Unit Umbilical Cord Blood Transplantation Research Articles

Outcomes After Double Unit Unrelated Cord Blood Transplantation (UCBT) Compared with Single UCBT In Adults with Acute Leukemia In Remission. An Eurocord and ALWP Collaboration Study

AbstractAbstract 910The Minnesota group has described that recipients of double unrelated cord blood transplantation (dUCBT) have a higher incidence of acute GVHD, lower relapse incidence (RI) but no difference in leukemia free survival (LFS) when compared to single unit UCBT (sUCBT) recipients. In order to confirm these results in a larger and more homogenous cohort of patients and to evaluate the effect of double UCBT in relapse and LFS, we have compared the outcomes after dUCBT (n=230) with sUCBT (n=377) in adult patients with acute myeloid or lymphoblastic leukemia in remission. There were some differences between the two groups: dUCBT recipients were heavier (median weight: 68kg vs 65kg, p<0.01), tended to be older (median age: 37 years vs 35 years, p=0.06), had lower frequency of poor cytogenetics (32% vs 36%, p=0.02), transplanted more recently (p<0.001), more frequently given RIC (53% vs 30%, p<0.001), and received less ATG/ALG (29% vs 70%, p<0.001) when compared to sUCBT recipients, respectively. No differences were observed in diagnosis (38% ALL and 62% AML), status of disease at transplant (CR1: 52%, CR2:40% and CR3:8%) and previous autograft (13%). As expected, dUCBT recipients received a graft containing a higher nucleated cell dose (median of 3.7×107/kg vs 2.6×107/kg; p<0.0001). Number of HLA disparities were not statistically different (5/6:32% and 4/6:58%) when compared to sUCB grafts. Two analyses for outcomes were performed: one in patients transplanted in CR1 and other in patients transplanted in CR2 or more. The differences between dUCBT and sUCBT remained the same in both analyses. Results: in patients transplanted in CR1, median follow-up was 17 months for dUCBT recipients (n=114) and 19 months for sUCBT recipients (n=203). Unadjusted univariate analysis showed that cumulative incidence (CI) of neutrophil recovery was 78% after dUCBT and 82% after sUCBT (p=0.11); acute GVHD was 45% and 27% (p<0.001), and chronic GVHD 21% and 27% (p=0.35), respectively. At 3 years, unadjusted CI of NRM and RI were 32% after dUCBT and 36% after sUCBT (p=0.89) and 15% and 25% (p=0.03), respectively. Estimated 3 years LFS was 53% after dUCBT and 39% after sUCBT (p=0.09). In multivariate analysis, adjusted for the differences between the 2 groups, dUCBT recipients have an increased risk of grade II-IV acute GVHD (HR 1.23, p=0.005) and decreased RI (HR:0.74, p=0.01) when compared to sUCBT recipients. In a multivariate analysis adjusted, neutrophil and platelets recovery, NRM and chronic GVHD were not statistically different after dUCBT or sUCBT. However, in a multivariate analysis, LFS was improved after dUCBT compared to sUCBT recipients (HR: 0.67, p=0.04).In patients transplanted in CR2 and CR3, median follow-up was 11 months for dUCBT recipients (n=116) and 22 mo for sUCBT recipients (n=174). Unadjusted univariate analysis showed that CI of neutrophil recovery was 85% after dUCBT and 83% after sUCBT (p=0.57); acute GVHD was 33% and 17% (p=0.003), and chronic GVHD 32% and 29% (p=0.64), respectively. At 3 years, unadjusted CI of NRM and RI were 34% after dUCBT and 36% after sUCBT (p=0.47) and 31% and 33% (p=0.68), respectively. Estimated 3 Y LFS was 35% after dUCBT and 31% after sUCBT (p=0.48). In multivariate analysis, adjusted for the differences between the 2 groups, outcomes after dUCBT recipients, namely neutrophil recovery, acute and chronic GVHD, NRM, RI and LFS were not statistically different between the two groups. In conclusion our study confirms the previous findings of higher incidence of acute GVHD, equivalent NRM and reduced relapse in adult recipients of dUCBT, mainly for those transplanted in CR1, showing a higher GVL effect with improved LFS. Outcomes after dUCBT in patients with CR2 and CR3 were not statistically different of sUCBT. Double UCBT has extended the use of UCBT for patients otherwise not eligible for single UCBT and importantly is associated with better outcomes in adults patients with AL transplanted in early phase of the disease. Disclosures:No relevant conflicts of interest to declare.

