HLA-haploidentical Related Donors Research Articles

A Novel Regimen of Unmanipulated HLA-Haploidentical Transplantation Using a Small Dose of Anti-T-Lymphocyte Globulin for Patients in High Tumor Burden

AbstractAbstract 4203The major drawback of HLA-haploidentical stem cell transplantation is graft-versus-host disease (GVHD): however, the GVHD can be overcome using substantial T cell depletion method (Perugia), the use of a high dose ATG (Beijing), or the posttransplantation cyclophophamide method (Johns Hopkins). These transplant procedures are found to be effective for the achievement of donor engraftment and immunological tolerance: however, graft-versus-leukemia (GVL) effects are not enough strong to prevent disease relapse. To harness GVL effect of HLA-haploidentical grafts, our regimen for unmanipulated haploidentical myeloablative transplantation is designed for GVH reaction to remain to some extent in the short time after transplantation using a small dose of ATG 2 mg/kg, coupled with GVHD prophylaxis containing a low dose of steroid (methylprednisolone 1 mg/kg). We hypothesize that allogeneic immunological response by donor T cells under low cytokine milieu exerts potent GVL effect without GVHD. This regimen was applied to patients with hematologic disease in an extremely high risk.From August 2008 to June 2012, 23 patients with high-risk or refractory hematologic diseases underwent unmanipulated peripheral blood stem cells using a graft from HLA-haploidentical related donor (11 cases were HLA 2 antigen-mismatched and 12 HLA 3 antigen-mismatched in the GVH direction). Patients’ characteristics are sex: male 11, female 12, age: 17–46 years old (median 34), disease: AML/MDS 7, ALL 10, ML 5, others 1. All patients except for 5 underwent transplantation in non-complete remission (non-CR) status, including 5 patients in induction failure, and 10 in resistant relapse. Eleven patients with leukemia who underwent in non-CR state had a median of 66% blasts in the bone marrow (range, 10.6 – 97.0 %). Patients received a conditioning treatment consisting of fuludarabine, cytarabine, cyclophsphamide, TBI 8Gy and ATG (thymoglobuline) 2 mg/kg. GVHD prophylaxis consisted of tacrolimus and methylprednisolone (1 mg/kg). One patient dies of pneumonia on day 3. Among 22 patients that could be evaluated, the engraftment rate was 95.5% (one patient had graft rejection because of donor-specific HLA antibody). Neutrophil (>0.5×109/l) and platelet (>20×109/l) engraftment was achieved on day 11 and on day 32, respectively. All patients who underwent transplantation in non-CR achieved CR after transplantation. Eleven patients (52.4%) had no GVHD. Nine patients (42.9%) developed grade II-III acute GVHD. One patient died of cardiac failure on day 46, 1 VOD on day 74, and 1 GVHD on day 235. Two patients died of relapse on days 70 and 548. Four of the 8 patients with leukemia who had more than 50% blasts in the bone marrow at the time of transplantation survive in CR. The overall survival is 60% at 3 years (Figure 1).Our regimen for HLA-haploidentical transplantation using a small dose of ATG coupled with low dose of steroid exerts a strong GVL effect even for patients who had chemorefractory disease, and transplantation-related toxicities, including GVHD, are acceptable. As a result, patients, of whom the majority had a high tumor burden, achieved a high rate of long-term survival. Thus, our strategy for haploidentical stem cell transplantation is promising, although our results will have to be confirmed in a large-scale study. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Nonmyeloablative Allogeneic (Allo) BMT for B-Cell Lymphoma with Posttransplant Rituximab: Donor Selection by Prioritizing FCGR3A-158 Polymorphism Over HLA Matching.

Abstract 3107 Background:In nonmyeloablative, HLA-haploidentical (haplo) related donor BMT with high-dose posttransplant cyclophosphamide (PT/Cy), we found no detrimental effect of greater HLA disparity on event-free survival (EFS; BBMT 2010;16:482–9). This raised the possibility that donor selection need not be dictated by the extent of HLA matching and that non-HLA graft characteristics that enhance antitumor activity may instead be prioritized. The Fc receptor polymorphism FCGR3A-158VV (population frequency 15–20%) is associated with enhanced ADCC and greater sensitivity to rituximab than 158FF. We hypothesized that donor selection based on permissive Fc receptor polymorphisms coupled with posttransplant rituximab would reduce relapse after BMT. Methods:A phase 2 study of nonmyeloablative, haplo or matched related donor BMT with PT/Cy and rituximab was developed for poor-risk B-cell lymphomas. The study uniquely prioritized donors with the most favorable FCGR3A-158 polymorphism (in order of priority, VV, VF, FF), thereby potentially conferring greater sensitivity to rituximab in the host. Donor polymorphism was prioritized over HLA matching and other variables. The primary endpoint was 1-y EFS. Donors were at least haplo first-degree relatives or half-siblings with high-resolution typing at HLA A, B, Cw, DRB1 and DQB1. All patients (pts) received Cy (14.5 mg/kg IV d -6, -5), fludarabine (30 mg/m2 IV d -6 to -2), TBI (200 cGy d -1) and T-cell replete bone marrow infusion. GVHD prophylaxis consisted of PT/Cy (50 mg/kg IV d 3, 4), mycophenolate mofetil (d 5–35) and tacrolimus (d 5–180) with filgrastim. Rituximab (375 mg/m2 weekly × 8) began d 30, contingent on ANC ≥ 500/μL and could be postponed for GVHD, infection or neutropenia. Results:In the 67 transplants (57 haplo) performed through 7/2012, 44 pts (66%) maintained or improved polymorphism quality. Thirteen donors (19%) had VV, 36 (54%) VF, 18 (27%) FF. In 11 cases (16%) a relative with a more favorable polymorphism was identified but unsuitable to donate. In 4 cases haplo donors were chosen over full matches due to polymorphism. Outcomes of the 49 pts (median age 60, range 34–74) transplanted through 12/2011 are presented, 39 (80%) having haplo BMT. Diagnoses were DLBCL without transformation (8), transformed lymphoma (12), high-grade large cell lymphoma (1), follicular lymphoma (10), mantle cell lymphoma (11), CLL (5), other (2). This was a poor-risk cohort including 10 (20%) with prior auto BMT, 9 (18%) with induction failure or resistant relapse and 14 (29%) in ≥ 3rd PR or CR. Yet, with 17-month median follow-up (range 6–33), the estimated 1-y EFS was 74% and 1-y overall survival (OS) was 90% (fig A). With haplo BMT the 1-y EFS and OS were 71% and 87%. In contrast, historically for these diseases, our 1-y EFS is 48% after haplo BMT with PT/Cy and no posttransplant rituximab. Assessment of EFS differences as a function of donor polymorphism was limited by the success of the overall approach and by sample size (fig B). On competing risk analysis, estimated 1-y cumulative incidences (CIs) of nonrelapse mortality (NRM) and relapse were 8% and 17%. Hematopoietic recovery was brisk, with CIs of ANC and platelet recovery of 98% and 88% by d 30. After posttransplant rituximab, ≥1 episode of late-onset grade 4 neutropenia was documented in 26/49 (53%) pts; 17 (35%) had ≥1 episode without apparent cause (e.g. viral infection, GVHD). Most cases had no major clinical consequence. On competing risk analysis, estimated CIs of acute grade II-IV and acute grade III-IV GVHD were 49% and 2%; the 1-y CI of chronic GVHD was 15%. At d 200 the CI of systemic steroid initiation for GVHD was 31%, with 8/24 cases (33%) of grade II GVHD requiring no systemic therapy. Conclusion:Posttransplant rituximab with nonmyeloablative, haplo or matched BMT and PT/Cy is associated with excellent short-term EFS and OS, without evident increase in severe GVHD or NRM. Efficacy was so high that it is not yet possible to determine whether donor selection by FCGR3A-158 polymorphism is beneficial. Conversely, no adverse consequences of this selection strategy were appreciated. This study suggests that donor prioritization based on non-HLA polymorphisms does not compromise EFS or OS and opens the way for further investigation of donor selection. [Display omitted] Disclosures:Kasamon:Genentech: Research Funding. Off Label Use: cyclophosphamide post-transplant for GVHD prophylaxis. Swinnen:Genentech: Honoraria, Research Funding.

