD4(+) T lymphocytes and the development of opportunistic infections. Despite drugs that inhibit viral spread, HIV infection has been difficult to cure because of uncharacterized reservoirs of infected cells that are resistant to highly active antiretroviral therapy (HAART) and the immune response. Here we used CD34(+) cells from infected people as well as in vitro studies of wild-type HIV to show infection and killing of CD34(+) multipotent hematopoietic progenitor cells (HPCs). In some HPCs, we detected latent infection that stably persisted in cell culture until viral gene expression was activated by differentiation factors. A unique reporter HIV that directly detects latently infected cells in vitro confirmed the presence of distinct populations of active and latently infected HPCs. These findings have major implications for understanding HIV bone marrow pathology and the mechanisms by which HIV causes persistent infection.

Background Binding of E-selectin (E-sel), an adhesion molecule expressed in the vasculature of the bone marrow, to sialyl Lex on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. GMI-1271 is a novel E-selectin antagonist that disrupts activation of cell survival pathways, enhances chemotherapy response with improved survival in mouse xenograft and syngeneic models and protects from chemotherapy toxicity in vivo (Becker 2013; Winkler 2013, 2014, 2016). We added GMI-1271 to salvage with MEC for relapsed/refractory AML patients or to induction with 7+3 for older treatment naïve (TN) AML patients. Methods A Phase (Ph) 1 trial escalated GMI-1271 (5-20 mg/kg) combined with MEC (mitoxantrone, etoposide, cytarabine) in pts with R/R AML, to evaluate safety, tolerability and anti-leukemic activity. Dose limiting toxicity (DLT) was defined as persistent cytopenias in the absence of disease or any Grade 3-5 non-hematologic toxicity beyond day 42. The recommended Ph 2 dose (RP2D) of GMI-1271 was 10 mg/kg. A Ph 2 study then enrolled 47 pts with R/R AML for GMI-1271 plus MEC chemotherapy. Responders could receive 1 cycle of consolidation with GMI-1271 plus MEC. We also enrolled a separate Ph 2 cohort of 25 pts ≥60 yrs with TN AML for GMI-1271 (10 mg/kg) plus cytarabine and idarubicin (7+3). Two cycles of induction were allowed. Responders could receive 3 cycles of consolidation with GMI-1271 plus intermediate dose cytarabine. Prior treatment of MDS was allowed; for R/R disease prior SCT was allowed. GMI-1271 was given 24 hrs prior, then every 12 hrs during and for 48 hrs post chemotherapy. E-sel ligand expression on leukemic blasts in blood and bone marrow was assessed by flow cytometry, for the percentage of blasts binding to E-sel-Fc chimera and HECA452 (antibody to sialyl Lex). Results 91 pts were enrolled (Ph 1 R/R=19; Ph 2 R/R=47, TN=25). Median age for R/R pts was 59 yrs (range 26-84) and 62% were males. Prior AML history included 32% primary refractory, 33% CR1 Median age for TN pts was 67 yrs (range, 60-79) 56% were males, and 32% had high-risk CG. 56% had secondary AML (sAML), 43% of sAML had prior hypomethylating therapy. GMI-1271 was well tolerated, adverse events were typical for AML induction in the TN population, and Grade 3/4 mucositis was not seen. 30 and 60 d mortality were 8 and 12%, respectively; two deaths were from sepsis before response assessment and one involved persistent disease. Median time to ANC 500 was 28d (range 21-63). 8 pts required two induction courses, and 4 (16%) proceeded to SCT by data cut-off. The CR/CRi rate was 68% (73% for de novo and 64% for sAML) and ORR was 80%. Median OS and DFS are not yet reached; median follow up is 6 mos. Median E-sel ligand expression (binding to HECA452) at baseline was 31% (range, 2-92%) of bone marrow blasts. Conclusion The addition of GMI-1271 to chemotherapy was well tolerated with high remission rate, low induction mortality, and low rate of mucositis suggesting improved tolerance of chemotherapy. In R/R AML, correlative studies showed blasts expressing the E-sel ligand were predictive of response. Initial survival outcomes are promising and updated survival outcomes will be presented at ASH. FDA granted Breakthrough Therapy Designation to GMI-1271 for treatment of adults with R/R AML and randomized trials are planned. Disclosures DeAngelo: Amgen: Consultancy, Research Funding; BMS: Consultancy; Immunogen: Honoraria, Research Funding; Celgene: Research Funding; ARIAD: Consultancy, Research Funding; Blueprint Medicines: Honoraria, Research Funding; Incyte: Consultancy, Honoraria; Glycomimetics: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals U.S.A., Inc.: Honoraria; Shire: Honoraria; Pfizer Inc.: Consultancy, Honoraria, Research Funding. Jonas: Celgene: Membership on an entity's Board of Directors or advisory committees; AbbVie, Celgene, Daiichi Sankyo, Pharmacyclics, Genentech/Roche, Glycomimetics, Esanex, Kalobios: Research Funding; Rigel: Consultancy. Liesveld: Seattle Genetics: Honoraria; Onconova: Honoraria. Advani: Pfizer: Consultancy; Takeda/ Millenium: Research Funding. O'Dwyer: Onkimmune Ltd: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; GlycoMimetics Inc: Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Magnani: GlycoMimetics, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Thackray: GlycoMimetics, Inc.: Employment, Equity Ownership. Becker: GlycoMimetics, Inc.: Research Funding.

