Craig, Michael

Abstract BACKGROUND: Our group recently reported on the results of Blood and Marrow Transplant (BMT) Clinical Trials Network (CTN) 1101 a randomized comparison between double umbilical cord blood (dUCB) and haploidentical bone marrow (haplo) with post-transplant cyclophosphamide (ptCy) in the nonmyeloablative setting that showed similar progression free survival (PFS) between the two treatment groups, but lower non-relapse mortality (NRM) and better of overall survival (OS) in the haplo arm. In this secondary analysis we sought to investigate if transplant center experience with haplo and or cord blood HCT had an impact on outcomes. PATIENTS AND METHODS: All patient randomized in BMT CTN 1101 were included. In order to determine the transplant center experience with either haplo or dUCB we queried the Center for International Blood and Marrow Transplant Research (CIBMTR) for number of transplants with each platform in the year prior to initiation of the study. Centers were then grouped as dUCB center (> 10 dUCB, n=117, 10 centers), Haplo center (>10 haplo and ≤10 dUCB, n=110, 2 centers), and ≤10 haplo and ≤10 dUCB HCTs (other center, n=140, 21 centers). Further analysis considered the alternative cut-off for haplo (> 5 vs ≤ 5) experience, and considered the outcomes based on the donor experience vs. others (e.g. dUCB > 10 vs. ≤ 10; haplo > 5 vs. ≤ 5). RESULTS: The effect of center experience on HCT outcomes shown in Figure, below . After adjusting for age, Karnofsky performance score and, disease risk index we found that there was no difference in outcomes between haplo and dUCB for centers that were experienced with dUCB or had limited to no experience with either dUCB or haplo. In contrast, in centers that were primarily experienced with haplo had better outcomes with this donor type, as compared to dUCB. The higher risk of treatment failure (relapse or death) and overall mortality in dUCB in haplo experienced centers was driven by significantly higher risk of relapse. We then considered the transplant experience with each of the donor types separately. In transplant centers that had performed > 10 dUCB, there were similar outcomes for recipients of both dUCB and haplo. Similarly, centers that had ≤ 5 haplo HCTs had no difference in outcomes between donor types suggesting an overlap with centers that had performed > 10 dUCB HCTs. Overall mortality was higher among dUCB recipients in centers that had performed ≤ 10 dUCB. Notably, the hazard ratio of non-relapse mortality favored haplo in all four donor experience type of transplant center, albeit not statistically significant. CONCLUSION: Except for dUCB recipients in centers with < 10 dUCB/year had worse overall mortality, primarily driven by relapse, the transplant center experience in the year prior to the initiation of BMT CTN 1101 had limited impact on the outcomes of this randomized clinical trial. Figure 1 Figure 1. Disclosures Brunstein: NANT: Research Funding; FATE: Research Funding; GamidaCell: Research Funding; BlueRock: Research Funding; AlloVir: Consultancy. Costa: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria. Cutler: Deciphera: Consultancy; Cimeio: Consultancy; Editas: Consultancy; Kadmon: Consultancy; Pfizer: Consultancy; Mallinckrodt: Consultancy; CareDx: Consultancy; Incyte: Consultancy; Omeros: Consultancy; Syndax: Consultancy; Mesoblast: Consultancy; Jazz: Consultancy. Horowitz: Sobi: Research Funding; Regeneron: Research Funding; Orca Biosystems: Research Funding; Tscan: Research Funding; Xenikos: Research Funding; Miltenyi Biotech: Research Funding; Stemcyte: Research Funding; Medac: Research Funding; Vor Biopharma: Research Funding; Kite/Gilead: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Kiadis: Research Funding; Seattle Genetics: Research Funding; Mesoblast: Research Funding; GlaxoSmithKline: Research Funding; Sanofi: Research Funding; Pfizer, Inc: Research Funding; Omeros: Research Funding; Magenta: Consultancy, Research Funding; Jazz Pharmaceuticals: Research Funding; Vertex: Research Funding; Genentech: Research Funding; Takeda: Research Funding; Novartis: Research Funding; Shire: Research Funding; Gamida Cell: Research Funding; Daiicho Sankyo: Research Funding; CSL Behring: Research Funding; Chimerix: Research Funding; Bristol-Myers Squibb: Research Funding; bluebird bio: Research Funding; Astellas: Research Funding; Amgen: Research Funding; Allovir: Consultancy; Actinium: Research Funding. Horwitz: Gamida Cell: Research Funding. McGuirk: Novartis: Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding; EcoR1 Capital: Consultancy; Pluristem Therapeutics: Research Funding; Novartis: Research Funding; Bellicum Pharmaceuticals: Research Funding; Astelllas Pharma: Research Funding; Gamida Cell: Research Funding; Fresenius Biotech: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau. Rezvani: US Department of Justice: Consultancy; Kaleido: Other: One-time scientific advisory board; Nohla Therapeutics: Other: One-time scientific advisory board; Pharmacyclics-Abbvie: Research Funding. Rybka: Spark Therapeutics: Consultancy; Merck: Consultancy. Vasu: Kiadis, Inc.: Research Funding; Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees.