Allogeneic hematopoietic cell transplantation for MDS: For whom, when and how?

Hematopoietic cell transplantation (HCT) is currently the only treatment with curative potential for patients with myelodysplastic syndrome (MDS). However, treatment-related mortality and relapse have remained major barriers to uniform success. Therefore, important questions remain to be answered, such as whom to transplant, when and how. With reduced intensity conditioning (RIC) regimens, patients in their 70s and patients with comorbid conditions have been transplanted successfully, although the relapse incidence with this approach tends to be increased in comparison to high intensity regimens. Success rates are higher in patients transplanted at an early stage of their disease. Encouraging is the fact, that results with unrelated donors who are HLA-matched by high resolution typing are comparable to those achieved with HLA genotypically identical siblings. The establishment of cord blood as a source of stem cells, and the recent success with HLA-haploidentical related donors will allow the offering of HCT to virtually all patients. Dependent upon disease stage and characteristics, some 25% to 75% of transplanted patients will be cured. While 20%–30% of patients experience chronic medical problems after HCT, 70% report a “good to excellent” quality of life. New studies must focus on further reducing GVHD for all patients and on overcoming high relapse rates in patients with high risk disease.

Desensitization for Mismatched Hematopoietic Stem Cell Transplantation (HSCT)

Abstract 1955 Introduction:Sensitization to donor HLA antigens is associated with an increased risk of engraftment failure in HLA mismatched hematopoietic stem cell transplantation (HSCT). However, the use of partially mismatched donors is increasing since, at best, only 30% of patients have an HLA identical sibling donor available for transplantation, and many are unable to find a matched unrelated donor in a timely fashion. A non-myeloablative, T cell replete regimen for HSCT that utilizes post-transplant high dose, cyclophosphamide for graft-versus-host-disease (GVHD) prophylaxis was pioneered at Johns Hopkins and has permitted transplantation of over 200 patients with HLA-haploidentical related donors. The use of HLA haplo-identical donors greatly increases the numbers of potential donors for most HSCT candidates. Review of the evaluations of 148 consecutive candidates for haplotransplantation revealed that 95% had at least one haplo-identical donor with an average of 2.7 donors/patient. However donor specific HLA antibody (DSHA) was observed in 10.8% of patients. We report here, successful desensitization of (DHSA) to levels safe for HSCT in six broadly sensitized patients who had poor-risk hematologic malignancies and for whom there were no other donors for whom HLA specific antibodies were not an issue. Methods:The desensitization protocol was modified from that developed for renal transplant patients at the Johns Hopkins University Comprehensive Transplant Center and included alternate day, single volume plasmapheresis (PP) with low dose, 100mg/kg, anti-CMV hyper immune immunoglobulin (IVIg) under immunosuppression with tacrolimus and mycophenolate mofetil. Varying numbers of PP/IVIg treatments were scheduled prior to the non-myeloablative conditioning regimen according to each patient’s DHSA level. PP/IVIg was stopped during conditioning. All but one patient received one additional PP/IVIg at transplant day −1. HLA antibodies were assessed by solid phase immunoassays using panels of pooled HLA antigens, HLA phenotypes, and single HLA antigens in microbead suspension array immunoassays (GenProbe Lifecodes Inc., San Diego, CA; One Lambda, Inc., Canoga Park, CA) Results and conclusions:All six patients prior to desensitization had DHSA at levels sufficient to yield positive flow cytometric crossmatch (FCXM) tests defined as 12K molecules of equivalent soluble fluorochromes (MESFs). The donor specific antibodies were reduced to levels well below a positive FXCM in all six patients by the end of the PP/IVIG treatments and before transplantation through an average of 4.2 PP/IVIg treatments. The average reduction in the donor specific antibody strength was 71.5% (range: 52–91%). In three patients, the DHSA levels were reduced to negative by time of transplant. A fourth patient was transplanted with a DHSA level just below that consistent with a positive FCXM, but by three months post-transplant had completely eliminated the DHSA. Two patients received one additional post-transplant PP/IVIg, resulting in stable DSA levels well below a +FCXM. Sufficient post-transplant follow-up of more than four months was available for four patients of which 3 received grafts from haploidentical donors and 1 from an HLA-mismatched unrelated donor. All four of these fully engrafted with no acute GVHD episodes. These results demonstrate that desensitization can extend the opportunity for HSCT to sensitized patients with no other donor options.Table 1:Degree of sensitization and DSA reduction by PP/IVIg.Donor TypePre-Treatment PRAbAverage # PP/IVIg (range)cEnd of Treatment % DHSA ↓ChildSibMUDaclass I (2)class II (4)31268.5954.2 (3–6)71.5 ± 12.8aTwo patients received grafts from unrelated donors (MUD) matched for all but one HLA allele. These were at the DQB1 and DPB1 loci.bPRA = panel reactive antibody. As indicated, the six patients were broadly sensitized with antibodies that would have excluded the majority of donors without intervention.cThe transplant for one patient was delayed due to unavailability of the unrelated donor. Treatment was extended to prevent antibody rebound. These additional treatments are not included. Disclosures:Luznik:Otsuka Pharmaceuticals: Research Funding.

Superiority of Haploidentical Related Hematopoietic Stem-Cell Transplantation Over Chemotherapy Alone for Patients with Intermediate- or Poor- Risk Acute Myeloid Leukemia in First Complete Remission,

Abstract 4161 Purpose:The role of HLA-haploidentical related donors (HRD) hematopoietic stem-cell transplantation (HSCT) in first complete remission (CR1) for adults with intermediate and poor risk acute myeloid leukemia (AML) is still not clear. Patients and Methods:Totally 428 newly diagnosed AML patients between 15 and 60 years old were studied between Jan 2006 and May 2010. Among 240 patients with intermediate and poor risk cytogenetics, 191patients achieved CR1 and received chemotherapy alone or HSCT as post-remission treatment. Of these, 141 patients received chemotherapy alone (n=78) or HRD HSCT (n=63) were analyzed. Results:Up to last follow-up time of May 2011, 44 out of 141 patients died (36 died of relapse and 8 died of TRM) and 97 patients are still alive. 49 out of 141 patients experienced relapse and 84 patients are still in continuous CR1. The cumulative incidence of relapse (CIR) at 4 years was 37.4%±4.4%. Overall survival(OS) and disease-free survival(DFS) at 4 year was 63.8%±5.0% and 55.5%±4.9%, respectively. The CIR of HRD HSCT group was significantly lower than chemotherapy group(12.8%±6.1% vs.57.4%±5.6%, p<0.0001). HRD HSCT improved survival achieved by chemotherapy alone significantly (DFS at 4 years, 71.8%±6.9% v 42.6%±6.1%, p<0.0001;OS at 4 years,75.7% ±7.0% v 54.6%±6.1%, p=0.0014). Univariate and multivariate analysis showed post-remission treatment choice (HRD HSCT or chemotherapy) and high WBC at diagnosis were independent risk factor affecting relapse, DFS and OS. Conclusion:HRD HSCT in CR1 is superior to chemotherapy alone for adults with intermediate and poor risk AML patients. Disclosures:No relevant conflicts of interest to declare.

