Cumulative Incidence Of Neutrophil Engraftment Research Articles

Impact of cord blood banking technologies on clinical outcome: a Eurocord/Cord Blood Committee (CTIWP), European Society for Blood and Marrow Transplantation and NetCord retrospective analysis.

Techniques for banking cord blood units (CBUs) as source for hematopoietic stem cell transplantation have been developed over the past 20 years, aimed to improve laboratory efficiency without altering the biologic properties of the graft. A large-scale, registry-based assessment of the impact of the banking variables on the clinical outcome is currently missing. A total of 677 single cord blood transplants (CBTs) carried out for acute leukemia in complete remission in centers affiliated with the European Society for Blood and Marrow Transplantation were selected. An extensive set of data concerning CBU banking were collected and correlations with clinical outcome were assessed. Clinical endpoints were transplant-related mortality, engraftment, and graft-versus-host disease (GVHD). The median time between collection and CBT was 4.1 years (range, 0.2-16.3 years). Volume reduction (VR) of CBUs before freezing was performed in 59.2% of available reports; in half of these the frozen volume was less than 30 mL. Cumulative incidences of neutrophil engraftment on Day 60, 100-day acute GVHD (II-IV), and 4-year chronic GVHD were 87, 29, and 21 ± 2%. The cumulative incidence of nonrelapse mortality (NRM) at 100 days and 4-year NRM were, respectively, 16 ± 2 and 30 ± 2%. Neither the variables related to banking procedures nor the interval between collection and CBT influenced the clinical outcome. These findings indicate a satisfactory validation of the techniques associated with CBU VR across the banks. Cell viability assessment varied among the banks, suggesting that efforts to improve the standardization of CBU quality controls are needed.

Outcomes of unrelated cord blood transplantation in patients with multiple myeloma: a survey on behalf of Eurocord, the Cord Blood Committee of Cellular Therapy and Immunobiology Working Party, and the Chronic Leukemia Working Party of the EBMT.

Although allogeneic stem cell transplantation is not a standard therapy for multiple myeloma, some patients can benefit from this intense therapy. There are few reports on outcomes after umbilical cord blood transplantation in multiple myeloma, and investigation of this procedure is warranted. We retrospectively analyzed 95 patients, 85 with multiple myeloma and 10 with plasma cell leukemia, receiving single or double umbilical cord blood transplantation from 2001 to 2013. Median follow up was 41 months. The majority of patients received a reduced intensity conditioning. The cumulative incidence of neutrophil engraftment was 97%±3% at 60 days, and that of 100-day acute graft-versus-host disease grade II-IV was 41%±5%. Chronic graft-versus-host disease at two years was 22%±4%. Relapse and non-relapse mortality was 47%±5% and 29%±5% at three years, respectively. Three-year progression-free survival and overall survival were 24%±5% and 40%±5%, respectively. Anti-thymocyte globulin was associated with decreased incidence of acute graft-versus-host disease, higher non-relapse mortality, decreased overall and progression-free survival. Patients with high cytogenetic risk had higher relapse, and worse overall and progression-free survival. In conclusion, umbilical cord blood transplantation is feasible for multiple myeloma patients.

Clinical Outcomes of HLA-DPB1 Mismatches in 10/10 HLA-Matched Unrelated Donor-Recipient Pairs Undergoing Allogeneic Stem Cell Transplant

(n1⁄44) or unrelated CB (n1⁄419). The conditioning regimens were myeloablative in 20 patients and reduced-intensity in 9. Twenty-seven patients achieved neutrophil engraftment at a median day of 19 (range, 10-34). The cumulative incidence of neutrophil engraftment was 93.1% at day 42 (patients engrafted, n1⁄427; dead before day 19, n1⁄42). At 3 years, the cumulative incidence of relapse and non-relapse mortality was 32.3% and 14.0%, respectively. In 15 patients who did not achieve CP before transplantation, 11 patients (73.3%) achieved CR after transplantation. With a median follow-up of survivors of 1144 days (range, 127-3705), overall survival (OS) and event free survival (EFS) at 3 years was 63.2% and 56.3%, respectively. In univariate analysis, the variables that influenced on OS were disease status at transplantation (CP vs. AP/BC, 85% vs. 42%, p1⁄40.012), karyotype (sole Ph-chromosome vs. additional cytogenetic abnormalities, 90% vs. 47.5%, p1⁄40.042) and conditioning regimen (MAC vs. RIC, 72.7% vs. 41.7%, p1⁄40.039). In multivariate analysis, the only variable that influenced on OS was disease status at transplantation (p1⁄40.015). Conclusion: We concluded that allogeneic hematopoietic cell transplantation from any cell sources could become a promising option for the patients with CML in advanced stage, especially if they achieved CP before transplantation.

Umbilical Cord Blood Transplantation with Non-TBI Regimens for Advanced Hematological Malignant Diseases

