Unrelated Donor Peripheral Blood Stem Cells Research Articles

Allogeneic Stem Cell Cryopreservation Is Associated with Equivalent Survival and Relapse Rates with Lower Rate of Severe Chronic Gvhd

The ongoing COVID-19 pandemic continues to raise challenges for safe administration of allogeneic hematopoietic stem cell transplantation (allo-HSCT). From March to August 2020, unrelated donor (URD) peripheral blood stem cell (PBSC) products were shipped to central national hubs and cryopreserved either at the site of collection or infusion, a shift from the traditional practice of infusing fresh stem cells. The National Marrow Donor Program (NMDP) instituted this mandate due to uncertainty around international transportation of stem cells as well as a fail-safe to prevent interruptions to a planned transplant if a donor contracted COVID-19 after the recipient started conditioning chemotherapy. We previously published our single institution experience demonstrating equivalent short-term clinical outcomes (overall survival [OS], progression free survival [PFS], relapse, and non-relapse mortality [NRM]) between adult recipients of fresh vs cryopreserved allogeneic stem cells (median follow up time 16 months [fresh] vs 8 months [cryopreserved]) (PMID: 34581754). We also demonstrated lower T-cell chimerism at day 30 and 100 after receipt of cryopreserved grafts. There is a paucity of data evaluating longer term outcomes of patients receiving cryopreserved stem cells compared to fresh. Currently there is variability among donation and transplant centers around the practice of cryopreservation prior to allo-HSCT. With ongoing surges of COVID-19 and evolution of new variants, the risk of donors or recipients contracting COVID-19 leading to delays or disruptions in planned allo-HSCT remains high. In January 2022 with the rise of the Omicron variant of COVID-19, the NMDP reinstated the cryopreservation recommendation. Anecdotal reports indicate multiple recent instances of a planned URD testing positive for COVID-19 after conditioning chemotherapy had started but before stem cell harvest, raising the potential for severe deleterious outcomes in the intended transplant recipient. Given the unremitting COVID-19 surges three years into the pandemic and continued uncertainty around longer-term survival and relapse rates of allo-HSCT using cryopreserved stem cells, we reanalyzed our prior cohort and added 116 additional patients (40 cryopreserved, 76 fresh) with at least 1-year follow up for a total of 141 and 279 patients receiving cryopreserved versus fresh (respectively) URD PBSCs between January 1, 2019, and July 31, 2021. The cohorts had similar baseline characteristics including donor/recipient age/sex, disease, and conditioning regimen/intensity. Patients receiving cryopreserved cells were more likely to receive post-transplant cyclophosphamide as part of the graft versus host disease (GVHD) prophylaxis regimen (24% vs 15%, p=0.015). Median follow-up time among survivors in this cohort was 22 months (range, 4-41 months). Two-year OS was not different in patients receiving fresh versus cryopreserved stem cells (63% vs 63%, p=0.73) (Figure 1A). Two-year PFS was also similar (57% for fresh, 52% for cryopreserved, p=0.27) (Figure 1A). Relapse (36% vs 30%, p=0.17) and NRM (12% vs 13%, p=0.79) at two years were comparable between patients receiving fresh versus cryopreserved stem cells (Figure 1B). In total, 8 patients died of COVID-19 in this cohort (4 fresh, 3 cryopreserved). Cumulative incidence of moderate/severe chronic GVHD (cGVHD) was higher in patients receiving fresh stem cells versus cryopreserved (24% vs 9%, p=0.0003). Whereas cryopreservation was associated with lower T-cell chimerism early after transplant, by 1-year post-transplant, T-cell chimerism was not different (2% vs 5% of fresh vs cryopreserved patients with T-cell chimerism <75% at 1 year, p=0.14). However, Day 30 T-cell chimerism <75% was associated with a reduction in OS and PFS regardless of cryopreservation of stem cells (data not shown). As the COVID-19 pandemic continues with frequent surges in case numbers and rapid viral evolution, the risk for interruptions in life-saving allo-HSCT therapies remains high. Our data show that allo-HSCT with cryopreserved URD PBSCs results in similar OS, PFS, relapse rates, and NRM at 2 years post-transplantation. We found that cryopreservation is associated with lower 1-year cumulative incidence of moderate/severe cGVHD without compromise in OS. While this is an intriguing finding, larger multicenter analyses are needed to confirm these observations. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Impact of cryopreservation and transit times of allogeneic grafts on hematopoietic and immune reconstitution