Alternative donor transplantation after reduced intensity conditioning: results of parallel phase 2 trials using partially HLA-mismatched related bone marrow or unrelated double umbilical cord blood grafts

AbstractThe Blood and Marrow Transplant Clinical Trials Network conducted 2 parallel multicenter phase 2 trials for individuals with leukemia or lymphoma and no suitable related donor. Reduced intensity conditioning (RIC) was used with either unrelated double umbilical cord blood (dUCB) or HLA-haploidentical related donor bone marrow (Haplo-marrow) transplantation. For both trials, the transplantation conditioning regimen incorporated cyclophosphamide, fludarabine, and 200 cGy of total body irradiation. The 1-year probabilities of overall and progression-free survival were 54% and 46%, respectively, after dUCB transplantation (n = 50) and 62% and 48%, respectively, after Haplo-marrow transplantation (n = 50). The day +56 cumulative incidence of neutrophil recovery was 94% after dUCB and 96% after Haplo-marrow transplantation. The 100-day cumulative incidence of grade II-IV acute GVHD was 40% after dUCB and 32% after Haplo-marrow transplantation. The 1-year cumulative incidences of nonrelapse mortality and relapse after dUCB transplantation were 24% and 31%, respectively, with corresponding results of 7% and 45%, respectively, after Haplo-marrow transplantation. These multicenter studies confirm the utility of dUCB and Haplo-marrow as alternative donor sources and set the stage for a multicenter randomized clinical trial to assess the relative efficacy of these 2 strategies. The trials are registered at www.clinicaltrials.gov under NCT00864227 (BMT CTN 0604) and NCT00849147 (BMT CTN 0603).

Prospective, Biological Randomized Study of T-Cell Depleted Nonmyeloablative Allogeneic Transplantation From HLA-Matched Related, Unrelated or Haploidentical Donors for Patients with Hematologic Malignancies

AbstractAbstract 3541We have previously shown that SCT from HLA-haploidentical related donors (HAPLO) after nonmyeloablative conditioning is feasible with a low incidence of grade III-IV acute GVHD or treatment-related mortality (TRM) (Rizzieri et al. JCO 2007). We now report our comparative study in patients who received SCT from a 6/6 HLA-matched related (MRD), 8–10/8 HLA-matched unrelated (MUD), or HAPLO donor, after nonmyeloablative conditioning. Methods:Patients with chemosensitive relapse or high risk disease with minimal residual disease at study entry were eligible. The conditioning regimen consisted of fludarabine, 40 mg/m2 for 4 days; melphalan, 140 mg/m2 for 1 day; and alemtuzumab, 20 mg for 4 days for patients with lymphoid or myelomatous diseases. Fludarabine and alemtuzumab at the same doses with busulfan, 130 mg/m2 for 2 days was used for patients with myeloid diseases. Mycophenolate mofetil was used for GVHD prophylaxis. Donor lymphocyte infusions were performed in 15 MRD patients and 4 HAPLO patients. Disease-free survival (DFS) and overall survival (OS) rates after SCT were estimated using the Kaplan–Meier method, and univariate comparisons were performed using the log-rank test. Cox proportional-hazards regression was used to evaluate variables that potentially affected the survival rates. Results:The lymphoid cohort included 52 patients with ALL (n = 6), lymphoma (n = 42), or myeloma (n = 4), whereas the myeloid cohort included 46 patients with AML/MDS (n = 40), and myeloproliferative disorder (MPD) (n = 6). The median subject age was 56.5 (range, 20–73) years with a median follow-up of 15 months among survivors. A total of 29, 40, and 29 patients received transplants from MRD, MUD, and HAPLO, respectively. All 29 patients engrafted after HCT from MRD. One of 40 patients who received SCT from MUD had a primary graft failure (GF), with 2 secondary GF and 1 early relapse. Two of them were rescued by subsequent nonmyeloablative SCT from the same MUD or new HAPLO donor. Among 28 HAPLO patients evaluable for engraftment, 8 had a primary GF, 6 of these had myeloid disease; 2 additional patients had donor cell recovery but without full recovery of normal blood counts. Three of the 8 were rescued with subsequent nonmyeloablative SCT from the same donor. The transplant regimen resulted in 11% TRM at day 100. Grade III-IV acute GVHD rates were 0/29 (0%), 4/40 (10%), and 5/29 (17%) in patients who received a transplant from a MRD, MUD, or HAPLO, respectively. CMV reactivation occurred in 57% of patients and 6% developed CMV disease. Other infectious complications included polyomavirus in 24% of patients, bacteria in 23%, respiratory viruses in 13%, and fungal infections in 7%. The common causes of death were progressive disease (30% for all cause of death) and infections (32%). The 1-year DFS rate after SCT from MRD, MUD, and HAPLO was 55% (95% CI, 33–73%), 39% (22–56%), and 34% (16–53%), respectively (Log-rank test, P = 0.094) (Figure 1); the corresponding 1-year OS rate was 66% (43–82%), 39% (21–55%), and 34% (16–53%), respectively (Log-rank test, P = 0.012) (Figure 2). Multivariate analysis revealed that SCT from MUD/HAPLO, compared with that from MRD, was the only adverse factor that affected the OS rate (HR for MUD, 2.62 (95% CI, 1.15–5.96), P = 0.022; HR for HAPLO, 3.17 (1.36–7.37), P = 0.007), but the OS rate after SCT from HAPLO did not significantly differ from that after SCT from MUD (P = 0.560). Other variables (recipient age, conditioning regimen, and disease status at transplant) were not significantly associated with the outcome. [Display omitted] Conclusions:The results show the feasibility of this approach with this regimen and the clinical outcomes in patients who received transplants from HAPLO are comparable to patients who received transplants from MUD. Development of strategies to improve immune recovery remains a current challenge. Disclosures:Off Label Use: Alemtuzumab for conditioning in allogeneic stem cell transplantation. Horwitz:Genzyme: Honoraria, Research Funding. Chao:Genzyme: Research Funding. Rizzieri:Genzyme: Speakers Bureau.