Allogeneic hematopoietic stem cell transplantation (HSCT) for advanced hematological diseases dose not reach a satisfactory result so far. Recently, umbilical cord blood transplantation (UCBT) is widely practiced for advanced hematological diseases by its tolerance of HLA matching. However, high incidence of transplant related complications such as engraftment failure, infections, pre-engraftment immune reaction (PIR) etc. are still issues to resolve. Although non-TBI regimens are easy to prepare, few reports investigated non-TBI regimens for UCBT. With respect to UCBT with non-TBI conditioning regimens, we examined efficacy and feasibility of them for high-risk hematological diseases.Non-CR hematological malignancies, and int-2/high risk MDS categorized by IPSS were defined as advanced hematological disease. From June 2011 to January 2015, 47 patients consecutively underwent UCBT at our center. Thirty-five of 47 patients (23 male, 12 female), who were suffered from advanced hematological diseases were undergone first-time UCBT with non-TBI conditioning regimens. There were five non-TBI regimens such as fludarabine (Flu) 180mg/m2 + intravenous buslufan (Bu) 12.8mg/kg + melpharan (Mel) 80mg/m2 (FB4M) and Flu 125mg/m2 + Mel 200 mg/m2 (FM200) as the myeloablative conditioning regimens (MAC) and Flu 125mg/m2 + Mel 140mg/m2 (FM140), Flu 180mg/m2 + Bu 6.4mg/kg + Mel 140mg/m2 (FB2M140) and Flu125mg/m2 + cyclophosphamide (Cy) 120mg/kg + ATG 2.5mg/m2(FCyATG) as the reduced intensity conditioning regimens (RIC) has been used at our center. We investigated patients' characteristics, engraftment, overall survival (OS), incidence of transplant related mortality (TRM) and disease related death (DRD). OS was calculated with Kaplan-Meier method and the cumulative incidence of neutrophil engraftment, TRM and DRD was calculated with Gray′s method. Statistical significance was regarded as less than 0.05 of p-value. Statistical analyses were carried out using EZR (Kanda Y. BMT 2013).Median age at UCBT was 57 years (21-70). Fourteen patients with myeloid diseases (11 AML, 3 MDS) and 21 lymphoid diseases (17 ATLL, 1 ALL, 3 NHL) were included. 25 patients used MAC, 21 patients received FB4M, 4 FM200 followed by UCBT. On the other hand, 10 patients recieved RIC, 8 patients with FM140 and 1 each FB2M140, and FCyATG. Median time to neutrophil engraftment was 23 days (14-58) and cumulative incidence of neutrophil engraftment at day100 with the competing risk as early death (14.3%; 95%CI: 0.51-28.0) was 82.9% (95%CI: 64.1-92.4). Cumulative incidence of TRM at day 100 after UCBT was 37.4% (95%CI: 21.5-53.3). Also cumulative incidence of DAD at 3 month after UCBT was 14.9% (95%CI: 5.3-29.2). These results suggested that additional use of melpharan will be contributed to high incidence of engraftment and low incidence of relapse. In patients with myeloid diseases, cumulative incidence of DAD at 6 months after UCBT was 7.9% (95%CI: 0.4-31.3). However, in the patients of lymphoid diseases, cumulative incidence of DAD at 6 months was relatively high (37.1%; 95%CI: 12.4-62.5). There was no statistical difference between myeloid diseases and lymphoid disease about the incidence of TRM at day100 after UCBT.Although a lot of problems to solve were still remained in lymphoid diseases (OS at 1 year: 21.4%; 95%CI: 9.3-66.8), UCBT with non-TBI regimens would be feasible in the aspect of neutrophil engraftment and can be a promising treatment strategy for patients who suffered from advanced myeloid diseases (OS at 1 year: 55%; 95%CI: 25.8-76.8). DisclosuresNo relevant conflicts of interest to declare.

Ex Vivo Mesenchymal Precursor Cell-Expanded Cord Blood Transplantation Following Reduced Intensity Conditioning Regimens

Introduction: Double-unit cord blood (CB) transplantation (DCBT) after myeloablative conditioning, where one CB unit is expanded ex-vivo with mesenchymal precursor cells (MPC)-co-culture led to significantly improved neutrophil and platelet engraftment compared to historical controls.1 Our aim was to determine the efficacy of this technique after reduced-intensity conditioning (RIC) regimens.Methods: We evaluated consecutive adult patients with hematological malignancies who received RIC regimens followed by DCBT where one unit was infused unmanipulated and second unit was expanded ex-vivo with MPC prior to infusion ("MPC group" n=27), as described previously,1 andcompared themwith historical cohort who received two unmanipulated CB units ("controls" n= 51) from 2003-2015. Two RIC regimens were used - Flu/Cy/TBI (flu 40 mg/m2, cy 50 mg/kg and TBI 200cGy) (n=40) and Flu/Mel (flu 40 mg/m2 and mel 140 mg/m2) (n=38) with rabbit ATG 3mg/kg. Tacrolimus and MMF were used for GVHD prophylaxis. Primary endpoint was median time to engraftment of neutrophils (≥ 0.5 X 109/L X 3 consecutive days) and platelets (≥ 20 X 109/L X 7 consecutive days without transfusion).Results: Diagnoses were AML/MDS (N=38; 49%), ALL (N=13; 17%),NHL (N=18; 23%), HD (N=3; 4%), CML (N=1; 1%), and CLL (N=4; 5%). Baseline patient characteristics were similar among the groups [Table 1]. Majority of CB units (66%) were 5-6/8 matched at HLA-A, B, C and DRB1 by high resolution testing. Infused median total nucleatedcells (TNC) (x107/Kg) were 4 and 8, and median CD34 cells (x105/Kg)were 4.3 and 19.7, respectively for control and MPC groups. Co-culture with MPCs led to expansion of TNC by a median of 11.1 and of CD34+ cells by a median of 49.3.Among engrafted patients, median time to neutrophil engraftment was 12 (range 1-28) days in MPC group as compared with 16 (range 5-48) days in controls (p=0.02); the median time to platelet engraftment was 31 days and 37 days, respectively (P=0.3). On day 26, the cumulative incidence of neutrophil engraftment was 78% in MPC group versus 67% in controls (P=0.1). On day 60, the cumulative incidence of platelet engraftment was 74% and 74%, respectively (P=0.7). [Figure 1]Conditioning regimen also affected the time to neutrophil recovery. Among patients with Flu/Mel, the median time to neutrophil engraftment was 14 days in MPC-group (n=13) compared with 22 days in controls (n=19) (p=0.001). Patients with Flu/Cy/TBI regimen had faster time to engraftment; median time to neutrophil engraftment was 6 days in MPC group (n=10) and 11 days in controls (n=27) (p=0.04). However, the median time to platelet engraftment was similar in MPC- and control groups in patients who received either Flu/Mel (37 vs 44 days, p=0.1) or Flu/Cy/TBI regimen (29 vs 31 days, p=0.5).There was no difference in the cumulative incidence of day 100 non-relapse mortality (4% vs. 11%, p=0.6), 6th month mortality (25% vs 24%, p=0.6), grade II-IV acute GVHD (28% vs 27%, p=0.9), 2-year chronic GVHD (29% vs 20%; p=0.9) and estimates of 2-year OS (32% vs. 34%) between patients with ex-vivo expanded and unmanipulated CB units.Conclusions: Transplantation of CB units expanded with MPC appeared to be safe and effective. Using MPC-expanded CB units significantly improved time to engraftment following Flu/Mel or Flu/Cy/TBI RIC regimens as compared with unmanipulated units.Table 1Patient characteristicsControl(N=51)MSC group(N=27)P valueAge, years (median, interquartile range)57 (48, 63)59 (49, 67)0.3Disease StatusCR1/CR220 (40%)12 (45%)Advanced31 (61%)15 (56%)0.7Disease Risk Index, n (%)V. High/High8 (16%)9 (33%)Intermediate38 (75%)16 (59%)Comorbidity index0-124 (47%)13 (48%)2-422 (43%)11 (41%)>45 (10%)3 (11%)0.97Flu/Mel regimen22 (43%)16 (59%)0.2