AbstractWe sought to evaluate the impact of cryopreservation of unrelated donor (URD) peripheral blood stem cell (PBSC) grafts on engraftment, chimerism, and immune reconstitution in the context of the COVID-19 pandemic. We reviewed stem cell product characteristics and clinical outcomes in 101 patients receiving cryopreserved PBSCs from URDs between January 1, 2019 and 31 December, 2020, compared with 203 patients receiving fresh URD PBSCs. We observed no differences in 6-month overall survival, progression-free survival, or nonrelapse mortality. Patients receiving cryopreserved PBSCs had delayed platelet engraftment and impaired reconstitution of white blood cells and T-cell subsets at day 30. Thirty-four percent of patients receiving cryopreserved grafts had CD3 chimerism <50% at day 30 after transplantation, compared with 14% of patients receiving fresh PBSCs (P = .0002). At day 100, this difference persisted (CD3+ chimerism <50%: 17% of cryopreserved cohort vs 6% of fresh cohort; P = .016). Greater product age at infusion was associated with increased graft failure, independent of cryopreservation. Receipt of grafts >48 hours old at time of cryopreservation or infusion significantly increased the risk of graft failure (subdistribution hazard ratio = 4.57; 95% confidence interval, 1.71-12.3; P = .0025). Our data indicate that cryopreservation is associated with similar overall short-term clinical outcomes compared with fresh PBSC. However, patients must be monitored closely for increased risk of other potentially adverse outcomes, including graft failure and poor immune recovery, particularly for grafts with older overall age at infusion. Longer-term follow-up is needed to determine impact on relapse and survival.

Transplantation of allogeneic cryopreserved hematopoietic cell grafts during the Covid-19 pandemic: A National Marrow Donor Program perspective.

Transplantation of allogeneic cryopreserved hematopoietic cell grafts during the Covid-19 pandemic: A National Marrow Donor Program perspective.

The efficacy and safety of co-transplantation of unrelated donor peripheral blood stem cells combined with umbilical mesenchymal stem cells in patients with refractory severe aplastic anemia-Ⅱ

The efficacy and safety of co-transplantation of unrelated donor peripheral blood stem cells (UD-PBSCs) combined with umbilical cord mesenchymal stem cells (UC-MSCs) in refractory severe aplastic anemia-Ⅱ(RSAA-Ⅱ) were analyzed retrospectively. Fifteen patients with RSAA-Ⅱ underwent UD-PBSCs and UC-MSCs co-transplantation, among whom 14 cases had hematopoietic reconstitution without severe graft versus-host disease (GVHD). The 5-year overall survival rate was 78.57%. Combination of UD-PBSCs and UC-MSCs transplantation could be a safe and effective option for RSAA-Ⅱ.

Reduced-Intensity Conditioning Followed by Related and Unrelated Allografts for Hematologic Malignancies: Expanded Analysis and Long-Term Follow-Up

Reduced-intensity conditioning (RIC) extends the curative potential of allogeneic hematopoietic cell transplantation (HCT) to patients with hematologic malignancies unable to withstand myeloablative conditioning. We prospectively analyzed the outcomes of 292 consecutive patients, median age 58 years (range, 19 to 75) with hematologic malignancies treated with a uniform RIC regimen of cyclophosphamide, fludarabine, and total body irradiation (200 cGy) with or without antithymocyte globulin and cyclosporine and mycophenolate mofetil graft-versus-host disease (GVHD) prophylaxis followed by allogeneic HCT at the University of Minnesota from 2002 to 6. Probability of 5-year overall survival was 78% for patients with indolent non-Hodgkin lymphoma, 53% for chronic myelogenous leukemia, 55% for Hodgkin lymphoma, 40% for acute myelogenous leukemia, 37% for myelodysplastic syndrome, 29% for myeloma, and 14% for myeloproliferative neoplasms. Corresponding outcomes for relapse were 0%, 13%, 53%, 37%, 39%, 75%, and 29%, respectively. Disease risk index (DRI) predicted both survival and relapse with superior survival (64%) and lowest relapse (16%) in those with low risk score compared with 24% survival and 57% relapse in those with high/very-high risk scores. Recipient cytomegalovirus (CMV)-positive serostatus was protective from relapse with the lowest rates in those also receiving a CMV-positive donor graft (29%). The cumulative incidence of 2-year nonrelapse mortality was 26% and was lowest in those receiving a matched sibling graft at 21%, with low (21%) or intermediate (18%) HCT-specific comorbidity index, and was similar across age groups. The incidence of grades II to IV acute GVHD was 43% and grades III to IV 27%; the highest rates were found in those receiving an unrelated donor (URD) peripheral blood stem cell (PBSC) graft, at 50%. Chronic GVHD at 1 year was 36%. Future approaches incorporating alternative GVHD prophylaxis, particularly for URD PBSC grafts, and targeted post-transplant antineoplastic therapies for those with high DRI are indicated to improve these outcomes.

GVHD Prevention in 2018: Tried and True or Something New?

Graft-versus-host disease (GVHD) is a major contributor to early and late morbidity and mortality after allogeneic stem cell transplantation. Despite results from a randomized controlled trial demonstrating an increased risk of chronic GVHD with use of growth factor-mobilized peripheral blood stem cells (PBSC) compared with bone marrow, PBSCs are the most widely used graft source in allogeneic transplantation for hematologic neoplasms in the U.S. This lecture will review established, recent, and novel strategies for GVHD prevention in unrelated donor PBSC transplantation and will highlight ongoing clinical research at Fred Hutchinson Cancer Research Center. Clinical trials aimed at defining standard-of-care GVHD prophylaxis after myeloablative and nonmyelablative conditioning will be presented. In addition, novel pharmacologic agents and graft manipulation strategies under investigation will be discussed. (Presented at the 1962nd Meeting, May 12, 2018).