Annual cancer drug expenditures exceed $100 billion globally.[1][1] The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 prohibits Medicare from negotiating drug prices.[2][2] Since the passing of this legislation, the average price for a newly approved cancer drug has

e18507 Background: FLT3+ AML patients (pts; 20%-30% of AML pts) often have rapid post-induction relapse, highlighting the need for therapies that improve the bridge to SCT. CPX-351 is a liposomal formulation that delivers a synergistic 5:1 molar ratio of cytarabine (C) and daunorubicin (D). CPX-351 demonstrated efficacy versus 7+3 in a randomized, open-label, controlled phase III trial in pts aged 60-75 years with newly diagnosed, high-risk AML; our analysis investigated outcomes in the subset of FLT3+ pts. Methods: Pts were randomized 1:1 to induction with 1-2 cycles of CPX-351 (100 u/m2 [C 100 mg/m2 + D 44 mg/m2] on Days 1, 3, and 5 [2nd induction: Days 1 and 3]) or 7+3 (C 100 mg/m2/day x 7 days [2nd induction: x 5 days] + D 60 mg/m2on Days 1, 2, and 3 [2nd induction: Days 1 and 2]). Pts with complete remission (CR) or CR with incomplete platelet or neutrophil recovery (CRi) could receive up to 2 consolidation cycles. Results: Of the pts who had FLT3 mutations assessed and received study treatment, 22/138 (16%) pts in the CPX-351 arm and 20/136 (15%) pts in the 7+3 arm had baseline FLT3 mutations. AML subtypes in FLT3+ pts were: tAML (19%); AML after MDS with (38%) or without (10%) prior hypomethylating agents; AML after CMMoL (12%); and de novo AML with MDS karyotype (21%). In FLT3+ pts, median OS was longer with CPX-351 (10.25 mo) versus 7+3 (4.55 mo; HR = 0.57 [95% CI: 0.24, 1.33]; P= 0.093) and the rate of CR+CRi was higher (68% vs 25%). A greater number of FLT3+ pts treated with CPX-351 were able to undergo SCT (n = 10/22 [45%]; 4 pts were alive as of this analysis, after a median post-SCT follow up of 692 days [range: 96-769]) compared with 7+3 (n = 2/20 [10%]; neither pt still alive). The on-study safety profile of CPX-351 in FLT3+ pts was comparable to 7+3 and consistent with the overall study population. Serious adverse events were experienced by 7 (32%) FLT3+ pts in the CPX-351 arm and 10 (50%) in the 7+3 arm. Conclusions: CPX-351 demonstrated numerical improvement in median OS in older pts with newly diagnosed, FLT3+ high-risk AML and allowed more pts to undergo SCT. The analysis was limited by small number of pts. Clinical trial information: NCT01696084.