Cord Blood Transplantation for Multiple Myeloma: A Study from the Multiple Myeloma Working Group of the Japan Society for Hematopoietic Cell Transplantation

Cord blood has been investigated as an alternative source for hematopoietic stem cell transplantation, but information about its use for multiple myeloma is limited. The purpose of this study was to evaluate the feasibility of cord blood transplantation (CBT) for patients with multiple myeloma. Eighty-six patients with multiple myeloma who underwent a first CBT between 2001 and 2011 were included in this retrospective study. Sixty-two of them had received other types of stem cell transplantation before CBT. The cumulative incidences of neutrophil engraftment at day 50, grade II to IV acute graft-versus-host disease (GVHD), and chronic GVHD were 81.4%, 39.0%, and 19.5%, respectively. The incidence of nonrelapse mortality at 2 years was 39.0%, but it was only 6.2% in patients who underwent planned tandem autologous/reduced-intensity conditioning CBT (auto/RIC-CBT). Progression-free survival (PFS) and overall survival (OS) at 6 years were 13.0% and 15.2%, respectively. Less than a partial response before CBT and lack of prior transplantation were independent significant adverse factors for PFS, whereas the presence of prior transplantation and planned tandem transplantation were associated with better OS. OS at 6 years in patients who underwent auto/RIC-CBT was 45.9%. In addition, the development of chronic GVHD was associated with superior PFS. In conclusion, we demonstrated that cord blood is feasible as an alternative graft source for myeloma patients. Although CBT provided long-term survival for a fraction of patients, optimal use of this graft requires further clinical studies.

Few and Nonsevere Adverse Infusion Events Using an Automated Method for Diluting and Washing before Unrelated Single Cord Blood Transplantation

Graft dilution and DMSO washing before cord blood (CB) administration using an automated system may offer low incidence of adverse infusion events (AIE), ensuring reproducible cell yields. Hence, we analyzed the incidences and significance of immediate AIE, cellular yield, and engraftment after single CB infusion. One hundred and fifty-seven patients (median age, 20 years; range, 1 to 60) received a single CB unit for treatment of hematologic and nonhematologic malignancies with myeloablative conditioning after graft dilution and washing. The median total nucleated cell (TNC) doses was 3.4 × 107/kg (range, 2 to 26) and the median post-thaw recovery was 84% (range, 45 to 178). The cumulative incidence of neutrophil engraftment at 50 days was 84% (95% confidence interval [CI], 83 to 93). A total of 118 immediate AIE were observed in fifty-two (33%) patients. All reported AIE were transient, graded from 1 to 2 by Common Terminology Adverse Events version 4. The most frequent toxicity was cardiovascular but without any life-threatening reaction. Infused TNC, recipient's weight, and rate of infusion per kilogram were risk factors associated with cardiovascular AIE in multivariate analysis (odds ratio [OR], 1.2 (95% CI, 1.1 to 1.4); P < .001; OR, .94 (95% CI, .9 to .97); P < .001; and OR, 1.5 (95% CI, 1.2 to 1.8); P < .001; respectively). In summary, use of an automated method for graft washing before CB administration showed low incidence of AIE without compromising cell yields and engraftment. Infused TNC dose, recipient's weight, and rate of infusion per kilogram were risk factors associated with infusion reactions.

Analysis of 129 Myeloablative Double-Unit Cord Blood Transplantation Recipients Demonstrates an Independent Association Between Non-Dominant Unit TNC Dose and Engraftment Suggesting a Facilitation Effect

▪Introduction: Double-unit cord blood (CB) transplantation (dCBT) has been investigated to augment engraftment in patients without an adequately dosed single CB unit. However, only one unit engrafts in the majority of patients and the role, if any, of the non-dominant unit is not established.Methods: To investigate whether the non-engrafting unit facilitates engraftment of the dominant unit, we studied 129 patients (median age 34 years, 76% > 16 years) who underwent myeloablative dCBT for hematological malignancies at our center in 10/2005-8/2013. Chimerism testing at 21 and 28 days after dCBT was used to identify dominant and non-dominant CB units which could be assigned even in cases of clinical graft failure based on bone marrow chimerism.Results: The cumulative incidence of neutrophil engraftment at day 45 was 95% (95%CI: 90-98) and occurred at a median of 24 days (range 12-43). The dominant CB unit was the only unit detected in the peripheral blood by day 28 in 111 patients (86%) whereas both the dominant and non-dominant units were detected in the remaining 18 patients [median non-dominant unit contribution to chimerism 20% (range 6-48)]. Recipients of units that had close unit-unit HLA- allele match (7-9/10 vs 1-6/10) were more likely to have both CB units detected at day 28 (27% vs 9%, respectively, p = 0.018). However, there was no engraftment advantage associated with persistence of the non-dominant unit 21-28 days post-dCBT with a median neutrophil recovery of 27 days (range 14-34) in those co-engrafting with both units vs 24 days (range 12-43) in those engrafting with a single unit. In univariate analyses, dominant unit infused total nucleated cell (TNC) dose, infused viable CD34+ cell dose, infused viable CD3+ cell dose, infused viable CD3-56+16+ cell dose, and percentage of viable CD34+ cells post-thaw (CD34+ cell viability) were all significantly associated with neutrophil engraftment. However, the TNC (Figure) and CD3+ cell doses of the non-dominant unit were also associated with neutrophil engraftment on univariate analysis [hazard ratio (HR) 1.35, p < 0.001 and HR 1.16, p < 0.001, respectively] whereas non-dominant unit CD34+ cell and CD3-56+16+ cell doses were not (HR 1.18, p = 0.107 and HR 1.06, p = 0.159, respectively). Neither donor-recipient HLA-match of dominant or non-dominant units, nor unit-unit HLA-match, were associated with time to neutrophil engraftment. Notably, on multivariate analysis, the dominant unit infused viable CD34+ cell dose, dominant unit CD34+ cell viability, and the non-dominant unit infused TNC dose were each independently associated with the speed and success of neutrophil engraftment (Table). To further assess potential effects of the non-dominant unit TNC dose, we evaluated the subset of patients in whom haematopoiesis by day 28 was purely derived from the dominant unit. Among these 111 patients, non-dominant unit TNC dose remained independently associated with engraftment in multivariate analysis (HR 1.21, p = 0.026). Finally, we hypothesized that the non-dominant unit TNC dose effect may be seen primarily in patients whose dominant units had a relatively low infused viable CD34+ dose. Indeed, analysis revealed the non-dominant unit TNC effect was only evident in the two-thirds of patients (n = 86) whose dominant unit infused viable CD34+ cell dose was low (< 1.20 x 105/kg, HR 1.37, p = 0.006). There was no association in patients whose dominant unit had a higher infused viable CD34+ cell dose (HR 1.03, p = 0.799).Conclusions: While infused viable CD34+ cell dose of the dominant unit is critical, the non-dominant unit TNC dose was also independently associated with neutrophil engraftment after dCBT. Therefore, despite their lack of engraftment, non-dominant units may facilitate engraftment of the dominant units in myeloablative dCBT recipients. These data suggest dCBT is associated with interactions that foster engraftment of the dominant unit. This finding supports continued investigation of dCBT, especially in adults who are more likely to receive units with low CD34+ cell doses. Furthermore, the mechanisms that underlie this observation warrant investigation.TableTable (n = 129 dCBT recipients)Multivariate AnalysisHR95% CIp valueDominant unit viable CD34+ cell x 105/kg (continuous)1.721.41-2.10< 0.001Dominant unit CD34+ cell viability (%)1.031.00-1.050.026Non-dominant unit TNC x 107/kg (continuous)1.191.01-1.400.035 [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Acute Myeloid Leukemia Transformed from Ph-Negative Myeloproliferative Neoplasm: A Study from the Adult AML Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)

