Double Umbilical Cord Blood Transplantation Research Articles

Ex Vivo Modulation of Mobilized Peripheral Blood: Characterization of HSC and T-Cell Responses to Prostaglandin E2

16,16 dimethyl prostaglandin E2 (FT1050) was previously identified to be a critical regulator of hematopoetic stem cell (HSC) homeostasis and we hypothesized that a brief ex vivo modulation could improve patient outcomes in umbilical cord blood (UCB) transplantation by increasing the “effective dose” of HSCs. Using preclinical models, we have demonstrated that pulse treating human HSCs with FT1050 significantly enhances the homing and engraftment of donor cells to the bone marrow niche, in part by upregulating CXCR4.To date, preclinical and clinical translation of this therapeutic paradigm has focused on UCB. In an initial clinical evaluation, ex vivo modulation of UCB with FT1050 (2 hours, on site, just prior to infusion) was found to accelerate neutrophil recovery (median 17.5 vs 21 days, p = 0.045) in adult patients undergoing double UCB transplantation (Cutler, 2013). In this Phase 1b study, we also observed low rates of viral reactivation (17% incidence of CMV viremia vs. 42-67% reported in the literature) and GvHD, suggesting that FT1050 may also be having a therapeutically relevant effect on the T-cell compartment of the treated UCB units. To explore the potential therapeutic application of ex vivo modulation of other allogeneic HSC sources, we conducted a series of in vitro studies characterizing the effect of FT1050 on HSCs and T-cells derived from mobilized peripheral blood (mPB).CD34+ cells isolated from mPB or UCB were treated with 10μM FT1050 for 2 hours at 37ºC. We showed that FT1050 binds to the EP2 and EP4 receptors on the cell surface, activating adenylate cyclase which results in a rapid increase in intracellular cAMP levels. Results of a competitive antibody binding assay demonstrated robust and comparable increases in cAMP levels in CD34+ cells from both UCB and mPB. Genome-wide expression analysis of FT1050 treated CD34+ cells showed a highly similar expression response in cells isolated from mPB and UCB, including a 20-fold increase in the key HSC homing receptor CXCR4. We also observed similar FT1050-dependent increases in the surface CXCR4 protein levels and significant improvements in transwell migration rates to gradients of SDF-1. Genome-wide expression analysis within the T-cell compartments from both UCB and mPB (e.g., CD8, CD4, NK, Tregs) revealed a highly similar set of FT1050 induced genes which are involved in cell cycle (e.g., CCND1, CCNE1), tolerance (e.g., DUSP5, FLT1) and anti-viral response (e.g., CD56, EFNB2). The results of this preclinical characterization study provides the basis upon which to explore the future use of FT1050 modulated mPB in a clinical setting. DisclosuresRobbins:Fate Therapeutics: Employment, Equity Ownership. Le:Fate Therapeutics: Employment, Equity Ownership. Troung:Fate Therapeutics: Employment, Equity Ownership. Foster:Fate Therapeutics: Employment, Equity Ownership. Rezner:Fate Therapeutics: Employment, Equity Ownership. Mitchell:Fate Therapeutics: Employment, Equity Ownership. Guerrettaz:Fate Therapeutics: Employment, Equity Ownership. Multani:Fate Therapeutics: Employment, Equity Ownership. Shoemaker:Fate Therapeutics: Employment, Equity Ownership.

Delayed Platelet Engraftment after Umbilical Cord Blood Transplant: Relationship to Circulating Levels of Thrombopoietin

▪Delayed platelet engraftment is an important contributor to the increased morbidity, poor quality of life, and cost after umbilical cord blood transplant (UCBT). Thrombopoietin (TPO) receptor agonists have played an important role in immune thrombocytopenic purpura (ITP) and other disorders of low platelets. Therefore, we investigated thrombopoietin levels after UCBT, to determine if treatment with TPO receptor agonists after UCBT might be warranted. Twenty-two consecutive patients with hematologic malignancies who underwent reduced intensity double UCBT were included in the analysis. The conditioning regimen was fludarabine, 30mg/m2/days -7, -6, -5, -4, -3, -2, melphalan 100mg/m2 on day -1, and total body radiation 200 cGy on Day 0. Graft vs host disease (GVHD) prophylaxis was tacrolimus and sirolimus. TPO levels (Quest Diagnostics) were measured pre-conditioning, on days 0, 14, 30, 60, and 100, and at 6, 9, 12 and 24 months post transplant. Additional TPO levels were measured in association with platelet transfusion, prior to, 30 minutes, 6 hours, and 24 hours post transfusion. The median age was 55 years (range 21 to 68).Nine patients had AML, 4 had MDS, 4 had NHL, 2 had ALL, 2 had MPD, 1 had HD. Median days to neutrophil engraftment (ANC > 500) were 24 days (range 13-54); median days to platelet engraftment >20,000 were 50 days (range 25-89), and; median days to platelet engraftment >50,000 were 53 days (range 31-132). 100 day treatment related mortality was 5.3%. At one year, overall survival was 48%. Normal TPO levels in our lab are 39 pg/ml (range 7-99): Median TPO levels after UCBT were as follows: Pre-conditioning: 205 pg/ml (range 9 to 2389), Day 0: 222 pg/ml (range 107 to 2501), Day 14: 2880 pg/ml (range 973 to >4000), Day 30: 2372 pg/ml (range 208 to >4000), Day 60: 781 pg/ml (range 319 to 2242), Day 100: 609 pg/ml (range 109.3 to 1653), Month 6: 380 pg/ml (range 121 to 3126), Month 12: 239 pg/ml (n=4; range 122 to 843). TPO levels fell 6 hours after platelet transfusion in 86% of patients, (decrease 8% to 49%). At 24 hours after platelet transfusion, TPO levels started to rise to baseline, with a decrease from baseline of 4-22%. In summary, 1) TPO levels are markedly elevated in the first month after UCBT, and fall after platelet recovery, returning to baseline at one year post transplant. 2) TPO levels fall 6 hours after platelet transfusion and start to rebound within 24 hours. 3) These data suggest that high levels of endogenous TPO do not alleviate the thrombocytopenia after UCBT and suggest that other modalities should considered. Further studies using other agents are planned.TableTPO Levels after UCBTTimeTPO Level pg/mlBaseline205Day 0222Day 142880Day 302372Day 60781Day 100609Month 6380Month 12239 DisclosuresAvigan:Astex Pharmaceuticals: Research Funding. Kuter:Amgen: Consultancy; Quest: Consultancy.