NaïVe T Cell Depletion of PBSC Grafts Results in Very Low Rates of Chronic Gvhd and High Survival

BackgroundGraft-versus-host disease (GVHD) frequently causes morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT) as a result of organ damage and infections. In HLA-identical HCT, GVHD results from recognition by donor T cells of minor histocompatibility (H) antigens on recipient tissues. Complete T cell depletion (TCD) of donor hematopoietic cell products is more effective than pharmacologic immunosuppression for preventing GVHD, but is complicated by delayed immune reconstitution and consequent life-threatening infections.Approaches to HCT which preferentially deplete the T cells that primarily cause GVHD and preserve pathogen-specific T cells may improve HCT outcomes.Mature CD3+ CD8+ and CD3+ CD4+ T cells can be classified into CD45RA+ CD62L+ naïve (TN) and CD45RO+ memory (TM) subsets, the latter of which includes effector memory (TEM) and central memory (TCM) cells. Murine studies in which allogeneic TCD bone marrow (BM) is transplanted with purified T cells from individual T cell subsets to irradiated minor H antigen disparate recipients have demonstrated that the most severe GVHD results from transplanting T cells of the TN subset. Purified TCM causes mild GVHD and TEM do not cause detectable GVHD and can transfer immunity to pathogens.In vitro studies have similarly demonstrated that human donor CD8+ T cells specific for recipient minor H antigens are found predominantly within the TN cell subset, suggesting selective TN cell depletion may alter the GVHD incidence and/or severity in human HCT.Methods and resultsWe developed an effective process for engineering human peripheral blood stem cell (PBSC) grafts that depletes CD45RA+ TN cells and retains CD34+ stem cells and functional CD45RO+ TM cells specific for a broad range of opportunistic pathogens (Bleakley BBMT 2014). We are conducting clinical trials to evaluate the selective depletion of TN cells from HLA-matched allogeneic PBSC grafts for the prevention of GVHD in patients with acute leukemia, the first of which has been published (Bleakley JCI 2015, N=35). Seventy patients have now been treated on three consecutive phase II trials. The median age was 34 years (1-56 years), 56% of patients had a diagnosis of ALL, 46% had previously relapsed or had detectable disease (MRD or relapse) at the time of HCT, and 23% had unrelated donor (URD) grafts. Intensive myeloablative, TBI-containing (13.2Gy) conditioning was used for 63 patients, whilst 7 patients received a medium intensity ’midi’ preparative regimen, including 4Gy of TBI. The TN-depletion procedure was successfully performed on URD PBSC products shipped overnight from donor centers throughout the US, as well as on MRD PBSC collected at our centers. Reliable engraftment with high-level donor chimerism was observed in recipients of ’midi’ as well as intensive myeloablative conditioning. The 2-year estimates of overall survival, disease-free survival, survival free of relapse and chronic GVHD (CRFS) and survival free of relapse, grade II-IV acute GVHD, and chronic GVHD (GRFS) are 79%, 73%, 69% and 63% respectively. Median follow-up among survivors is 26 months. The frequency and severity of chronic GVHD is remarkably low (5%) compared to historical rates of 40-60% chronic GVHD in HLA-matched PBSC transplantation with conventional calcineurin inhibitor-based immunosuppression. Relapse and non-relapse mortality (NRM) are acceptably low at 19% and 8%, respectively. No NRM occurred in patients <40 years. Updated results will be presented.ConclusionsThe outcomes of recipients of TN-depleted PBSC grafts compare very favorably to published results of HCT for patients with acute leukemia. For example, the 69% incidence of CRFS at 2 years in TN-depleted recipients compares with reported 2-year GRFS rates of 37% and 17% in recipients of allogeneic PBSC from HLA-matched related donors with or without ATG (Kroger et al. NEJM 2016). Our results suggest that TN-depletion of PBSC grafts may reduce the risk of chronic GVHD without negatively impacting other important HCT outcomes. DisclosuresRiddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Cell Medica: Consultancy, Honoraria; Adaptive Biotechnologies: Consultancy, Honoraria.

