Autologous Recovery Research Articles

Efficacy Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Children with Severe Aplastic Anemia

To study the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with severe aplastic anemia (SAA). A total of 11 children with SAA were treated with HLA matched siblings (n = 7), umbilical cord blood (n = 2) and haploidentical HSCT (n = 2). Among 11 children patients, 10 patients achieved engraftment, but 3 children patients experienced secondary graft failure, after donor lymphocyte infusions (DLI), they achieved engraftment again. One patient received cord blood transplantation and experienced primary graft rejection, but acquired autologous recovery. The median time for neutrophils to reach over 0.5 × 10(9)/L was 14 days (10-19 days) in the 9 children received bone marrow or bone marrow and peripheral blood allo-HSCT, while the median time for platelets to reach over 20 × 10(9)/L was 17 days (8-42 days). For the patient received double cord blood transplantation, the time of neutrophile and platelet level recovery was 16 days and 41 days, respectively. If HLA-matched sibling donor is available, allo-HSCT can be recommended as the first line of treatment for children with SAA. It is feasible for children with SAA to receive allo-HSCT from selective donor, including cord blood and haploidentical HSCT. Donor lymphocyte infusions can improve engraftment.

(211)Astatine-Conjugated Monoclonal CD45 Antibody-Based Nonmyeloablative Conditioning for Stem Cell Gene Therapy.

Most hematopoietic stem cell gene therapy studies require host conditioning to allow for efficient engraftment of gene-modified cells. Conditioning regimens with lower treatment-related toxicities are especially relevant for the treatment of nonmalignant blood disorders, such as hemoglobinopathies and immunodeficiencies, and for patients who are otherwise ineligible for conventional high-dose conditioning. Radioimmunotherapy, which employs an α- or a β-emitting radionuclide conjugated to a targeting antibody, is effective for delivering cytotoxic doses of radiation to a cell type of interest while minimizing off-target toxicity. Here, we demonstrate the feasibility of using a nonmyeloablative dose of a monoclonal anti-CD45 antibody conjugated to the α-emitter Astatine-211 ((211)At) to promote engraftment of an autologous gene-modified stem cell graft in the canine model. The doses used provided myelosuppression with rapid autologous recovery and minimal off-target toxicity. Engraftment levels were low in all dogs and reflected the low numbers of gene-modified cells infused. Our data suggest that a cell dose exceeding 1×10(6) cells/kg be used with nonmyeloablative doses of (211)At-anti-CD45 monoclonal antibodies for sustained engraftment in the dog model.

Low-dose total-body irradiation and alemtuzumab-based reduced-intensity conditioning regimen results in durable engraftment and correction of clinical disease among children with chronic granulomatous disease.

HSCT with MAC is associated with durable donor engraftment for patients with CGD; however, MAC is limited by high rates of RRT. We used a novel RIC regimen with LD-TBI (200 cGy × two doses), fludarabine (30 mg/m(2) × three doses), and proximal alemtuzumab (0.5 mg/kg/dose × one dose) and unrelated donor grafts for consecutive patients with high-risk CGD who were not candidates for MAC at our institution. Among four children with CGD transplanted at our institution, three PBSC recipients are alive with sustained donor engraftment (median follow-up: two yr) and resolution of pre-HSCT active infections while one patient with bone marrow graft is alive after graft failure and autologous recovery. RIC may be a curative option for children with high-risk CGD.

Outcomes of Second Unrelated Donor Cord Blood Transplants (UCBT) Performed in Children with Graft Failure of Autologous Recovery Following the First UCBT

Outcomes of Second Unrelated Donor Cord Blood Transplants (UCBT) Performed in Children with Graft Failure of Autologous Recovery Following the First UCBT

Haplo-Cord UCB SCT with Low Cell Dose, Well Matched UCB Units. a Prospective Multicenter Study

The outcome of umbilical cord blood transplantation is governed by UCB cell dose and matching. But stringent cell dose requirements limit access to well matched units. In haplo –cord transplant, early engraftment is determined by the adult graft. Elsewhere we have shown that excessive doses of haplo-identical cells resulted in failure of the UCB graft. Here we investigated the effect of a lower UCB cell dose threshold on ability to identify well matching units. We also prospectively evaluated the effects of UCB cell dose and matching (combined with a fixed dose haplo-graft ) on cord engraftment, platelet recovery, neutrophil recovery and acute GVHD, PFS and OS.We enrolled three consecutive cohorts with increasingly lower UCB cell dose thresholds (1) UCB cell dose >2x 10^ NC/kg (2)≥1x 10^ NC/kg and (3)≥.5x 10^ NC/kg. Additional selection criteria included (1) best HLA match (initially based on 6 HLA, as of mid 2013 based on 8 HR antigens (2)UCB viability, (3) avoidance of DSA antibodies and (4) NIMA compatibility. We continued enrollment on each cohort until at least 10 patients were evaluable for day 100 chimerism. If more than 7 of ten evaluable patients in a cohort achieved >40% UCB chimerism by d 100, the next cohort was started. This rate of success was achieved in all three cohorts, so we have continued accrual in the lowest cell dose. Sixty patients have been accrued at two institutions over 19 months. 43/60 pts had AML or MDS. The majority had ASBMT advanced and intermediate disease. Nearly half of the pts were of minority descent. Conditioning in all pts consisted of fludarabine-melphalan (three pts also received TBI 400) and GVHD prophylaxis of tacrolimus and mycophenolate. Haplo identical CD34 selected cells were co-administered at a dose of 3-5 x10^6 CD34 cells/kg. Pt characteristics and preliminary outcomes are summarized in the table below.TableCohort123Minimum TNC x10^5/kg210.5n152025Age486264ASBMT Low/Int/Adv4/5/67/5/78/6/11Weight (kg)73 (56-96)72 (50-136)85(46-122)Caucasian/Other7/813/712/13Median UCB TNC collected (x10^7/kg) and range2.7 (2.1-8.3)2.1 (1.4-2.9)1.7 (0.9-2.7)UCB TNC/kg>3x10^7/kg7 (46%) (0 UCB failure)1 (5%) (0 UCB failure)2 (8%) (0 UCB failure)2-3 x10^7/kg8 (54%) (0 UCB failure)9 (45%) (2 UCB failure)(32%) (0 UCB failure)1.5-2 x10^7/kg05 (25%) (0 UCB failure)8 4 (16%) (0 UCB failure)1-1.5 x10^7/kg05 (25%) (0 UCB failure)10 (40%) (4 UCB failure)<1 x10^7/kg001 (4%) (1 UCB failure)High Resolution HLA match8/801 (5%)4 (16%)7/82 (6%)7 (35%)7 (28%)6/803 (15%)8 (32%)5/86 (40%)9 (45%)5 (20%)<5/88 (54%)01 (4%)Median Time to ANC>500 (range)14 (10-60)12 (9-18)12 (9-51)Median Time to Plt >20 (range)35 (15-88)20 (13-NR)21 (10-NR)% with >40% UCB chimerism @d1001008376* Analysis of UCB graft characteristics includes all patients. Engraftment and GVHD analysis excludes 10 patients with early fatal complications or relapse. Chimerism analysis excludes two additional patients with missing information. NR= not reachedThe average HLA matching was significantly better (P<.001) in groups 2 and 3 (66% with >6/8 match), than in group 1 (6% with >6/8 match). UCB cell doses were significantly lower in groups 2 and 3 (55% with UCB cell dose <2x10^7/kg vs none in group 1). There were no significant difference between the groups in hematologic recovery, OS, PFS or UCB engraftment.Seven of 50 evaluable pts had failure of the UCB graft (<40% UCB chimerism on d 100). 4 of them had 100% haplo chimerism, 2 had autologous recovery and 1 had partial <40% UCB chimerism. The incidence of UCB failure increased with decreasing UCB cell dose (P<0.001 U test), with five of seven graft failures occurring in patients receiving UCB doses <1.2 x10^7/kg.This novel cord blood selection algorithm allows identification of well-matched UCB cells (at least 6/8 HR) in two thirds of patients. In approximately one third of cases the best matching UCB unit has a cell dose <1.5 x10^7/kg. Very low UCB cell doses appear to be associated with somewhat increased risk of UCB graft failure-delay. Long-term follow up will establish the impact of this selection algorithm on OS, PFS, chronic GVHD. Disclosuresvan Besien:Miltenyi Biotec: Research Funding. Stock:Sigma-Tau: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Mark:Celgene: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Millennium: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Onyx: Research Funding, Speakers Bureau.