Abstract Background: Responses to the novel HDAC inhibitor romidepsin were observed in patients (pts) with T-cell lymphoma in a phase 1 NCI trial. Aims: To evaluate the efficacy and tolerability of romidepsin in the treatment of advanced cutaneous T-cell lymphoma (CTCL). As an exploratory endpoint, to examine the molecular effects of romidepsin in both CTCL and peripheral T-cell lymphoma (PTCL). Methods: This Phase 2, open-label, multi-arm, multicenter study enrolled 71 CTCL pts from the NCI and 9 extramural sites. PTCL pts were also enrolled. Clinical results for pts with CTCL and biomarker analyses for both PTCL and CTCL are presented here; clinical results for the PTCL pts are presented elsewhere. This study is now closed to accrual. Pts with recurrent CTCL (Stages IA-IVB) received romidepsin at 14 mg/m2 as a 4-hr infusion on days 1, 8 and 15 q 28 days. Responses were assessed using a composite endpoint that evaluated overall changes in skin (modified Physicians Global Assessment), lymph nodes, extranodal visceral lesions and abnormal circulating T-cells. Molecular endpoints evaluated in NCI pts were: histone acetylation in peripheral blood mononuclear cells (PBMCs); MDR-1 gene expression in PBMCs and in biopsy samples; and blood fetal hemoglobin levels. Results: 71 pts (48 men and 23 women) with a mean age of 56 yrs (range 28–84) were enrolled and received romidepsin; 63 pts received ≥2 cycles of therapy. Mean number of prior therapies was 3.4 (range 1–10). Objective disease response rates (ORR) are presented in the table. Overall disease control (CR+PR+SD90) was 62% in all pts and 70% in pts who received ≥2 cycles. Target skin lesions were followed and changes were generally similar to overall skin changes. Median duration of response (DOR) was 11 months (mo) and the maximum DOR as of data cut-off was 5.5+ yrs. The most frequent drug-related AEs (all grades, all cycles) were generally mild, including nausea (82%; 4% ≥grade 3), fatigue (73%; 14% ≥ grade 3), electrocardiogram T-wave amplitude decreased (69%, 0% ≥grade 3); hemoglobin decreased (59%, 9% ≥grade 3), and platelet count decreased (59%; 13% ≥grade 3). Six pts died within 30 days of study drug administration: 2 after salvage chemotherapy, 1 with ARDS due to PD, 2 with infection, and 1 of unknown cause; 2 of these deaths were considered possibly related to treatment. An increase in all biomarkers measured was observed, although not in all pts. Correlation between global histone H3 acetylation (AcH3) at the 24-hr time point and Cmax, AUC, and clearance was observed (r = 0.37, 0.36, and −0.44, respectively, p = 0.03). Pts with major responses were more likely to have higher levels of AcH3 at 24 hr. Conclusions: This study demonstrates tolerability and durable clinical benefit (ORR of 35% and median DOR of 11 mo in all pts) of romidepsin in pts with recurrent CTCL. Significant responses were observed at all stages of disease, including an ORR of 32% in all pts with stage ≥IIB and 20% in all pts with stage IV. Time to response was rapid, within 2 mo in most pts, and responses were durable, >6 mo in most pts. Molecular analyses confirmed that romidepsin inhibits its target deacetylases in pts. Increases were not observed in all pts, perhaps reflecting, in part, variable drug exposure or variable response to HDAC inhibition. Correlation of global acetylation with PK parameters suggests that increased drug exposure results in increased global acetylation. All Pts N=71 Pts ≥ 2 cycles N=63 ORR (CR+PR), n (%) 25 (35%) 25 (40%) PR, n (%) 21 (30%) 21 (33%) CR, n (%) 4 (6%) 4 (6%) SD90, n(%) 19 (27%) 19 (30%) Overall disease control (CR+PR+ SD90) 44 (62%) 44 (70%) DOR 11 (1+ mo, 5.5+ yrs) 11 (1+ mo, 5.5+ yrs) OR for pts with stage ≥ IIB, n (%) 20/62 (32%) 20/55 (36%) SD90= stable disease for ≥90 days