StemRegenin-1 (SR1) Expansion Culture Abrogates the Engraftment Barrier Associated with Umbilical Cord Blood Transplantation (UCBT)

Background. The use of UCB has been substantially limited by the low finite number of CD34+ cells, resulting in prolonged periods of cytopenia and high risk of graft failure, restricting its widespread application particularly for adults. SR1 is an aryl hydrocarbon receptor antagonist that enables CD34 cell proliferation in the presence of SCF, Flt-3L, IL-6 and TPO without differentiation. Therefore, we tested the safety and efficacy SR1 expanded UCB (referred to as 'HSC835’).Patients and Methods: Patients with high-risk hematologic malignancy were enrolled in a Phase 1/2 dose escalation study. All were treated with cyclophosphamide 120 mg/kg, fludarabine 75 mg/m2 and total body irradiation 1320 cGy with cyclosporine and mycophenolate mofetil post-transplant immune suppression. Seventeen patients received HSC835 along with its CD34 depleted fraction and an unmanipulated UCB unit and two patients thus far received HSC835 as a stand-alone graft.Results: For the first 17, SR-1 expansion culture yielded a median of 1,440 x 106 CD34+ cells (range, 140.2-6361.9) as compared to the input number of 4.4 x 106 (range, 2.1-15.6) after CD34 selection – a 328-fold (range, 65.9-844.0) expansion of CD34+ cells. Relative to recipients of a standard double UCB graft without manipulation (n=111) containing a median of 0.5 x 106 CD34+ cells/kg (0.1-2.1) with 87% engraftment, HSC835-treated patients received a median of 12.3 x 106 CD34+ cells/kg (2.3-48.5) with 100% engraftment. Of the 11/17 patients in whom the HSC835 predominated, neutrophils recovered at a median of 11 days (6-23) as compared to 23 days (14-30) for those in whom the unmanipulated unit predominated (Figure). Similarly, as compared to the 111 double UCBT controls, both neutrophil and platelet recoveries were remarkably shortened in HSC835 recipients (p<0.001 and p=0,001, respectively). Importantly, chimerism was stable 0.4-2 years out. Single unit chimerism in all lineages was derived from HSC835 in six and the unmanipulated unit in six. However, stable dual myeloid chimerism was observed in 5 with T cells completely derived from the unmanipulated unit. Interestingly, neutrophil recovery occurred faster in those with dual myeloid chimerism at a median of 7 days (6-10) (Figure, o) as compared to those with single myeloid chimerism (·). Unit predominance was determined by graft-graft immune reactions, as evidenced by the presence of interferon-γ producing T cells directed against the losing graft, and not by HSC exhaustion, as evidenced by absence of late graft failures or marked change in telomere length (10.5Kb to 10Kb). Therefore the subsequent study will evaluate the safety and efficacy of HSC835 as a sole source. Thus far, 2 have been treated with promising early engraftment results. Receiving doses of 25 and 18 x 106 CD34/kg, neutrophil recovery was observed on day 12 and 8, respectively.Conclusion: HSC835 dramatically accelerates hematopoietic recovery, abrogating the principal barrier to the successful use of UCB. Such impressive CD34+ expansion potentially heralds a paradigm shift for both UCB transplantation and cord blood banking. With such high CD34+ cell doses, all patients will have an adequate single UCB unit with an improved chance of identifying a 5-6/6 HLA matched unit since the entire UCB inventory will be available irrespective of weight. Furthermore, units with cell counts <1 billion nucleated cells should no longer be discarded, crucial for improving collection efficiencies, and increasing the size of the registry, particularly important for enhancing representation of ethnic/racial minority populations. [Display omitted] DisclosuresWagner:Novartis: Research Funding. Maahs:Novartis: Employment. Laughlin:Novartis: Employment. Perry:Novartis: Employment. Boitano:Novartis: Employment. Cooke:Novartis: Employment. Bleul:Novartis: Employment.

Ex Vivo Pharmacologic Modulation in a Nutrient-Rich Medium to Accelerate Engraftment of Human Umbilical Cord Blood

Umbilical cord blood (UCB) offers many potential advantages as a source of hematopoietic stem cells (HSCs) for allogeneic transplantation, including ease of collection, rapid availability, flexibility of HLA-matching, lower rates of GvHD and potentially lower relapse rates. However, the low HSC content of UCB compared to other graft sources results in a prolonged time to engraftment, and higher rates of graft failure and early mortality.Pulse ex vivo exposure of HSCs to 16,16-dimethyl PGE2 (FT1050) has been demonstrated to enhance HSC engraftment potential, which could benefit clinical UCB transplant. FT1050 modulation promotes multiple mechanisms, including increased proliferation, reduced apoptosis, and improved migration and homing [North 2007&2009; Hoggatt 2009]. Improved HSC homing is mediated by induction of CXCR4 gene expression leading to increased cell surface CXCR4. Further optimization of the UCB modulation process demonstrated that incubation with 10µM FT1050 for 2 hrs at 37C resulted in a maximal biological response of the FT1050-UCB (ProHema®).A Phase 1 trial was performed to evaluate the safety of FT1050-UCB paired with an unmanipulated UCB unit in reduced-intensity double UCBT (dUCBT) [Cutler 2013]. We observed durable, multi-lineage engraftment of FT1050-UCB with acceptable safety. Earlier neutrophil engraftment was observed relative to historical controls (median 17.5 vs. 21 days (historical control), p=0.045), coupled with preferential engraftment of the FT1050-UCB unit in 10 of 12 subjects. A Phase 2 multi-center clinical trial of FT1050-UCB in adult patients undergoing dUCBT for hematologic malignancies was then initiated. Subjects are randomized 2:1 to FT1050-UCB-containing vs. standard dUCBT after high-dose conditioning. The primary endpoint is a categorical analysis of neutrophil engraftment using a pre-specified control median. Data on the initial 11 subjects, of which 8 were randomized to receive FT1050-UCB, continue to demonstrate acceptable safety with adverse events attributed to FT1050-UCB limited primarily to common infusion-related side effects. Of the 8 FT1050-UCB subjects, 1 died prior to neutrophil engraftment, with the remaining 7 subjects engrafting at a median of 28 days vs. 31 days for the 3 control subjects. With median overall follow-up of 16.1 months, 4 of 8 subjects on the FT1050-UCB arm are alive with a median survival not reached (> 11.0 months). 1 of 3 control subjects is alive with median survival of 6.0 months.During the clinical translation process, the media used during FT1050 modulation of UCB was identified as a key variable. Standard UCB washing media, consisting of a nutrient-free saline solution of low molecular weight dextran and human serum albumin (LMD/HSA), is used clinically to stabilize fragile cells post-thaw by reducing lysis. This media was used in the Phase 1 trial and to initiate Phase 2. Early during the Phase 2 trial, we identified a novel cell-stabilizing nutrient-rich formulation (NRM), containing glucose, amino acids and other HSC-supporting nutrients that promoted full FT1050 modulation of UCB and increased cell viability. The expression of key FT1050-pathway genes was significantly higher with NRM compared to intermediate levels observed with LMD/HSA. Modulation of human CD34+ (hCD34+) cells with FT1050 in NRM led to an 8-fold increase over LMD/HSA in induced CXCR4 gene expression (20-fold total), which translated to significantly increased surface CXCR4 protein. In vivo homing models demonstrated that UCB CD34+ cells modulated with FT1050 in NRM resulted in a 2.2-fold homing increase relative to vehicle (p < 0.001) compared to a 1.6-fold increase with LMD/HSA (p = 0.002), with a significant difference between the two media conditions (p = 0.04). A xenotransplantation study in NSG mice with hCD34+ cells modulated with FT1050 in either NRM or LMD/HSA demonstrated a 2-fold increase in circulating hCD45+ cells 12-weeks post-transplant with NRM (p = 0.007; unpaired t-test). These findings supported the incorporation of NRM into the FT1050-UCB manufacturing process in order to further improve its clinical engraftment potential. Enrollment of a 60-patient Phase 2 trial has been initiated that incorporates this manufacturing change. DisclosuresShoemaker:Fate Therapeutics: Employment, Equity Ownership. Rezner:Fate Therapeutics: Employment. Guerrettaz:Fate Therapeutics: Employment. Robbins:Fate Therapeutics: Employment. Medcalf:Fate Therapeutics: Employment. Wolchko:Fate Therapeutics: Employment, Equity Ownership. Ferraro:Fate Therapeutics: Employment. Multani:Fate Therapeutics: Employment.