Multiple unit umbilical cord blood transplantation with total body irradiation, etoposide and antithymocyte globulin for adult haematological malignancy patients

Multiple unit umbilical cord blood transplantation with total body irradiation, etoposide and antithymocyte globulin for adult haematological malignancy patients

Multiple Unit Umbilical Cord Blood Transplantation (MU UCBT) With Total Body Irradiation, Etoposide And Antithymocyte Globulin For Adult Hematologic Malignancy Patients

MU UCBT is an alternative donor transplant approach for adult hematologic malignancy (HM) pts. TBI and VP16 is an effective conditioning regimen, but its utility in MU UCBT is not well known. From 10/03-2/09 we enrolled 16 adult HM pts on a trial with this regimen prior to MU-UCBT. Eligibility included lack of an HLA matched related or unrelated donor. Pts had to have at least a 4/6 HLA matched UCB unit with at least 0.5 × 107 nucleated cells/kg and a 2nd UCB unit with at least a 4/6 HLA match to the 1st UCB unit.

Multiple Unit Umbilical Cord Blood Transplantation with Total Body Irradiation, Etoposide and Antithymocyte Globulin for Adult Hematologic Malignancy Patients.

Abstract 4344Multiple unit umbilical cord blood transplantation (MU-UCBT) has become an acceptable alternative donor transplant approach for adult hematologic malignancy patients without a bone marrow or peripheral blood stem cell donor. Total body irradiation (TBI) and etoposide (VP16) is an effective conditioning regimen for allogeneic hematopoietic stem cell transplantation, but its utility in MU-UCBT has not been well described. From 10/03-2/09 16 adult hematologic malignancy patients were enrolled on a clinical trial at our institution using this regimen prior to MU-UCBT. Patients were eligible if they did not have an HLA matched related or unrelated donor. They also were required to have at least a 4/6 HLA matched UCB unit with at least 0.5 × 107 nucleated cells/kg and a second UCB unit that was at least a 4/6 HLA match with the first UCB unit. The minimum required cryopreserved total nucleated cell (TNC) dose for the combined units was 1 × 107/kg or an infused CD34+ cell dose of 1.5 × 105/kg. Patients received TBI 1,320 cGy (fractionated over days -7 through -4), VP16 60 mg/kg (day -3) and antithymocyte globulin (ATG) 30 mg/kg (days -3 through +1). GVHD prophylaxis consisted of tacrolimus and mycophenolate mofetil. The median age was 47 yrs (range, 18-60) and diagnoses included: 8 AML, 3 CML-accelerated/blast phase, 2 MDS, 1 ALL, 1 CLL 1 NHL. Comorbidity index scores were 9 low, 6 intermediate and 1 high. The median time from diagnosis to UCBT was 8 mos (range, 1-89). HLA match results of the 1st UCB unit infused (UCB1) with the recipient included five 4/6, ten 5/6 and one 6/6 matches, and for the 2nd UCB unit (UCB2) with recipient there were one 3/6, five 4/6, and ten 5/6 matches. The median thawed TNC doses infused for UCB1 and UCB2 were 1.6 × 107/kg (range, 1.0-2.4 × 107/kg) and 1.2 × 107/kg (range, 0.8-2.4 × 107/kg), respectively; the thawed CD34+ cell doses were 0.6 × 105/kg (range, 0.01-2.4 × 105/kg) and 0.6 × 105/kg (range, 0.2-3.1 × 105/kg), respectively. Twelve were evaluable for engraftment analyses; 3 others had early deaths and 1 had graft failure and was rescued with infusion of cryopreserved remission autologous bone marrow. Sustained engraftment in the 12 was observed from a single UCB unit in all cases and the winning unit was UCB1 in 5 (42%). The winning unit had larger median CD8 (p=0.009) and thawed CD34+ cell (p=0.006) doses infused. The median time to achievement of T-cell complete donor chimerism was 30 days (range, 13-139). Median times to neutrophil and platelet engraftment were 20 days (range, 14-48) and 46 days (range, 29-86), respectively. Median time hospitalized was 39 days (range, 20-74). Grade 2-4 and 3-4 acute GVHD developed in 3 pts (19%) and 1 pt (6%), respectively. Chronic GVHD developed in 5 pts (31%) and 4 (25%) were extensive. Graft failure occurred in 2 pts. Six developed CMV infection and 15 developed other infections. There have been 2 (13%) relapses (1 MDS, 1 AML). Eight pts (50%) remain alive at a median follow-up of 15 mos (range, 5-35). Causes of death include 4 infections, 1 graft failure, 1 pulmonary toxicity, 1 CNS bleed, 1 relapse (AML). Incidence of death at 1 and 2 years are 45% (6% relapse, 39% non-relapse) and 59% (6% relapse, 53% non-relapse), respectively. We conclude that the TBI, VP16 and ATG conditioning regimen for MU-UCBT is effective in adult hematologic malignancy patients. Further strategies to enhance immune reconstitution and prevent infections post-transplant are clearly warranted. Disclosures:Off Label Use: Etoposide (VP16) may be considered off-label. Total body irradiation (TBI) and etoposide (VP16) is an effective conditioning regimen for allogeneic hematopoietic stem cell transplantation, but its utility in multiple unit umbilical cord blood transplantation has not been well described. This abstract shares results of a novel trial with TBI/VP/ATG for multiple unit umbilical cord blood transplantation.