Unrelated Umbilical Cord Blood Transplant for Children with β-Thalassemia Major.

Beta thalassemia major, one of the most prevalent hemoglobinopathy throughout the word, can be cured by allogenic stem cell transplantation (SCT) (Bone Marrow Transplant 36:971-975, 2005). Many patients, however, lack a suitably matched related sibling donor. Unrelated umbilical cord blood (UCB) can be used as an alternative stem cell source for these patients. This report describes SCT for nine children with beta-thalassemia major using partially HLA-matched unrelated UCB. Conditioning included oral busulfan 16mg/kg (day -10 to -7), cyclophosphamide (Cy) 200mg/kg (day -5 to -2), fludarabine 90mg/kg (day -13 to -11), and antithymocyte globulin (rabbit) 7.5mg/kg (day -3 to -1). The infused cell dose was 10.71×10(7)/kg total nucleated cells (TNC) (range 6.5-17×10(7)/kg TNC). The patients ranged in age from 1.5 to 7years, in weight from 10.5 to 17kg. A second transplant with two unrelated cord blood units was attempted in two patients who had primary graft failure. The retransplant recipients were preconditioned with i.v Cy 120mg/kg (day -3 to -2). Five of the nine patients engrafted promptly with 50-100% donor chimerism (56%). They engrafted at a median of 17days (range 12-19). One patient is transfusion free for 36months; a second patient is transfusion free for 18months and a third is transfusion free for 9months. There was no transplant related mortality. Four of the nine children had autologous recovery without engraftment. Primary graft rejection is the major complication. Post transplant complications were mild hepatic veno-occlusive disease, acute GVHD grade II, and CMV interstitial pneumonia. The chronic GVHD was limited and could be controlled by Methylprednisolone combined with Mycophenolate. The lack of a marrow donor registry in India makes UCBT from related and unrelated donors a good alternative. Transplant should be delayed until the child is at least 18months of age. The dose of UCB stem cells is the most important factor for engraftment. UCB has the advantages of rapid availability and low risk of severe GVHD despite donor-recipient HLA disparity (Transplant Proc 37:2667-2669, 2005). We demonstrate the feasibility of this procedure in the setting of a developing country.

Clinical Profile and Outcome of Patients with Graft Rejection Following Related HLA Matched Allogeneic Stem Cell Transplant for β Thalassemia Major

Allogeneic stem cell transplant (SCT) remains the only curative option for patients with β thalassemia major (TM). Graft rejections post SCT are unfortunately a common problem in this condition. There is limited data on the clinical profile and long term outcome of patients who have had a graft rejection post allogeneic SCT. We undertook a retrospective analysis of patients who had a graft failure post allogeneic SCT for TM at our center. From October, 1991 to April, 2013, 400 HLA matched related transplants for TM was done at our center. The median age was 8 years (range: 1-24) and there were 250 (62.5%) males. 154 (38.5%) were Lucarelli Class II and 229 (57.2%) were in the Class III risk group. Majority (72%) received a busulfan based conditioning regimen while 22% received a treosulfan based regimen. Bone marrow was the source of stem cells in 81% and PBSC in the rest. Majority of the patients received a CSA plus short course methotrexate GVHD prophylaxis regimen. There were 48 (12%) graft rejections in this cohort. Among these 26 (54%) were primary graft failures (PGF) while 22 (46%) were secondary graft failures (SGF). The median time to a secondary graft failure was 122 days (range: 40 - 2210). Of the 26 PGF, 9(34.6%) had autologous recovery with recurrence of transfusion dependence while 17(65.4%) had pancytopenia. 11 (42.3%) of PGF died prior to second transplant, 10 had a second transplant and 3(11.53%) had recurrence of TM but were alive and well. Among the 22 SGF, 10(45.5%) had autologous recovery. Of the SGF, 2 died prior to a second transplant while 9 had a second transplant and the remaining (n=11) had recurrence of TM and were on conservative management. Among the 29 cases that did not receive a second transplant 14 died at a median time of 20 days from date of documented rejection (range: 0-3268). The major cause of death in this group was graft failure with infection (n=10) and regimen related toxicity (RRT; N=4). Of the remaining cases, 14 have recurrent TM and are alive and well on conservative management while one patient is alive with pancytopenia and is transfusion dependent. 19 (39%) of the patients with graft rejection underwent a second allogeneic SCT. The median time from graft rejection to second transplant was 6 months (range: 0-42). Conditioning regimen for second SCT was busulfan based in 5 (26.3%), treosulfan based in 5 (26.3%) and the remaining received non-myeloablative conditioning regimens (fludarabine based, low dose TBI, OKT3, Cy-OKT3) in view of pancytopenia. The source of stem cells was BM in 7(36.84%) and PBSC in the rest. All cases conditioned with treosulfan based regimen received a PBSC graft. The OS and EFS of the patients that had a second transplant was 41.4±12.8% and 37.6±12.2% respectively. None of the patients conditioned with a treosulfan based regimen died or had a second graft rejection (data summarized in [table 1][1]). Of the remaining 14 patients 11 died of second graft rejection while 3 (all busulfan based conditioning) are alive and well at 3, 23 and 81 months from second transplant. View this table: Table 1 Clinical profile and outcome of patients with graft rejections who underwent a second allogeneic SCT with a treosulfan based conditioning regimen and PBSC graft. All patients engrafted and are alive and transfusions independent at last follow up In conclusion graft rejection following allogeneic SCT for patients with TM are associated with poor clinical outcomes. Following a second transplant there is a high incidence of deaths due second graft rejection and infections. A treosulfan based reduced toxicity myeloablative regimen with a PBSC graft has potential to significantly improve the outcome in this group of patients. Disclosures: No relevant conflicts of interest to declare. [1]: #T1

Dynamics of Graft Function Measured by DNA-Technology in a Patient with Severe Aplastic Anemia and Repeated Stem Cell Transplantation

Although bone marrow transplantation (BMT) from an HLA identical sibling is considered as treatment of choice in pediatric patients with severe aplastic anemia (SAA), a significant number of them experience graft failure (GF) after BMT. We report a case of an 8-year-old male patient with SAA who presented with a complicated posttransplant course due to parvovirus B19 infection and GF. A subsequent attempt to support the graft by antithymocyte globulin (ATG) and a peripheral stem cell boost resulted in transitory autologous recovery of hematopoiesis followed by mixed chimerism, supported by donor lymphocyte infusions (DLIs) and finally graft rejection with relapse of SAA. Permanent complete chimerism was achieved by a second BMT. Dynamics of graft function, measured by a single nucleotide polymorphism (SNPs) analysis, are discussed.