Unrelated Donor Peripheral Blood Stem Cell Transplantation Combined with Umbilical Cord Mesenchymal Stem Cells in Patients with Hematologic Malignancies

To explore the safety and efficiency of unrelated donor peripheral blood stem cells (URD-PBSC) transplantation combined with umbilical cord mesenchymal stem cells (UC-MSC). The clinical data of 49 patients received unrelated donor peripheral blood stem cells transplantation (URD-PBSCT) for treating hematologic malignancies were retrospectively evaluated, including 12 ANLL, 17 ALL, 18 CML and 2 MDS. Out of them, 22 patients received the URD-PBSCT combined with UC-MSC and 27 patients received only URD-PBSCT. The average number of infusing UC-MSC was 1.0 × 10⁶/kg in the UC-MSC+URD-PBSCT group. As compared with URD-PBSCT group, in UC-MSC+URD-PBSCT group the median recovery time of neutrophilc granulocytes was shorter (12 d vs 15 d) (P = 0.041), the incidence and severity of chronic graft versus host disease (cGVHD) were lower (20.0% vs 51.9%) (P = 0.026) (5.0% vs 33.3%) (P = 0.040), the incidence of CMV infection after transplantation was higher (81.8% vs 51.9%) (P = 0.028). In addition to these, the differences were not statistically significant in term of implantation level, PLT reconstitution, aGVHD, lung infection, hemorrhagic cystitis, 1-year relapse and survival between the 2 groups (P > 0.05). The transplantation of URD-PBSC combined with UC-MSC is effective and safe. The speed of neutrophils reconstitution is faster. The incidence and severity of cGVHD are lower, but the attention should be paid to prevent the CMV infection.

Reduced intensity conditioning and co-transplantation of unrelated peripheral stem cells combined with umbilical cord mesenchymal stem/stroma cells for young patients with refractory severe aplastic anemia

Five young patients with a long history of severe aplastic anemia (SAA) who had failed initial CSA treatment and lacked a HLA-matched sibling donor, underwent co-transplantation of unrelated donor peripheral blood stem cells (UD-PBSCs) and umbilical cord mesenchymal/stroma stem cells (UC-MSCs). After FLU+CTX+ATG±2GY TBI conditioning, all patients received UD-PBSCs and UC-MSCs. There were no side effects attributable to the infused MSCs, and no severe complications or infections were observed in any patient after transplantation. After transplantation, one patient experienced primary graft failure, the reason for which may be related to a long history (>17years) of SAA. The other four patients achieved complete hematopoietic recovery and complete donor hematopoietic chimerism. We did not observe severe aGVHD or cGVHD. These data suggest that co-transplantation of UD-PBSCs and UC-MSCs is an acceptable alternative treatment for young patients with a long history of intensively treated SAA.

Improved Outcomes After Reduced Intensity Conditioning Matched Unrelated Donor Hematopoietic Stem Cell Transplantation In Children With Chronic Granulomatous Disease

BackgroundHematopoietic stem cell transplantation (HSCT) is the only available cure for chronic granulomatous disease (CGD). Preexisting infections tend to put CGD patients at high risk for myeloablative HSCT related complications, making reduced intensity conditioning (RIC) an attractive option for these patients. However, published studies using RIC HSCT in CGD have shown a high rate of graft rejection. ObjectivesTo characterize the clinical features and outcomes of high-risk children with chronic granulomatous disease transplanted at Children's Hospital of Los Angeles with a RIC regimen. MethodsPatients with CGD with pre-existing co-morbidities that precluded the use of myeloablative HSCT and who received RIC HSCT were selected for review. Conditioning regimen consisted of targeted dose Campath (with level monitoring), Fludarabine 30 mg/m2/dose x 3 doses and Total Body Irradiation 200 cGy x 2 doses. Tacrolimus (or cyclosporine) and Mycophenolate Mofetil (MMF) were used for graft-versus-host disease (GVHD) prophylaxis. ResultsFour children (median age 102 months, range 24-180 months) with severe CGD (serious bacterial/fungal infections pretransplantation) and significant comorbidities (Table 1) received RIC matched unrelated donor HSCT. Two patients received a 9/10 HLA allele matched graft, and the other two received a 10/10 HLA allele matched graft. Three patients received peripheral blood stem cells (PBSCs), and the one other patient received a bone marrow (BM) graft. For the PBSC grafts, the mean total nucleated cell (TNC) dose was 24.3 x 10e8/kg (range 11.9-24.5 x 10e8/kg), the mean CD34+ cell dose was 9.4x10e6/kg (range 3.7-11.8 x 10e6/kg), and the mean CD3+ cell dose was 60.3x10e7/kg (range 33.8-77.1 x 10e7/kg). The patient who received a bone marrow graft developed primary graft failure and autologous recovery 4 months after HSCT. Only one patient who was non-compliant with immune-suppressive medications developed grade 4 acute graft-versus-host disease (GVHD) with subsequent extensive chronic GVHD. None of the other patients have any evidence of active GVHD at the most recent follow up. Median follow up of all patients is 23.5 months (range 13-28 months) and three of the four patients are alive with a high donor chimerism (100%). DiscussionPatients with CGD often have multiple co-morbid conditions that lead to an increased risk of transplantation related mortality with myeloablative conditioning regimens. RIC regimens are increasing being used to decrease the short and long term toxicity of transplantation. Previous studies have suggested a high rate of graft rejection with RIC in CGD. Most of the published data on RIC HSCT in CGD patients pertains to the use of bone marrow grafts from HLA-matched siblings. In our series, we demonstrate that RIC (campath, fludarabine, and TBI) matched unrelated donor PBSC transplantation in CGD patients with life threatening infections leads to excellent engraftment, durable donor chimerism, and correction of neutrophil dysfunction, excellent survival and a low incidence of severe graft-vs-host disease. Thus, RIC HSCT represents a possible curative strategy for CGD patients with co-morbidities who are not eligible for myeloablative HSCT. Disclosures:No relevant conflicts of interest to declare.