Double Umbilical Cord Blood Transplantation after Novel Myeloablative Conditioning Using a Regimen of Fludarabine, Busulfan, and Total Lymphoid Irradiation

We conducted a pilot study evaluating double umbilical cord blood transplantation (dCBT) after myeloablative conditioning with fludarabine and busulfan 3.2 mg/kg i.v. × 4, followed by total lymphoid irradiation at 400 cGy (FluBu4/TLI) for any indicated hematological disorder for patients without a suitable donor. Twenty patients with predominantly high-risk disease underwent dCBT according to protocol. The regimen was well tolerated, with mucositis as the primary observed toxicity (n = 19). The cumulative incidence of neutrophil engraftment was 89% (95% confidence interval [CI], 64% to 97%), with a median time to recovery of 16 days (range, 12 to 31 days). All evaluable patients with neutrophil engraftment achieved complete donor chimerism by day 40. The cumulative incidence of grades III and IV acute graft-versus-host disease (GVHD) at day 100 was 10% (95% CI, 2% to 27%), and the cumulative incidence of chronic GVHD was 35% (95% CI, 16% to 55%) by the end of the study. At 1 year, the cumulative incidence of treatment-related mortality (TRM) was 35% (95% CI, 16% to 55%). The leading cause of nonrelapse mortality was acute GVHD (n = 4), followed by graft failure (n = 2) and chronic GVHD (n = 1). TRM was significantly associated with a pretransplantation hematopoietic cell transplantation–specific comorbidity index score ≥ 3 (P = .005). At 1 year, disease relapse occurred in 6 patients and overall survival was 40% (95% CI, 19% to 60%). We conclude that FluBu4/TLI is an adequate preparative regiment before dCBT, providing high engraftment rates and relatively early neutrophil recovery. The best survival outcomes were seen in patients without significant comorbidities before transplantation, and outcomes are comparable to previously published dCBT studies.

Haplo+cord transplantation: Neutrophil and platelet recovery and long-term survival compared to double umbilical cord blood (UCB) transplantation—A case-cohort analysis.

7004 Background: Double UCB (dUCB) SCT can result in long-term survival and low rates of chronic GVHD. Limitations are delayed engraftment and early TRM. We previously reported that co-infusion of ...

T-cell replete haploidentical donor transplantation using post-transplant CY: an emerging standard-of-care option for patients who lack an HLA-identical sibling donor.

Availability of an HLA-identical sibling (MRD) or suitably matched unrelated donor (MUD) has historically been a limiting factor in the application of allogeneic hematopoietic transplantation. Although almost all patients have an HLA-haploidentical family donor, prior attempts at transplantation from such donors using T-cell replete grafts and conventional immunosuppression were associated with unacceptable rates of GVHD, and when stringent ex vivo T-cell depletion was used to control GVHD, rates of graft rejection and post-transplant infections were prohibitive. The recent approach to HLA-haploidentical donor transplantation developed in Baltimore that uses T-cell replete grafts and post-transplant CY (Haplo-post-HCT-CY) to control post-transplant allo-reactivity appears to have overcome many of the obstacles historically associated with haploidentical donor transplantation. In particular, TRM rates of <10% are usual and rapid reconstitution of immunity leads to a low rate of post-transplant infections and no post-tranplant lymphoproliferative disorders (PTLD), consistent with the hypothesis that post-transplant CY selectively depletes proliferating alloreactive T cells responsible for GVHD and graft rejection while preserving resting memory T cells essential for post-transplant immunologic recovery. In parallel trials using similar non-myeloablative conditioning regimens, Haplo-post-HCT-CY produced similar overall survival to double umbilical cord blood transplantation(DUCBT) in adult patients (62% vs 54%), with low rates of TRM (7% vs 24%), severe acute GVHD (0% vs 21%) and chronic GVHD (13% vs 25%). Furthermore, recent non-randomized comparisons adjusted for risk factors show that Haplo-post-HCT-CY achieve at least equivalent outcomes to conventional MRD and MUD transplants. Although most experience has been obtained using BM, emerging data suggest that a G-CSF mobilized PBSC graft can also safely be used for Haplo-post-HCT-CY. Haplo-post-HCT-CY also avoids the graft acquisition costs of DUCBT and MUDs and the cost of cell selection associated with T-depleted grafts. Although randomized comparisons will be forthcoming, Haplo-post-HCT-CY can already be considered a valid standard-of-care in patients who lack conventional donors thus extending the availability of allogeneic transplants to almost all patients. This donor source may also challenge the routine preference for a MUD in patients lacking an MRD.

Double Umbilical Cord Blood Transplantation after Novel Myeloablative Conditioning Using FluBu4/TLI

We conducted a pilot study evaluating double umbilical cord blood transplantation (dCBT) after myeloablative (MA) conditioning with Fludarabine/Busulfan 3.2mg/kg IV × 4, followed by Total Lymphoid Irradiation at 400cGy (FluBu4/TLI) for any indicated hematological disorder without a suitable donor. Twenty patients with predominantly high-risk disease underwent dCBT according to protocol. The regimen was well tolerated, with mucositis as the primary observed toxicity (n=19). The cumulative incidence of neutrophil engraftment was 89% (95% C.I., 64-97%), with a median time to recovery of 16 days (range: 12-31 days). All evaluable patients with neutrophil engraftment achieved complete donor chimerism by day 40. The cumulative incidence of grade III/IV acute GVHD at day 100 was 10% (95% C.I., 2-27%), and the cumulative incidence of chronic GVHD was 35% (95% C.I. 16-55%) by the end of the study. At one year, the cumulative incidence of treatment related mortality (TRM) was 35% (95% C.I. 16-55%). The leading cause of non-relapse mortality was acute GVHD (n=4), followed by graft failure (n=2), and chronic GVHD (n=1). Treatment-related mortality was significantly associated with a pre-transplant HCT-CI score ≥3 (p=0.005). At one year, disease relapse occurred in six patients, and overall survival was 40% (95% C.I. 19-60%). We conclude that MA FluBu4/TLI is an adequate preparative regiment prior to dCBT, providing high engraftment rates, and relatively early neutrophil recovery. The best survival outcomes were seen in patients without significant comorbidities pre-transplant, and are comparable to previously published dCBT studies.

