ALBERT

Description: Twenty five patients have been enrolled on this trial to date. There were 14 males and 11 females aged 0.6–54 years. Patients’ diagnoses and stage included: NHL in CR2 or refractory (n=2), AML (n=7), including 5 pts with secondary AML, ALL 〉 CR3 (n=4), CML in CP2 (N=1) and high risk MDS (n=11) including 5 pts with secondary MDS. Eight pts had a matched related donor, 14 pts an unrelated donor and 3 pts a mismatched related donor. Cytoreduction consisted of busulfan (Bu) (0.8–1 mg/Kg/dose x 10 doses), melphalan (Mel) (70 mg/Kg/day x 2) and fludarabine (Flu) (25 mg/m2/day x 5). Graft rejection prophylaxis included rabbit ATG (Thymoglobulin) (2.5 mg/Kg/day x 2). Four pts tolerated only one of two doses of the ATG, 2 pts received equine ATG and one pt Alemtuzumab. Twenty one pts received G-CSF mobilized peripheral blood stem cell transplants that were T-cell depleted by CD34 selection and E-rosetting while the other four pts received Soybean agglutinin E-rosette depleted marrow grafts. Cell doses were 1.3–20.5 x 106 CD34 cells/Kg. and 0 -100 x 103 CD3 cells/Kg. Engraftment occurred in 24 pts. One pt suffered a graft failure; This pt had initial low busulfan levels, and received bone marrow derived stem cells with a low cell dose from a 5/6 HLA-matched unrelated donor. Acute graft-versus-host disease occurred in four pts: grade 1 (n=2) and grade 2 (n=2) and no pts developed any grade 3-4 severe GvHD. Two patients were diagnosed with chronic GvHD: localized (n=1) and extensive (n=1). Two patients developed sepsis early post BMT, with secondary multi organ failure and early mortality, while for the rest of the patients, regimen-related toxicity was acceptable. Relapse occurred in 9 pts. Mortality included 7 pts from relapse, two pts from sepsis and multi-organ failure, 3 pts from infections, and one pt from unknown causes. The overall survival (OS) and disease-free survival (DFS) at 2 yrs for the entire patient cohort were respectively 44% and 42 %; The DFS was 50% for patients with secondary MDS or AML. In summary, the cytoreduction with Bu Mel and Flu allowed consistent engraftment of T-cell depleted grafts and was associated with acceptable outcome for patients with secondary MDS or AML.

Description: Between 05/98 and 06/04, 15 consecutive patients with FA received hematopoietic stem cell transplants (SCT) from alternative donors at our Center. There were 7 males and 8 females aged 5 to 24 years (median 11.5). Hematologic diagnoses included aplastic anemia (AA) (N=5), myelodysplastic syndrome (MDS) in RAEB (N=4), RAEBT (N=1) or acute myelogenous leukemia (AML) (N=5). High risk features included: Age 〉 20 years (n=4), prior multiple transfusions (n=11), prior androgen treatment (n=12), prior infections (n=10), or advanced MDS or AML (n=9). Eight pts had related mismatched donors transplants with respective matching at 3/6 (6/10), 4/6 (6/10), 4/6 (7/10) (n=2)), 5/6 (8/10) (n=3) and 5/6 (9/10) HLA-antigens. Seven pts had unrelated donors transplants with respective matching at 5/6 (7/10), 5/6 (8/10) (n=2), 5/6 (9/10) and 6/6 (10/10) (n=3) HLA-antigens. Cytoreduction included single dose total body irradiation (SDTBI) (450 cGy), fludarabine (Flu) (30 mg/m2 x 5) and cyclophosphamide (Cy) (10 mg/Kg x 4). Immunosuppression included rabbit anti-thymocyte globulin (Thymoglobulin) and tacrolimus for all patients. Grafts were G-CSF mobilized CD34+ and E-rosette negative (E-) peripheral blood stem cell transplants for 12 pts and soybean agglutinin negative (SBA-) and E-rosette negative marrow transplants for 3 pts. Cell doses of the grafts were 1.5 – 29.6 x 106 CD34 cells/Kg and 0 – 26 x 103 CD3 cells/Kg. As evidenced by RFLP or FISH, all 15 evaluable pts were fully engrafted and complete chimeras. Fourteen pts were evaluable for graft-versus-host disease (GvHD). GvHD of the skin and of the gut was suspected in two pts but resolved completely prior to immunosuppressive treatment. With a median follow-up of 2.5 years (range 0.2–6), 13 of 15 pts are alive and 11 of 15 are alive disease-free. There were two deaths: one pt died from sepsis/ARDS at 2 months post SCT and one pt from pneumonitis/ARDS and EBV-infection 6 months post SCT. Three pts relapsed (MDS-RAEB x 1 – AML x 2): One pt relapsed 7 months post transplant, received a 2nd transplant from the same donor following busulfan and Flu and is alive, disease-free 18 months post SCT, while the other two pts are awaiting a second SCT. In summary, this cytoreductive regimen used with T-cell depleted stem cell transplants from unrelated or HLA-mismatched related donors for the treatment of high risk patients with Fanconi anemia, results in rapid hematopoietic engraftment and lymphohematopoietic reconstitution with minimal GVHD and a high disease-free survival.