Analysis of the recovery of cryopreserved and thawed CD34+ and CD3+ cells collected for hematopoietic transplantation

Cryopreservation is often used to store cellular therapies, but little is known about how well CD3+ or CD34+ cells tolerate this process. Viable CD34+ cell recoveries were analyzed from related and unrelated donor granulocyte-colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cell (PBSC) products and viable CD3+ cell recoveries from G-CSF-mobilized and nonmobilized apheresis products from related and unrelated donors. All products were cryopreserved with 5% dimethyl sulfoxide and 6% pentastarch using a controlled-rate freezer and were stored in liquid nitrogen. Related donor products were cryopreserved immediately after collection and unrelated donor products greater than 12 hours postcollection. The postthaw recovery of CD34+ cells from related donor PBSCs was high (n = 86; 97.5 ± 23.1%) and there was no difference in postthaw CD34+ cell recovery from unrelated donor PBSCs (n = 14; 98.8 ± 37.2%; p = 0.863). In related donor lymphocyte products the postthaw CD3+ cell recovery (n = 48; 90.7 ± 21.4%) was greater than that of unrelated donor products (n = 14; 66.6 ± 35.8%; p = 0.00251). All unrelated donor lymphocyte products were from G-CSF-mobilized products, while most related donor lymphocyte products were from nonmobilized products. A comparison of the CD3+ cell recovery from related donor G-CSF-mobilized products (n = 19; 85.0 ± 29.2%) with that of unrelated donor products found no significant difference (p = 0.137). The postthaw recovery of CD34+ cells was high in both related and unrelated donor products, but the recovery of CD3+ cells in unrelated donor G-CSF-mobilized products was lower. G-CSF-mobilized unrelated donor products may contain fewer CD3+ cells than non-G-CSF-exposed products upon thaw and, when indicated, cell doses should be monitored.

Increased Incidence of Chronic Graft-Versus-Host Disease (GVHD) and No Survival Advantage with Filgrastim-Mobilized Peripheral Blood Stem Cells (PBSC) Compared to Bone Marrow (BM) Transplants From Unrelated Donors: Results of Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Protocol 0201, a Phase III, Prospective, Randomized Trial

Abstract 1▪▪This icon denotes a clinically relevant abstract Background:Randomized trials demonstrated that filgrastim-mobilized PBSC compared to BM from HLA-identical siblings improved engraftment kinetics, increased risks of acute and chronic GVHD, but also decreased relapse and improved survival in patients with high risk leukemia. Retrospective analyses of unrelated donor transplants did not appreciate the same PBSC protective effect. Patients and Methods:The BMT CTN, sponsored by the NHLBI and NCI, conducted a Phase III, randomized, multicenter, trial of unrelated donor PBSC versus BM. The primary objective was to compare two-year survival probabilities in the two study arms using an intent-to-treat analysis. Both patients and donors provided informed consent. Fifty centers in the U.S. and Canada enrolled patients between January, 2004 and September 2009. Median follow up is 36 months (interquartile range 25 – 37 months). Randomization was performed in a 1:1 ratio to either PBSC or BM and stratified by transplant center and disease risk. Of the 278 subjects randomized to BM, 5% had no transplant, and 4.3% crossed over to PBSC; of the 273 randomized to PBSC, 4% had no transplant, and 0.4% crossed over to BM, so subjects on both arms had greater than 90% compliance with the assigned therapy. Patient primary disease (AML, ALL, CML, MDS, CMML, and MF), disease risk, gender, age, race, ethnicity, CMV serology, performance status, comorbidity, organ function, conditioning regimen, GVHD prophylaxis, use of growth factors, and donor characteristics were all well balanced between the two groups. Overall, 90% were adults over age 20, 47% had AML, 28% had high risk disease, 48% were conditioned with cyclophosphamide plus total body irradiation, and 71% received tacrolimus plus methotrexate for GVHD prophylaxis. Results:There were no observed differences in outcomes between the two groups except for a higher incidence of overall chronic GVHD (see Table) and more common chronic extensive GVHD with PBSC (46% vs. 31%). There were no survival differences according to graft sources in planned subset analyses of low and high risk malignancy or in those received HLA-matched or mismatched grafts. Primary causes of death were relapse in 54% vs. 49%, graft failure in 7% vs. 0%, acute or chronic GVHD in 22% vs. 34%, others in 16% vs. 16% of the BM and PBSC arms, respectively.Table 1Outcomes at 2 yearsPBSCBMp-valueOverall survival, intent-to-treat51% (45%-57%)46% (40%-52%)0.25Overall survival, transplanted52% (46%-58%)48% (42%-54%)0.37Disease-free survival, transplanted47% (40%-53%)44% (38%-50%)0.60Relapse28% (22%-34%)28% (23%-34%)0.88Non-relapse mortality26% (20%-31%)27% (22%-33%)0.67ANC > 500 by day 2895% (80%-99%)86% (78%-92%)0.09Acute GVHD II-IV by day 10047% (40%-53%)46% (39%-52%)0.87Acute GVHD III-IV by day 10016% (12%-21%)14% (10%-19%)0.37Any chronic GVHD53% (45%-60%)40% (33%-47%)0.02 Conclusion:This large randomized trial shows that PBSC from unrelated donors is associated with higher rates of chronic GVHD compared to BM, although rates of acute GVHD, relapse, non-relapse mortality and overall survival are similar. Disclosures:Off Label Use: Cyclophosphamide, busulfan, melphalan, fludarabine, anti-thymocyte globulin, irradiation were used to eradicate malignancy. Tacrolimus, cyclosporine, methotrexate were used for GVHD prophylaxis. Westervelt:Novartis: Speakers Bureau.