Phenotypic and Functional Characteristics of NK Cells Associated with Cytomegalovirus (CMV) Reactivation after Allogeneic Hematopoietic Stem Cell Transplantation (HCT)

s / Biol Blood Marrow Transplant 20 (2014) S128eS150 S146 virus (EBV) is a gammaherpes virus that is reactivated from latent to lytic cycle and can cause aggressive lymphomas known as post transplant lymphoproliferative disorder (PTLD) in immunocompromised hosts. We attempted to distinguish immune reconstitution profiles in double UCBT recipients who developed EBV viremia from those who did not. Thirty-one patients with hematologic malignancies received dUCBT with melphalan, fludarabine, ATG conditioning and tacrolimus plus sirolimus for GvHD prophylaxis. During the first 12 months after dUCBT, 14 of 31 (45%) patients developed EBV viremia and four (13%) developed PTLD. At one month after dUCBT, patients with EBV viremia displayed higher numbers of CD19+ B cells (p1⁄40.04) and CD4+CD25+ Treg cells (p1⁄40.03) compared with patients who never became viremic. Surprisingly, EBV viremia correlated with increased numbers of CD3+ (p1⁄40.04), CD4+ (p1⁄40.015) and CD8+ (p1⁄40.021) T cells, but this response was ineffective at controlling the virus. One explanation for this unexpected result might be skewing towards a late effector memory T cell phenotype, a stage in which T cells are incapable of mounting protective immune responses. We examined naive vs. memory T cell distribution and determined that patients who developed EBV reactivation had higher numbers of memory cell subsets (CD4+CD45RO+, p1⁄40.023; CD8+CD45RO+, p1⁄40.019) at two months after dUCBT. Analysis of repertoire diversity by deep-sequencing on PCR-amplified CDR3 regions of the TCRb gene using the ImmunoSEQ assay showed a more diverse TCR repertoire, as determined by higher entropy (p1⁄40.03) and lower clonality (p1⁄40.03), among patients who did not develop EBV reactivation. Assessment of SCF and IL-7, critical regulators of hematopoietic stem cell and naive T cell homeostasis, respectively, showed that patients without EBV viremia had higher levels of SCF (p1⁄40.0016) and IL-7 (p1⁄40.046) compared with patients who developed viremia and PTLD. Our findings suggest that control of EBV reactivation after dUCBT might be linked to the support of naive T cell homeostasis, which enables maintenance of a diverse TCR repertoire.

Autoimmune Demyelinating Polyneuropathy as a Manifestation of Chronic Graft-versus-Host Disease after Adult Cord Blood Transplantation in a Patient with Chronic Lymphocytic Leukemia.

Immune mediated demyelinating disease after allogeneic stem cell transplantation is a rare entity with unclear etiology. Acute inflammatory demyelinating polyneuropathy (AIDP) has been reported after related and adult unrelated allogeneic stem cell transplantation but no such case has been reported after unrelated cord blood transplantation. We hereby present the first case of AIDP after double umbilical cord blood transplantation (DUCBT). A 55-year-old man with chronic lymphocytic leukemia (CLL) received a cord blood transplant for relapsed refractory disease with high risk cytogenetics. On day 221, patient presented with skin rash, tingling in both lower extremites, and ascending paralysis that progressed rapidly over the course of 2 days. The workup resulted in a diagnosis of AIDP and administration of intravenous immunoglobulins plus steroids was initiated. Motor and sensory powers were fully recovered and his chronic GVHD was managed for several months with single agent sirolimus.

Umbilical Cord Blood Transplantation in Hematologic Diseases in Patients Over 15 Years Old: Long-term Experience at the Pontificia Universidad Católica de Chile

Most patients who require a sibling stem cell transplantation do not have a matched donor. In our experience, only 1/3 patients have a matched unrelated donor (MUD); therefore, the majority of the patients will require umbilical cord blood (UCB). Patients treated for hematologic diseases with UCB transplants were included. UCB selection and conditioning regimens were performed according to the Minnesota group. Graft-versus-host disease (GVHD) prophylaxis, infection prevention, and patient care were performed according to institutional guidelines. We analyzed patients and graft demography, neutrophil and platelet recovery, chimerism kinetics, GVHD incidence, overall (OS), progression-free survival (PFS) and transplant-related mortality (TRM). We included 29 patients with a median age of 34.8 years (range 15–55). Eighteen were male and the median weight was 72.6 kg (range 54–100). Nineteen patients had acute leukemia. Myeloablative (MA) conditioning was used in 27 patients. Seventeen received double UCB (DUCB) grafts. Median total nucleated cell (107/kg) was 4.2 (range 3.9–4.9) and 4.4 (range 2.8–6.3) for single UCB (SUCB) and DUCB transplants, respectively. Median time for neutrophil engraftment was 24.7 (range 14–43) and 25.8 days (range 14–52) after SUCB and DUCB transplants, respectively. Median time for platelet engraftment was 147 (range 30–516) and 81 days (range 37–200) after SUCB and DUCB transplants, respectively. All the patients receiving MA conditioning had >95% chimerism shortly after transplant. Cumulative incidence of grades II–IV and III–IV acute GVHD was 41% and 20%, respectively. Localized chronic GVHD was seen in 14% of the patients. Median follow-up was 16.7 months (range 1–63). Five-year OS and PFS were 38% and 39%, respectively. One-year TRM was 42%. UCB transplantation is associated with potential cure of hematologic malignancies and our results are similar to other series. Studies are needed to decrease mortality and improve immune reconstitution.

First application of the EBMT risk score in double umbilical cord blood transplantation for hematologic malignancies: Significant impact on different outcomes

First application of the EBMT risk score in double umbilical cord blood transplantation for hematologic malignancies: Significant impact on different outcomes

Guilain-Barre' Syndrome (GBS) Post Adult Cord Blood Transplantation In a Patient With Chronic Lymphocytic Leukemia (CLL)