Abstract Background: The histone deacetylase (HDAC) inhibitors are a class of epigenetic agents undergoing clinical testing. HDAC inhibitors modulate expression of genes involved in cell cycle regulation, leading to induction of differentiation or apoptosis. Romidepsin, a novel, HDAC inhibitor, has previously demonstrated activity as a single agent in patients (pts) with T-cell lymphoma in a phase 1 NCI study. Aims: To evaluate the efficacy and tolerability of romidepsin in the treatment of advanced PTCL and as an exploratory endpoint, to examine the molecular effects of romidepsin in both PTCL and cutaneous T-cell lymphoma (CTCL). Methods: This Phase 2, open-label, multi-arm, multicenter study enrolled 43 PTCL pts from the NCI and 9 extramural sites. CTCL pts were also enrolled in this study. The clinical results for pts with PTCL are presented here; the clinical results for the pts with CTCL and the biomarker analyses for both PTCL and CTCL are presented elsewhere. This study is now closed to accrual. Pts with relapsed or refractory PTCL or primary cutaneous anaplastic large cell lymphoma were eligible. Pts received romidepsin 14 mg/m2 as a 4-hr infusion on days 1, 8 and 15 every 28 days. Responses were assessed using elements of the IWG criteria and RECIST, as appropriate, for pts with lymph node involvement and extranodal disease. Results: 43 pts (23[53%] men and 20 [47%] women) with a mean age of 58.1 (range: 27 to 84) years were treated with romidepsin. 31 pts received ≥ 2 cycles of therapy. Mean number of prior therapies was 3.9 (range 1 to 12). Objective disease response rates (ORR) are summarized in the table. The mean number of cycles of treatment was 6.8 (range 1–37) and the overall median duration of response was 8.3 months (range 1.6 months to 4.8+ yrs) for all pts. The median duration of response for the 7 pts who achieved CR was 8.5 months (range 4.6 months to 4.8+yrs). The most frequent drug-related AEs (all grades, all cycles) were generally mild and included: nausea (86%; 0% ≥grade 3), fatigue (79%; 0% ≥grade 3), decreased platelets (70%; 7% ≥grade 3), and decreased AGC (63%; 5% ≥grade 3). One death, in a pt with significant cardiovascular disease who had achieved a CR, was considered possibly related to treatment. Conclusions: This study demonstrates tolerability and durable clinical benefit (ORR of 39% and median duration of response of 8.3 months) of romidepsin in pts with recurrent or refractory PTCL. Based on these promising results, a Phase 2B protocol investigating romidepsin in pts with progressive or relapsed PTCL is ongoing at multiple international centers. All Pts N=43 Pts ≥ 2 cycles N=31 ORR (CR+PR), n (%) 17 (39%) 17 (55%) PR, n (%) 10 (23%) 10 (32%) CR, n (%) 7 (16%) 7 (23%)

Abstract Background: Older patients (pts) with AML unfit for intense induction chemotherapy have a poor prognosis with a 5 year survival of <10%. 225Ac-lintuzumab is composed of 225Ac linked to a humanized anti-CD33 monoclonal antibody. Data were previously presented on the initial 13 pts who received 2.0 µCi/kg/dose on Days 1 and 8 (ASH, 2017, Abstract 616). Although that dose resulted in a high response rate of 69%, there were 6 pts with Grade 4 thrombocytopenia lasting >6 weeks and 5 CRi patients did not reach an ANC of ≥ 500/µL. Therefore, the activity level was reduced to 1.5 µCi/kg/dose for further evaluation. Methods: This study enrolled older pts with untreated AML who were considered to be unfit for standard induction chemotherapy. Pts aged 60 to 74 years were required to have significant co-morbidities, while all pts ≥ 75 years were eligible. Other eligibility criteria included ECOG PS 0-2, CD33 expression on > 25% of blasts, and a peripheral blast count <200/µL within 10 days of the first dose to optimize targeting of bone marrow (BM) blasts. Hydroxyurea was used to lower peripheral blast counts. 1.5 µCi/kg of 225Ac-lin were administered IV on Days 1 and 8. G-CSF was given starting 10 days after the 2nd dose and spironolactone was given for up to 1 year to minimize the risk of radiation-induced nephrotoxicity. Pts were evaluated for the CD33 splicing polymorphism SNP rs12459419. Results: 18 pts were included in this prespecified Interim Analysis. An additional 9 pts were treated at this dose and will be included in an updated analysis at the ASH meeting. The median age of the 18 pts was 73.5 years (range 60-87) and median ECOG Performance Status was 1 (0 in 3 pts, 1 in 9 pts, & 6 in 2 pts). 