BACKGROUND/METHODS: Long-term survivors with Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-neg MPNs) can eventually develop acute myeloid leukemia (AML, i.e. blast transformation). Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be the only curative treatment for such patients. To clarify its outcome, we retrospectively studied the cases with AML transformed from Ph-neg MPNs using the national registry data of JSHCT. The cases transplanted after 2000 were collected. RESULTSThirty-nine cases were extracted (male, n=21; female, n=18). Median age was 57 years (range, 22-71). Underlying Ph-neg MPNs included essential thrombocythemia (ET, n=21), primary myelofibrosis (PMF, n=11) and polycythemia vera (PV, n=7). FAB classification was M0 (n=4), M1 (n=4), M2 (n=10), M3 (n=0), M4 (n=1), M5 (n=3), M6 (n=0), M7 (n=1) and unknown (n=16). Median value of WBC at diagnosis of AML was 8300/uL (250-338000). Karyotype at diagnosis of AML was normal (n=6), complex (n=12), others (n=17) and unknown (n=4). Thirty-two cases (82%) were not in remission at the time of allo-HSCT (1st relapse, n=7; primary induction failure, n=18; untreated, n=12). Median duration between diagnosis of AML and allo-HSCT was 134 days (range, 24-369). The donors were related bone marrow or related mobilized peripheral blood stem cell (rBM/rPBSC, n=8), unrelated bone marrow (uBM, n=15) and unrelated umbilical cord blood (uCB, n=16). Myeloablative conditioning regimens (MAC) were used in 15 cases, and the remaining 24 cases were conditioned by reduced-intensity regimens (RIC), according to CIBMTR definition (Giralt S, et al, 2009). Cumulative incidence of neutrophil engraftment was 74.4% at day 60 (patients engrafted, n=29; death before day 60, n=6; relapse before day 60, n=4). At 2 years after transplant, overall survival (OS) was 29.2%. The median duration of follow up of survivors was 1989.5 days (range, 285-3270). In univariate analysis, age (>57 vs. <57, p=0.87), underlying MPNs (PMF vs. ET vs. PV, p=0.16), disease status at allo-HSCT (CR vs. non-CR, p=0.09), conditioning regimen (MAC vs. RIC, p=0.95) and donor selection (rBM/PBSC vs. uBM vs. uCB, p=0.10) had no impact on OS. The only variable that influenced on OS was chromosome at diagnosis of AML (normal vs. others vs. complex, p=0.02). The cumulative incidence of relapse and non-relapse mortality at 3 years was 34.4% and 38.1%, respectively. CONCLUSIONAlthough the prognosis of AML transformed from Ph-neg MPNs is dismal in general, the study suggested a promising result that there were curable patients with allo-HSCT. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Allogeneic Hematopoietic Cell Transplantation Is a Curative Treatment Option for Advanced-Stage Chronic Myeloid Leukemia in the TKI Era, a Single Institution Retrospective Study of 29 Post AP/BC Cases

BACKGROUNDThe prognosis of chronic myeloid leukemia (CML) in advanced stages (accelerated phase, AP or blast crisis, BC) is still extremely poor even with tyrosine kinase inhibitors (TKIs) and allogeneic hematopoietic cell transplantation (allo-HCT) is the only curative treatment for them. METHOD: Using our database, we retrospectively collected CML patients transplanted at Toranomon Hospital between June 2004 and March 2014, after the introduction of TKIs in Japan. RESULT: Twenty-nine consecutive patients were extracted. The median age was 52 years (range; 16-70). The disease status at diagnosis was chronic phase (CP, n=11), accelerated phase (AP, n=5) and blast crisis (BC, n=13). All the patients were treated with TKIs before transplantation, including imatinib (n=15), nilotinib (n=1), dasatinib (n=6), imatinib/dasatinib (n=4), nilotinib/dasatinib (n=1) and imatinib/nilotinib/dasatinib (n=2). All the 11 patients in CP at diagnosis progressed into AP/BC in their course and only 3 patients achieved second CP (MinorCyR, n=1; PCyR, n=1; MMR, n=1) at transplantation. On the other hand, 11 of 18 patients in AP/BC at diagnosis achieved CP (MinorCyR, n=1; PCyR, n=4; CCyR, n=3; MMR, n=3) at transplantation and the remaining 7 patients did not achieve CHR (Fig. 1). The median HCT-CI and EBMT score at transplantation was 2 (range, 0-5) and 5 (range, 0-7), respectively. Additional cytogenetic abnormalities developed until transplantation in 8 of 11 patients (73%) in CP at diagnosis and in 11 of 18 (61%) in AP/BC at diagnosis. Point mutations in ABL gene were detected in 9 of 20 patients (45%) in their course. Four of 7 patients (57%) in CP at diagnosis had ABL mutations, including T315I (n=1), E255K (n=2) and L359C (n=1). Five of 13 (38%) in AP/BC at diagnosis had ABL mutations, including T315I (n=4) and V299L (n=1). Overall, 14 of 29 (48%) patients underwent transplantation in CP stage (MinorCyR, n=2; PCyR, n=5; CCyR, n=3; MMR, n=4). The donors were related PBSC (n=6), unrelated BM (n=4) or unrelated CB (n=19). The conditioning regimens were myeloablative in 20 patients and reduced-intensity in 9. Twenty-seven patients achieved neutrophil engraftment at a median day of 19 (range, 10-34). The cumulative incidence of neutrophil engraftment was 93.1% at day 42 (patients engrafted, n=27; dead before day 19, n=2). At 3 years, the cumulative incidence of relapse and non-relapse mortality was 32.3% and 14.0%, respectively. In 15 patients who did not achieve CP before transplantation, 11 patients (73.3%) achieved CR after transplantation. With a median follow-up of survivors of 1144 days (range, 127-3705), overall survival (OS) and event free survival (EFS) at 3 years was 63.2% and 56.3%, respectively. In univariate analysis, age (<53 vs. ≥53, p=0.19), EBMT score (<5 vs. ≥5, p=0.32) and donor selection (rPB/uBM vs. uCB, p=0.17) had no impact on OS at 3 years. The variables that influenced on OS were disease status at transplantation (CP vs. AP/BC, 85% vs. 42%, p=0.012), karyotype (sole Ph-chromosome vs. additional cytogenetic abnormalities, 90% vs. 47.5%, p=0.042) and conditioning regimen (MAC vs. RIC, 72.7% vs 41.7%, p=0.039). In multivariate analysis, the only variable that influenced on OS was disease status at transplantation (HR=0.16, 95% CI 0.04-0.70, p=0.015). No patients received maintenance therapy with TKIs. All 9 patients who relapsed after transplantation were re-treated with TKIs. Three patients achieved MMR and the remaining 6 patients who failed received 2nd transplantation. CONCLUSION: We concluded that allo-HCT from any cell sources is a curative treatment option even for the CML patients who had AP/BC stage during their course of the disease. Remarkably good OS can be expected for those who achieved CP status before transplantation, suggesting better disease control before allo-HCT could be one of the critical factors to improve the final outcome. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Unrelated Donor (UD) Cord Blood (CB) Stem Cell Transplantation (SCT) from a Single CB Unit in Older Adults: Excellent Engraftment and Low Early Mortality with a Preparative Regimen of Melphalan (M), Thiotepa (T), Fludarabine(F), and Rabbit (r) Anti Thymocyte Globulin (ATG)

