Diagnosis Of Severe Aplastic Anemia Research Articles

Early Initiation of Oral Therapy with Cyclosporine and Eltrombopag for Treatment Naïve Severe Aplastic Anemia: Interim Results of a Phase II Trial

Introduction: Severe aplastic anemia (SAA), a life-threatening bone marrow failure disease, is treated with allogeneic bone marrow transplantation or immunosuppression (IST). Pancytopenia meeting “Camitta” criteria and an empty bone marrow (<30% cellularity) establish the diagnosis of SAA. However, neither diagnosis nor therapeutic interventions are straightforward, resulting in delays of therapy. SAA must be differentiated from hematologic malignancy, and constitutional forms should be excluded by functional or genetic testing. Administration of IST usually occurs at a tertiary care center, and in younger patients' evaluation for BMT is first required. Ongoing immune mediated destruction of stem cells further depletes marrow reserve and increases regenerative stress with such delays. In this phase II study, we tested the feasibility and safety of early initiation of cyclosporine (CSA) to block T cells and eltrombopag (EPAG) to stimulate hematopoiesis followed by standard of care therapies to expedite treatment (NCT04304820). Methods: Twenty-six patients with treatment-naive SAA were enrolled since 2020. Patients were 3 years or older and median age was 35 years. Exclusion criteria included a diagnosis or high clinical suspicion for inherited disease or evidence of myeloid neoplasm. To ensure rapid initiation of therapy, enrollment was not dependent on pending specialized tests (telomere length, chromosomal breakage, cytogenetics, or genomics). Lower dose CSA (2mg/kg) and full dose EPAG were initiated after confirming eligibility. Upon completion of evaluation and confirmation of acquired SAA diagnosis, all subjects received standard IST (horse ATG, CSA, and EPAG; Figure 1A). Primary feasibility endpoint assessed a composite measure of misdiagnosis, non-compliance, and treatment-related serious adverse events (TRSAE) during oral therapy. Secondary endpoints were efficacy at 6 months, relapse, clonal evolution, and overall survival. Results were compared to a historical cohort of 139 patients treated with hATG, CSA, and EPAG initiated the same day (NCT01623167). Results: All patients completed the protocol-defined treatment period, with median time on oral therapy of 17 days (range 0 - 86 days). All subjects ultimately were confirmed to have acquired SAA (no misdiagnoses), all tolerated oral treatment well without any TRSAE, and patients were compliant with local and study-site follow-up. Thus, there were zero events for the primary feasibility endpoint. A single SAE during oral treatment occurred in subject #1, enrolled at the height of the COVID pandemic and was severely ill with persistently positive COVID-19 PCR and recurrent ileitis requiring hospitalization care; his time to standard IST was the longest (86 days). There was significant increase in absolute neutrophil count (ANC; median 0.315x10 3/mL vs 0.570, p=0.041) in a brief interval of oral therapy prior to receiving hATG. There was also a trend towards improvement in absolute reticulocyte count (29x10 3/mL vs. 35.8) and a decrease in absolute lymphocyte count (1.5x10 3/mL vs. 1.3; Figure 1B). Compared to historical cohort, less patients (19% vs 52%) had very SAA (ANC <200 K/uL); age, sex, race, and pre-treatment blood counts were similar in two cohorts. Hematologic response occurred in 68% at 6 months with 45% complete responses, rates similar to the historical cohort (80% and 40%, respectively). Time to platelet and red blood cell transfusion independence was 43 and 51 days, respectively. Only age (18-40 years) was predictive for 6 month response. With median follow-up of 396 days, the cumulative incidence of relapse at 2 years was 17%, lower than in the historical cohort (27%). Clonal evolution to secondary myeloid malignancy was not increased compared to historical cohort; one subject had myelodysplastic syndrome with excess blasts 1 with deletion 20q, and two had transient trisomy 8 without dysplasia. Overall survival was 96.2%; no deaths occurred during study treatment period of oral medications only. Conclusion: Early initiation of CSA and EPAG is a feasible and safe approach to rapidly treat patients with SAA as a bridge to standard therapies and it may lead to improved blood counts, in turn, decreasing early infectious complications. Hematologic response was comparable to our historic cohort. Rates of long-term complications need to be confirmed in a larger cohort with ongoing study enrollment.