Second Umbilical Cord Blood Transplant (UCBT2) In Adult Patients With Engraftment Failure Or Autologous Hematopoiesis After UCBT

IntroductionUmbilical cord blood transplantation (UCBT) is often complicated by delayed engraftment and higher rates of engraftment failure. We sought to investigate the outcomes of patients undergoing UCBT2 after engraftment failure compared to those who had autologous hematopoietic recovery and did not receive UCBT2. MethodsWe reviewed the medical records of 186 patients who received UCBT between 2001 and 2011 at the Case Comprehensive Cancer Center [Seidman Cancer Center, University Hospitals Case Medical Center and Taussig Cancer Institute, Cleveland Clinic]. Standard definitions of engraftment were used. Patients who died or had progressive disease before day 30 were excluded (n=9), as they were considered inevaluable for engraftment. ResultsTwenty-seven patients (15%) had primary engraftment failure; twelve had autologous hematopoietic recovery and 15 presented no recovery (Table). The median total nucleated cell dose for the first UCBT was 2.56x107 cells/kg (range 1.23 x107 - 5.69x107), not statistically different from patients achieving engraftment (p = 0.29). The cause of engraftment failure could not be identified in 22 patients.Table 1Demographic characteristics and outcomes of patients with primary engraftment failure or autologous hematopoietic recovery after UCBT.Median Age (Range) (years)49 (20-65)Female / Male10 / 17DiagnosisAML13ALL3CML4NHL3PCM1MDS2Aplastic Anemia1UCBT #1UCBT #2Conditioning RegimenReduced Intensity2315Myeloablative40Number of UnitsUCBT #1UCBT #2110421411>230Autologous HematopoiesisSecond UCBTp valueOverall Survival (days)301273ns40 month cumulative incidence of relapse92%50%p = 0.017Among patients with engraftment failure without autologous recovery, 2 patients did not receive further salvage and died at 40 and 48 days after first UCBT; 2 others received backup autologous hematopoietic cell infusions and 11 received UCBT2. In patients with autologous hematopoietic recovery, 8 did not receive a UCBT2 because disease remission had been attained (n=4), active infection (n=1), relapsed disease beyond 40 days after UCBT (n=1) or absence of compatible donor (n=1).Fifteen patients (engraftment failure [n=11]); autologous recovery, [n=4]) underwent UCBT2, at a median of 43 days (range 33-244) from first to second UCBT. All patients received non–myeloablative second conditioning regimens. Four patients received one UCB unit and 11 received two units. Neutrophil engraftment after UCBT2 was observed in 10 of 15 patients at a median of 30 days (range, 13-35).The median survival for the entire cohort was 272 days (range 40–2130); one year overall survival was 36%. Engraftment and overall survival were not statistically different between those receiving 1 or 2 UCB units for UCBT2. Overall survival was not statistically different between patients who underwent UCBT2 and those who had autologous recovery or backup autologous infusions without further salvage.The proportion of patients in remission was similar in the 2 subgroups (UCBT2, 53%; autologous recovery, 50%). Relapse occurred in 2/15 patients who underwent UCBT2 and 8/10 patients who had autologous recovery or backup infusions. Forty months after transplantation, the cumulative incidence of relapse was 92% after autologous recovery vs. 50% after UCBT2 (Figure). Non–relapse mortality after UCBT2 was 73%. [Display omitted] ConclusionEngraftment failure after UCBT frequently has no identifiable cause, and is associated with high morbidity and mortality. UCBT2 is feasible and can result in engraftment in the majority of patients, but is limited by patient condition after transplant as well as the availability of compatible grafts. UCBT2 is associated with significantly better disease control than continued autologous hematopoiesis, but additional efforts are necessary to reduce the high risk of non-relapse mortality in this group of patients. Disclosures:Hill:Celgene: Honoraria, Research Funding.

Clinical Profile and Outcome Of Patients With Graft Rejection Following Related HLA Matched Allogeneic Stem Cell Transplant For β Thalassemia Major

Allogeneic stem cell transplant (SCT) remains the only curative option for patients with β thalassemia major (TM). Graft rejections post SCT are unfortunately a common problem in this condition. There is limited data on the clinical profile and long term outcome of patients who have had a graft rejection post allogeneic SCT. We undertook a retrospective analysis of patients who had a graft failure post allogeneic SCT for TM at our center. From October, 1991 to April, 2013, 400 HLA matched related transplants for TM was done at our center. The median age was 8 years (range: 1-24) and there were 250 (62.5%) males. 154 (38.5%) were Lucarelli Class II and 229 (57.2%) were in the Class III risk group. Majority (72%) received a busulfan based conditioning regimen while 22% received a treosulfan based regimen. Bone marrow was the source of stem cells in 81% and PBSC in the rest. Majority of the patients received a CSA plus short course methotrexate GVHD prophylaxis regimen. There were 48 (12%) graft rejections in this cohort. Among these 26 (54%) were primary graft failures (PGF) while 22 (46%) were secondary graft failures (SGF). The median time to a secondary graft failure was 122 days (range: 40 - 2210). Of the 26 PGF, 9(34.6%) had autologous recovery with recurrence of transfusion dependence while 17(65.4%) had pancytopenia. 11 (42.3%) of PGF died prior to second transplant, 10 had a second transplant and 3(11.53%) had recurrence of TM but were alive and well. Among the 22 SGF, 10(45.5%) had autologous recovery. Of the SGF, 2 died prior to a second transplant while 9 had a second transplant and the remaining (n=11) had recurrence of TM and were on conservative management. Among the 29 cases that did not receive a second transplant 14 died at a median time of 20 days from date of documented rejection (range: 0-3268). The major cause of death in this group was graft failure with infection (n=10) and regimen related toxicity (RRT; N=4). Of the remaining cases, 14 have recurrent TM and are alive and well on conservative management while one patient is alive with pancytopenia and is transfusion dependent. 19 (39%) of the patients with graft rejection underwent a second allogeneic SCT. The median time from graft rejection to second transplant was 6 months (range: 0-42). Conditioning regimen for second SCT was busulfan based in 5 (26.3%), treosulfan based in 5 (26.3%) and the remaining received non-myeloablative conditioning regimens (fludarabine based, low dose TBI, OKT3, Cy-OKT3) in view of pancytopenia. The source of stem cells was BM in 7(36.84%) and PBSC in the rest. All cases conditioned with treosulfan based regimen received a PBSC graft. The OS and EFS of the patients that had a second transplant was 41.4±12.8% and 37.6±12.2% respectively. None of the patients conditioned with a treosulfan based regimen died or had a second graft rejection (data summarized in table 1). Of the remaining 14 patients 11 died of second graft rejection while 3 (all busulfan based conditioning) are alive and well at 3, 23 and 81 months from second transplant.Table 1Clinical profile and outcome of patients with graft rejections who underwent a second allogeneic SCT with a treosulfan based conditioning regimen and PBSC graft. All patients engrafted and are alive and transfusions independent at last follow upSerial NoAge (years)SexLiver size (cms)Lucarelli ClassStem cell dose (x10E6/kg)Acute GVHDChronic GVHDLast follow up (mths)17M2310.34NILYes10.422M4213.7NILNIL3.635M4310NILNIL3.6418M2310Grade 4NIL4.9518M13315NILNIL2.9 In conclusion graft rejection following allogeneic SCT for patients with TM are associated with poor clinical outcomes. Following a second transplant there is a high incidence of deaths due second graft rejection and infections. A treosulfan based reduced toxicity myeloablative regimen with a PBSC graft has potential to significantly improve the outcome in this group of patients. Disclosures: No relevant conflicts of interest to declare.