Prophylactic Effects of Interleukin-2 Receptor Antagonists against Graft-versus-Host Disease Following Unrelated Donor Peripheral Blood Stem Cell Transplantation

Basiliximab and daclizumab, two interleukin-2 receptor antagonists (IL-2RAs), prevent graft failure in renal transplantation, which also effectively treat steroid-refractory graft-versus-host disease (GVHD). However, only a few studies report that IL-2RAs prevent GVHD. Here we first retrospectively explored the prophylactic effects of basiliximab or daclizumab against GVHD in 82 patients with hematologic malignancies following unrelated donor-peripheral blood stem cell transplantation (URD-PBSCT). All recipients achieved engraftment. The rates of grade II-IV and III-IV acute GVHD (aGVHD) were 35.4% and 15.9%, respectively. Chronic GVHD (cGVHD) developed in 38.7% of evaluable patients. The transplantation-related mortality was 13.4%, while relapse rate was 8.5%. The 2-year overall survival (OS) reached 77.1% and disease-free survival (DFS) accumulated to 72.2%. The side effects of basiliximab and daclizumab were moderate and tolerable. There were no significant differences in aGVHD onset and survival between the daclizumab and basiliximab groups. However, basiliximab presented superior prophylactic effects on cGVHD than daclizumab. In conclusion, basiliximab or daclizumab prevents GVHD efficiently and feasibly following URD-PBSCT, and contributes to favorable outcome. Basiliximab has a similar effect on aGVHD but superior activity against cGVHD. Further prospective and randomized control studies are needed.

HLA-C Antigen Mismatch Is Associated with Worse Outcome in Unrelated Donor Peripheral Blood Stem Cell Transplantation

The association between HLA matching and outcome in unrelated-donor peripheral blood stem cell (PBSC) transplantation has not yet been established. In the present study, a total of 1933 unrelated donor-recipient pairs who underwent PBSC transplantation between 1999 and 2006 for acute myelogenous leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome, or chronic myelogenous leukemia and received high-resolution HLA typing for HLA-A, -B, -C, -DRB1, -DQA1, and -DQB1 were included in the analysis. Outcomes were compared between HLA-matched and HLA-mismatched pairs, adjusting for patient and transplant characteristics. Matching for HLA-A, -B, -C, and -DRB1 alleles (8/8 match) was associated with better survival at 1 year compared with 7/8 HLA-matched pairs (56% vs 47%). Using 8/8 HLA-matched patients as the baseline (n = 1243), HLA-C antigen mismatches (n = 189) were statistically significantly associated with lower leukemia-free survival (relative risk [RR], 1.36; 95% confidence interval [CI], 1.13-1.64; P = .0010), and increased risk for mortality (RR, 1.41; 95% CI, 1.16-1.70; P = .0005), treatment-related mortality (RR, 1.61; 95% CI, 1.25-2.08; P = .0002), and grade III-IV graft-versus-host disease (RR, 1.98; 95% CI, 1.50-2.62; P < .0001). HLA-B antigen or allele mismatching was associated with an increased risk for acute GVHD grade III-IV. No statistically significant differences in outcome were observed for HLA-C allele (n = 61), HLA-A antigen/allele (n = 136), HLA-DRB1 allele (n = 39), or HLA-DQ antigen/allele (n = 114) mismatches compared with 8/8 HLA-matched pairs. HLA mismatch was not associated with relapse or chronic GVHD. HLA-C antigen-mismatched unrelated PBSC donors were associated with worse outcomes compared with 8/8 HLA-matched donors. The study's limited power due to small sample size precludesconclusions about other mismatches.