Immune mediated demyelinating disease after allogeneic stem cell transplantation is a rare entity with unclear etiology. Acute inflammatory demyelinating polyneuropathy (AIDP) has been reported post related and unrelated allogeneic stem cell transplantation but no such case has been reported post unrelated cord blood transplantation. We hereby present the first case of GBS post double umbilical cord blood transplantation (DUCBT).A 55 year old male with relapsed refractory CLL received DUCBT with two 5/6 matched cord units (antigen level HLA-A, HLA-B and allele level HLA-DRB1) with fludarabine, cytoxan and total body irradiation based reduced intensity conditioning regimen. Graft versus host disease (GVHD) prophylaxis was with cyclosporine and mycophenolate. Early post transplant course was complicated by grade 4 acute GVHD of the gut with a complete resolution with steroid therapy and successful taper of all immunosuppression by day 180. 7 months post transplantation, patient presented with skin rash and tingling in both feet that progressed rapidly to lower extremity paralysis over the course of 2 days. Physical exam showed macula-papular rash affecting his upper extremities, upper chest and back area. Neurologic exam was significant for motor weakness in lower extremities 2/5, plantar flexion and knee flexion 3/5. He had loss of deep tendon reflexes in both lower extremities (Achilles and Patellar) and upper extremities (biceps and triceps).Workup revealed normal blood counts, organ function, vitamin B12, folate, TSH level, free cortisol. Serum electrophoresis and immunfixation was also normal. Magnetic resonance imaging of the central nervous system showed mild neural foramina narrowing at the L4-L5 level. Serology for Lyme disease, Epstein Bar virus (EBV), syphilis, cytomegalo virus (CMV), Hepatitis, HIV, toxoplasma, enterovirus and human herpes virus 6 was negative. Blood tests for autoimmune markers including (anti-nuclear antibody)ANA, acetylcholine esterase and volted calcium channel antibodies were normal. A lumbar puncture was performed and showed a high protein level of 67mg/dl, 1 nucleated cell/mm3 and normal glucose level. Cerebrospinal fluid was negative for oligoclonal bands, West Nile virus, cryptosporidium, HHV6, herpes virus 1 and 2, gram stain and cultures. Nerve conduction studies and needle electormyegraphy was suggestive of acute demyelinating polyneuropathy.Based on the above workup, he was diagnosed with GBS and started on therapy with intravenous immunoglobulin at 0.5gm/kg for 4 days and prednisone 1mg/kg daily for the treatment of GVHD. Etiology of GBS was presumed to be related to GVHD as his workup was negative for campylobacter, HIV and CMV. He improved significantly over the next 4 weeks and became ambulatory without assistance but his weakness symptoms relapsed as his prednisone was tapered. Prednisone was increased again to 1mg/kg and sirolimus was started. Patient was successfully tapered of prednisone and remains fully ambulatory without assistance or evidence of GVHD on single agent sirolimus 13 months post DUCBT.This is the first case of autoimmune demyelinating polyneuropathy post DUCBT with association of GVHD that was managed successfully with a combination of intravenous immunoglobulins, steroids and sirolimus. Disclosures:No relevant conflicts of interest to declare.

Ex Vivo expansion Of Umbilical Cord Blood CD34+ Cells Under Hypoxic Conditions Using Novel Compound#999 With Cytokines

Introduction Umbilical cord blood is an increasingly utilized source for hematopoietic stem transplantation. However the limitation is inadequate hematopoietic stem and progenitor cell (HSPC) dose leading to poor engraftment and prolonged neutropenia. Umbilical cord blood transplants (UCBT) were initially restricted to small sized children and adults. The advent of double umbilical cord blood transplants (DUCBT) led to both children and adults transplants with sufficient numbers of HSPCs. However there continue to be issues with insufficient engraftment, extended duration of cytopenia, risk of infections and prolonged duration of hospital stay. There is ongoing research to investigate optimal ex vivo umbilical cord blood (UCB) HSPC expansion with the intention to ensure sustained engraftment, reduce the prolonged periods of neutropenia and curtail the high risk of infectious complications in the immediate post-transplant period. HSPC expansion with cytokines alone produces about 7-fold increase of HSPC over 12-14days. However most IRB approved protocols require that a significant percentage of these cord blood cells be transplanted without manipulation and then the expanded cells be transplanted later. To detect a significant advantage to this expanded fraction we have calculated that HSPCs need to be expanded 8-10 fold. To achieve this we have combined an optimal cytokine combination with hypoxia and the additive of Aryl hydrocarbon Receptor (AhR) antagonist Stem Reginin1 (SR1); previously reported to facilitate HSPC expansion (Boitano et al 2010 Science). Objectives Here we evaluated if there was any potential synergistic effect of combining AhR antagonist SR1 with hypoxia for ex vivo HSPC expansion. Additionally we looked at the effect of adding #999; a small molecule identified using high-throughput screening that selectively expands murine hematopoietic stem cells. Methods UCB derived phenotypic CD34+ cells were cultured in the presence of stem cell factor (SCF), Flt3 ligand (Flt3L) and thrombopoietin (TPO) on a feeder layer of OP9 cells transduced with lentiviral vector expressing red fluorescent protein in both normoxia and hypoxia (3% oxygen). Total cell numbers (TNC) were counted, CD34+ cells were measured through flowcytometry and the self-renewal and multi-lineage differentiation was measured through week-5 cobblestone area forming (CAFC) and colony forming (CFC) assays respectively. Results CD34+ cells cultured in the presence of SCF, Flt3L and TPO (50ng/ml each) resulted in a 100fold expansion of CD34+ cells compared to input cells at 2 weeks. SR1 when added to the above cytokine cocktail led to a 200-fold expansion while #999 used with cytokines resulted in 118-fold expansion at 2weeks. Using both small molecules together in the presence of cytokines did not show an additive effect (207fold increase). Repeating the above experiments in hypoxia (3% oxygen) showed 196-fold increase with cytokines alone, 289-fold increase with SR1, 211-fold increase with #999 and again no additive effect of SR1 and #999 together. CD34+ cells cultured with SR1 or #999 with cytokines produced approximately 1.9 and 1.2 times more CFC than those with cytokines alone respectively. SR1 treated cells on week-5 CAFC showed 3-fold and #999 treated cells 1.3-fold more cobblestones compared to cytokines alone. In hypoxia CD34+ cells cultured with #999 gave rise to more colonies as compared to both SR1 (2-fold more) and cytokines (3-fold more). CAFC data for these are pending. The degree of HSPC expansion with SR1 in addition to cytokines can be increased in hypoxic conditions. # 999 when used with cytokines in hypoxia can also lead to the same degree of HSPC expansion as SR1 in normoxia. The combination of SR1 and #999 showed no additive effect in either normoxia or hypoxia. Conclusion Compound 999 when used in hypoxia leads to a significant expansion of HSPCs compared to cytokines alone or SR1 plus cytokines in normoxia. In vivo xenograft murine studies are been conducted so as to compare and evaluate the engraftment potential of these ex vivo expanded CD34+ cells in irradiated NSG mice. Disclosures: Mukherjee: Onconova Therapeutics: Research Funding. Ebert:Genoptix: Consultancy; Celgene: Consultancy.

Double Umbilical Cord Blood Transplantation Offers Stable Donor Engraftment and The Prospect Of Cure In Adult Patients With High-Risk Hematologic Malignancies