Negative effect of KIR alloreactivity in recipients of umbilical cord blood transplant depends on transplantation conditioning intensity

We examined the clinical impact of killer-immunoglobulin receptor-ligand (KIR-L) mismatch in 257 recipients of single (n = 91) or double (n = 166) unit umbilical cord blood (UCB) grafts after myeloablative (n = 155) or reduced intensity (n = 102) conditioning regimens. Analyses of double unit grafts considered the KIR-L match status of the dominant engrafting unit. After myeloablative conditioning, KIR-L mismatch had no effect on grade III-IV acute graft-versus-host disease (GVHD), transplantation-related mortality (TRM), relapse, and survival. In contrast, after reduced intensity conditioning, KIR-L mismatch between the engrafted unit and the recipient resulted in significantly higher rates of grade III-IV acute GVHD (42% [CI, 27-59] vs 13% [CI, 5-21], P < .01) and TRM (27% [CI, 12%-42%] vs 12% [CI, 5%-19%], P = .03) with inferior survival (32% [CI, 15%-59%] vs 52% [CI, 47%-67%], P = .03). Multivariate analysis identified KIR-L mismatch as the only predictive factor associated with the development of grade III-IV acute GVHD (RR, 1.8 [CI, 1.1-2.9]; P = .02) and demonstrated a significant association between KIR-L mismatch and increased risk of death (RR, 1.8; 95% CI, 1.0-3.1; P = .05). Our results do not support the selection of UCB units based on KIR-L status and suggest that KIR-L mismatching should be avoided in reduced intensity UCB transplantation.

CD34+ Viability Is a Critical Determinant of the Engraftment Potential of Umbilical Cord Blood (UCB) in Double Unit Transplantation.