▪Background:Success of single unit UD-CBSCT has been limited by graft failure, delayed engraftment and high early mortality. Preparative regimen of Busulfan with TF and horse ATG has reduced early mortality and improved engraftment in single unit UD-CBSCT in adults (Sanz. BMT 2012: 47; 1287-1293). M with TF and r-ATG has previously been used as a preparative regimen in double expanded UD-CBSCT in adults (De-Lima. NEJM 2012: 367; 2305-2315). Outcomes of this regimen will be of interest in single unit UD-CBSCT.Methods:We retrospectively analyzed the outcomes of all patients that underwent UD-CBSCT from single unit using MTF-rATG conditioning at UMass Memorial Medical Center.Results:Twenty five underwent single unit UD-CBSCT from January 2009 to June 2014. There were 15 males and 10 females. The median age was 63 years (range, 28 -81) and median weight was 68.9 kg (range, 58.9 - 119). Nine patients (36%) were over age 65 years. Diagnosis was AML/MDS (n= 18), CLL (n= 2) and others (n=5)- ALL/Aplastic Anemia/MM/NHL/Blastic NK cell malignancy. Disease status CR1 (n=11), CR2 (n=1) and persistent disease (n=13). Four patients had undergone a prior autologous SCT.Preparative regimen consisted of T (5-10 mg/kg) day -7, F (30 mg/m2) from day -6 to -2, M (100-140 mg/m2) day -1 and r-ATG (3 mg/kg). Graft versus host disease (gvhd) prophylaxis consisted of mycophenolate mofetil (day -1 to 56) and tacrolimus (level 5-15 ng/ml) starting day -1. Tacrolimus was replaced in 2 patients: Sirolimus (n=1) and Cyclosporine (n=1). HLA matching was 6/6 (n=1), 5/6 (n=1) and 4/6 (n=23). The median total nucleated cell (TNC) dose based on pre-cryopreserved sample was 3x10e7/kg (range, 1.9 - 5.3). The median TNC and CD34 cells infused was 2.5x10e7/kg (range, 1.3-4.2) and 1.13x10e5/kg (range, 0.16-3.05) respectively.Day 100 mortality was 16% (CI,6-37%). Cumulative incidence of neutrophil engraftment (NE) was 92% (CI, 62- 99%) and that of platelet engraftment (PE) was 84% (CI, 57- 95%) Figure 1 & 2. The median time of NE was 19 days (range, 13-37) and that of PE was 40 days (range, 24-73). All 23 patients surviving beyond day 10 engrafted their neutrophils. “Transplant Success“ defined by a composite end point (NE by day 26, PE by day 60 and survival at day 100) was 60% (CI,38% -77%). The incidence of acute gvhd (I &II only) was 18% (CI,6-41%) and that of chronic gvhd was 25% (CI10-49%). 9 patients are currently alive at a median followup of 932 days (range, 97-1875 ) .All survivors are gvhd free and off immune suppression.The 2 year overall survival (OS) based on Kaplan Meier estimate is 36 %(CI,18-55%). Figure 3Discussion:Preparative regimen of MFT-rATG results in excellent engraftment, low early mortality and acceptable “Transplant Success” in single unit UD-CBSCT in older adults. Our outcomes in high risk older adults compare favorably to other studies using “double cord” or “cord blood expansion” strategies. [Display omitted] [Display omitted] [Display omitted] DisclosuresNath:Celgene: Consultancy, Honoraria. Off Label Use: Thiotepa,Melphalan,rabbit ATG,Fludarabine, mycophenolate mofetil All these have been used in preparative regimens and gvhd prophylaxis for allogeneic stem cell transplantation. Cerny:Incyte: Consultancy, Honoraria; Ariad Pharmaceuticals: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria.