Description: Key Points The genetic cause of SCID impacts on survival and immune reconstitution and should be considered in tailoring HCT for individual patients. Total and naive CD4+ cell counts in SCID patients 6 and 12 months post-HCT predict long-term survival and sustained immune reconstitution.

Description: Background Acute graft-versus-host disease (aGVHD) is common after double-unit cord blood transplantation (CBT) with an incidence of grade II-IV aGVHD as high as 55% by day 180 in patients transplanted without ATG. aGVHD is associated with increased morbidity and transplant-related mortality (TRM). Mycophenolate mofetil (MMF) combined with a calcineurin-inhibitor is commonly used to prevent GVHD after CBT. However, unlike the 1 gram (gm) every 8 hours dosing that is now standard in adult donor allografts, MMF dosing in CBT has traditionally been every 12 hours. Our center has increased MMF dose from 1 gm every 12 (q12) to 1 gm every 8 (q8) hours in an effort to reduce severe aGVHD after double-unit CBT. However, the efficacy of this intervention is not established and a theoretical concern is that intensified MMF dosing could result in an increased risk of delayed engraftment or graft failure. Methods We evaluated 171 double-unit CBT recipients (median age 39 years, range 0.9-71) transplanted with either myeloablative (MA, n = 133) or non-myeloablative (NMA, n = 38) conditioning for high-risk hematologic malignancies between 10/2005 and 4/2013. CB units were 4-6/6 HLA-A, -B antigen, -DRB1 allele matched to the recipient (16 6/6, 171 5/6, 155 4/6). All patients received GVHD prophylaxis with intravenous calcineurin-inhibitor (predominantly CSA) and MMF from day -3 without ATG. Prior to 9/2009, 80 patients (47%) received MMF 1 gm IV q12 (and those 12 years and ≥50 kg (or 15 mg/kg/dose if 〉12 years but

Description: Abstract 3080 As compared to single-unit CBT, DCBT may improve engraftment and protect against relapse. Therefore, we have adopted DCBT for both children and adults with acute leukemia, myelodysplasia (MDS), and myeloproliferative diseases (MPD). However, determinants of disease-free survival (DFS) have yet to be fully established. Furthermore, whether DFS after DCBT is comparable in patients of European and non-European ancestry is of special interest. Therefore, we analyzed the DFS of 75 DCBT recipients with acute leukemia in morphologic remission or aplasia (n = 69), and MDS/MPD with ≤ 5% blasts (n = 6) transplanted from 10/2005-4/2011. Nearly all patients had high-risk disease. Children 0–15 years (n = 23) had the following characteristics: median age 9 years (range 0.9–15); median weight 37 kg (range 7–72); 30% European; and 26% CMV sero-positive. Diagnoses were 43% AML (or biphenotypic), 52% ALL, and 4% MDS/MPD, and all received high-dose conditioning. The children received grafts with a median infused TNC × 107/kg of 3.3 (larger unit) and 2.6 (smaller unit), and 2% of units were 6/6 HLA-A, -B antigen, -DRB1 allele matched, 63% 5/6, and 35% 4/6. Adults ≥ 16 years (n = 52) had the following characteristics: median age 41 years (range 16–69); median weight 69 kg (range 47–105); 48% European; 69% CMV sero-positive; and diagnoses were 63% AML (or biphenotypic), 27% ALL, and 10% MDS/MPD. Fifty percent received high-dose and 50% reduced intensity conditioning. Their units had a median infused TNC/kg of 2.7 and 1.9, and 3% were 6/6 HLA-matched, 47% 5/6, and 50% 4/6. All patients (pediatric and adult) received calcineurin-inhibitor/ mycophenolate mofetil immunosuppression, and none received anti-thymocyte globulin. Sustained donor neutrophil engraftment was seen in 91% of children and 94% of adults at medians of 20 and 26 days, respectively. The incidence of grade II-IV acute GVHD by day 180 was 44% in children and 58% in adults. Day 100 transplant-related mortality (TRM) was 9% in children and 19% in adults. The 2-year relapse incidence was 9% in children and 6% in adults. With a median follow-up of survivors of 26 months (range 4–70), 2-year Kaplan-Meier estimate of DFS was 78% in children and 64% in adults (Figure). Differences in survival by age did not reach