Low-Dose Total Body Irradiation and Fludarabine Conditioning for HLA Class I-Mismatched Donor Stem Cell Transplantation and Immunologic Recovery in Patients with Hematologic Malignancies: A Multicenter Trial

HLA-mismatched grafts are a viable alternative source for patients without HLA-matched donors receiving ablative hematopoietic cell transplantation (HCT), although their use in reduced intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning HCT has been not well established. Here, we extended HCT to recipients of HLA class I-mismatched grafts to investigate whether NMA conditioning can establish stable donor engraftment. Fifty-nine patients were conditioned with fludarabine (Flu) 90 mg/m(2) and 2 Gy total body irradiation (TBI), followed by immunosuppression with cyclosporine (CsA) 5.0 mg/kg twice a day and mycophenolate mofetil (MMF) 15 mg/kg 3 times a day for transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSCs) from related (n = 5) or unrelated donors (n = 54) with 1 antigen +/- 1 allele HLA class I mismatch or 2 HLA class I allele mismatches. Sustained donor engraftment was observed in 95% of the evaluable patients. The incidence of grade II-IV acute and extensive chronic graft-versus-host disease (aGVHD, cGVHD) was 69% and 41%, respectively. The cumulative probability of nonrelapse mortality (NRM) was 47% at 2 years. Two-year overall and progression-free survival (OS, PFS) was 29% and 28%, respectively. NMA conditioning with Flu and low-dose TBI, followed by HCT using HLA class I-mismatched donors leads to successful engraftment and long-term survival; however, the high incidence of aGVHD and NRM needs to be addressed by alternate GVHD prophylaxis regimens.

Rapid Lymphocyte Recovery And Intravenous Immunoglobulin Independence In Children With Severe Combined Immunodeficiency (SCID) Undergoing Allogeneic Stem Cell Transplantation With Reduced Intensity Conditioning (RIC)

Allogeneic SCT is curative for patients with SCID. We evaluated a RIC SCT approach in these patients for engraftment, toxicity and immune reconstitution. Between 2000 and 2008, RIC transplant was performed in 14 SCID patients (8 males and 6 females; median age 5 months (range 1.1–98.3)). Median time from diagnosis to transplant was 1.8 months (range 1.0–96.3). Donor sources included: HLA-matched related donor peripheral blood stem cells (PBSC) (n = 1), unrelated donor PBSC (7), related cord blood (CB) (1) and unrelated CB (6).

Peripheral Blood Grafts from Unrelated Donors Are Associated with Increased Acute and Chronic Graft-versus-Host Disease without Improved Survival

Few studies have tested the benefits of using peripheral blood stem cell (PBSC) grafts versus bone marrow (BM) grafts for unrelated donor transplantation. Yet there has been a substantial change in clinical practice, with increasing numbers of adults receiving unrelated donor PBSC grafts. We compared outcomes after 331 PBSC and 586 BM transplants in adults with leukemia and myelodysplastic syndrome (MDS) who were followed for a median of 3 years after transplantation. PBSC recipients were less likely to have chronic myelogenous leukemia (CML) and more likely to have MDS, to have poor performance scores, and to be transplanted more recently. Outcomes were analyzed using Cox regression models. Rates of grades 2-4 acute graft-versus-host disease (GVHD) (58% versus 45%, P < .001) and chronic GVHD (cGVHD) (56% versus 42%, P < .001) were significantly higher with PBSC than with BM transplants. Rates of grade II-IV aGVHD were similar with PBSC and BM transplants. The 3-year probabilities of treatment-related mortality (TRM), leukemia recurrence, leukemia-free, and overall survival (OS) were similar in the 2 groups with 3-year leukemia-free survival rates of 30% and 32% after transplantation of PBSC and BM, respectively. Unlike results after HLA-matched sibling donor PBSC transplants, we did not identify a survival advantage with PBSC grafts in patients receiving unrelated donor transplants for advanced leukemia. The higher rate of cGVHD after PBSC transplants and, consequently, more frequent late adverse events warrant extended follow up of PBSC recipients.

Comparative 2-Arm Study for Acute Graft-Versus-Host Disease; Antithymocyte Globulin Is More Effective Than Mycofenolate Mofetil on Outcome of Allogeneic Peripheral Blood Stem Cell Transplantation from Mismatched Unrelated Donors.