Double Cord Blood Transplantation: Incidence, Organ Involvement and Risk Factors of Acute Graft Versus Host Disease. a Retrospective Analysis on Behalf of Eurocord, ALWP and Cqwp-EBMT

Double umbilical cord blood transplantation (dUCBT) has extended the applicability of UCBT for hematologic disorders especially to adult patients (pts) for whom the low cellular content of a single unit is a limiting factor. However the use of dUCBT has been, recently, associated with a higher incidence of acute graft-versus-host disease (aGVHD) when compared with single UCBT (sUCBT). Moreover, several retrospective and prospective studies have addressed risk factors for aGVHD with some conflicting results. Whether the number of total nucleated cells, HLA disparities, type of conditioning regimen or GVHD prophylaxis have an impact on aGVHD incidence in dUCBT is yet to be established in a larger series of patients. With this background, this report analyzed 921 adult recipients who underwent dUCBT for hematologic malignancies from 2005-2012 in EBMT centers.Median age was 46 (range, 18-72) years (yrs) and 59% were males. Diagnosis was acute leukemia in 56%, MDS/CML in 19% and lymphoid malignancies in 25%; 22% of pts received at least one prior autologous HSCT. Reduced-intensity conditioning (RIC) was used in 68% of pts and the most common regimen for both myeloablative conditioning (MAC) and RIC was Cyclophosphamide-Fludarabine-TBI (TCF) (40% and 78%, respectively). ATG was used in 30% of pts. GVHD prophylaxis consisted of a MMF based regimen in 774 pts (84%); cyclosporine±steroids in 103 (11%) and MTX-based regimen in 44 (5%). HLA incompatibilities were classified using the cord blood unit bearing the highest degree of mismatch with the recipient: 1% were HLA matched 6/6, 25% were 5/6, 67% were 4/6, and 7% <4/6. Median TNC collected was 4.8x10e7/kg.With a median follow-up of 26 months (range, 3-98) aGVHD was absent in 418 patients (46%), 169 pts developed grade I (18%), 194 grade II (21%), 103 grade III (11%) and 37 grade IV (4%). One-hundred day cumulative incidence (CI) of aGVHD grade II-IV was 36%±2% and III-IV 15%±2%, with a median time of onset of 28 days (range, 4-97). Of those pts with grade II-IV aGVHD, 82% had skin, 66% gastro-intestinal tract (GIT) and 25% liver involvement. The most common organ involvement in pts with grade III-IV aGVHD was GIT (89%) followed by skin (71%) and liver (39%). Treatment of grade II-IV aGVHD was steroid alone in 91% of pts. For pts with grade III-IV aGVHD steroid was used alone in 77% of pts, 11% received steroid+monoclonal antibodies, 3% steroid+MTX and 9% other treatments (figure 1). At day 60, CI of neutrophil engraftment was 84%. Out of the 712 pts at risk, 218 developed chronic GVHD (cGVHD) with a CI at 2 yrs of 25%±5%. Of these, 102 pts (47%) had previous aGVHD grade II-IV and 116 (53%) had de novo cGVHD. CI of early NRM (at day 100) was 13%. At 2 yrs, the probability of PFS was 37%, NRM 35% and relapse 28%.In multivariate analysis, the following factors were associated with an increased incidence of grade II-IV GVHD: use of MAC (HR: 1.45 (1.12-1.91), p=0.005), absence of ATG (HR: 2.39 (1.78-3.30), p<0.001) and ≥2 HLA mismatches (HR: 1.35 (1.01-1.81), p=0.048) – figure 2; whereas advanced stage disease at transplantation (HR: 1.76 (1.10-2.80), p=0.02) and absence of ATG (HR: 2.54 (1.56-4.13), p<0.001) were associated with increased incidence of aGVHD grade III-IV. Presence of 2 or higher HLA mismatches was associated with increased incidence of cGVHD (HR: 1.5 (1.1-2.05), p=0.01). In a time dependent model the presence of grade II-IV aGVHD was associated with lower relapse risk (HR: 0.71 (0.54-0.94), p=0.02), higher NRM (HR: 1.4 (1.1-1.76), p=0.005) and increased incidence of cGVHD (HR: 1.92 (1.59-2.63), p<0.001).Despite previous analysis showing increased incidence of acute and chronic GVHD after dUCBT, our study demonstrated that the GVHD incidence remains relatively low in dUCBT setting when compared to published data on HLA matched adult donor. In pts developing grade II-IV aGVHD, skin was the most common organ affected, followed by GIT and liver. Steroid alone was the backbone treatment of aGVHD and the association of steroid and other therapies (mainly monoclonal antibodies) was mostly seen in pts affected by grade III-IV aGVHD. Acute GVHD grade II-IV seems to be influenced by the intensity of the conditioning regimen, the use of ATG, and HLA compatibility; therefore prospective trials evaluating the role of these factors in dUCBT should be addressed. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Impact of ABO Incompatibility on Engraftment , Transfusion Requirement and Survival after Unrelated Cord Blood Transplantation：a Single Institute Experience in China

Few reports have focused on the impact of ABO incompatibility on the clinical outcomes, after unrelated cord blood transplantation (UCBT). Therefore, we retrospectively analyzed the impact of ABO mismatching on the clinical outcomes of 177 patients with hematologic malignancies, which underwent single UCBT in Anhui Provincial Hospital from May 2008 to April 2014. The study patients included 86 ABO-identical, 52 minor, 32 major, and 11 bidirectional ABO-incompatible recipients. All of them received a homogeneous intensified myeloablative pre-transplantation conditioning regimen of total body irradiation (TBI)cyclophosphamide (CY) [TBI (total,12 Gy; four fractions) and CY (60 mg/kg daily for 2 days)] (age≥14 years) or BuCY2 [busulfan (0.8 mg/kg every 6 h for 4 days) and CY]. Medians of 3.85×107/kg (range, 1.03-10.43) total nucleated cell (TNC) and 2.0×105/kg (range, 0.45-6.88) CD34+cells were transfused.Of the 177 patients who underwent UCBT, 169 achieved successful neutrophil engraftment. In patients receiving ABO-identical, minor, major, and bidirectional ABO-incompatible UCBT, the cumulative incidences of neutrophil engraftment were 92.7%, 100%, 96.9% and 90.9%, respectively (P=0.509). The median days to achieve neutrophil engraftment were 17, 18, 17, and 20, respectively (P=0.409). The cumulative incidences of platelet engraftment were 81.7%, 86.5% , 87.5% and 63.6%, respectively(P=0.436) .And the median days to achieve platelet engraftment for the 4 groups were 36, 40, 36, and 38, respectively; (P=0.545). All of the data did not show any significant difference among the 4 groups. Neutrophil engraftment(cumulative incidence, 95.5% versus 95.3% , P=0.861; median day, 17 versus 18, P=0.717) also did not differ significantly between the ABO-identical/minor ABO-incompatible and major/bidirectional ABO-incompatible recipients (HR1.08, P=0.680). And platelet engraftment (83.6% versus 81.4%, P=0.964; median day, 38 versus 37, P=0.699) reached the similar result (HR1.104, P=0.621).We investigated the results from a 169-patient population with neutrophil engraftment, the average units of platelets (Plts) and red blood cells (RBCs) transfused during the hospitalization after the UCBT were 0.204 units/kg(range, 0.03-1.45)and 0.159 units/kg (range, 0-1.56).In patients with ABO-identical, minor, major, and bidirectional ABO-incompatible UCBT, the average units of Plts transfused after UCBT were 0.221, 0.202, 0.169, and 0.195 units/kg(P=0.53), respectively, and the average units of RBCs transfused were 0.151, 0.156, 0.163, and 0.221 units/kg (P=0.847), respectively. No significant differences in the transfusion requirements among the 4 groups were noted, so did the comparison between the ABO-identical/minor ABO-incompatible and major/bidirectional ABO-incompatible recipients.With a median follow-up of 12 months (range, 3-74 months), the disease-free survival (DFS) rates among the ABO-identical, minor, major, and bidirectional ABO-incompatible groups were 67.1%, 57.7%, 62.5 % and 54.5%, respectively (P=0.804), and the overall survival (OS) also did not differ significantly among the four groups (68.3%, 61.5%, 65.6%, and 63.6%, respectively; P=0.929). When it came to the comparison between the ABO identical/minor incompatible group and the ABO major/bidirectional incompatible group, the DFS (63.4% versus 60.5%; P=0.995) and OS estimates (65.7% versus 65.1%; P=0.820) were not significantly different, either. What’s more, none of the patients clinical developed severe immune hemolysis or pure red-cell aplasia after transplantation.In summary, the results above indicated that :1) ABO incompatibility did not seem to have a significant impact on clinical outcomes after UCBT, such as engraftment, transfusion requirements and survival. 2) No patients developed pure red-cell aplasia after UCBT. 3) In addition, we also compared the outcomes between the ABO-identical and bidirectional ABO-incompatible groups, even it did not show any significant difference, the former did better on platelet engraftment (81.7% versus 63.6%) and DFS (67.1 versus 54.5%). The reason led to this result may be the lack of bidirectional ABO-incompatible recipients. Therefore, we’d better avoid selecting bidirectional ABO-incompatible in UCBT to improve the patients’ recovery and survival time. DisclosuresNo relevant conflicts of interest to declare.