Outcomes of Allogeneic Hematopoietic Cell Transplantation In Aplastic Anemia Using Intermediate Dose Alemtuzumab Based-Conditioning

Unlike in hematologic malignancies, graft versus host disease (GVHD) has no therapeutic benefit in aplastic anemia (AA) and its prevention is highly desirable. Using conventional GVHD prophylaxis in AA, 30–40% of patients develop acute and chronic GVHD resulting in significant mortality and morbidity with long-term health issues and poor quality of life. Previous studies reported the favorable effect of alemtuzumab on acute GVHD in related and unrelated donor hematopoietic cell transplantation (HCT) for AA (Gupta et al, BBMT 2004; Gupta et al, BMT 2005). In these studies, a higher dose of alemtuzumab (75-100 mg) close to stem cell infusion was used. We subsequently designed a conditioning strategy using an intermediate dose of alemtuzumab (50-60 mg), and report our institutional experience at Princess Margaret Cancer Centre, Toronto, Canada using this strategy.Between January 2005 and June 2013, 40 patients underwent HCT for AA at our centre. The median age at HCT was 35 years (range 17-59). The etiology of AA was idiopathic in 70%. Fifteen (38%) were positive for paroxysmal nocturnal haemoglobinurea (PNH) clones and 2 patients had symptomatic hemolytic PNH prior to HCT. Upfront HCT was used in 17 (42%) patients, and 23 (58%) had failed one or two courses of ATG-based immunosuppressive therapy (IST). Donors were HLA-identical matched siblings in 28 (70%) and matched unrelated donors (MUD) in 12 (30%). As the preferred source of hematopoietic cells was bone marrow, 34 (85%) received BM grafts and 6 (15%) received peripheral blood grafts. Twenty four (60%) patients were CMV seropositive. Conditioning regimens included: High-dose cyclophosphamide (50 mg/kg x 4 days from days -5 to -2) with alemtuzumab 50 mg (10, 20, 20 mg on days -8, -7 and -6 respectively) in 9 (23%) patients; fludarabine (30 mg/m2 x 4 days from days -5 to -2) with low-dose cyclophosphamide (10 mg/kg x 4 days from days -5 to -2) and alemtuzumab 60 mg (30 mg x 2 days on days -7 and -6) in 28 (70%) patients. In 3 (7%) patients busulphan was used instead of low-dose cyclophosphamide because of symptomatic PNH or presence of monosomy 7. In the first 10 (25%) patients, alemtuzumab was used as an IV infusion; the subsequent 30 (75%) patients received subcutaneous alemtuzumab. Cyclosporine was also used for GVHD prophylaxis starting on day -1 and slowly tapered in the absence of GVHD at 6 months.The median follow up time of survivors was 3.6 years (range 0.2-7.9). The median neutrophil (≥0.5 x109/l) and platelet (≥20 x109/l) engraftment times were 18 days (range 11-112) and 12 (range 2-395) respectively. Four patients had graft failure (2 primary and 2 secondary). Two of these patients died and two are long-term survivors (one after second HCT and the other had autologous recovery). The cumulative incidences of acute and chronic GVHD were 27.7% (95% CI 13.5-41.8) and 21.3% (95% CI 7.9-34.7) respectively. No patients developed grade 3-4 acute GVHD or severe chronic GVHD (NIH criteria). Viral complications were seen frequently: CMV reactivation (79%); HSV (18%); VZV (25%) and BK hemorrhagic cystitis (8%). None developed CMV disease. Three patients developed an EBV-related lymphoproliferative disorder. All three patients were heavily treated with ≥2 courses of ATG- IST prior to HCT.The 3-year estimated overall survival was 85% (95% CI 74-97). The majority of patients had no significant long-term health issues. Of the 18 women of childbearing age (16-45 years), 6 patients conceived. An asymptomatic drop in FEV1 ≥20% was seen in only 4 of 21 patients who had survived >2 years. Two patients developed secondary malignancies (1 smouldering myeloma and 1 squamous cell carcinoma).In conclusion, this intermediate dose alemtuzemab based conditioning in AA is a simplified approach that results in excellent survival and has a favorable impact on GVHD, and long-term health issues. Nevertheless, close monitoring for viral complications such as CMV reactivation, and EBV monitoring particularly in patients who fail IST prior to HCT is important. Disclosures:Off Label Use: Alemtuzumab for GVHD prophylaxis in allogeneic hematopoietic cell transplantation for aplastic anemia.

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.

Allogeneic Hematopoietic Stem Cell Transplantation Of Patients With Wiskott-Aldrich Syndrome With Total Body Irradiation (TBI), Thiotepa and Fludarabine Or Cyclophosphamide Followed By T-Cell Depleted Grafts From Alternative Donors

Wiskott-Aldrich syndrome (WAS) is a rare X-linked congenital immunodeficiency syndrome characterized by micro-thrombocytopenia, eczema, autoimmune syndromes and malignancies that are often fatal. Early hematopoietic stem cell transplant (HSCT) experience for patients with WAS from alternative donors was associated with poor outcome including a high rate of graft rejection. Since 1998 we have transplanted 13 patients with WAS with grafts from alternative donors. Specifically, 9 of these patients received T cell depleted transplants and are the focus of this abstract. Grafts were from matched unrelated donors (N=5) mismatched unrelated donors (N=2) mismatched related donors (N=2). Patient age at transplant ranged from 1.1-21.5 years (median 3.3). Cytoreduction included Hyperfractionated TBI with Thiotepa and Cyclophosphamide or Fludarabine (N=7) Busulfan with Melphalan and Fludarabine (N=1) Cyclophosphamide with Thiotepa and Fludarabine (N=1). Prior to 2002 no children under 24 months received TBI. Subsequently CNS shielding was used with TBI for patients under the age of 3. All patients received ATG for graft rejection prophylaxis. Six patients had previously undergone splenectomy. Stem cell grafts were Lectin/E rosette separated T cell depleted bone marrow (N=4) or Isolex/E rosette separated T-cell depleted PBSC (N=5). Eight patients engrafted with median neutrophil engraftment on day 12 (11 -16). One patient who received cytoreduction with Cyclophosphamide, Thiotepa and Fludarabine suffered primary graft failure, had autologous recovery and went on to receive a second transplant and is alive and well. All patients developed Grade I – II mucositis. One patient suffered an early toxic death after developing acute encephalopathy during cytoreduction with Busulfan (8mg/kg) Melphalan (140mg/m2) and Fludarabine (125mg/m2) and one other patient with a prior history of lymphoma had progression of lymphoma and early death post HSCT. One developed acute GvHD (Grade III GI). Three patients developed autoimmune disorders associated with mixed chimerism. All three patients had complete resolution of their autoimmune disease and two of these three patients reverted to full donor chimerism. With a post HSCT follow-up period of a median of 7.5 years (3-15 years) seven of these nine patients are alive and disease-free. In summary, T-cell depleted grafts appear to extend transplant as a treatment option for patients with WAS who are without matched related donors. Recent successful experience with T cell depletion following chemotherapy only regimens for other patient populations will provide a way to explore non-TBI based cytoreduction and T cell depletion as an approach for future patients. Disclosures: No relevant conflicts of interest to declare.