significance. Univariate analysis of variables potentially influencing 2-year DFS (with log rank estimates of significance) in all patients is shown in the Table. There were no differences in 2-year DFS according to ancestry, remission status, and conditioning intensity. There was also no difference in 2-year DFS according to engrafting unit-recipient HLA-match (4-6/6 or 10 allele), or engrafting unit infused TNC dose/kg. However, patients who were CMV seronegative had a higher 2-year DFS (85% vs 55%, p = 0.018). Multivariate analysis revealed recipient CMV serostatus was a predictor of DFS independent of patient age, and its effect was mediated by an influence on TRM. We have previously shown that DCBT extends transplant access to minority patients. We now demonstrate that DCBT can achieve high and comparable DFS in both European and non-European pediatric and adult patients with acute leukemia and MDS/MPD. While these are very encouraging results further investigation in racial/ethnic sub-groups is needed. Nonetheless, our findings support DCBT as an immediate alternative therapy for high-risk acute leukemia in patients without suitable unrelated volunteer donors, especially given the very low incidence of relapse. Disclosures: No relevant conflicts of interest to declare.

Description: Key Points ST2 is independently associated with aGVHD after day 28 in cord blood transplantation recipients. High ST2 levels predict for increased TRM in cord blood transplantation recipients.

Description: Abstract 3546 Between August 1988 and December 2009, 40 pediatric patients (pts) received an allogeneic HSCT for the treatment of very high risk ALL in CR1. They were 22 males and 18 females, aged 0.8 –19.2 years (median 10.0). Thirty eight patients had very high risk features: high white cell count greater than 200,000/mm3 (N=7), hypodiploidy (N=6), including double hypodiploidy (N=3), high risk cytogenetics with t(9;22) (N=14) or Mixed Lineage Leukemia (MLL) (N=3), and induction failure (N=23). Induction failure was defined morphologically by a single marrow aspirate revealing greater than 35% blasts by day +7 of induction, or greater than 5% blasts by day +14 or day +28 of induction. The remaining two patients included one infant ALL with a WBC 〉100,000/mm3 and one patient with ALL, Evans Syndrome and a prior CNS hemorrhage and fungal infection. Twenty two patients had one VHR feature while 16 patients had two VHR features. Patients received marrow or peripheral blood stem cell transplants from HLA-matched siblings (N=14) or volunteer unrelated donors (N=21) or unrelated double cord blood transplants (N=5). Unrelated donors were HLA-matched for 12 pts, but mismatched for nine pts at one (N=6) or two Class I antigens (N=3). All cord blood donors were matched at 4 or 5/6 HLA-antigens. Twenty three patients received T-cell depleted grafts following cytoreduction with hyperfractionated total body irradiation (HF-TBI) 1,375-1,500 cGy, Thiotepa (Thio) 5 mg/Kg/day × 2 and Cyclophosphamide (CY) 60 mg/Kg/day × 2. Grafts were marrow T-cell depleted with soy bean agglutinin and e-rosetting for 15 patients or peripheral blood stem cells T-cell depleted by CD34 selection and E-rosetting for 8 patients. Twelve pts received unmodified grafts following cytoreduction with a TBI-CY based regimen (N=8) or chemotherapy regimen (N=4). Five patients received double cord blood grafts following HF-TBI 1,375 cGY, Fludarabine 25 mg/m2/day × 3 and CY 60 mg/Kg/day × 2. Graft-versus-host disease (GvHD) prophylaxis for the BMT recipients included cyclosporine (CSA) + methotrexate or steroids, and for the cord blood recipients, CSA and mycophenolate mofetil. With a median follow-up of 11.1 years (range 0.6–21.9 yrs), the 10-year overall survival and disease-free survival of the entire cohort were 78% and 70% respectively, and 80% and 72% respectively when excluding the accidental death. Two recipients of T-cell depleted grafts suffered a graft failure (one early and one late), both of whom received a secondary T-cell depleted graft from a (different) mismatched related donor, engrafted and are alive and well. Two recipients