11 pts had prior AHDs (6 MDS, 2 CMML, 2 NHL, 1 myelofibrosis), and 9 had prior treatment for AHDs. Of the pts with known cytogenetic and molecular genetic results, 1 had favorable-risk, 3 had intermediate-risk, and 5 had adverse-risk AML using NCCN guidelines. The median baseline BM blast % was 40.5% (range, 22-66%) with a median CD33 expression of 62% (range, 26-100%) of AML cells. Objective responses were seen in 4 pts (22%): 3 complete remissions with incomplete platelet count recovery (CRp) and 1 complete remission with incomplete hematologic recovery (CRi). Among the responders with known cytogenetics, 1 pt had adverse genetics and 1 had Intermediate-risk genetics.Of the pts with remission, 3 had CT genotype for the CD33 splicing polymorphism SNP rs12459419 (including 2 CRp) and 1 had CC genotype. 3 of the responders are in follow up at Days 59, 169 and 266 without further treatment. Myelosuppression was seen in all pts including Grade 4 thrombocytopenia with marrow aplasia for > 6 weeks after the first dose in 4 pts. 1 pt with prior MDS had pancytopenia for > 4 months. The 3 pts with CRp achieved an ANC ≥ 1000/µL at Days 28, 38, and 40 from the first dose of 225Ac-lin. The pt with CRi did not reach an ANC of 500/µL. Non hematologic Grade ≥3 Treatment-Emergent adverse events (AEs) that were at least possibly related were 4 patients with febrile neutropenia, as well as 1 patient each with fungal pneumonia, acute respiratory failure, pulmonary edema, chest pain, sepsis, gastric hemorrhage, generalized muscle weakness, atrial fibrillation with rapid ventricular response and typhilitis. No pts had an infusion-related reaction requiring dose interruption. Veno-occlusive disease did not occur. The 30-day mortality rate was 16.7% (1 cardiac arrest and 2 with multi organ failure). Conclusions: Preliminary data from this Interim Analysis of 225Ac-lin monotherapy in older AML pts unfit for intensive therapy indicate a lower rate of myelosuppression at 1.5 µCi/kg/dose but also a lower response rate than was seen at 2.0 µCi/kg/dose. Although the study met the prespecified response criteria for continuing enrollment, it will be closed to further accrual in recognition that targeted radiation, like other therapies, will likely have the best outcomes when used in combination with other therapies in pts with active AML. An extensive development program in AML, MDS, and multiple myeloma is planned. One study will utilize 225Ac-lin in combination with salvage chemotherapy and another with venetoclax. 225Ac-lin will be used as a single agent for AML postremission therapy. In addition, 225Ac-lin will be used as targeted conditioning prior to hematopoietic stem cell transplant in pts with MDS with a complex karyotype and as a conditioning agent prior to autologous transplant in MM. Table. Table. Disclosures Atallah: Jazz: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Abbvie: Consultancy; BMS: Consultancy. Orozco:Actinium Pharmaceuticals: Research Funding. Craig:Novartis: Research Funding; Actinium Pharmaceuticals: Research Funding; Celgene: Research Funding. Levy:Takeda (Millennium Pharmaceuticals, Inc.): Consultancy. Finn:Ochsner Clinic Foundation: Employment. Perl:NewLink Genetics: Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Arog: Consultancy; Astellas: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy; Pfizer: Membership on an entity's Board of Directors or advisory committees. Park:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Consultancy, Research Funding; Shire: Consultancy; AstraZeneca: Consultancy; Adaptive Biotechnologies: Consultancy; Kite Pharma: Consultancy; Pfizer: Consultancy; Novartis: Consultancy. Roboz:Astex Pharmaceuticals: Consultancy; Bayer: Consultancy; Aphivena Therapeutics: Consultancy; Celltrion: Consultancy; Celgene Corporation: Consultancy; Novartis: Consultancy; Celgene Corporation: Consultancy; Pfizer: Consultancy; Argenx: Consultancy; Roche/Genentech: Consultancy; AbbVie: Consultancy; Cellectis: Research Funding; Aphivena Therapeutics: Consultancy; Roche/Genentech: Consultancy; Sandoz: Consultancy; Bayer: Consultancy; Sandoz: Consultancy; Jazz Pharmaceuticals: Consultancy; Otsuka: Consultancy; Astex Pharmaceuticals: Consultancy; Daiichi Sankyo: Consultancy; Orsenix: Consultancy; Janssen Pharmaceuticals: Consultancy; AbbVie: Consultancy; Jazz Pharmaceuticals: Consultancy; Argenx: Consultancy; Janssen Pharmaceuticals: Consultancy; Eisai: Consultancy; Otsuka: Consultancy; Pfizer: Consultancy; Eisai: Consultancy; Orsenix: Consultancy; Cellectis: Research Funding; Daiichi Sankyo: Consultancy; Novartis: Consultancy; Celltrion: Consultancy. Tse:Brown Cancer Center, University of Louisville School of Medicine: Employment; Jazz: Consultancy; Amgen: Consultancy; Amgen: Honoraria; Amgen: Honoraria. Mawad:Swedish Cancer Institute: Employment. Rizzieri:Novartis: Consultancy; Pfizer: 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; 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; Teva: 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; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Berger:Actinium Pharmaceuticals: Employment, Equity Ownership. Jurcic:Astellas: Research Funding; Daiichi-Sankyo: Research Funding; Incyte: Consultancy; Celgene: Research Funding; AbbVie: Consultancy, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding; Syros Pharmaceuticals: Research Funding; Actinium Pharmaceuticals, Inc: Research Funding; Genetech: Research Funding; Kura Oncology: Research Funding.

Abstract Background Eukaryotic translation initiation factor 5A (eIF5A) has been implicated in the regulation of cell proliferation, apoptosis, and inflammation. SNS01-T is a novel therapeutic with a dual mechanism of eIF5A modulation: inducing cell death via siRNA-mediated inhibition of hypusinated eIF5A while simultaneously causing over-expression of pro-apoptotic eIF5AK50R via a DNA plasmid with a B-cell promoter to induce tumor cell death, using a PEI vector. SNS01-T significantly inhibits tumor growth and increases survival in mouse models of myeloma (MM), mantle cell and diffuse large B-cell lymphoma. Methods This is an open label, phase 1-2 dose escalation study in pts with refractory B-cell cancers, comprising 4 SNS01-T dose cohorts: 0.0125, 0.05, 0.2 and 0.375 mg/kg twice weekly IV for 6 weeks. Key inclusion criteria are: MM per IMWG criteria or lymphomas or plasma cell leukemia with histologic confirmation; measurable disease, relapsed or refractory after ≥2 prior regimens; not eligible for standard therapy known to extend life expectancy. Primary endpoints are safety and tolerability of SNS01-T. Secondary endpoints include pharmacokinetics, tumor response (M protein, % plasma cells, radiologic response) and time to relapse or progression. Efficacy assessments were performed at baseline and after 12 infusions in all pts (week 6); myeloma pts were also assessed at week 3. Results All cohorts will have completed enrollment in August 2014 and dosing in cohort 4 will be complete by September. A total of 21 pts have been treated, of whom 18 currently have data available. Demographics are provided in Table 1. Abstract 4464. Table 1:DemographicsSNS01-T DoseOverall(n=18)0.0125 mg/kg(n=6)0.05 mg/kg(n=4)0.2 mg/kg(n=4)0.375 mg/kg(n=4)Median age (range)63 (55-77)61.5 (57-66)63 (60-77)68 (66-74)58 (55-71)Male, n (%)12 (67)5 (83)03 (75)4 (100)Caucasian, n (%)17 (94)6 (100)3 (75)4 (100)4 (100)Median weight in kg (range)84 (53-117)81 (69-103)58 (53-87)86 (77-92)97 (81-117)Median performance status (range)1 (0-2)1 (0-1)1 (0-2)0 (0-2)1 (0-1)Cancer type, n (%) Multiple myeloma DLBCL15 (83) 3 (17)6 (100) 03 (75) 1 (25)2 (50) 2 (50)4 (100) 0Median prior therapies (range)5 (2-17)4.5 (3-12)6.5 (2-13)7.5 (2-17)7 (5-14) Treatment-emergent adverse events (TEAE) were reported for all pts. The most frequently reported System Organ Classes were General Disorders and Administration Site Conditions (72%) and Gastrointestinal Disorders (56%), with somewhat higher reporting frequency in dose cohorts 3 and 4. The most commonly reported AEs were fatigue (50%), nausea (33%), infusion-related reaction (33%), chills (28%), thrombocytopenia (22%) and pyrexia (17%). Thrombocytopenia, nausea, fatigue, infusion reaction appeared to show some degree of dose relationship. Grade ≥3 TEAEs occurred in 50% of pts with no obvious dose relationship. The only grade ≥3 TEAE reported in >1 pt was thrombocytopenia (17%). There have been no treatment-related deaths. There was 1 DLT at dose level 4 (0.375 mg/kg). Pt 51-001 did not receive premedication prior to the third infusion of SNS01-T and consequently experienced a grade 4 infusion reaction, from which all symptoms resolved within 24 hours. Study treatment was discontinued and the protocol was amended to require the following premedication at each SNS01-T infusion: a corticosteroid, antihistamine and acetaminophen are obligatory, plus an opioid as clinically indicated. Preliminary efficacy was explored. To date, 2 pts have shown stable disease of myeloma at week 3 with some decrease in serum and urine disease markers and one pt with DLBCL had a 15% decrease in small lymph node disease with approximately a 5 month duration. These patients were in cohorts 3 and 4. Conclusions SNS01-T administration was feasible in all 4 dose cohorts with prophylaxis for infusion reactions. Early signs of potential efficacy are encouraging. Expansion of efficacy testing to more patients and combination studies are planned. Disclosures Siegel: Senesco: PI Other. McDonald:Senesco: PI Other. Novitzky:Senesco: PI Other. Bensinger:Senesco: PI Other. Craig:Senesco: PI Other. van Rhee:Senesco: PI Other. Gutierrez:Senesco: PI Other. Libby:Senesco: PI Other. Thompson:Senesco: Consultancy, Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Bexon:Senesco: Consultancy. Barranco:Senesco: Consultancy. Taylor:Senesco: Research Funding. Dondero:Senesco: Employment. Browne:Senesco: Employment. Kurman:Senesco: Consultancy. Lust:Senesco: PI Other.

Abstract The optimal source of donor hematopoietic stem cells (HSC) is controversial. Granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood (G-PB) has replaced bone marrow (BM) as the most common allograft source in adults but is associated with donor morbidity and higher rates of chronic graft versus host disease (GVHD) compared to BM. The CXCR4 antagonist plerixafor (Px) mobilizes HSC into the PB (Px-PB) faster than G-CSF and preliminary data suggest both quantitative and qualitative differences in allograft content that may impact clinical outcomes. We sought to assess the efficacy and safety of transplanted allografts collected following mobilization with Px alone in HLA-identical sibling transplantation. This was a Phase II, two-strata, multi-center prospective trial (NCT01696461) to evaluate Px-PB allografts prior to reduced intensity conditioning (RIC) and myeloablative conditioning (MAC) based hematopoietic cell transplantation (HCT). Patients aged 18-65 years with an HLA-ID sibling donor and a hematological malignancy suitable for HCT were eligible. The primary objective was to determine the proportion of donors whose cells could be successfully mobilized and collected with a sufficient CD34+ cell dose using Px as the sole mobilizing agent. Px mobilization was considered successful if ≥ 2.0x10^6 CD34+ cells/kg recipient weight were collected in no more than two leukapheresis (LP) collections. All donors receiving Px were included in the analysis of the primary objective based on the intention-to-treat principle. Secondary objectives included the incidence of acute and chronic adverse events in donors, rates of hematopoietic engraftment, donor chimerism, rates of acute and chronic GVHD, non-relapse mortality (NRM), progression free survival (PFS) and overall survival (OS) for the recipients. From July 2013 to December 2014, 64 donor/recipient pairs were enrolled at 12 centers. Donors received Px at 240μg/kg subcutaneously 4 hours prior to LP. LP was performed processing at least 4X blood volume for up to two consecutive days (a third day was allowed for low CD34+ cell yields after 2 LP procedures) to achieve a target CD34+ cell dose of ≥ 4.0 x 10^6/kg recipient weight with a minimum goal of ≥ 2.0 x 10^6/kg. All allografts were cryopreserved. GVHD prophylaxis included cyclosporine or tacrolimus in combination with methotrexate, mycophenolate mofetil, or sirolimus. G-CSF was given routinely post HCT only to MAC recipients. Patient demographics are provided in Table 1. The median donor age was 56 years (18-65). 