Compared to single unit historical controls double unit UCB transplantation (UCBT) has been associated with improved engraftment and survival in adult recipients, despite sustained donor engraftment of only one of the units. However, the mechanism of this advantage and unit predominance is not understood. Our hypothesis was that superior CD34+ and CD3+ viability (measured by 7-AAD staining) would be associated with unit predominance. Therefore, we evaluated 26 double unit UCBT recipients [median age 36 yrs (9–64); median weight 73 kg (40–111)] with high-risk hematologic malignancies who received myeloablative (n=15) or non-myeloablative (n=11) conditioning according to age and diagnosis. Units were 6/6 (n=2), 5/6 (n=25) and 4/6 (n=25) HLA-A, B antigen, DRB1 allele matched to the patient and ≥3/6 to each other. Flow cytometric evaluation was performed within 2 hours of thaw using CD45-FITC/CD34-PE/7-AAD/CD3-APC (dual-platform, modified ISHAGE protocol). 25/26 patients (96%) demonstrated donor engraftment by STR evaluation of day+21 bone marrow with one unit predominating (the “winner”). The % post-thaw CD34+ and CD3+ viability for the 26 double unit pairs is shown. Patients could be divided into 3 groups: 1) 10 in whom one of the 2 units had CD34+ viability ≥75% (always the winner) and the other <75% (always the loser); 2) 15 in whom both units had CD34+ viability ≥75% (either one was the winner); and 3) 1 in whom both units had CD34+ viability <75% and neither unit engrafted. CD3+ viability strongly correlated with CD34+ viability and was not an independent predictor of unit predominance. In univariate analysis infused viable CD3+ dose/kg was associated with unit predominance, while infused TNC/kg, viable CD34+/kg, CFU-total/kg, CFU-GM/kg, HLA-match and order of infusion were not. In summary, all engrafting units had CD34+ viability ≥75% and none of the units with CD34+ viability <75% engrafted (p: 0.007). Thus, in our analysis of unit predominance we have demonstrated that the % post-thaw CD34+ viability (but not the infused viable CD34+ dose) dictated the “engraftment potential” of a UCB unit, and, using the threshold of ≥75% viability, 12/52 units (23%) were unacceptable. When both CB units had CD34+ viability ≥75%, other factors (possibly related to CD3+ dose) determine unit predominance. Importantly, the finding that CD34+ viability is a marker of unit quality on the day of the transplant, if confirmed, has major implications for the clinical practice of UCBT. It suggests that double unit UCBT is superior because this approach significantly increases the chance that patients will receive at least one unit with engraftment potential. [Display omitted]

Early engraftment kinetics of two units cord blood transplantation

Cord blood transplantation (CBT) is a promising alternative means of allogeneic stem cell transplantation. However, limited cell doses may compromise outcome. To enhance engraftment, CBT has been conducted using two units with promising results. However, little is known about the mechanism of engraftment. Here, we analyzed the early engraftment kinetics of eight patients given two unit umbilical CBT. Early engraftment kinetics revealed dominancy of one of two units from the day of engraftment (absolute neutrophil count > 0.5 x 10(9)/l). The median value of percentage of the predominant unit by chimerism analysis at the time of engraftment was 88% (60-100%). Two units CBT was found to be a safe, effective and promising alternative treatment option with good engraftment potential. Dominancy occurred early after CBT and is probably influenced by multiple factors.

Progressive Emergence of a Dominant Unit during Dual Unit Umbilical Cord Blood (UCB) Culture.

Umbilical cord blood (UCB) as a stem cell source for allogeneic transplantation is limited by the cell dose a single unit can provide to adult recipients. One approach to overcoming the cell dose limitation is the use of two UCB units. However, murine and human clinical studies have shown that after infusion of two UCB units, one unit dominates as early as 3 weeks post engraftment. To understand the biology that determines the engraftment of each donor, we investigated the effect of dual donor competition on hematopoietic progenitors from 3 unrelated units and 2 units from dizygotic twins during methylcellulose and LTC-IC co-culture of equal numbers of mononuclear cells from each unit pair. Donor chimerism was evaluated in primary CFU (t=0) and secondary CFU from LTC-IC cultures (weeks 4 and 5) by PCR of informative polymorphic short tandem repeats (STR analysis). In 10 units analyzed, the CFU frequency per 100,000 mononuclear cells was 152 ± 18 and the LTC-IC frequency was 1 in 20,000 ± 5.81. The mononuclear cell composition was CD34: 1.07 ±.29%; CD3: 56.3 ± 4.1%; CD33: 17.4 ± 3.4%; and CD19: 8.42 ± 1.1%. In 4 UCB pairs, the unit with the higher primary CFU frequency dominated by an average ratio of 2:1 based on STR analysis of the primary CFU co-culture. In secondary CFU derived from the LTC-IC cultures, the skewing progressively became more pronounced with the same unit identified in primary culture predominating by an average ratio of 7:1. In mixed cultures, the absolute number of primary CFU from the dominant units increased by 15 ± 2% over the number from individual units while CFU from the non-dominant units decreased by 37 ± 4%. Interestingly, there was no dominant unit in primary CFU cultures from one set of dizygotic twins and the CFU number from each unit increased by 30% in the mixed culture. This set of twins emerged with a dominant unit during LTC-IC culture, yielding a donor ratio of 2:1. We found no correlation between the predominating unit and the CD34 percentage or LTC-IC frequency. However, in all 5 dual UCB experiments, the unit with the higher CD3 percentage dominated in primary CFU cultures and was intensified during LTC-IC culture. These results demonstrate an early and progressive dominance of one donor based on CFU analysis during mixed UCB culture. The correlation with CD3 content suggests both an immediate and protracted T-cell effector mechanism even though the LTC-IC culture does not promote T-cell proliferation. Additionally, the increase in the absolute cell number of the dominant unit may suggest a graft vs. graft progenitor cell growth-stimulatory effect which may explain the observed more rapid engraftment of the dominant unit after dual UCB transplantation. Thus, immediate UCB competition predicts the dominant unit during in vitro culture and presumably mimics the process occurring after clinical dual UCB transplantation.