Unrelated Cord Blood Transplantation For Infant Acute Leukemia Diagnosed Within 1 Year Of Age: Outcomes and Risk Factor Analysis On Behalf Of Eurocord and PDWP-EBMT

Infant acute leukemia has poor prognosis due to both chemo-resistance and toxicity in these very young patients (pts). Allogeneic stem cell transplantation (HSCT) is indicated for all pts with infant AML and ALL beyond first complete remission (CR). While some cooperative protocols exist for infant ALL with clear criteria for HSCT in CR1 pts, there is no international consensus for HSCT in infants with CR1 AML. In this population of low body weight pts, with aggressive disease, unrelated cord blood (UCB) is an attractive stem cell source due to high cell content and prompt donor availability.We retrospectively analyzed 254 children with ALL (n=154) or AML (n=95) diagnosed within 1 year (y) of age (median age 5.7 months (range 0.03-12)). Median age at UCBT was 1.15 y (range 0.3-11). Pts received single-unit unrelated UCBT after myeloablative conditioning regimen (MAC) from 1995 to 2012 in EBMT centers.Pts were transplanted in CR1 (n=135, 54%), CR2 (n=79, 32%) or more advanced disease (n=35, 14%). Data on cytogenetic at diagnosis were available for 182 pts (ALL=111, AML= 71), 24% were intermediate risk and 76% poor risk. For pts with ALL, 82 had chromosome 11 abnormalities defined as (t(4;11)-n=47, 11q23 abnormalities not otherwise specified-n=25, and others-n=10). For pts in CR1 median time from diagnosis to UCBT was 6 months (range 2.8- 20.7 months) and median duration of remission prior to transplant was 127 days (range 15-326 ).CB units (21%) were identical to recipient, 57% had 1 HLA disparity (antigen level for HLA-A and B, allelic level for DRB1), and 22% had 2 HLA disparities. Median TNC dose at infusion was 9.4x107/kg (range 1- 18x107/kg). Most pts received busulfan (Bu) based conditioning (75%, n=186). The most frequent regimens were Bu+cyclophosphamide (Cy) (n=68), Bu+Cy+Melphalan (n=43), Bu+Cy+Fludarabine+Thiotepa (n=31). Thirty one pts received conditionings that included TBI. ATG was used in 79% of pts. GVHD prophylaxis consisted either of CSA±steroids or CSA±MMF in 72% and 11% of pts, respectively.Median follow-up was 42 (range 3-170) months. Cumulative incidence (CI) of day 60 neutrophil recovery was 89±2%, with median time of 21 (range 7-55) days. CI of engraftment was 88% for those receiving TNC<9.4x107/kg, and 93% for pts receiving TNC>9.4x107/kg, p=0.006. At day 100, 90% of pts had full donor chimerism (data available for 73% of pts who engrafted). Of the 28 pts who had graft failure, 11 died within 30 days after UCBT, 7 had autologous recovery, and 10 received a subsequent HSCT (3 autologous, 7 allogeneic). Of the 7 pts with a second allo-HSCT, 4 are alive at a median of 2 years.CI of day 100 acute GVHD (grade II-IV) was 39±3%, median time of onset was 18 days (range 6-100). Among 96 pts who experienced grade II-IV acute GVHD, 58 had grade II, 24 had grade III, and 14 had grade IV. CI of 1 y chronic GvHD was 10±3%.CI of 1y TRM was 25±3%. CI of TRM was higher for infants transplanted for ALL than for AML (31% and 15% , respectively, p= 0.004. One hundred and fifteen pts died. The causes of death were relapse (n=55), infection (n=30), GvHD (n=9), or other transplant-related events (n=21).CI of 4y relapse was 26±4%. It was 28% for pts transplanted for ALL and 21% for AML, p=0.32. CI of 4y relapse was 19%, 31% and 50% for pts transplanted in CR1, CR2 or more advanced disease, p=0.007. Age at diagnosis less than 3 months was associated with a trend for higher CI of relapse at 4y (36% versus 22%, p=0.06).Leukemia-free-survival (LFS) at 4y was 49±3%; it was 40% and 69% for those transplanted for ALL and AML, respectively p=0.001. According to diagnosis and disease status, 4y LFS for ALL was: 50% for pts in CR1, 36% for CR2 and 0% for advanced disease, (p=0.001). For AML it was: 82% for pts in CR1, 58% for CR2 and 11% for advanced disease, (p=0.001). LFS was better for pts transplanted with a short delay from diagnosis to transplant (within 6 months of diagnosis, 60% versus 45%, p=0.01). For pts with chromosome 11 abnormalities, 4y LFS was 45%. In multivariable model, diagnosis of ALL (HR 1.8, p=0.004), advanced disease status at UCBT (HR 2.4, p<0.0001) and age at diagnosis less than 3 months (HR 1.5, p=0.02) were independently associated with worse LFS.UCBT is a suitable option for infants with acute leukemia in remission. TRM was higher for ALL pts probably due to the intensity of pre transplant therapies. Contrarily to what is usually observed in children older than 1 year, in our study pts transplanted with UCB for AML had better prognosis than ALL recipients. Disclosures:No relevant conflicts of interest to declare.

Outcomes Of Allogeneic Cord Blood Transplantation For Leukodystrophies; A Joint Study of Eurocord and “Inborn Errors WP-EBMT”