We have experienced many HLA-mismatched unrelated donor hematopoietic stem cell transplantation (HSCT) for patients with high-risk AML. The availability of unrelated donors, who were categorized as high-risk for acute GvHD posttransplant, based on well understanding of impact of HLA allele or antigen mismatch immunobiology on various clinical outcomes, was investigated. With the use of different immunosuppression conditioning regimens, according to the patient-risk grouping, will allow stable HLA-mismatched unrelated donor HSCT to meet the needs best of the individual patient. Beginning on March 2004, 23 consecutive adult patients were enrolled in treatment protocols and follow-up was carried out through July 31, 2006. Patients with AML, age in the range between 17 and 58, who were all in 1st or 2nd complete remission, had high-risk assessment, in various performance status, received mainly total body irradiation containing conventional myeloablative transplantation. Specifically, for patients who were supposed to receive peripheral blood stem cells (PBSCs) from HLA-mismatched unrelated donors at the level of HLA antigen (N=5) or 1-2 alleles (N=7) at the HLA-A, B, Cw, and DR loci; if antithymocyte globulin (ATG;Thymoglobulin, SangStat), at a dose of 1.25 mg per kilogram of body weight per day, was given intravenously on days D-3 and D-2 followed by FK-506 from D-1 and short-term methotrexate at D+1, D+3, D+6, D+11 at a dose of 5mg/m2 intravenously, they were enrolled as group A (N=10). In contrast, if mycofenolate mofetil was started from D+21 and tapered out until D+60 instead of ATG, they were in the group B (N=13). Patients with unrelated donors were screened for HLA-A, B, and DRB1 alleles with the use of high-resolution (DNA sequencing) molecular typing method. Median age for group A, B were 36 (range, 17–58), 32 (range, 17–48), respectively. Sex ratio was similar between 2 groups. Group A received with a median CD34 dose of 4.2 (3.6–8.8) ×106/kg compared with 2.4 (1.6–5.5) ×106/kg of the group B. Median time to neutrophil (>0.5×109/kg) and platelet (>20×109/kg) regeneration was 13 vs 15 days, 14 vs 17 days in the group A and B respectively. After median follow-up of 9 months (range, 2–20) and 16 months (range, 3–29) for each group, acute GvHD was observed in 40% and 77%, respectively. However, 31% was greater than grade II acute GvHD in the group B and one of them died due to severe GvHD grade IV, despite none (0%) in the group A. Only 2 patients (29%) in the group A developed limited type chronic GvHD, but 3 patients in the group B together with 3 of extensive type (46% in total). Also, one case of graft rejection was observed in the group B (4%). The cumulative incidence of each group transplant related mortality (TRM) was 0% and 15%, respectively. The relapse rate was 0% in each group. Therefore, in our experience, in order to reduce TRM using unrelated donor PBSCs, particularly in the HLA-mismatched setting, it is required to cautiously apply ATG as a critical immunosuppression used in this group A as the benefits from reduction of GvHD/rejection.

Nonmyeloablative unrelated donor (URD) hematopoietic cell transplantation (HCT) for the treatment of patients (PTS) with poor-risk, relapsed or refractory multiple myeloma

We carried out HLA-matched URD peripheral blood stem cell (PBSC) transplantation in 24 pts with poor-risk multiple myeloma after nonmyeloablative conditioning with fludarabine (90 mg/m2) and 2 Gy total body irradiation. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. The median age of the 19 men and 5 women was 53 (range, 23-66) years. Conventional metaphase cytogenetics obtained in 14 pts showed Δ13 in 6 pts and complex abnormalities in 9 pts. Stage III disease was present in 83% and 17% had stage II disease.

Nonmyeloablative Unrelated Donor (URD) Hematopoietic Cell Transplantation (HCT) for the Treatment of Patients (pts) with Poor-Risk, Relapsed or Refractory Multiple Myeloma.

We carried out HLA-matched URD peripheral blood stem cell (PBSC) transplant in 24 pts with poor-risk multiple myeloma after nonmyeloablative conditioning with fludarabine (90 mg/m2) and 2 Gy total body irradiation. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. The median age of the 19 men and 5 women was 53 (23 – 66) years. Conventional metaphase cytogenetics obtained in 14 pts showed Δ13 in 6 pts and complex abnormalities in 9 pts. Stage III disease was present in 83% and 17% had stage II disease. The median time from diagnosis to URD HCT was 25 (range, 8–130) months, and 96% were beyond 1st complete remission (CR) or had never achieved CR1, despite multiple lines of chemotherapy (median 4.5, range 2–10). At study entry, 17 pts (71%) had chemotherapy-refractory disease and 14 pts (58%) had failed autologous HCT. Thirteen pts had planned autologous-URD tandem HCT, while 11 proceeded directly to URD HCT. The median follow-up was 2.5 years after allografting. One pt experienced non-fatal graft rejection. The incidences of acute grades II, III and chronic graft-versus-host disease were 54%, 13% and 75%, respectively. Non-relapse mortality was 22% at 2.5 years. CRs were observed in 11 pts (46%) and partial remissions (PR) in 3 (13%). Best disease responses were seen in pts given tandem autologous-URD HCT with CR in 8 pts and PR in 2 pts (77% CR+PR rate). The estimated overall survival (OS) at 2.5 years for all 24 pts was 65% and progression-free survival (PFS) 41%. Pts receiving tandem autologous-URD HCT had superior OS and PFS, 76% and 63% (Fig. A), compared to pts proceeding directly to URD HCT, 52% and 14% (Fig. B), respectively (PFS p-value=.03). Risk factors for worse OS included pts with significant medical comorbidities (p=.03), chemotherapy-refractory disease prior to HCT (p=.03), and pts who had failed autologous HCT (p=.07). Pts who failed autologous HCT had 48% OS and 30% PFS at 2.5 years. For pts with poor-risk, relapsed or refractory multiple myeloma, cytoreductive autologous HCT followed with nonmyeloablative conditioning and URD HCT is very promising treatment with low non-relapse mortality, high complete remission rates and prolonged PFS. The results also suggest that URD HCT may provide improved graft-versus-myeloma effect compared with HLA-matched sibling HCT without an increase in the risk of non-relapse mortality. [Display omitted]