Unmanipulated Bone Marrow Transplantation From Haploidentical Related Donor for Patients with High-Risk Hematological Malignancies

AbstractAbstract 2350In this study we investigated the feasibility and clinical value of non T-cell depleted bone marrow transplantation (BMT) from HLA haploidentical related donor in patients with high risk hematological malignancies. Materials and Methods.Between August 2005 and May 2010, 71 patients were transplanted for acute myeloid leukemia (AML) (n=42), acute lymphoblastic leukemia (n=13), chronic myeloid leukemia (n=5), Hodgkin lymphoma (n=5), plasmacell leukemia (n=3), myelofibrosis (n=2) and myelodisplastic syndrome (n=1). Their median age was 35 years (5-71). At time of BMT, all patients were at very high risk: 39 were in early (complete remission 1 or 2) and 31 in more advanced stage of disease. Seventeen of them were given a previous transplant either autologous (n=14) or allogenic (n=3). All donors were HLA identical at 1 haplotype and mismatched for 2 (n=24) or 3 (n=47) loci on the unshared haplotype. As pretransplant regimen, 10 patients received a reduced intensity conditioning consisting of Fludarabine (Flu) alone (n=1), Flu + Thiotepa (Thio) + Melphalan (n=2) or Flu + Thio + i.v.Busulphan (Bu) (n=7), and 61 patients received a myeloablative therapy consisting of Aracytin + Cyclophosphamide combined with TBI (n=7) or Treosulphan (n=11) or Bu (n=11), whereas the last 32 consecutive patients underwent transplant after conditioning with the association of Thio + Flu + i.v. Bu. All patients received an identical graft-versus-host disease (GvHD) prophylaxis consisting of Fresenius Antithymocyte Globulin (5 mg/Kg/d from day -4 to -1) combined with Cyclosporine (1,5-3 mg/Kg/day i.v. from day -7 to +28 and orally 5 mg/Kg until day +365), Methotrexate (15 mg/sqm on day +1 and 10 mg/sqm on day +3, +6 and +11), Mycophenolate Mofetil (1 g/d from day +7 to +100) and the anti-CD 25 monoclonal antibody Basiliximab (20 mg i.v. on day 0 and +4). Bone marrow cells were harvested from all donors after priming with Filgrastim at 3–4 microg/Kg/d from day -7 to -1. Bone marrow cells were infused fresh and unmanipulated on day 0. Results.The median dose of total nucleated, CD34+ and CD3+ cells infused was 7.8 (1-28) ×108/kg, 2.1 (0.8-11) ×106/Kg and 28 (10-98) ×106/Kg, respectively. One patient had a primary graft failure and 5 patients died too early to be evaluated for engraftment. Results in terms of cumulative incidence (CI) of PMN engraftment, acute and chronic GvHD, relapse, transplant related mortality (TRM) and overall survival (OS) estimated with the Kaplan Meyer method are given in the Table. After a median follow-up of 16 (3-56) months, the 3 years probability of OS and disease-free survival (DFS) was 43% and 37% respectively for all patients (see Figure). The 3 years OS for the 42 patients with AML was 48% (61% for 30 patients transplanted in early stage and 18% for 12 patients transplanted in advanced stage, P=0.01). The 1 year OS for the 32 patients transplanted with the conditioning therapy employed in the last 2 years (Thio + Flu + i.v. Bu) was 72% in 18 patients transplanted in early stage and 52% in 14 patients transplanted in advanced stage (P=0.47).Early stageAdvanced stageAll patientsP valueN.393271CI of PMN engraftment at day 3087±0.381±0.588+0.7NSCI of acute GvHD grade II - IV34±0.716±0.626±0.3NSCI of acute GvHD grade III - IV9±0.43±0.16±0.1NSCI of chronic GvHD8±0.214±0.811±0.1NSCI of relapse at 2 years30±0.737±133±0.4NSCI of TRM at 1 year21±0.441±0.530±0.3NSCI of TRM at 2 years24±0.548±1.336±0.6NSOS at 3 years54±9.226±9.943±70.03 [Display omitted] Conclusions.BMT from haploidentical donor using G-CSF primed, unmanipulated bone marrow cells and an intensive regimen for GVHD prophylaxis is correlated with high engraftment rate, low incidence of acute and chronic GVHD, acceptable TRM and favourable patient outcome. The results seem particularly encouraging for AML patients grafted at an early disease stage. In alternative to transplant from matched unrelated donor or cord blood, this approach can be offered to high risk patients with hematological malignancies particularly for those who are on urgency for a transplant.Results are given as % ± standard error Disclosures:No relevant conflicts of interest to declare.

A Potent Thymic Function Is Associated with a Low Risk of Relapse In Leukemia Patients Treated with Haploidentical Stem Cell Transplantation

AbstractAbstract 1258Hematopoietic Stem Cell Transplantation (HSCT) is an effective treatment for many malignant and non malignant diseases in children. Since less than 30% of the patients have an HLA identical related donor, alternative donor/sources of Hematopoietic Stem Cells need to be considered, such as unrelated bone marrow (BM) and Cord Blood (CB) donors or HLA-haploidentical related donors. However, these types of HSCT are associated with a significant delay in immune reconstitution that favors both a high incidence of opportunistic infection and, in the absence of an alloreactive, natural killer cell-mediated effect, disease relapse. Indeed, T-cell depletion of the allograft in the haploidentical setting or T-cell naivety in CB, as well as HLA-disparity and use of serotherapy before HSCT, contribute to this impaired immune reconstitution. In view of the role played by the thymus in immune reconstitution post-allogeneic HSCT, it would be informative to compare thymic-dependent immune reconstitution after these types of HSCT.We have studied immune reconstitution and thymic function through signal joint (sj) and beta T cell Receptor Excision Circles (TREC) quantification in a group of 33 haplo-HSCT pediatric patients and in a group of 24 unrelated CB-HSCT. Patients were transplanted mainly for hematological malignancies (n=46, including 31 Acute Lymphocytic Leukemia and 9 Acute Myeloid Leukemia). All children received a myeloablative conditioning regimen, including the combination of total body irradiation and chemotherapy (n=33) or chemotherapy alone (n=24). In haplo-HSCT, no pharmacological immune-suppression was given after the allograft, while patients given CB-HSCT received cyclosporine-A and steroids as Graft vs. Host Disease (GvHD) prophylaxis. In haplo-HSCT patients the median number of CD34+ cells infused/kg was 20.7 × 106 (range 8.7–41), while in patients given CB-HSCT the median number of nucleated cells infused/kg was 7.1) × 107 (range 1.4–12.5). The only significant difference between the 2 groups was that haplo-HSCT patients were older (p=.0008) than CB-HSCT patients (median age being 7.7 and 3.4 yrs, range 3–17 and 0.75–16 yrs, respectively). Patients treated for an hematological malignancy had a significant lower pre-transplant TREC value (p = .0002 and .004 for sj and beta TREC respectively) than those affected by non-malignant diseases in both groups. Number of sj and betaTREC per 150 000 PBMC or absolute counts per μl of blood, showed a very similar thymic function in both groups despite the older age of haplo-HSCT patients. TREC levels were comparable to those found before transplantation starting from 6 months after HSCT. Cumulative incidence of acute or chronic GvHD was low in both groups, with no significant impact on thymic function.In haplo-HSCT, but not in CB transplantation, patients treated for hematological malignancies (n=27) who relapsed (n=8) had a significantly lower level of thymic function (sjTREC) than those who did not relapse (n=19), before (p=0.03), after 3 (p=0.014) and 6 months (p=0.015) from the allograft. In this group of patients, relapse was not associated with age, conditioning regimen or number of CD34+ cells infused. In conclusion, we demonstrate the crucial importance of thymic function in the Graft-vs. Leukemia effect in the haplo-HSCT setting. Monitoring thymic function could be of predictive value in these patients. Disclosures:No relevant conflicts of interest to declare.