BackgroundThis study aims to describe transplant outcomes and disease-specific clinical outcomes of allogeneic cord blood transplantation (CBT) in leukodystrophies. Leukodystrophies are rare inborn errors of metabolism (IEM) in which the development and maintenance of brain myelin is primarily affected. They are characterized by rapid neurological deterioration. Hematopoietic stem cell transplantation (HSCT) has been shown to halt disease progression for selected leukodystrophies, including adrenoleukodystrophy (ALD), Krabbe disease (globoid cell leukodystrophy) and metachromatic leukodystrophy (MLD). The fast availability of unrelated cord blood (UCB) makes HSCT feasible in leukodystrophy patients who lack an HLA-matched sibling. Patients and methodsAll patients transplanted for leukodystrophies with related and unrelated umbilical cord blood in EBMT centers between 1996 and 2012 were included. HSCT data were collected from the EUROCORD database. An additional questionnaire on disease-specific clinical outcomes was sent to participating centers. Included in the questionnaire were enzyme- and (for ALD) fatty acid levels, general disease status, performance score, MRI/MRS status, peripheral neuropathy, school attendance and performance, mental development testing, adrenal insufficiency (for ALD only), vision and hearing. Kaplan-Meier estimates were used to calculate overall survival (OS) and cumulative incidence methods for secondary outcomes, including neutrophil and platelet engraftment, incidence of graft-versus-host disease (GvHD), donor chimerism and disease-specific characteristics at most recent follow-up. The two-sided log-rank test was used for univariate comparisons. ResultsSeventy patients (31 ALD, 5 Krabbe, 34 MLD) were available for analysis, with a median age at transplant of 6.5 years (range 0-43 years). Median follow-up for survivors was 46 months. Overall survival at 4 years was 60% (±6%). Cumulative incidences of neutrophil and platelet engraftment were 88% (±4%) at day 60, and 73% (±6%) at day 180, respectively. Ten patients experienced graft failure and 5 had autologous recovery; 4 received a 2nd HSCT (2 CBT, 1 Haplo, 1 BM) and of those 3 were alive in a median of 60 months after HSCT. Acute-GvHD (grade II-IV) occurred in 16 patients (22% ±5%) at day 100 and chronic GvHD in 9 patients (13% ±5%). Out of the 24 patients who died, 18 (67%) died of transplant-related causes and 6 (33%) died of disease progression. Higher survival was seen in patients who had no or 1 HLA mismatch (OS 81%), compared to patients who received UCBT with 2 HLA mismatches (OS 47%, p 0.02).On 37 patients (53%), information on disease-specific characteristics was available. OS among these patients was 68% (±8), which was not significantly different from patients without disease-specific information (p=0,307). Of the 37 patients, 19 (51%) were asymptomatic at transplant, 14 (38%) had mild disease and 4 (11%) were severely affected. Overall survival was dramatically worse in patients with severe disease at transplant; all 4 severely affected patients died, while 79% of patients with mild disease and 76% of asymptomatic patients survived. At most recent follow-up, disease status was stable in 15 (57.7%), had improved in 2 (7.7%) and worsened in 9 (34.6%) surviving patients. The majority of patients showed abnormalities on MRI-scanning pre-HSCT (n=25, 68%). In patients with normal MRI-scans pre-transplant OS was 69%; in patients with abnormal MRI-scans 75%. At most recent follow-up, MRI-scans were stable in 12 (43.9%), improved in 5 (17.8%) and worsened in 11 (39.3%) patients. Eighteen patients (50%) showed peripheral neuropathy pre-HSCT, of which 13 were mildly affected and 5 severely affected. Of patients who had no signs of peripheral neuropathy pre-HSCT, 70% survived, versus 77% of patients who were mildly affected and 40% of those severely affected. At most recent follow-up, peripheral neuropathy was stable in 14 (56%), had improved in 3 (12%) and worsened in 8 (32%) patients. ConclusionWe found an overall survival of 60% at 4 years after CBT for leukodystrophies, with relatively low rates of GvHD. Use of a mismatched donor (>1 HLA mismatch) negatively impacts survival. Data on clinical characteristics suggest that overall survival is strongly influenced by disease status at transplant. Disclosures:No relevant conflicts of interest to declare.

A Pilot Study Of Continuous Infusion Mycophenolate Mofetil For Graft Versus Host Disease Prophylaxis

Mycophenolate mofetil (MMF), an ester prodrug of mycophenolic acid (MPA) has been used successfully for graft-versus-host disease (GVHD) prophylaxis. Most MMF dosing regimens and pharmacokinetic (PK) parameters have been established in solid organ transplant recipients. Empiric fixed-dose-escalation strategies have failed to achieve target MPA exposure, especially in the early period following conditioning therapy. We hypothesized that a PK-based dosing approach using a novel continuous infusion (CI) method of MMF will be able to achieve and maintain target MPA exposure. The objective of this study was to evaluate the safety and feasibility of this MMF dosing approach in pediatric BMT recipients. Fifteen patients were enrolled in the study. The median age at transplant was 8.4 years (0.9 – 21.5); eight were female and seven were male. Thirteen patients were transplanted for hematologic malignancies and two patients for nonmalignant diseases. Stem cell sources included matched-sibling bone marrow in seven, 10/10 allele matched donor bone marrow in four, and unrelated cord blood in four cases. All patients received a myeloablative conditioning regimen with either cyclophosphamide-TBI (n=8) or busulfan-cyclophosphamide (n=7). In addition, of eight unrelated donor transplants, six patients received equine ATG and two received fludarabine. All patients received cyclosporine A and MMF for GVHD prophylaxis. Intravenous (IV) cyclosporine was initiated on day -2 as a continuous infusion (target blood level: 160 to 250 ng/mL). IV MMF was started on day “0” in a dose of 15 mg/kg every 8 hours. After a minimum of five doses, serial blood samples were collected within one dosing interval for the 1st PK analysis. Using these results, MMF was converted from intermittent IV to CI administration to target total MPA AUC0-24 of 40-80 mcg/mL/hr. MMF dose was adjusted to maintain a total MPA steady-state concentration (Css) of 1.7-3.3 mcg/mL. CI MMF was converted to every-8-hour oral dosing when patients were tolerating oral medications. A 2nd PK study was performed after a minimum of five oral doses, and dose adjustments were made to maintain a total MPA trough concentration (Ctrough) of 1-3.5 mcg/mL. MMF was continued until day 42, and in the absence of acute GVHD, tapered off over 8 weeks. On the initial 15 mg/kg q8 IV MMF dose schedule, MPA half-life was 1.3±1.3 hrs and AUC0-24 was 44.3±60.3 mg* hr/L. During the CI schedule, MMF dose was 44±16 mg/kg/day and MPA AUC0-24 38.4±20.7 mg* hr/L, and thirteen of fifteen (87%) patients achieved MPA Css within target of 1.7–3.3 mcg/mL. On conversion to oral route, median MMF dose was 45±19mg/kg/day, MPA half-life 1.95±2.3 hrs and AUC0-24 38.3±16.0 mg* hr/L. MPA clearance was 17±14 ml/min/kg. Higher steady state MPA concentrations were achieved with CI method (Css 1.6 ±0.9 mcg/mL) compared with intermittent IV or oral dosing (Ctrough 0.7±0.9 mcg/mL). All patients achieved neutrophil engraftment at 13 ± 11 days post-transplant, and platelet engraftment at 45 ± 72 days post-transplant. Seven out of 15 patients (47%) developed stage I-IV acute GVHD. Three patients had stage III-IV aGVHD (20%); they were steroid-refractory but went into remission with additional therapy. For 11 patients with a minimum of one year follow-up post-transplant, one (9%) developed “overlap” chronic GVHD. MMF was discontinued without weaning in four patients: in three of them due to concern of delay in blood count recovery and all of them achieved hematopoietic engraftment, and in one patient with severe aGVHD due to potential concern for MMF gut toxicity. One patient with severe congenital neutropenia developed autologous hematopoietic recovery by day 52. One patient with ALL died of relapse 150 days after transplant. With a median follow-up of 23 months (range 100 days to 3.6 y), 14 out of 15 patients are alive, and one-year event-free survival and overall survival are 83% and 92% respectively. In conclusion, we show that continuous infusion of MMF is feasible and well-tolerated. In this pilot PK study, we observed no toxic deaths, excellent engraftment, and low rates of grade III-IV aGVHD and cGVHD. The PK studies showed significantly lower half-life and higher drug clearance in pediatric BMT recipients compared to stable pediatric renal transplant patients. This regimen deserves further validation in a larger cohort of pediatric patients undergoing myeloablative transplantation. Disclosures: Off Label Use: Use of Mycophenolate Mofetil for Graft versus Host Disease Prophylaxis.