of unmodified marrow grafts relapsed 4.9, and 18.9 months post BMT, one of whom is still alive disease free following treatment with chemotherapy. One recipient of a double cord blood graft relapsed three months post transplant. The overall risk of relapse for the entire cohort was 15%. Six pts died; cause of death was: relapse (N=2), secondary malignancy (N=2), acute GvHD (N=1), and accidental death (head trauma) (N=1). Grade 2–4 GvHD was diagnosed in recipients of unmodified grafts (N=3), double cord blood graft (N=2) and T-cell depleted grafts (N=1). The OS and DFS for recipients of T-cell depleted transplants following TBI THIO CY were both 83% with a 0% relapse rate. In summary, the outcome of allogeneic HSCT for children with very high risk ALL in CR1 in our series appears to be superior to that reported with chemotherapy for patients with these very high risk features. Moreover, the use of hyperfractionated TBI, Thio and CY followed by T-cell depleted grafts from related or unrelated donors was associated with a very good outcome with no relapse and minimal GvHD. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2231 Background: PNH arises from a genetic mutation of hematopoietic stem cells which leads to the acquired nonmalignant clonal expansion of cells lacking glycosyl phosphatidylinositol-anchored proteins (GPI-APs). Lack of GPI-APs translates into PNH's most significant clinical features: bone marrow failure, intravascular hemolysis and thrombosis. PNH rarely occurs in children and has been reported to have a distinct clinical presentation compared to the adult population. Results: We provide a clinical description of 11 consecutive pediatric patients (pts) aged 11–17 years (median age 13.9 years) diagnosed with PNH since 1993 at a single institution. Bone marrow failure was the presenting clinical finding in 10 pts, including aplastic anemia (AA) (N = 9), hypoplastic myelodysplastic syndrome (MDS) (N = 1), and isolated red cell anemia (N = 1). This rate of bone marrow failure at presentation is higher than the reported rate of 24–33% seen in adult pts. Immunosuppressive therapy was the initial treatment for 8 patients with aplastic anemia and this included: antithymocyte globulin (N = 8), Cyclosporine (N = 8) and prednisone (N = 6). Partial response to immunotherapy was seen in all pts. Five pts had evidence of myelodysplastic features, including one at diagnosis. These included dysplasia with monosomy 7 for 2 pts, 5q deletion for one pt, and dysplasia with normal cytogenetics for 2 pts. The monosomy 7 abnormality was transient and resolved spontaneously for the 2 pts, while the pt with 5q deletion proceeded to transplantation. None of these pts developed excessive blasts or leukemic transformation. Thrombosis occurred in six pts with four of the pts experiencing several sites and episodes of thrombosis. Diagnosis of thrombosis occurred at presentation in one patient. Thrombosis in the remaining five pts first occurred 5–88 months from diagnosis (mean 58.8 months). This rate of thrombosis (55%) is similar to the reported rate of thrombosis in adult pts (40%) but is higher than recent reports of pediatric PNH in the literature. Treatment of thrombosis included anticoagulation and thrombolysis when appropriate. Intermittent episodes of intravascular hemolysis occurred in all 11 pts. Gross hemoglobinuria occurred in only one patient at initial presentation. This rate of gross hemoglobinuria at presentation is similar to other series of pediatric PNH, but much lower than the reported rate of 33–50% in adult pts. Of the 11 pts, 4 underwent hematopoietic stem cell transplant (HSCT) of whom 2 pts are alive and disease free. Eculizumab, a monoclonal antibody directed against the complement protein C5 was initiated in 3 pts of whom 2 pts currently have stable disease; the third non-compliant patient developed progression of thrombotic disease but has since restarted eculizumab therapy. Two pts died following complications related to thrombosis and two patients are transfusion independent with stable disease. Conclusions: This series represents a large single center cohort of