Outcomes of early relapse following non-myeloablative allogeneic transplant for lymphoma

Abstract Abstract 1204 Poster Board I-226 Non-myeloablative allogeneic transplantation (NMAT) has provided the potential benefit of allogeneic hematopoietic stem cell transplantation (allo-SCT) to a broader cohort of lymphoma patients via lowered non-relapse mortality (NRM). NMAT also provides a post-transplant platform of a chemotherapy-naive graft for both myelosuppressive and immune-mediated anti-tumor therapies, though the lack of high-dose conditioning may also heighten the risk for early relapse. Herein, we describe the survival as well as factors associated with outcomes for lymphoma patients experiencing relapse within 200 days of NMAT. Between December, 1997 and April, 2009, 267 lymphoma/CLL patients underwent NMAT at our center, of which 70 (35%) relapsed within 200 days from transplant. Histologies were categorized as aggressive (n= 36) including diffuse large-B-cell (n=22), blastic mantle cell lymphoma (n=10) and T-lymphoblastic lymphoma (n=4), and indolent (n=21) with chronic lymphocytic leukemia (n=15), follicular lymphoma (n=3) and classic mantle cell lymphoma (n=3). We also evaluated patients with Hodgkin Lymphoma (n=13). Conditioning regimens included 2 Gy total body irradiation (TBI), fludarabine 30 mg/m2 daily x 3 days + 2 Gy TBI, and Y-90-Ibritumomab-tiuxetan+ fludarabine 30 mg/m2 daily x 3 days + 2 Gy TBI in 13, 41, and 16 patients, respectively. Grafts were from HLA-matched related (n=34) or unrelated (n=31), HLA-mismatched unrelated (n=3) and HLA-haploidentical related (n=2) donors. Interventions to treat relapse included chemotherapy and/or radiation therapy in 43 (61%) patients and no therapy or withdrawal of immunosuppression in the remaining 27 (39%). Donor lymphocyte infusion (DLI) was attempted in 9 patients. Overall survival (OS) from time of relapse at 3 and 5 years among all 70 patients was 28% (95% CI 16-41%) and 19% (95% CI 9-32), respectively. Aggressive histology was associated with increased mortality relative to indolent histology (HR for death=2.57 [1.28-5.14, p=0.008]), while Hodgkin Lymphoma had similar outcome to the indolent group (HR=1.04 [0.42-2.53, p=.94]). The 3-year OS among patients with aggressive and indolent histologies was 14% (95% CI 3-33%), and 43% (95% CI 21-64%), respectively ( Figure ). Later relapse was associated with improved survival (p=.01) with patients relapsing between 31 and 100 days and those relapsing between 101 and 200 days having a reduced hazard of mortality relative to those relapsing less within 30 days (HR=0.36 [0.17-0.75, p=.006]; HR=0.30 [0.13-0.69, p=.005], respectively). When both histology and time to relapse were included in one model, these associations were somewhat reduced but the qualitative conclusions remained. In particular, patients with aggressive disease had a 2.16-fold (1.10-4.23, p=.03) increase in mortality compared to patients with Hodgkin or indolent lymphoma; the group that relapsed from 31 to 100 days was 0.41 (0.19-0.88, p=.02) times as likely to die compared to the group that relapsed within 30 days and the group that relapsed 101-200 days was 0.43 (0.17-1.04, p=.06) times as likely to die compared to the early-relapse group. Patients with chemoresistant disease pre-transplant were 1.46 times more likely to die than those with responding disease, but this difference was not statistically significant (95% CI, 0.82-2.62, p=.20). Fifty-nine patients relapsed with measurable disease and had a higher risk of mortality compared to 11 patients with only blood or marrow evidence of relapse, but the difference in mortality was not statistically significant (HR=1.53 [0.71-3.29, p=.28]). Pre-relapse graft-versus-host disease, bone marrow involvement, remission status at transplant, number of prior therapies, comorbidity score, and disease bulk were not statistically significantly associated with survival. These data indicate that despite early relapse of lymphoma after NMAT, some patients can experience prolonged survival with the best outcomes in patients with indolent histology and later relapse, though further improvement in disease control for patients with aggressive lymphoma and very early relapse is needed. Download : Download high-res image (82KB) Download : Download full-size image Disclosures: No relevant conflicts of interest to declare.

Rapamycin-Based GvHD Prophylaxis Is Effective in T-Cell Replete Unmanipulated Haploidentical Peripheral Stem Cell Transplantation for Advanced Haematological Malignancies: Results in 46 Patients.

Abstract 666 Background:Results of haploidentical stem cell transplantation (SCT) after standard extensive T-cell depletion for advanced leukemias are poor (Ciceri et al, 2008). In contrast, significant leukemia-free-survivals are produced after T-cell replete SCT from matched related, unrelated and cord-blood donors, even in advanced phases of disease (Kolb HJ, 2009). New protocols based on T-cell repletion are warrented in patients receiving haplo-SCT, in order to offer to all candidates patients with advanced leukemia the potential of cure of allogeneic SCT.Rapamycin is an immunosuppressive drug that arrests cell cycle in G1 phase through the inhibition of DNA transcription, RNA translation and protein synthesis. Morover, in contrast to calcineurin inhibitors, it promotes the generation and expansion of T regulatory cells (Tregs). Aim:We investigated the safety of infusion of T-cell replete unmanipulated peripheral blood stem cells (PBSC) from family haploidentical donor with a combination Rapamycin, Mycophenolate and ATG as GvHD prophylaxis, to preserve early Treg function (TrRaMM study, Eudract 2007-5477-54). Patients and Methods:Since 2007, forty-six patients underwent allogeneic transplantation for AML (25 pts), ALL (7 pts), sAML (6 pts), MDS (3 pts), CML-BC (2 pts), NHL (2 pts) or HD (1 pt). The median age was 50 years (range 14-69). At time of transplantation 5 pts were in early phase, and 41 were in advanced phase. Median time from diagnosis to transplantation was 351 days (range 81-1387); 8 patients were enrolled for relapse after allogeneic SCT from MRD or MUD. Median comorbodity index score was 1 (0-5). The conditioning regimen included Treosulfan (14 g/m2 for 3 days), Fludarabine (30 mg/m2 for 5 days) and an in vivo T and B-cell depletion, by ATG-Fresenius (10 mg/kg for 3 times) and Rituximab (a single 500 mg dose). All pts received allogeneic peripheral blood cells from an HLA-haploidentical related donor without any in vitro positive selection of CD34+ cells. GvHD prophylaxis consisted of Rapamycin (target level 8-15 ng/ml, till day +60) and MMF (15 mg/kg tid till day +30). Results:All patients engrafted, and all but eight were in disease remission at first marrow evaluation on day +30. Cumulative incidence of grade 2-4 aGvHD was 33% (95% CI: 18-48); cumulative incidence of grade 3-4 aGvHD was 12% (95% CI: 2-22). Interestingly, half of patients with GvHD developed it at immunosuppressive prophylaxis withdrawal for disease relapse. Only six patients developed cGvHD. Cumulative incidence of TRM and relapse incidence were 26% (95% CI: 11-41) and 53% (95% CI: 35-71) respectively. None developed EBV reactivation. Patients experienced an early and sustained immunoreconstitution with a median 221 circulating CD3+cells/μL (range 43-1690) from day 30. The immune-reconstitution was polarized towards central memory cells (CD45RA-CD62L+ cells 32.7% ± 4.8) that produced IL-2 (IL-2+ cells 26.2% ± 5.3). Of interest, at day +90 from transplant, Tregs were significantly expanded (CD4+CD25+CD127-Foxp3+ cells 15.6% ± 4.8 on total CD3+ cells, P<0,05 vs donor controls). After a median follow-up of 6 months, overall survival is 64% (95% CI: 50-78), and projected OS at 1 year is 46% (95% CI: 31-61). Conclusions:Rapamycin-Mycophenolate-ATG are effective to prevent GvHD in T-cell replete unmanipulated haploidentical peripheral stem cell transplantation for advanced haematological malignancies. This associates with an early T-cell immunoreconstitution characterized by the in vivo expansion of early-differentiated T cells and Tregs, and translates in promising leukemia-free survival in patients with advanced resistant leukemia. Further studies are warranted to gain insight on the role of rapamycin as platform for exploitation of Tregs in allogeneic HSCT from mismatched donor. Disclosures:No relevant conflicts of interest to declare.