Allogeneic stem cell transplantation (allo-SCT) remains the main therapeutic option for patients with high-risk hematologic malignancies, albeit with the requirement of a properly matched and timely available donor. Dual-unit umbilical cord blood transplantation (dUCBT) has become an alternative modality, which offers immediate access to allo-SCT for most adult patients who lack an appropriate volunteer donor.We retrospectively analyzed the outcomes of consecutive dUCBT procedures that were undertaken by our center over a seven-year period, with focus on factors affecting engraftment and survival.Between 2006 and 2013, 40 patients underwent dUCBT at a median age of 37 years (range, 16-60) for various hematologic malignancies (acute myeloid leukemia: 22, myelodysplastic syndrome: 5, chronic myelogenous leukemia: 2, acute lymphoblastic leukemia: 6, mixed-phenotype acute leukemia: 2, plasmacytoid dendritic cell neoplasm: 1, hepatosplenic T cell lymphoma: 1, chronic lymphocytic leukemia: 1). The majority of patients (73.7%) had advanced or intermediate-phase disease at the time of transplantation, with a median time from diagnosis to transplant of 17.7 months (range:3.1-92.3). Recipient body weight ranged from 48 to 110 kg (median, 73). The conditioning regimen was myeloablative in 33 (82.5%) patients (busulfan-based in 22, and total body irradiation-based in 11 cases). Antithymocyte globulin was not administered during conditioning, with the exception of one case.Most units (55/80, 68.75%) were 4/6 antigen matched to recipient at HLA-A, -B, and -DRB1 loci, and the remaining were 5/6 matched. By retrospective high-resolution typing for class I HLA alleles, histocompatibility was demoted in 62.3% of units. By additional allele-level typing at HLA-C and -DQB1 loci, the degree of compatibility varied from 8/10 to 3/10, with 80.5% of the units being ≤6/10 matched to the patient. The median dose of cryopreserved total nucleated cells (TNC) per unit was 2.53 x 107/kg (range, 1.09-5.66). At infusion, patients received in total a median of 4.55 x 107 TNC/kg (range, 2.65-9.3) and 1.7 x 105CD34+ cells/kg (range, 0.54-5.14) from both units.The cumulative incidence (CI) of neutrophil engraftment was 92.5% (37/40 patients), with achievement of an absolute neutrophil count (ANC) greater than 500/uL at a median of 20 days (range, 12-52) (Figure 1). Platelet recovery (>50x109/L) occurred at a CI of 63.2%, and a median time of 84 days (range, 32-363). No influence of cell dose (TNC or CD34+) or of the degree of HLA match on the incidence and kinetics of engraftment could be detected. Acute graft-versus-host disease (aGVHD) of grades II-IV and III-IV developed in 85% and 12.65% of patients, respectively. The CI of chronic GVHD was 31% (extensive in 54.5% of cases). There was a statistical trend for increased incidence of cGVHD with <6/10 HLA match at the allele level (p=0.068; HR, 3.35; 95% confidence interval [ci], 0.92-12.24). Non-relapse mortality (NRM) reached 43.1% (95% ci, 27.0-58.2) at 10.3 months, but no case of NRM was noted thereafter (Figure 2). Major causes of NRM were infection/sepsis (n=11), GVHD (n=3), and engraftment failure (n=3). The CI of relapse was 22.7% (95% ci, 10.7-37.5). Relapse was the cause of death of 6 patients. With a median follow-up of 30 months (range, 2-84), overall (OS) and disease-free survival (DFS) rates at 2 years were 36.5% (95% ci, 21-52) and 34.2% (95% ci, 19.3-49.6), respectively (Figure 3). Sixteen of 40 patients are alive and disease-free for a median time of 30 months from transplant. Age ≤37 years, recipient CMV seronegativity, and early disease phase at transplant were associated with improved OS in univariate analysis. Age remained as the only independent risk factor for OS in multivariate analysis of OS (p=0.022). Age ≤37 years was also found to be associated with reduced NRM (p=0.055), and favorable DFS (p=0.04). [Display omitted] [Display omitted] [Display omitted] In conclusion, dUCBT can lead to stable donor engraftment even across multiple HLA disparities and can overcome the barrier of cell dose. Despite considerable early mortality, dUCBT offers the possibility of long-term survival in about one third of adult patients with poor-prognosis hematologic malignancies, for whom allo-SCT would not be otherwise feasible. Disclosures:No relevant conflicts of interest to declare.

Factors Affecting Unit Predominance In Double Umbilical Cord Blood Transplantation

BackgroundUmbilical cord blood transplantation is seen as an alternative source of hematopoietic support for patients who lack suitable HLA-matched donors. Disadvantages of this method include the relatively low cellularity, late engraftment and consequently restrictive use to pediatric patients, due to the low number of hematopoietic progenitors. Transplantation of two cord blood units has been seen as a strategy to overcome the low yield, often leading to the long-term establishment of hematopoiesis supported by a single cord blood unit. Predictive factors of the predominant unit are still unclear. Total nucleated cell count, CD34+, CD3+ dose were independent factors associated with unit predominance, although this is still a controversial issue. MethodsThis retrospective study included 21 patients with hematologic malignancies and immunodeficiencies who underwent double unit cord blood transplantation. We analysed HLA mismatch, ABO group, total nucleated cell count (TNC), CD34+ dose and post-thaw viability and their correlation with the prevalent unit. Transplantations were performed from 2007 to 2013. Six patients were excluded due to incomplete information and another three died before engraftment. ResultsMedian NC and CD34+ doses were similar between engrafted and non-engrafted units. Nine transplantations (60%) resulted in engraftment of the higher TNC unit. TNC dose in the predominant units varied between 2.02-3.05x107/kg (median dose: 2.651x107/kg), and in the non-engrafted units between 1.69x107/kg-4.39x107/kg (median dose: 2.44x107/kg), which was not statistically significant (p= 0.65). Sixty percent of the transplantations (9 patients) also resulted in engraftment of the unit with higher CD 34+ (median dose: 2.05x106/kg), compared to 40% (6 patients) in which the lower dose unit prevailed (median dose: 1.95 x106), also not statistically significant (p= 0.861). As for ABO, 26% of the units were ABO matched with the recipient, while the majority was HLA mismatched (93%). ConclusionMultiple factors related to the unit and patient influence UCB predominance. In the sample studied, no particular variant played a specific role, probably due to the limited sample size. Current evidence suggests that immunologic-related mechanisms (CD34+ and CD3+ dose) are involved, yet further studies are necessary for a better understanding of which factors lead to unit engraftment. Disclosures:No relevant conflicts of interest to declare.

Safety and Exploratory Efficacy Of Ex Vivo Expanded Umbilical Cord Blood (UCB) Hematopoietic Stem and Progenitor Cells (HSPC) Using Cytokines and Stem-Regenin 1 (SR1): Interim Results Of a Phase 1/2 Dose Escalation Clinical Study