pediatric pts diagnosed with PNH. This report highlights the high rate of bone marrow failure in pediatric pts with PNH. This differs from the adult population, and emphasizes the need for PNH testing in all children with AA or MDS, as well as children with unexplained Coombs-negative hemolysis or thrombosis. Both the high prevalence of hemolysis and high risk of thrombosis should warrant early treatment with eculizumab for pediatric pts with PNH. HSCT remains the only curative option for pediatric pts with PNH but its risk must be considered relative to the patient's disease severity, compliance and response to long-term treatment with anticoagulant and/or anticomplement therapy. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1971 Rituximab, a chimeric IgG1 kappa monoclonal antibody against the pan-B cell marker CD20, has proven effective in treating B cell malignancies, including EBV-PTLD. To determine its potential role in prevention of EBV-PTLD, 25 patients were enrolled on a prospective IRB approved trial (11/1/03-2/1/07) of monthly rituximab (375 mg/m2/dose, maximum 6 doses), starting 30–45 days after a TCD unrelated (n=23) or HLA-mismatched HCT (n=2). Eligibility included EBV seropositive patient, negative hepatitis B surface antigen, ANC 〉1500 cells/uL, remission, and negative plasma EBV PCR at baseline. Per protocol, rituximab was stopped prior to 6 doses in patients who achieved a circulating CD4 count 〉200 cells/ul, at which time their risk of EBV-PTLD was considered minimal. The median patient age (range) was 22.0 (8.0-68.0) years. Patients underwent transplantation for acute leukemia (n=18), CML (n=2), NHL (n=2), MDS (n=2), or Fanconi anemia/AML (n=1). Only two patients developed fever and chills, without respiratory distress or hypotension, within the first hour of their initial infusions, which proved to be due to coincidental line infections for which both were treated and recovered uneventfully. Both patients refused further rituximab. Six patients received all 6 planned doses; 5 patients received fewer than 6 doses due to recovery of CD4 count 〉200 cells/ul before the planned 3rd (n=4) or 5th dose (n=1). The remaining 12 patients received 1 (n=2), 2 (n=4), 3 (n=2), or 4 doses (n=4), due to persistent neutropenia (45d after the prior rituximab dose (n=4), recurrent disease (n=2), prolonged parainfluenza upper respiratory tract infection (n=1), secondary graft failure (n=1), abnormal LFTs of unclear etiology (n=1), GVHD requiring phase I therapy (n=1), aseptic meningitis (n=1) attributed to intravenous gammaglobulin, or pneumococcal sepsis (n=1). At a median follow-up of 5.8 (4.4-5.7) years, 16 of 25 patients are alive, 13 disease-free. Five patients died of recurrent hematologic malignancy, three of GVHD, and one of non-alcoholic steatohepatitis. Of the 25 patients accrued to the protocol, none developed EBV viremia or EBV-PTLD, compared to 23% (p18 months), including 6 patients who remain on monthly IVIG a median of 40 (25–66) months following rituximab. In this cohort, 30 patients were immunized with a series TDAP, PCV7 or PCV13, HIB, and/or inactivated polio vaccines. Following the third vaccine, 13 patients (43%) failed to respond to any vaccine, 6 patients (20%) had incomplete responses, and 11 patients (37%) responded to all vaccines administered. Lack of vaccine response was associated with a paucity of memory switched B cells. This study demonstrates the effectiveness of rituximab in preventing EBV viremia in high risk recipients of a T cell depleted HCT. It also suggests that rituximab affects B cell function long-term, despite quantitative, but not necessarily qualitative recovery of B cells. Further studies investigating the minimal number of rituximab doses required to prevent EBV viremia/EBV-PTLD in high risk patients and the mechanism of prolonged B cell impairment following its use are needed. Disclosures: Off Label Use: Rituximab for the prevention of EBV-LPD post HCT. Papadopoulos:Biogen-Idec: Membership on an entity's Board of Directors or advisory committees, family member on board of Biogen-Idec who receives royalties from Hoffman La-Roche.