Early Multilineage Chimerism Predicts The ‘Winning' Unit In Double Cord Blood Transplantation

BackgroundUmbilical cord blood (UCB) is an established alternative haemopoietic cell source for use in clinical transplantation for life-threatening malignant and non-malignant disorders. One challenge in using UCB in adolescents and adults has been delayed engraftment due to the finite and limited cell dose of a single unit, which has been shown to be a key determinant of engraftment, transplant related mortality and survival. The use of double unit transplantation, pioneered at the University of Minnesota, has become one of the most successful approaches to overcome this limitation to date. This group have also developed a reduced intensity conditioning (RIC) regimen, successfully broadening access to UCB transplant to older patients and those with co-morbidities. The kinetics of granulocyte, T cell and B cell chimerism in this setting require detailed study. MethodsSince 2009, the British Society of Blood and Marrow Transplantation have conducted a prospective, phase II study of UCB transplantation using the Minnesota RIC conditioning regimen (Fludarabine 200mg/m2, Cyclophosphamide 50mg/kg and TBI 2Gy), with Ciclosporin and Mycophenolate Mofetil graft versus host disease prophylaxis. Lineage specific chimerism was performed at days 7, 14, 21, 28, 35, 60, 100, 180, 360 and 720 post transplant and analysed at laboratories associated with participating centres. Results28 consecutive adult trial patients who have received a double unit transplant, have engrafted and have chimerism data up to at least day 35 are included in this analysis. The ‘winning' unit had a median unit:recipient match of 4/6 (range 4-6/6), with a median pre freeze total nucleated cell (TNC) count of 189x107 (range 83-250) and CD34 of 84x105 (range 23-169). The ‘losing' unit had a median unit:recipient match of 5/6 (range 4-6/6), with a median pre freeze total nucleated cell (TNC) count of 183x107 (range 127-303) and CD34 of 55x105 (range 42-95). Despite the low white count early post transplant, peripheral blood (PB) lineage specific chimerism for mononuclear cells (PBMC), T cells and granulocytes was feasible in nearly all patients. B cell chimerism was unsuccessful or not available in 55% of time points. The pattern of early T cell and granulocyte chimerism is summarised in the table.From day 60 onwards, the median granulocyte and T cell chimerism remained 100% winning unit. However, T cell chimerism at day 14 identified the winning unit in all patients with a result at this time point (n=25). Contribution to the B cell compartment was 100% winning unit by day 35, with 83% recipient at day 7 and 24% at day 14 and 4% losing unit at day 7 and 14. ConclusionsLineage specific chimerism is technically feasible in the immediate post transplant period and gives important insights into the kinetics of double cord blood unit engraftment. Although the ‘losing' unit may contribute to the B and T cell compartments in the first 2 weeks, it contributes little after day 21. The winning unit is clearly identifiable by day 14 in all lineages. Early granulocyte recovery (driven by G-CSF) in the RIC setting is seen to be primarily due to autologous recovery until around day 21 after which the winning unit predominates. These data provide an insight into the biology of engraftment that may also inform additional novel strategies such as ex vivo CD34 expansion and adding in haploidentical stem cells. Disclosures:No relevant conflicts of interest to declare.Table% Median contribution (range)Day post transplantRecipientWinning unitLosing unitT CELLS770 (22-94)23 (0-73)5 (0-41)144 (0-30)87 (29-100)0 (0-38)210 (0-35)100 (52-100)0 (0-34)280 (0-24)100 (32-100)0 (0-44)350 (0-3)100 (58-100)0 (0-42)600 (0-4)100 (91-100)0 (0-8)GRANULOCYTES7100 (84-100)0 (0-16)0 (0-10)1455 (1-100)28 (0-99)0 (0-20)210 (0-99)80 (0-100)0 (0-25)280 (0-54)99 (15-100)0 (0-6)350 (0-27)99 (21-100)0 (0-16)600 (0-8)100 (40-100)0 (0-52)

Sequential Treatment After Allogeneic Stem Cell Transplantation for Chronic Myelogenous Leukemia.

AbstractAbstract 3129 BackgroundTyrosine kinase inhibitors (TKI) have revolutionized treatment of chronic myeloid leukemia (CML), nonetheless as seen in follow-up of the IRIS study, almost 30% of patients discontinued imatinib due to inadequate response or intolerance. Allogeneic stem cell transplant (ASCT) remains the only effective treatment to produce durable complete remissions in CML; curative effect is largely derived from immune graft-versus-leukemia (GVL) effect mediated by alloreactive donor T cells reacting against residual host malignant cells. We evaluated sequential therapy after a nonmyeloablative preparative regimen, designed to reduce risks of toxicity, graft-versus-host disease (GVHD) and treatment related mortality. Patients with residual CML 3 months post ASCT received imatinib and those without a complete molecular remission after an additional 3 months received donor lymphocyte infusions (DLI).Patients and Methods Objective:To increase frequency of achievement of complete molecular response (CMolR) following reduced intensity ASCT. Eligibility:CML in chronic phase (CP) with failure to respond/intolerance to one or more TKIs. Patients received a reduced intensity preparative regimen involving fludarabine 40 mg/m2 × 4 days, busulfan 130 mg/m2 × 2 days, and antithymocyte globulin (Thymoglobulin) 2.5 mg/kg daily × 3 days followed by ASCT from an HLA identical or one antigen mismatched related or unrelated donor. GVHD prophylaxis was tacrolimus and methotrexate (5 mg/m2 on SCT days 1, 3, 6 and 11). Patients who had engraftment but residual disease by quantitative PCR for bcr-abl rearrangement at 3 months post ASCT received imatinib treatment with dose titrated to hematologic toxicity. Those with residual disease 6 months post ASCT and no active GVHD received DLI. Patients were treated between 4/2003 - 6/2008; median follow up was 74 months (4–99). Outcome of interest was progression free survival (PFS) and overall survival (OS), estimated using Kaplan-Meier estimate, and survival comparisons between groups was by log rank test. ResultsPatient characteristics summarized in Table 1; response analysis in Table 2. 41 patients were entered on study, all were previously treated with a TKI; at time of ASCT, 10 were in first chronic phase (CP1), 8 had isolated clonal evolution (CE) and 23 had a history of advanced CML (>CP1, or accelerated phase). One patient died within 100 days post HSCT and 3 had graft failure; one required a second transplant; 2 had autologous recovery with CMolR and are both alive. At 3 months, all patients in CP1 or with CE (18/44%) obtained complete cytogenetic response (CCgR); 15(36%) of 23 advanced patients achieved CCgR. CMolR was attained by 8 patients, 4 in CP1. No one with minimal residual disease achieved a CMolR without intervention. 22 patients received treatment with TKIs post ASCT; and of those 9 later received DLI. CMolR was achieved in 12 of 22 patients who had molecular progression post ASCT. 26 patients are alive at last follow up and 15 deaths were due to, relapsed leukemia (9), GVHD (3), and infection (3), respectively. ConclusionIn conclusion, sequential therapy including reduced intensity HSCT, post transplant treatment with TKI, and donor lymphocyte infusion was associated with a low rate of treatment related mortality. This approach is capable of prolonged cytogenetic and molecular complete remissions and survival. Disease status at time of transplant was the most important prognostic factor. This is an effective option for patients in chronic phase who have failed to respond optimally to TKI based treatment.Table 1- Patient CharacteristicsN (%)N (%)Age at TP, med (range)42 (14–69)Median f/up in alive, mo74 (4–99)Age ≥50 yr10 (76)% OS60% (42–74)≤5031 (24)% PFS56% (38–70)Donor TypeMRD21/51%Disease statusMUD19/46%CP110/24%Ag MM rel1/2%CP214/34%TKI prior to transplantN (%)≥CP35/12%Imatinib33/80%AP13/7%Dasatinib6/15%AP21/2%Nilotinib1/2%CE8/20%Bafetinib1/2%Table 2- Responses After Sequential Therapy Protocoln= 41Response to prep regimen at 3 moMolecular CR to imatinib (n=22)Molecular CR to DLI (n=9)Alive/CCgR/CMolRRelapse/DeadCP1 n=10CCgR = 10 (100%)1 of 41 of 210/10/50/0CMolR = 4 (40%)CP2/CE/AP1 n=25CCgR = 21 (84%)4 of 175 of 717/16/118/10CMolR= 3 (12%)AP2/≥CP3 n=6CCgR = 2 (33%)1 of 1none1/1/15/5CMolR = 1 (17%)Disease statusOSpPFSpN=15 diedN=17CP11000.0200.01CP2/AP1/CE25912≥CP3/AP2655 [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Graft-Specific HLA-Antibodies Do Not Influence Unit Dominance and Do Not Prevent High Rates of Sustained Donor Engraftment in Recipients of Double-Unit Cord Blood Transplantation