64% of the donors were male. Donors underwent one (23%), two (72%), or three (5%) LP procedures. 63 of 64 (98%) donors achieved the primary objective. The median total CD34+ cell dose/kg recipient weight collected within 2 days was 4.6 (0.9-9.6). Maximal donor toxicity following Px injection and LP was grades 0 (30%), 1 (52%), 2 (17%), and 3 (2%). Bloating, flatulence, abdominal pain, headache, paresthesisas, injection site reaction, and dizziness were the most commonly observed toxicities. Bone pain was not observed. The one grade 3 toxicity was a vasovagal episode felt related to LP and unlikely to Px. Toxicities typically resolved within a week of LP. The median follow up is 6.3 months. Median days to ANC (>0.5 x10^9/L) and Platelet count (>20 x 10^9/L) recovery were 13.5 (10-148) and 19 (1-76) after MAC and 14.5 (0-25) and 18 (0-141) after RIC, respectively. The cumulative incidence of acute GVHD grades 2-4 and 3-4 at day 100 were 47% (95% CI: 30-64) and 9% (95% CI: 2-22) after MAC and 19% (95% CI: 6-38) and 5% (95% CI: 0-18) after RIC. Probability of NRM at day 100 was 4% (95% CI: 0-13) and 0% after MAC and RIC, respectively. The probability of OS at day 100 was 97% (95% CI: 88-100) and 90% (95% CI: 78-98) after MAC and RIC, respectively. In conclusion, this is the first multi-center trial to demonstrate that as an alternative to G-CSF, Plerixafor rapidly, safely, and effectively mobilizes sufficient numbers of CD34+ cells from HLA-ID sibling donors for HCT following both RIC and MAC regimens. Engraftment was generally prompt and early results of secondary endpoints in recipients are encouraging. Longer follow-up and more extensive analysis of donor allografts and recipient outcomes will be presented at the time of the meeting. Research support was provided in part by Genzyme, a Sanofi Company. Table 1. Characteristics of recipients Table 1. Characteristics of recipients Disclosures Chen: Bayer: Consultancy, Research Funding. Devine:Genzyme: Research Funding.

Abstract Introduction eIF5A is the only known protein to be modified by hypusination and is highly conserved across species. Hypusinated eIF5A, the predominant form in normal and cancer cells, is involved in cell survival and inflammatory pathway activation. siRNAs targeting eIF5A inhibit NF-kB activation and reduce pro-inflammatory cytokine production. Accumulation of the unhypusinated lysine form of eIF5A is associated with apoptosis. Mutants of eIF5A that cannot be hypusinated (e.g. eIF5AK50R) are pro-apoptotic in vitro and have anti-tumoral activity in vivo in multiple cancer types including melanoma and lung cancer. SNS01-T is a novel therapeutic with a dual mechanism of eIF5A modulation: inducing cell death via siRNA-mediated inhibition of hypusinated eIF5A while simultaneously causing over-expression of pro-apoptotic eIF5AK50R via a DNA plasmid with a B-cell promoter to induce tumor cell death. SNS01-T significantly inhibited tumor growth and increased survival in mouse models of myeloma (MM), mantle cell and diffuse large B-cell lymphoma. The phase 1-2 study of SNS01-T has completed 4 planned dosing cohorts 0.0125, 0.05, 0.2 and 0.375 mg/kg twice weekly IV for 6 weeks in pts with refractory B-cell cancers. Methods PK and PD secondary endpoints included characterization of PK by measuring pExp5A plasmid DNA and eIF5A siRNA in blood and bone marrow (BM), assessing potential immunogenicity of SNS01-T by measuring serum concentrations of antibodies against SNS01-T nanoparticles, and measuring serum concentrations of select proinflammatory cytokines by enzyme-linked immunosorbent assay in serum and plasma samples. Blood PK timepoints were 30 minutes before the first infusion and at 30 minutes, 2, 6, and 24 hours after the first infusions on Week 1, Week 3, and Week 6 and at the 4, 8, and 12 week visits after the last infusion; BM samples were collected 1 day after the final infusion. Serum and plasma PD sampling timepoints were 30 minutes before and at 2, 6, and 24 hours after the first infusion on Week 1, Week 3, and Week 6, and at 4 weeks after the final infusion. Cytokines assayed included TNF-α, IFN-α, IFN-ß, IFN-g, CXCL1, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, and