Outcomes of Early Relapse Following Non-Myeloablative Allogeneic Transplant for Lymphoma.

Abstract 1204Poster Board I-226Non-myeloablative allogeneic transplantation (NMAT) has provided the potential benefit of allogeneic hematopoietic stem cell transplantation (allo-SCT) to a broader cohort of lymphoma patients via lowered non-relapse mortality (NRM). NMAT also provides a post-transplant platform of a chemotherapy-naïve graft for both myelosuppressive and immune-mediated anti-tumor therapies, though the lack of high-dose conditioning may also heighten the risk for early relapse. Herein, we describe the survival as well as factors associated with outcomes for lymphoma patients experiencing relapse within 200 days of NMAT. Between December, 1997 and April, 2009, 267 lymphoma/CLL patients underwent NMAT at our center, of which 70 (35%) relapsed within 200 days from transplant. Histologies were categorized as aggressive (n= 36) including diffuse large-B-cell (n=22), blastic mantle cell lymphoma (n=10) and T-lymphoblastic lymphoma (n=4), and indolent (n=21) with chronic lymphocytic leukemia (n=15), follicular lymphoma (n=3) and classic mantle cell lymphoma (n=3). We also evaluated patients with Hodgkin Lymphoma (n=13). Conditioning regimens included 2 Gy total body irradiation (TBI), fludarabine 30 mg/m2 daily x 3 days + 2 Gy TBI, and Y-90-Ibritumomab-tiuxetan+ fludarabine 30 mg/m2 daily x 3 days + 2 Gy TBI in 13, 41, and 16 patients, respectively. Grafts were from HLA-matched related (n=34) or unrelated (n=31), HLA-mismatched unrelated (n=3) and HLA-haploidentical related (n=2) donors. Interventions to treat relapse included chemotherapy and/or radiation therapy in 43 (61%) patients and no therapy or withdrawal of immunosuppression in the remaining 27 (39%). Donor lymphocyte infusion (DLI) was attempted in 9 patients. Overall survival (OS) from time of relapse at 3 and 5 years among all 70 patients was 28% (95% CI 16-41%) and 19% (95% CI 9-32), respectively. Aggressive histology was associated with increased mortality relative to indolent histology (HR for death=2.57 [1.28-5.14, p=0.008]), while Hodgkin Lymphoma had similar outcome to the indolent group (HR=1.04 [0.42-2.53, p=.94]). The 3-year OS among patients with aggressive and indolent histologies was 14% (95% CI 3-33%), and 43% (95% CI 21-64%), respectively (Figure). Later relapse was associated with improved survival (p=.01) with patients relapsing between 31 and 100 days and those relapsing between 101 and 200 days having a reduced hazard of mortality relative to those relapsing less within 30 days (HR=0.36 [0.17-0.75, p=.006]; HR=0.30 [0.13-0.69, p=.005], respectively). When both histology and time to relapse were included in one model, these associations were somewhat reduced but the qualitative conclusions remained. In particular, patients with aggressive disease had a 2.16-fold (1.10-4.23, p=.03) increase in mortality compared to patients with Hodgkin or indolent lymphoma; the group that relapsed from 31 to 100 days was 0.41 (0.19-0.88, p=.02) times as likely to die compared to the group that relapsed within 30 days and the group that relapsed 101-200 days was 0.43 (0.17-1.04, p=.06) times as likely to die compared to the early-relapse group. Patients with chemoresistant disease pre-transplant were 1.46 times more likely to die than those with responding disease, but this difference was not statistically significant (95% CI, 0.82-2.62, p=.20). Fifty-nine patients relapsed with measurable disease and had a higher risk of mortality compared to 11 patients with only blood or marrow evidence of relapse, but the difference in mortality was not statistically significant (HR=1.53 [0.71-3.29, p=.28]). Pre-relapse graft-versus-host disease, bone marrow involvement, remission status at transplant, number of prior therapies, comorbidity score, and disease bulk were not statistically significantly associated with survival. These data indicate that despite early relapse of lymphoma after NMAT, some patients can experience prolonged survival with the best outcomes in patients with indolent histology and later relapse, though further improvement in disease control for patients with aggressive lymphoma and very early relapse is needed. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

HLA-Haploidentical Stem Cell Transplantation for Hematologic Malignancies

Partially HLA-mismatched related, or HLA-haploidentical, donor stem cell transplantation (SCT) is a feasible therapeutic option for advanced hematologic malignancies patients who lack an HLA-matched related or unrelated donor. Advances in conditioning regimens, graft manipulation, and pharmacologic prophylaxis of graft-versus-host disease (GVHD) have reduced the risk of fatal graft failure and severe GVHD, two of the most serious complications of traversing the HLA barrier. Clinical observations reveal a potential role for natural killer (NK) cell alloreactivity in reducing the risk of relapse of acute myeloid leukemia after HLA-haploidentical SCT. NK cell infusions attempt to harness the graft-versus-leukemia effect without producing GVHD. The availability of multiple potential HLA-haploidentical related donors for most patients opens the possibility of optimizing transplantation outcome through intelligent donor selection.

Greater HLA Disparity Is Associated with Reduced Risk of Relapse and Improved Event-Free Survival after Nonmyeloablative, HLA-Haploidentical BMT with Post-Transplantation High-Dose Cyclophosphamide