AbstractAbstract 960 Background:Pre-transplant human leukocyte antigen (HLA)-antibodies have an established role in failed engraftment after single-unit cord blood (CB) transplantation (CBT). Their role in double-unit CBT (DCBT) engraftment, however, is more controversial. Some transplant centers advocate pre-transplant screening of the recipient for HLA-antibodies, and avoidance of units with the corresponding antigens if antibodies are detected. Methods:We evaluated the influence of pre-transplant HLA-antibodies on sustained donor neutrophil engraftment and unit dominance in 82 recipients (median 48 years, range 2–69) of 4–6/6 HLA-A, B antigen, DRB1 allele matched double-unit CB grafts, and transplanted for hematologic malignancies at MSKCC from July 2008 to July 2012. HLA-antibodies were measured by the HLA Laboratory of the American Red Cross Blood Service using Single Antigen Luminex beads and analyzed by HLA Fusion software. The cut-off for positive results was a normalized mean fluorescence intensity value > 1000. Results:Overall, 28/82 (34%) patients were positive for HLA-antibodies [16 (19.5%) had antibodies without graft specificity, and 12 (14.5%) had antibodies with graft specificity]. These patients were more likely to be female with acute leukemia and cytomegalovirus seropositive. All patients with graft-specific antibodies received myeloablative conditioning; 5 had antibodies against class I HLA, 6 against class II, and one patient had antibodies to both Class I/II. Moreover, of these 12 patients, 6 had antibodies against one unit, and 6 had antibodies against both units. Neutrophil engraftment according to antibody presence is summarized in the Table. 64 of 66 (97%) evaluable myeloablative DCBT recipients (Table 1A) engrafted at a median of 24 days (range 12–40); one patient without antibodies and one with antibodies against both units had primary graft failure, both in the setting of early onset multi-organ failure. Both patients were 100% donor with one unit but did not recover counts. Of the 6 patients with antibodies to one unit, 3 engrafted with that unit and 3 with the opposite unit. Of the 6 patients with antibodies against both units, one had clinical graft failure as described above, and the 5 others had sustained donor engraftment (4 with one unit and one with both). In engrafting myeloablative recipients, the median time to neutrophil recovery was 8 days slower in patients with graft-specific antibodies, but the engrafting unit in these patients also had the lowest infused dose: median CD34+ cell dose/kg if no antibodies 0.83 × 105/kg, non-specific antibodies 1.09 × 105/kg, and antibodies specific to graft 0.65 × 105/kg. In non-myeloablative recipients, 15/16 (94%) engrafted (Table 1B). The single patient with graft rejection and autologous recovery had HLA-antibodies that were not graft specific. Conclusions:11 of 12 double-unit CBT recipients with graft-specific antibodies engrafted successfully. While myeloablative recipients with graft-specific antibodies engrafted more slowly, this may be explained by a lower infused CD34+ cell dose of their engrafting units. Multivariate analysis of larger patient numbers will be required to further evaluate the effect of graft-specific antibodies on engraftment speed. At this time, however, the presence of graft-specific antibodies should not preclude DCBT, and whether their presence should influence graft selection is not clear. Furthermore, there is no suggestion that the presence of HLA-antibodies influences unit dominance after DCBT.TableSustained Donor Neutrophil Engraftment According to HLA-antibodies1A) Myeloablative Conditioning (n=67)Median (Range) Time to Neutrophil Recovery (> 0.5)N (%) Sustained EngraftmentNo antibodies (n=41)23 days (range 12–38)39/40 (1 non-evaluable)Antibodies: not graft-specific (n=14)23 days (range 12–37)14/14Antibodies: graft-specific (n=12)31 days (range 13–40)11/12Against engrafting unit (n=3)28 days (range 24–31)3/3Against non-engrafting unit (n=3)31 days (range 25–32)3/3Antibodies against both units (n=6)33 days (range 13–40)5/61B) Non-Myeloablative Conditioning (n=15)Median (Range) Time to Neutrophil Recovery (> 0.5)N (%) Sustained EngraftmentNo antibodies (n=13)10 days (range 8–20)13/13Antibodies: not graft specific (n=2)19 days in 1 patient (other had graft failure/autologous recovery)1/2Antibodies: graft specific (n=0)-- Disclosures:Giralt:Celgene: Honoraria, Research Funding.

Unmanipulated Haploidentical Bone Marrow Transplantation and Post-Transplant Cyclophosphamide for Hematologic Malignanices Following A Myeloablative Conditioning.

AbstractAbstract 3034Despite a large number of unrelated donors (UD), not more than 30% of patients who have activated a donor search, undergo an allogeneic UD stem cell transplant. HLA haploidentical family members are being increasingly considered as an alternative donors, both using T cell depleted or T cell replete grafts. Post-transplant high dose cyclophosphamide (PT-CY), introduced by the Baltimore group, has shown very promising results following non myeloablative conditioning regimens. We are now reporting 50 patients with high risk hematologic malignancies, who received a myeloablative regimen, followed by unmanipulated haploidentical bone marrow transplant (hBMT) and PT-CY. The myeloablative conditioning consisted of thiotepa (10 mg/kg), busulfan (9,6 mg/m2′), fludarabine (150 mg/m2′)(n=35), or total body irradiation (9,9–12 Gy), fludarabine (120 mg/m2′) (n=15). The median age was 42 years (18–66); 23 patients were in remission and 27 had active disease; 10 patients were receiving a second allograft. Graft versus host disease (GvHD) prophylaxis consisted in PT-CY on day+3 and +5, cyclosporine (from day 0), and mycophenolate (from day +1).The median nucleated cell dose was 3.6 ×108′/kg (range: 1,4 – 7,7). The median time to neutrophil counts of >0.5×109/L was 18 days (range, 13–30 days) and to platelet counts of >20×109/L 23 days (range, 14 – 58 days), respectively. There was no correlation between infused number of nucleated cells and days of neutrophil engraftment. The cumulative incidence of engraftment was 90%for neutrophils and 86% for platelets. Three patients died before engraftment, and 2 patients had autologous recovery: 45 patients (90%) had full donor chimerism on day +30. The cumulative incidence of grade II-III acute GvHD was 12%, and of moderate chronic GvHD 10%. With a median follow up for surviving patients of 333 days (149–623), the cumulative incidence of transplant related mortality is 18%, and the rate of relapse 26%. The actuarial 22 months disease free survival is 68% for patients in remission and 37% for patients with active disease (p<0.001). Causes of death were pneumonia (n=3), haemorrhage (n=3), sepsis (n=3) and relapse (n=7).In conclusion, a myeloablative conditioning regimen followed by h-BMT with PT-CY, results in a low risk of acute and chronic GvHD and encouraging rates of transplant related mortality and disease free survival. Disclosures:No relevant conflicts of interest to declare.