IL-12. Results Table 1 shows data available for interpretation as of August 2014. The remaining samples are under analysis and will be presented. Abstract 2121. Table 1:Data available for interpretation (number of patients)SNS01-T DoseOverall(n=18)0.0125 mg/kg(n=6)0.05 mg/kg(n=4)0.2 mg/kg(n=4)0.375 mg/kg(n=4)Blood PK DNA and RNA156441Bone marrow PK82321Serum antibodies to SNS01-T nanoparticles186444Serum and plasma cytokines156441 Plasmid and siRNA blood levels generally peaked 30 minutes post-dosing at weeks 1, 3 and 6 of dosing. Both plasmid and siRNA exhibited rapid clearance from the blood, with levels dropping to near pre-dosing levels within 24 hours of administration. pExp5A plasmid DNA was detectable in the bone marrow of 2 pts at cohort 1, 2 at cohort 2, 1 at cohort 3 and 1 at cohort 4. eIF5A siRNA was not detectable in bone marrow. No antibodies to SNS01-T nanoparticles were detected at any timepoint at any dose level. Cytokines remained within the expected range of inter-patient variability, similar to baseline across all timepoints at the first 2 dose levels. At dose level 3, levels of IL-6, IL-8 and TNF-α in particular increased at the 2 and 6 hour timepoints but had recovered to baseline levels 24-hours post dosing. This effect was more pronounced at the first infusion. Conclusions PCR analysis demonstrated the presence of both plasmid DNA and siRNA components of SNS01-T in blood at all dose levels, with a dose-dependent increase in plasmid copy number. Plasmid DNA was also detected in bone marrow collected 24 hours after the final infusion of SNS01-T. Pro-inflammatory cytokines did increase within hours of infusion but returned to baseline within 24 hours, synchronous with the clinical infusion reactions (see Abstract 70148). No evidence of an anti-SNS01-T antibody response was observed in any subject. Phase 2 trials are planned. Disclosures Bexon: Senesco: Consultancy. Craig:Senesco: PI Other. Siegel:Senesco: PI Other. Bensinger:Senesco: PI Other. Novitzky:Senesco: PI Other. McDonald:Senesco: PI Other. Gutierrez:Senesco: PI Other. Libby:Senesco: PI Other. van Rhee:Senesco: PI Other. Heidel:Senesco: Consultancy. Thompson:Senesco: Consultancy, Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Barranco:Senesco: Consultancy. Taylor:Senesco: Research Funding. Browne:Senesco: Employment. Kurman:Senesco: Consultancy. Lust:Senesco: PI Other. Dondero:Senesco: Employment.

Abstract Plerixafor, a direct antagonist of CXCR4/stromal-derived factor 1, can safely and rapidly mobilize allografts without the use of granulocyte colony-stimulating factor (G-CSF). We conducted a phase 2, multicenter, prospective study of plerixafor-mobilized HLA-identical sibling allografts for allogeneic hematopoietic cell transplantation in recipients with hematological malignancies. Donors (n = 64) were treated with subcutaneous plerixafor (240 µg/kg) and started leukapheresis (LP) 4 hours later. The primary objective was to determine the proportion of donors who were successfully mobilized: defined as collection of ≥2.0 × 106 CD34+ cells per kilogram recipient weight in ≤2 LP sessions. Recipients subsequently received reduced intensity (RIC; n = 33) or myeloablative (MAC; n = 30) conditioning. Sixty-three of 64 (98%) donors achieved the primary objective. The median CD34+ cell dose per kilogram recipient weight collected within 2 days was 4.7 (0.9-9.6). Plerixafor was well tolerated with only grade 1 or 2 drug-related adverse events noted. Bone pain was not observed. Plerixafor-mobilized grafts engrafted promptly. One-year progression-free and overall survivals were 53% (95% confidence interval [CI], 36% to 71%) and 63% (95% CI, 46% to 79%) for MAC and 64% (95% CI, 47% to 79%) and 70% (95% CI, 53% to 84%) for RIC recipients, respectively. Donor toxicity was reduced relative to G-CSF mobilized related donors. This is the first multicenter trial to demonstrate that, as an alternative to G-CSF, plerixafor rapidly and safely mobilizes sufficient numbers of CD34+ cells from matched sibling donors for HCT. Engraftment was prompt, and outcomes in recipients were encouraging. This trial was registered at clinicaltrials.gov as #NCT01696461.