Background: Although a lower relapse risk has been reported after allogeneic BMT with increasing HLA disparity, this potential benefit has been offset by higher rates of acute graft-versus-host disease (GVHD) and non-relapse mortality (NRM). However, it is possible that the type of GVHD prophylaxis could influence the balance between GVHD toxicity and relapse.Patients and methods: We retrospectively analyzed the outcomes of 185 patients with poor-risk hematologic malignancies enrolled on three similar clinical trials of related-donor, haploidentical BMT incorporating high-dose post-transplantation cyclophosphamide (Cy) for GVHD and graft rejection prophylaxis (as published in BBMT 2008; 14:641–50). Molecular typing was at an allele level for HLA-A, -B, -Cw, and -DRB1 and at an allele group level for -DQB1. All received Cy (14.5 mg/kg IV on days −6, −5), fludarabine (30 mg/m2 IV on days −6 to −2), total body irradiation (200 cGy on day −1), and non-T-cell depleted bone marrow infusion. GVHD prophylaxis consisted of Cy (50 mg/kg IV) either once (on day 3; n = 48) or twice (on days 3, 4; n = 137), mycophenolate mofetil for 35 days, and tacrolimus for up to 6 months, with filgrastim begun after the last dose of Cy. Most patients (median age 50, range 1–71) had advanced disease and 49 (26%) had failed autologous BMT. Diagnoses were MDS (22), CMML (3), acute leukemia or lymphoblastic lymphoma (58), CML (11), CLL (15), multiple myeloma (9), non-Hodgkin lymphoma (42), and Hodgkin lymphoma (25).Results: Median follow-up after BMT is 20 months (range, 2–71 months) in those without events. Nonengraftment attributed to primary graft failure or to residual bone marrow malignancy occurred in 29 of 177 evaluable patients (16%). Cumulative incidences of grade II–IV acute GVHD and chronic GVHD were 31% and 15%, respectively. Cumulative incidences of NRM and relapse or progression at one year were 15% and 50%, respectively. Actuarial event-free survival (EFS) at one year was 35%, with grade II–IV acute GVHD by day 100 associated with a trend toward lower cumulative incidence of relapse (p = 0.08) but a significantly higher cumulative incidence of NRM (p = 0.002) on subgroup analysis. Notably, increasing degrees of HLA mismatch at either class I or class II loci had no significant effect on cumulative incidence of acute or chronic GVHD or NRM. In contrast, the presence of a DRB1 antigen mismatch in the GVH, but not host-versus-graft (HVG), direction was associated with a significantly lower cumulative incidence of relapse (Figure a; p = 0.04) and improved EFS (Figure c; p = 0.009), whereas DQB1 antigen and class II allele mismatch status had no effect. Additionally, the presence of two or more class I allele mismatches (composite of A, B, and Cw) in either direction was associated with a significantly lower cumulative incidence of relapse (Figure b; p = 0.045 for GVH direction, p = 0.01 for HVG direction) and improved EFS (Figure d; p = 0.07 for GVH direction, p = 0.001 for HVG direction).Conclusion: Greater HLA disparity appears to be beneficial after nonmyeloablative, HLA-haploidentical BMT that incorporates high-dose post-transplantation Cy. These results suggest an anti-tumor effect of partially HLA-mismatched BMT that is irrespective of clinically significant GVHD. Potential effectors of anti-tumor immunity include HLA-DRB1 reactive CD4+ T-cells, class I reactive CD8+ T-cells, and/or natural killer cells recognizing missing self. Since most patients have several potential HLA-haploidentical related donors, the results support a strategy of choosing a donor who is incompatible for both HLA-DRB1 antigen and multiple HLA class I alleles. [Display omitted]

Comparison of Outcomes of HLA-Matched Related, Unrelated, or HLA-Haploidentical Related Hematopoietic Cell Transplantation following Nonmyeloablative Conditioning for Relapsed or Refractory Hodgkin Lymphoma

We compared the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) for patients with relapsed or refractory Hodgkin lymphoma (HL) based on donor cell source. Ninety patients with HL were treated with nonmyeloablative conditioning followed by HCT from HLA-matched related, n=38, unrelated, n=24, or HLA-haploidentical related, n=28 donors. Patients were heavily pretreated with a median of 5 regimens and most patients had failed autologous HCT (92%) and local radiation therapy (83%). With a median follow-up of 25 months, 2-year overall survivals, progression-free survivals (OS)/(PFS), and incidences of relapsed/progressive disease were 53%, 23%, and 56% (HLA-matched related), 58%, 29%, and 63% (unrelated), and 58%, 51%, and 40% (HLA-haploidentical related), respectively. Nonrelapse mortality (NRM) was significantly lower for HLA-haploidentical related (P=.02) recipients compared to HLA-matched related recipients. There were also significantly decreased risks of relapse for HLA-haploidentical related recipients compared to HLA-matched related (P=.01) and unrelated (P=.03) recipients. The incidences of acute grades III-IV and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were 16%/50% (HLA-matched related), 8%/63% (unrelated), and 11%/35% (HLA-haploidentical related). These data suggested that salvage allogeneic HCT using nonmyeloablative conditioning provided antitumor activity in patients with advanced HL; however, disease relapse/progression continued to be major problems. Importantly, alternative donor stem cell sources are a viable option.

Hematopoietic SCT from partially HLA-mismatched (HLA-haploidentical) related donors

Hematopoietic SCT from a partially HLA-mismatched (HLA-haploidentical) first-degree relative offers the benefits of rapid and near universal donor availability but also the risks that result from traversing the HLA barrier; namely, graft failure, severe GVHD and prolonged immunodeficiency. Improvements over the last 10 years in conditioning regimens, graft engineering and pharmacological immunoprophylaxis of GVHD have substantially reduced the morbidity and mortality of HLA-haploidentical SCT. Highly immunosuppressive but nonmyeloablative conditioning extends the availability of HLA-haploidentical SCT to elderly hematologic malignancy patients lacking HLA-matched donors and permits recovery of autologous hematopoiesis in the event of graft failure. Current regimens for HLA-haploidentical SCT are associated with a 2-year non-relapse mortality of 20+/-5%, relapse of 35+/-15% and overall survival of 50+/-20%. Major developmental areas include harnessing natural killer cell alloreactivity to reduce the risk of disease relapse and improving immune reconstitution by delayed infusions of lymphocytes selectively depleted of alloreactive cells. Hematologic malignancy patients who lack suitably matched related or unrelated donors can now be treated with HLA-haploidentical related donor or unrelated umbilical cord blood SCT. Future clinical trials will assess the relative risks and benefits of these two graft sources.

Correction of Clinical Manifestations of Canine Mucopolysaccharidosis I with Neonatal Retroviral Vector Gene Therapy

Mucopolysaccharidosis I (MPS I) (Hurler syndrome) is due to deficient alpha-L-iduronidase (IDUA) activity and is the most common of the MPS disorders. Neonatal MPS I dogs were injected intravenously (IV) with a gamma retroviral vector containing a complete long-terminal repeat (LTR) and an internal human alpha(1)-antitrypsin (hAAT) promoter upstream of the canine IDUA complementary DNA (cDNA). This resulted in stable serum IDUA activity of 366 +/- 344 units (U)/ml (28-fold normal) for up to 1.8 years, which likely derived primarily from secretion of IDUA by transduced liver cells. Retroviral vector (RV)-treated dogs had >18% of normal IDUA activity in organs and had decreased severity and/or incidence of hernias, chest deformities, joint disease, facial dysmorphia, corneal clouding, valvular heart disease, and aortic dilatation as compared with untreated MPS I dogs. The marked reduction that was observed in lysosomal storage in the brain of RV-treated dogs may have been due in part to expression from the LTR of the vector in cells in the brain. This possibility will be explored in future studies, because the potential for insertional mutagenesis has raised concerns about using vectors with an intact LTR. If proven safe, this gene therapy technique may be utilized in treating children with Hurler syndrome.

HLA-Haploidentical Related Hematopoietic Stem Cell Transplantation and Mesenchymal Stem Cell Transplantation in Patients with Hematologic Malignancies.