BackgroundDespite enhanced tolerability of HLA mismatch, the reduced number of HSPC in an UCB graft limits the use of this stem cell source because of delayed hematopoietic recovery and increased risk of graft failure, particularly in adults. For this reason, we explored the effectiveness of SR1, an aryl hydrocarbon receptor antagonist, in the presence of cytokines to expand HSPC ex vivo prior to transplantation. Patients and MethodsNine patients with high-risk lympho-hematopoietic malignancy and two partially HLA (4-6/6)-matched UCB units were treated with cyclophosphamide 120 mg/kg, fludarabine 75 mg/m2 and total body irradiation 1320 cGy followed by double UCB transplantation. Unit1 (the unmanipulated larger of the two units) was infused followed by SR1-expanded UCB HSPC (derived from CD34 selected Unit2 cells cultured for 15 days) as well as rethawed CD34 negative Unit2 cells. GVHD prophylaxis was cyclosporine A and mycophenolate mofetil. ResultsCulture in the presence of SR1 resulted in a median of 248-fold (range, 66-446) expansion of CD34+ cells. The median number of CD34+ cells and CD3+ cells infused for Unit1 and Unit2 were 0.3 x 106/kg (range, 0.2-0.9) and 11.0 x 106/kg (range, 1.4-48.9), and 7.3 x 106/kg (range, 4.6-10.6) 2.8 x 106/kg (range, 0.4-4.9), respectively. There were no infusional toxicities noted. Based on a presumed graft-graft interaction, the HSC835 product predominated in 5 of 9 patients and resulted in sustained hematopoiesis for a median follow up of 303 days (range 140-401). The median time to neutrophil recovery (days to absolute neutrophil count of ≥500/uL) was shorter in recipients of HSC835 (i.e., 16 days [range, 6-23] versus 24 days [range, 22-30]) with the speed of neutrophil recovery correlating with the number of CD34+ cells infused (r2 = -0.87, p<0.05, Figure 1). With a median follow-up of 161 days (range, 40-401), six patients are alive. Primary causes of death were CMV pneumonitis, alveolar hemorrhage and interstitial pneumonitis in three patients. [Display omitted] ConclusionThe AHR antagonist SR1 is a potent inhibitor of HSC differentiation, resulting in marked expansion of HSPC. Hematopoietic reconstitution as early as day 6 is dependent on CD34+ cell dose in the expanded product, HSC835. Based on the long-term engraftment potential of HSC835 in half of the patients using the double UCB platform and the accelerated neutrophil recovery seen in patients recovering with HSC835, future patients will receive HSC835 alone eliminating the confounding graft-graft effects and potentially further reducing the time to neutrophil recovery. Disclosures:Wagner:Novartis: Research Funding. Brunstein:Novartis: Research Funding. McKenna:Novartis: Research Funding. Sumstad:Novartis: Research Funding. Maahs:Novartis: Employment. Boitano:Novartis: Employment. Cooke:Novartis: Employment. Bleul:Novartis: Employment.

Reconstitution Of EBV-Specific Immunity In Adult Recipients Of Double Cord Blood Transplantation Depends On SCF and IL-7 Levels and Maintenance Of a Diverse TCR Repertoire

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for allogeneic HSC transplantation but reconstitution of T cell immunity remains problematic even with double UCB transplantation (dUCBT). This is related to the small T cell numbers of the UCB graft, the naïve nature of these T cells and often the use of ATG as part of the conditioning regimen. Consequently, UCBT recipients are susceptible to viral infections that require intact T cell immunity for their containment. Epstein Barr virus (EBV) is a gammaherpes virus that is transmitted orally. EBV initially replicates in a lytic cycle in the epithelium of the oropharynx and then establishes a latent state in memory B cells. Reactivation of EBV from latent to lytic cycle is mediated by physiologic stress of the memory B cell pool and by defects in antiviral T cell immunity, and can cause aggressive lymphomas known as post transplant lymphoproliferative disorder (PTLD) in immunocompromised hosts. The specific immunological correlates of EBV reactivation in adult UCBT recipients have not been examined. In the present study we attempted to distinguish immune reconstitution profiles in UCBT recipients who developed EBV viremia from those who did not, in order to better understand the immune profile of UCBT recipients who control gammaherpes virus reactivation. Thirty-one patients with hematologic malignancies received dUCBT with melphalan, fludarabine, ATG conditioning and tacrolimus plus sirolimus for GvHD prophylaxis. EBV viral load was determined on a weekly basis after dUCBT. Immunophenotype of peripheral blood lymphocytes, serum cytokine levels and T cell receptor excision circle analysis (TREC) values, were examined prior to and at 1, 2, 3, 6 and 12 months after UCBT and were compared between EBV viremic and non-viremic patients using the Wilcoxon-rank sum test. During the first 12 months after dUCBT, 14 of 31 (45%) patients developed EBV viremia and four (13%) developed PTLD. At one month after dUCBT, patients who developed EBV viremia displayed higher numbers of CD19+ B cell numbers (p=0.04) and CD4+CD25+ T regulatory cells (p=0.03) compared with patients who never became viremic. Surprisingly, development of EBV viremia correlated with increased numbers of CD3+ (p=0.04), CD4+ (p=0.015) and CD8+ (p=0.021) T cells. This finding was counterintuitive, as one might expect better quantitative peripheral T cell reconstitution in patients with recovering immunity and no EBV reactivation. One mechanism of impaired immune reconstitution after UCBT is skewing towards a late effector memory T cell phenotype, a stage in which T cells are incapable of mounting protective immune responses. We examined whether development of EBV viremia was associated with altered naïve versus memory T cell distribution. We determined that patients who developed EBV reactivation had higher numbers of memory cell subsets (CD4+CD45RO+, p=0.0023; CD8+CD45RO+, p=0.019) at two months after dUCBT. Neither development nor control of EBV viremia correlated with TREC recovery, which occurred after the time period of EBV viremia. We were unable to identify EBV-specific T cells in any patient group due to the very low T cell numbers during the time of viremia. However, analysis of repertoire diversity by deep-sequencing on PCR-amplified CDR3 regions of the TCRb gene using the ImmunoSEQ assay showed a more diverse TCR repertoire, as determined by higher entropy (p=0.03) and lower clonality (p=0.03), among patients who did not develop EBV reactivation, compared with those who developed EBV viremia and PTLD. Assessment of serum levels of SCF (a c-kit ligand), IL-7, thrombomodulin, VEGF and angiopoetin-1 showed that patients without EBV viremia had significantly higher levels of SCF (p=0.0001) and IL-7 (p=0.05), at 1 and 2 months after dUCBT, compared with patients who developed EBV reactivation and PTLD. SCF-mediated signaling via c-kit is integral to the homing and longevity of uncommitted hematopoietic stem cells whereas IL-7 is a critical factor for survival and homeostasis of naïve T cells. Together our findings suggest that control of EBV reactivation after dUCBT might be linked to the support of naïve T cell homeostasis, which enables maintenance of a diverse TCR repertoire.▪ Disclosures:No relevant conflicts of interest to declare.

Outcomes After Unrelated Cord Blood Transplantation For Adults With Primary Or Secondary Myelofibrosis: A Retrospective Study On Behalf Of Eurocord and Chronic Malignancy Working Party-EBMT

BackgroundAllogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative option for patients (pts) with myelofibrosis (MF). Patients with MF transformed to Acute Myeloid Leukemia (AML) have a very short life expectancy without transplantation (< 4 months). Umbilical cord blood transplantation (UCBT) from unrelated donor is a valid alternative to conventional allogeneic HSCT for pts with hematologic malignancies who do not have an HLA matched donor. Delayed engraftment and graft failure are the limitations of this procedure and represent a major issue for MF. Patients and MethodsWe analyzed 42 adults (28 males and 14 females) who underwent a single (n=15) or double (n=27) HLA mismatched UCBT between 2005 and 2012 in 26 EBMT centers reported to Eurocord. At diagnosis, 21 had primary MF (PMF), 5 polycythemia vera (PV), and 16 essential thrombocytemia (ET). Twelve patients transformed to acute myeloid leukemia (AML) before UCBT. Among pts with pre-transplant information available, 13/25 had severe marrow fibrosis; 8/16 had a high Lille score at diagnosis and 13/27 had JAK2 V617F mutation; 13/35 underwent splenectomy and 16/30 had an abnormal karyotype. The median time from diagnosis to transplant was 80 months (range 5-316), while in the subgroup of pts with transformation to AML, it was 119 months (range 5-246). Five pts had a prior transplant (1 autologous, 3 allogeneic and 1 had 2 consecutive allogeneic transplants). The median age at UCBT was 54 years (range 28-69). Conditioning regimens were reduced intensity (RIC) (n= 29) or myeloablative (MAC) (n=13). The most common conditioning in both MAC (n=5) and RIC (n=16) was Cyclophosphamide and Fludarabine associated with total body irradiation (TBI). Overall, 27 pts received TBI with a dose of 12-14 Gy in MAC (n=6) and 2-4 Gy in RIC (n=21); 20 pts received anti-thymoglobulin (ATG) in the conditioning regimen. The median infused total nucleated and CD34+ cells were 3,4x107/Kg (range 0,3-6,8) and 1,3x105/Kg (range 0,04-3,8),respectively. ResultsMedian follow-up for survivors was 25 months (range 6 -72). The cumulative incidence (CI) of neutrophil engraftment was 64% (28 pts) with a median time of 29 days, and among the 12 pts transformed to AML, 10 engrafted in a median time of 30 days, while 18 of 30 pts without transformation engrafted in a median time of 28 days. Of the 14 pts who did not reach neutrophil engraftment, 7 had no hematological recovery, 6 of them died after a median of 3 months and 1 pt is alive at 14 months post UCBT. The remaining 7 pts had an autologous reconstitution, and 4 of them are alive with progressive disease at a median time of 42 months. Pts who received RIC conditioning had better engraftment (79% versus 36%, p=0.02).Twelve pts developed acute GvHD of grades II-IV; 7 pts had limited chronic GvHD with a median time of onset of 144 days.Overall, 17 pts relapsed (6 had transformed into AML before transplantation) at a median time of 5 months. The CI of relapse at 2 years was 29%±2%. The CI of transplant-related mortality at 1 year was 33%±2%. Causes of death were relapse (n=9), post-transplant lymphoproliferative disease (n=3), GvHD (n=3), multiorgan failure (n=1), bacterial infection (n=3), acute respiratory distress syndrome (n=2), infection of unknown origin (n=3), cardiac toxicity (n=1) and fungal infection (n=1). OS at 2 years was 44±8%: 80%, 21% and 52% for pts transplanted respectively for MF secondary to PV, ET and PMF (p=0.07). No difference in OS was seen in the subgroup of pts with JAK2 mutation. OS was 51% versus 29% for pts receiving double or single UCBT (p=0.15), and it was 37% for AML-transformed pts. Pts who did not receive ATG, had an OS of 59% versus 24% for those who received ATG (p=0.01). Among pts who underwent RIC (n=29), 13 had a TBI based conditioning without ATG, and 7 are alive. Failure-engraftment free survival at 2 years was 29±7%, better in pts receiving double UCBT as compared with single (40% versus 8% , p=0,01), and in pts receiving TBI (43% versus 7%, p=0,03). ConclusionGraft failure was a major concern for these pts. Despite a limited number of patients, our results indicate that life expectancy can be increased with UCBT particularly for patients with advanced stage MF. Furthermore, the use of RIC TBI based regimen without ATG and double CB might improve outcomes. Disclosures:Gluckman:Cord use: Honoraria; gamida: Honoraria.

Unrelated Umbilical Cord Blood Transplantation: Characteristics and Outcomes In Older Patients With Hematological Malignancies In Europe and United States: A Eurocord/European Group For Blood and Marrow Transplantation (EBMT) and Center For International Blood and Marrow Transplant Research (CIBMTR) Study

IntroductionTransplantation with umbilical cord blood rather than adult donor cells is a valid alternative for adults with malignant and non-malignant hematological diseases. The use of unrelated umbilical cord blood transplantation (UCBT) in adults has increased recently for 2 reasons: use of 2 cord blood units to obtain an adequate number of cells; and, use of reduced-intensity conditioning regimens (RIC) for older persons who are unable to tolerate myeloablative conditioning regimens. Recent data from Eurocord and CIBMTR indicate that 35% of adults UCBT recipients are older than 50 years. This study describes the increasing use of UCBT and the patient characteristics and transplant strategies used in older (>50 years) patients receiving UCBT in Europe and United States, as well as UCBT outcomes in this population. MethodsRetrospective registry based cross-sectional study on patients transplanted in Europe and North America; Patients: 1529 patients 50 years or older who received UCBT for hematologic malignancies or non-malignant hematologic disorders from 2005 through 2011, and whose transplants were reported to EUROCORD/EBMT or CIBMTR. 848 patients were transplanted in North America; 681 were transplanted in Europe. Acute myeloid leukemia (AML) (50%) was the most frequent indication in both registries, followed by myelodysplastic syndrome (MDS) and non-Hodgkin Lymphoma (NHL). Myeloma (MM) was the indication for UCBT for 15% of patients in Europe, but accounted for only a single case in the US (Refer to table 1 for complete UCBT distribution according to diagnosis). Most AML patients (80%) in both registries were transplanted in CR1 or CR2. RIC regimens were used more frequently for patients in Europe: 76% of patients reported to Eurocord versus 49% reported to CIBMTR for patients in the age range 50-59y and 93% in Eurocord and 69% in CIBMTR for patients 60y or older. Graft-versus-host disease prophylaxis in Europe was predominantly with cyclosporine and prednisone; tacrolimus and mycophenolate was more often used in the US. Double UCBT accounted for 61% of cases reported to Eurocord and for 71% of cases reported to CIBMTR.Table 1Number of UCBT by DiagnosisEurocord, n=681CIBMTR, n=848ALL5266AML283435MDS/MPD138121CML2121CLL4468NHL83118HD310MM491Solid Tumor4Bone Marrow Failure Syndrome44 ResultsProbability of 2-y overall survival (OS) was similar in both cohorts. In Eurocord, 2-y OS rates were 33% for AML in CR1, 48% in CR2, 10% with advanced disease for patients aged 50-59y; corresponding rates in older patients were 58%, 29% and 15%, respectively. In CIBMTR, 2-y OS rates were 41% for AML in CR1, 30% in CR2 and 15% with advanced disease for patients aged 50-59y; corresponding rates for older patients were 22%, 29%, and 16%, respectively. For other malignancies, in Eurocord, for patients aged 50-59y, 2-y OS rates were 57% in MM, 52% in ALL (acute lymphocytic leukemia), 49% in NHL, 47% in CLL (chronic lymphocytic leukemia) and 25% in MDS. In CIBMTR, corresponding OS rates were 54% in ALL, 48% in MDS, 41% in NHL and 40% in CLL ConclusionThe number of UCBT for the elderly has been increasing over the years, and survival rates are comparable for this population in Europe and North America, with similar trends in both registries. The encouraging results of this survey show that UCBT is a good alternative source of stem cells for elderly patients with hematologic diseases. Comparative studies between umbilical cord blood and other stem cell sources are needed to define the best graft indication for patients aged 50 years and older lacking an HLA identical adult donor. Disclosures:No relevant conflicts of interest to declare.