Description: Abstract 3144 Based on encouraging results with the use of clofarabine (CLO) for reinduction treatment of acute leukemias, we have developed two allograft protocols for patients with hematologic malignancies with a cytoreductive regimen, using CLO in combination with melphalan (Mel) and thiotepa (Thio). Patients on protocol #1 received unmodified bone marrow (BMT), peripheral blood stem cells (PBSCT), or unmodified double unit cord blood (dCBT). Patients on protocol #2 received CD34+ T-cell depleted stem cells (TCD-SCT). Cytoreduction consisted of CLO 20 mg/m2/day × 5, Thio 10 mg/Kg/day × 1 and Mel 70 mg/m2/day × 2. Graft-versus-host disease (GvHD) prophylaxis consisted of tacrolimus (Tacro) and methotrexate (MTX) with unmodified BMT or PBSCT, tacro and mycophenolate mofetil (MMF) with unmodified dCBT, and none with TCD-SCT. Rabbit ATG at 2.5 mg/Kg × 2 or 3 doses was used for the prevention of rejection with the TCD-SCT. To date, 64 pts were treated with this regimen including: unmodified BMT/PBSCT 27 patients, dCBT 15 patients, and TCD-SCT 22 patients. The median age for patients was 10.2 years (range 0.9–58.7) for unmodified SCT and 41.5 (range 0.6–67.2) for TCD-SCT. This was the second SCT for 13 of 27 pts in the BMT-PBSCT group, 2 of 15 pts in the CBT group, and 4 of 22 pts in the TCD group. Patient diagnoses included acute lymphoblastic leukemia (ALL) (N=36), acute myelogenous leukemia (AML) (N=23), and myelodysplastic syndrome (MDS) (N=5). Patients with ALL or AML in first remission (CR1) or CR2 and MDS in CR1 or refractory anemia (RA) were categorized as having good risk disease (GRD), while all other pts were considered to have poor risk disease (PRD), irrespective of all other factors. There were 15 of 27 pts with PRD in the BMT/PBSCT group, 10 of 15 pts in the CBT group, and 9 of 22 pts in the TCD-SCT group. For the unmodified BMT/PBSCT group, donors were HLA-matched related (N=11), mismatched related (N=1), matched unrelated (N=12), or mismatched unrelated (N=3). All CBT recipients received double-unit grafts from 2 mismatched unrelated donors. For the TCD-SCT group, donors were HLA-matched related (N=8), mismatched related (N=1), matched unrelated (N=4), or mismatched unrelated (N=9). Engraftment occurred in 59 of 61 evaluable pts; three pts died before engraftment. One pt recipient of unmodified BMT/PBSCT suffered a late graft failure, and one pt recipient of CBT suffered an early graft failure in the context of sepsis. Grade 2–4 acute GvHD occurred in 8/26 (31%) evaluable pts in the BMT/PBSCT group, 5/13 (38%) evaluable pts in the CBT group, and 4/20 (20%) evaluable pts in the TCD-SCT group. With a median follow-up of 20.5 months for the unmodified SCT groups and 15.4 months for the TCD group, the overall survival (OS) and disease-free survival (DFS) rates were: 53.7% and 41.0% for the BMT/PBSCT group, 51.3% and 41.5% for the CBT group, and 64.1% and 60.7% for the TCD-SCT group. This cytoreductive regimen represents a promising approach for the transplantation of patients with acute leukemias without the use of total body irradiation. This regimen is also sufficiently immunosuppressive to insure consistent engraftment of T-cell depleted transplants. Lastly, it appears to be relatively well tolerated for younger pts requiring a second SCT. Disclosures: Off Label Use: Clofarabine.