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only way to cure many hematologic malignancies. HLA-haploidentical related HSCT was performed in case of lack of HLA-matched donors. From the results of in-vitro and animal studies, Mesenchymal stem cells (MSCs) transplanted simultaneously with hematopoietic stem cells (HSCs) may support hematopoietic regeneration and have the immunomodulatory effect. MSCs together with HSCs transplantation from the same HLA-haploidentical donor were used in patients with hematologic malignancies.Patients and Methods: Three patients were chronic myeloid leukemia (blast crisis), chronic myeloid leukemia (chronic phase) and refractory T-cell lymphoblastic lymphoma (leukemia phase) respectively. Complete demographic and clinical details of these 3 patients are shown in Table 1. Bone marrow mononuclear cells obtained from their HLA-haploidentical related donors were cultured and expanded in vitro about 2 months before transplantation. Immunophenotype of the harvested cells were detected in order to identify them. After conditioned by cytosine arabinoside/cyclophosphamide/total body irradiation regimen, patients were co-transplanted with HSCs and ex-vivo expanded MSCs. Cyclosporine, methotrexate, antithymocyte globulin, mycophenolate mofetil and anti-CD25 monoclonal antibody were used together for prophylaxis of GVHD. Clinical features after transplantation in these patients were observed.Results: About 2×106 MSCs per kilogram of recipients' weight were successfully expanded from bone marrow samples. These cells were CD73, CD90, CD105 positive and CD34, CD45, CD38, CD10, CD20, CD33, HLA-DR negative by flow cytometric analysis. No adverse response was observed during and after infusion of MSCs. Hematopoietic reconstruction was successful in all the patients. And they had full donor-type chimerism 1 month after transplantation. N1 received donor lymphocyte infusion (DLI) to prevent the relapse. N2 relapsed and received the therapy of STI571 combined with DLI. She had a complete remission at last. No graft-versus-host disease (GVHD) was observed in N1 and N2 until they received DLI. N1 died of infection 11 months after transplantation. N2 and N3 now have been followed up for 41 and 31 months respectively. Clinical features of patients after transplantation are shown in Table 2.Conclusions: Bone marrow derived MSCs can be tolerant well in HLA-haploidentical HSCT. Its exact effect in human HLA-haploidentical allogeneic HSCT needs to be studied further.Tab.1Patient Demographic and Clinical DataPatientDiagnosisAgeSexCourse of disease before transplantationDonorMismatched HLA lociN1T-LPL22F7 yrmother3N2CML-BC32F6mosibling brother3N3CML-CP22M5mofather3Abbr: LPL - lymphoblastic lymphoma; CML - chronic myeloid leukemia; BC - blast crisis; CP - chronic phase; yr - year; mo - monthTab.2Clinical features of patients after transplantationPatientHematopoietic reconstructionDonor-type chimerismTime of relapsetime of DLIacute GVHDchronic GVHDsurvivalN115 d100%no5 moIV (after DLI)extensivedie in 11 moN216 d100%6mo6 moIV (after DLI)no>41 moN315 d100%nonoIlimited>31 moAbbr: DLI - donor lymphocyte infusion; d - day; mo - month

Hurler Syndrome: II. Outcome of HLA-Genotypically Identical Sibling and HLA-Haploidentical Related Donor Bone Marrow Transplantation in Fifty-Four Children

Untreated patients with Hurler syndrome (MPSIH) experience progressive neurologic deterioration and early death. Allogeneic bone marrow transplantation (BMT) ameliorates or halts this course. The Storage Disease Collaborative Study Group was formed to evaluate the effectiveness and toxicity of BMT. Effectiveness was defined as engrafted survival with continuing cognitive development. Fifty-four patients deficient in leukocyte alpha-L-iduronidase enzyme activity (median age, 1.8 years; range, 0.4 to 7.9) received high-dose chemotherapy with or without irradiation and BMT from HLA-genotypically identical sibling (GIS) or HLA-haploidentical related (HIR) donors between September 16, 1983 and July 14, 1995; all children were included in this report. Thirty-nine of 54 patients (72%) engrafted following the first BMT. The probability of grade II to IV acute graft-versus-host disease (GVHD) at 100 days was 32% for GIS and 55% for HIR patients. The probability of extensive chronic GVHD was 0% for GIS and 24% for HIR patients. The actuarial probability of survival at 5 years was 64% for all patients, 75% for GIS patients, 53% for HIR patients, and 53% for patients with donor marrow engraftment. The baseline Mental Developmental Index (MDI) was examined both for children less than and greater than 24 months of age at BMT. Children transplanted before 24 months had a mean baseline MDI of 78, while those transplanted after 24 months had a mean baseline MDI of 63 (P = . 0002). Both baseline and post-BMT neuropsychologic data were available for 26 of 30 engrafted survivors. Of 14 patients transplanted before 24 months of age, nine demonstrated developmental trajectories that were normal or somewhat slower than normal. In contrast, of 12 patients transplanted after 24 months of age, only three showed developmental trajectories that were normal or somewhat slower than normal (P = .01). For children with a baseline MDI greater than 70, there was a significant correlation between the MDI at follow-up study and leukocyte alpha-L-iduronidase enzyme activity (P = .02). Children were more likely to maintain normal cognitive development if they were fully engrafted following BMT from a donor with homozygous normal leukocyte alpha-L-iduronidase enzyme activity. Children who developed acute GVHD of grade II or worse had significantly poorer cognitive outcomes (P < .009). No difference in the post-BMT MDI was observed between patients whose preparative therapies did (n = 10; radiation dose, 300 to 1,400 cGy) or did not (n = 16) include radiation. We conclude that MPSIH patients, particularly those less than 24 months of age with a baseline MDI greater than 70, can achieve a favorable long-term outcome with continuing cognitive development and prolonged survival after successful BMT from a related donor with homozygous normal enzyme activity.

Hurler Syndrome: II. Outcome of HLA-Genotypically Identical Sibling and HLA-Haploidentical Related Donor Bone Marrow Transplantation in Fifty-Four Children

AbstractUntreated patients with Hurler syndrome (MPSIH) experience progressive neurologic deterioration and early death. Allogeneic bone marrow transplantation (BMT) ameliorates or halts this course. The Storage Disease Collaborative Study Group was formed to evaluate the effectiveness and toxicity of BMT. Effectiveness was defined as engrafted survival with continuing cognitive development. Fifty-four patients deficient in leukocyte α-l-iduronidase enzyme activity (median age, 1.8 years; range, 0.4 to 7.9) received high-dose chemotherapy with or without irradiation and BMT from HLA-genotypically identical sibling (GIS) or HLA-haploidentical related (HIR) donors between September 16, 1983 and July 14, 1995; all children were included in this report. Thirty-nine of 54 patients (72%) engrafted following the first BMT. The probability of grade II to IV acute graft-versus-host disease (GVHD) at 100 days was 32% for GIS and 55% for HIR patients. The probability of extensive chronic GVHD was 0% for GIS and 24% for HIR patients. The actuarial probability of survival at 5 years was 64% for all patients, 75% for GIS patients, 53% for HIR patients, and 53% for patients with donor marrow engraftment. The baseline Mental Developmental Index (MDI) was examined both for children less than and greater than 24 months of age at BMT. Children transplanted before 24 months had a mean baseline MDI of 78, while those transplanted after 24 months had a mean baseline MDI of 63 (P = .0002). Both baseline and post-BMT neuropsychologic data were available for 26 of 30 engrafted survivors. Of 14 patients transplanted before 24 months of age, nine demonstrated developmental trajectories that were normal or somewhat slower than normal. In contrast, of 12 patients transplanted after 24 months of age, only three showed developmental trajectories that were normal or somewhat slower than normal (P = .01). For children with a baseline MDI greater than 70, there was a significant correlation between the MDI at follow-up study and leukocyte α-l-iduronidase enzyme activity (P = .02). Children were more likely to maintain normal cognitive development if they were fully engrafted following BMT from a donor with homozygous normal leukocyte α-l-iduronidase enzyme activity. Children who developed acute GVHD of grade II or worse had significantly poorer cognitive outcomes (P < .009). No difference in the post-BMT MDI was observed between patients whose preparative therapies did (n = 10; radiation dose, 300 to 1,400 cGy) or did not (n = 16) include radiation. We conclude that MPSIH patients, particularly those less than 24 months of age with a baseline MDI greater than 70, can achieve a favorable long-term outcome with continuing cognitive development and prolonged survival after successful BMT from a related donor with homozygous normal enzyme activity.