Dominant unit CD34+ cell dose predicts engraftment after double-unit cord blood transplantation and is influenced by bank practice

AbstractWe investigated the unit characteristics associated with engraftment after double-unit cord blood (CB) transplantation (dCBT) and whether these could be reliably identified during unit selection. Cumulative incidence of neutrophil engraftment in 129 myeloablative dCBT recipients was 95% (95% confidence interval: 90-98%). When precryopreservation characteristics were analyzed, the dominant unit CD34+ cell dose was the only characteristic independently associated with engraftment (hazard ratio, 1.43; P = .002). When postthaw characteristics were also included, only dominant unit infused viable CD34+ cell dose independently predicted engraftment (hazard ratio, 1.95; P < .001). We then examined the determinants of infused viable CD34+ cell dose (precryopreservation count, postthaw recovery, and postthaw viability) in 402 units thawed at our center. This revealed close correlation between precryopreservation and postthaw CD34+ cell counts (r2 = 0.73). Median CD34+ cell recovery was 101%, although it ranged from 12% to 1480%. Notably, units from non–Netcord Foundation for the Accreditation of Cellular Therapy (Netcord-FACT)–accredited banks were more likely to have low recovery (P < .001). Furthermore, although median postthaw CD34+ cell viability was 92%, 33 (8%) units had <75% viable CD34+ cells. Units from non–Netcord-FACT–accredited banks and units with cryovolumes other than 24.5 to 26.0 mL were more likely to have poor postthaw viability. Precryopreservation CD34+ cell dose and banking practices should be incorporated into CB unit selection.

The impact of HLA matching on outcome of single unit unrelated cord blood transplantation: a retrospective single center clinical analysis

To retrospectively study the impact of human leukocyte antigen (HLA) mtyping mismatching between donor and recipient on outcome of single unit unrelated cord blood transplantation (sUCBT). 139 patients with hematological malignancies received sUCBT in single center from May 2008 to August 2012 were analyzed. Of 139 patients at enrollment, 22 were 0 mismatched (mm), 69 1 mm, 48 2 mm by low-resolution HLA-A, -B, and high-resolution (HR) DRB1. All patients'conditioning regimen was myeloablative, and a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) was given for graft-versus-host disease (GVHD) prophylaxis for all patients. The cohort of patients were followed-up until December 15, 2013. Patients of 0 mm had a statistically significant higher cumulative incidence of neutrophil engraftment by day 42 than those of 1 and 2 mm (P=0.042 and 0.002, respectively), patients of 0 mm with either a higher prefreeze total nucleated cell (TNC) dose (>5 × 10⁷/kg) or lower dose (<5 × 10⁷/kg) had a statistically significant higher cumulative incidence of neutrophil engraftment by day 42 than those of 2 mm (P=0.01 and 0.02, respectively). Patients of 0 mm had a statistically significant lower cumulative incidence of acute GVHD by day 100 than those of 1 and 2 mm (P=0.006 and 0.001, respectively). The difference of 1-year transplant-related mortality (TRM) between 0 and 2 mm patients was statistically significant (P=0.03). Patients of 2 mm received UCB units with a TNC dose less than 5 × 10⁷/kg had a higher 1-year TRM than of 0 mm patients (P=0.03). Patients of 0 mm had a statistically significant higher 3-year disease free survival (DFS) than those of 2 mm (P=0.03), compared with patients of 2 mm given CB units with a TNC dose less than 5 × 10⁷/kg, 0 mm patients and 1mm patients received UCB units with a TNC dose greater than 4 × 10⁷/kg had higher DFS rates (P=0.02 and 0.02, respectively). The HLA typing mismatching between donor and recipient had a great impact on neutrophil engraftment and long term DFS after sUCBT, 2mm cord blood unit with less TNC (<5 × 10⁷/kg) was not an optimum UCB graft.

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.

Engraftment kinetics and graft failure after single umbilical cord blood transplantation using a myeloablative conditioning regimen.