Double Unit Myeloablative Umbilical Cord Blood (UCB) Transplantation in Adults & Adolescents: High Incidence of Engraftment and Low Transplant-Related Mortality.

UCB cell dose is a critical determinant of hematopoietic recovery & survival after UCB transplantation (UCBT) & is the major barrier to adult UCBT. Therefore, we have investigated the combined transplantation of 2 partially HLA-matched UCB units to augment graft cell dose. Twenty-three patients with high-risk hematologic malignancy [median 24 yrs (range: 13–53)] received two UCB units [median infused dose 3.5 x 107 NC/kg (range 1.1–6.3); larger unit 1.9 (0.6–3.6) & smaller unit 1.5 (0.5–2.7)]. Of the 46 units used, only 3 were 6/6, 16 were 5/6 & 27 were 4/6 HLA-A,B,DRB1 antigen matched unit to the recipient. All patients received myeloablative conditioning using cyclophosphamide 120 mg/kg (60 mg/kg days −7 & −6), & TBI 1320 cGy in 8 fractions with cyclosporine-A (CSA) from day -3 for at least 6 months. In addition, the first 2 patients received ATG 15 mg/kg every 12 hours days −3 to −1 & methylprednisone (MP) 1 mg/kg every 12 hours days 5–19. Subsequent patients (n = 21) received fludarabine 75 mg/m2 (25 mg/m2 days −8 to −6) & mycophenolate mofetil 1 gm twice daily from days −3 to +30 instead of ATG/MP. All evaluable patients (n = 21) engrafted at a median of 23 days (range 15–41). At day 21, engraftment was derived from both donors in 24% and a single donor in 76%, with one unit predominating in all patients (median chimerism in day 21 BM 100%). Notably, the predominating unit had a relatively low infused cell dose [median 1.8 x 107 NC/kg (range 0.7–3.6); 1.5 x 105 CD34+/kg (range 0.6–10.4)]. While neither NC, CD34+ & CFU-GM dose, nor HLA-A,B,DRB1 match, predicted which unit would predominate, the predominating unit had a significantly higher CD3+ dose (p < 0.01). However, the NC, CD34+ & CFU-GM doses of the predominating unit were significantly associated with the speed of neutrophil recovery. For example, the median day of neutrophil recovery for patients (n=11) with a predominating unit of 1.6–10.4 x 105 CD34+/kg was day 19.5 (range 15–27) vs day 26 (range 15–41) in patients (n=10) with a predominating unit of 0.6–1.5 x 105 CD34+/kg (p=0.01). Incidences of grade II–IV & III–IV acute GVHD were 65% (95%CI: 42–88) and 13% (95%CI: 0–26) at day 100, respectively, with 23% (95%CI: 6–40) having chronic GVHD at 1 year. Six month transplant-related mortality was 22% (95%CI: 5–39). With a median follow-up of 10 months (range: 3.5 months–2.5 yrs), disease-free survival (DFS) is 57% (95%CI: 35–79) at 1 year, with 72% (95%CI: 49–95) of patients alive at 1 year if transplanted in remission. These data clearly demonstrate the safety of double unit UCBT. Despite the low infused CD34+ cell dose of the predominating unit, all evaluable patients achieved sustained engraftment, with a low incidence of severe acute GVHD despite HLA-disparity. This has resulted in a low TRM, & DFS is high if patients are transplanted in remission. While the NC & CD34+ cell doses of each unit do not predict unit predominance, these parameters in the predominating unit determine the speed of neutrophil recovery. As a suitable double unit graft can be identified for the majority of adults, this approach represents a major extension of access to HSC transplantation.