Umbilical cord blood transplant recipients are exposed to an increased risk of graft failure, a complication leading to a higher rate of transplant-related mortality. The decision and timing to offer a second transplant after graft failure is challenging. With the aim of addressing this issue, we analyzed engraftment kinetics and outcomes of 1268 patients (73% children) with acute leukemia (64% acute lymphoblastic leukemia, 36% acute myeloid leukemia) in remission who underwent single-unit umbilical cord blood transplantation after a myeloablative conditioning regimen. The median follow-up was 31 months. The overall survival rate at 3 years was 47%; the 100-day cumulative incidence of transplant-related mortality was 16%. Longer time to engraftment was associated with increased transplant-related mortality and shorter overall survival. The cumulative incidence of neutrophil engraftment at day 60 was 86%, while the median time to achieve engraftment was 24 days. Probability density analysis showed that the likelihood of engraftment after umbilical cord blood transplantation increased after day 10, peaked on day 21 and slowly decreased to 21% by day 31. Beyond day 31, the probability of engraftment dropped rapidly, and the residual probability of engrafting after day 42 was 5%. Graft failure was reported in 166 patients, and 66 of them received a second graft (allogeneic, n=45). Rescue actions, such as the search for another graft, should be considered starting after day 21. A diagnosis of graft failure can be established in patients who have not achieved neutrophil recovery by day 42. Moreover, subsequent transplants should not be postponed after day 42.

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.

A Novel Reduced-Intensity Conditioning Regimen for Unrelated Umbilical Cord Blood Transplantation in Children with Nonmalignant Diseases

Reduced-intensity conditioning (RIC) regimens have the potential to decrease transplantation-related morbidity and mortality. However, engraftment failure has been prohibitively high after RIC unrelated umbilical cord blood transplantation (UCBT) in chemotherapy-naïve children with nonmalignant diseases (NMD). Twenty-two children with a median age of 2.8 years, many with severe comorbidities and prior viral infections, were enrolled in a novel RIC protocol consisting of hydroxyurea, alemtuzumab, fludarabine, melphalan, and thiotepa followed by single UCBT. Patients underwent transplantation for inherited metabolic disorders (n = 8), primary immunodeficiencies (n = 9), hemoglobinopathies (n = 4) and Diamond Blackfan anemia (n = 1). Most umbilical cord blood (UCB) units were HLA-mismatched with median infused total nucleated cell dose of 7.9 × 107/kg. No serious organ toxicities were attributable to the regimen. The cumulative incidence of neutrophil engraftment was 86.4% (95% confidence interval [CI], 65% to 100%) in a median of 20 days, with the majority sustaining > 95% donor chimerism at 1 year. Cumulative incidence of acute graft-versus-host disease (GVHD) grades II to IV and III to IV by day 180 was 27.3% (95% CI, 8.7% to 45.9%) and 13.6% (95 CI, 0% to 27.6%), respectively. Cumulative incidence of extensive chronic GVHD was 9.1% (95% CI, 0% to 20.8%). The primary causes of death were viral infections (n = 3), acute GVHD (n = 1) and transfusion reaction (n = 1). One-year overall and event-free survivals were 77.3% (95% CI, 53.7% to 89.8%) and 68.2% (95% CI, 44.6% to 83.4%) with 31 months median follow-up. This is the first RIC protocol demonstrating durable UCB engraftment in children with NMD. Future risk-based modifications of this regimen could decrease the incidence of viral infections. (www.clinicaltrials.gov/NCT00744692).

The Outcome Of Allogeneic Hematopoietic Cell Transplantation In Children With FLT3/ITD-Positive Acute Myelogenous Leukemia

FLT3 is a receptor tyrosine kinase expressed on hematopoietic progenitors that regulates hematopoietic development. FLT3 internal tandem duplication (FLT3/ITD) is a somatic mutations whose presence is associated with poor outcome in adults and children with AML. In children with FLT3/ITD who have high allelic ratio (ITD-AR), the progression free survival is estimated to be <20%. Hematopoietic stem-cell transplantation (HSCT) has been a recommended therapeutic option for children who are positive for FLT3. There is limited data on the post transplant outcome for children with FLT3/ITD.We conducted a retrospective study to determine the outcome for all children with FLT3/ITD positive AML who underwent allogeneic HSCT in 4 pediatric centers. Data was collected and analyzed to identify the potential risk factors for overall survival (OS) and event-free survival (EFS). The association with OS and EFS was evaluated by Cox proportional hazard regression with results reported using hazard ratio (95% CI). The survival curve and cumulative incidence were calculated using the Kaplan-Meier method.Between March 2007 and June of 2012, 29 AML patients with FLT3/ITD received HSCT. Median age at HSCT was10.2 years (range 4.5-21.9), 16 were males, and 26 were in first complete remission (CR), 2 with refractory disease and 1 in second CR. Among those with minimal residual disease testing, it was present in 3 (12%) patients in 1stCR. FLT3-ITD allelic ratio at the time of diagnosis was available in 25 patients and among those patient 14 (56%) the ratio was >0.4 (range 0.03-15.99). Eleven patients (38%) received stem-cells from HLA identical siblings while in 18 (62%) an alternative donors stem-cell was utilized (mismatched related donor (n=2), unrelated donor (n=7) or cord blood (n=9)). Eighteen patients (62%) received a total body irradiation (TBI) based preparative regimen while 11 (38%) received a busulfan-based regimen. Graft-versus-host disease (GVHD) prophylaxis consisted of calcineurin inhibitor and mycophenolate for recipients of cord blood HSCT and calcineurin inhibitor plus methotrexate for the rest. Three (10%) patients experienced primary graft failure following cord blood HSCT. All 3 patients received a second graft that resulted in sustained engraftment. The cumulative incidence of neutrophil engraftment at day 42 was 89.6%. Sixteen (55%) patients developed grade 2-4 GVHD and 11 (38%) developed chronic GVHD (6 with severe and 5 mild). None of the patients experienced transplant related mortality. Eleven (38%) patients experienced relapsed disease. The cumulative incidence of relapse at 2 years was 34.7% with 95% CI (20.4%, 54.9%). At 2-years the probability of EFS and OS was 65.3% with 95% CI (45.1%, 79.6%) and 82.2% with 95% CI (58.5%, 91.3%) respectively. Using univariable analysis there was no difference between the EFS of patients who received related donors versus alternative donors, (HR 2.64 (0.79-8.76) p=0.1) and those with residual disease at the time of transplant versus those in complete remission (HR 0.88(0.19-4.09, p=0.8). Patients with higher FLT3/ITD ration at diagnosis had significantly worse EFS (HR 1.42 (1.04-1.93) p=0.03). The use of TBI in the preparative regimen was associated with superior EFS and OS (HR 0.29 (0.08-0.99), p =0.04) and (HR 0.07 (0.01-0.62), p= 0.002) respectively.In conclusion the use of allogeneic HSCT is associated with improved EFS and OS in children with FLT3/ITD positive AML compared to what has been reported in those treated with chemotherapy alone. Disclosures:No relevant conflicts of interest to declare.