Allogeneic Peripheral Blood Stem Cell Transplantation for Bone Marrow Failure Syndromes Using CD34+-Selected Progenitor Cells Co-Infused with a Reduced Number of Non-Mobilized T-Cells

Background Severe aplastic anemia (SAA) patients who fail immunosuppressive therapy (IST) may be candidates for curative allogeneic hematopoietic stem cell transplantation (HCT). Patients with SAA are often heavily transfused with underlying immune-mediated disease, which increases their risk for graft rejection when bone marrow (BM) is used as a graft source. Peripheral Blood Stem Cell (PBSC) grafts have been associated with better engraftment but at a cost of a higher incidence of graft-versus-host disease (GVHD). We developed a novel protocol combining high numbers of GCSF-mobilized CD34+ peripheral blood stem cells with a BM transplant-equivalent dose of T-cells (collected from donors before GCSF administration) to improve engraftment and decrease the risk of GVHD associated with a conventional, unmanipulated PBSC HCT. Methods In this phase II trial, eligible patients included those age 4-80 years with a diagnosis of SAA or other bone marrow failure (BMF) syndromes with ≥ 9/10 HLA-matched related (sibling/family) donors (MRD) or 10/10 matched unrelated donors (MUD). All patients received conditioning with cyclophosphamide (day -7 to -6), anti-thymocyte globulin (day -5 to -2), and fludarabine (day -5 to -1). For MUD patients, low dose total body irradiation (200 cGy) was added to the regimen on day -1. GVHD prophylaxis included cyclosporin (day -4 until at least day +30) and methotrexate (5 mg/m2 , day +1, +3 and +6). The primary outcome of the study was chronic GVHD at 1 year. Secondary outcomes included mortality, engraftment and chimerism, acute and chronic GVHD, immune reconstitution, and comparisons of MRD vs. MUD patients. Results Thirty-five patients (27 with MRD and 8 with MUD) were transplanted between February 2011 and December 2021. Patients had a median age of 30 (range 6-70) years, 46% were males and 54% were females, including 31 having SAA, 3 with SAA transformed to myelodysplastic syndrome (MDS), and one with MDS; 11 patients also had PNH clone pre-transplant. The median numbers of transplanted CD34+ and CD3+ T-cells were 8 ´ 106 cells/kg and 2 ´ 107 cells/kg, respectively. After HCT transplants, all patients had neutrophil recovery with a median 14 (10-32) days. Except for 2/35 (6%) patients having late graft failure, all other 33 (94%) patients achieved sustained engraftment. Platelet recovery was reached in 29 (83%) patients at a median 19 (13-321) days. A total of 97% of patients achieved >95% donor myeloid chimerism (median 14 days), and 94% of patients achieved >95% donor T-cell chimerism (median 30 days). Reactivation of CMV occurred in 21/29 (72%) patients at risk with none developing CMV disease. Full immune reconstitution occurred for most patients by 1-year post-transplant. With a median follow-up of 5 years, the estimated 200-day survival and overall survival were 89% and 85%, respectively. The cumulative incidence of acute grade II-IV GVHD was 23%, and 1-year chronic GVHD rate was 11%, which was significantly lower than our hypothesis that this regimen would lower the chronic GVHD rate to 50% (P < .001). The subgroups of patients with MRD and MUD were compared (Table 1): patients with MUD showed a slower time to achieve neutrophil recovery (P = .001) and platelet recovery (P = .03), and a slightly high graft failure incidence (2 cases), but most other outcomes were similar, compared to patients with MRD. Conclusion For patients with SAA and other BMF syndromes, transplanting high doses of mobilized CD34+ selected cells from MRD and MUD donors combined with a bone marrow transplant equivalent of non-mobilized donor T-cells (a partially T-cell depleted PBSC transplant) achieves rapid and durable donor engraftment and excellent survival. The cumulative incidence of both acute and chronic GVHD with this regimen was significantly lower than that historically reported with conventional PBSC transplants. Notably, low acute and chronic GVHD rates were also achieved in SAA patients with disease refractory to conventional IST who received a graft from a 10/10 HLA-matched MUD donor, although hematopoietic recovery was slightly delayed compared to recipients of a partially T-cell depleted graft from a MRD donor. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Alemtuzumab for Treatment-Naïve and Relapsed-Refractory Severe Acquired Aplastic Anemia

Introduction: Antithymocyte globulin (ATG) + cyclosporine is effective in restoring hematopoiesis in severe aplastic anemia (SAA). Horse ATG appears to be better than rabbit ATG. Limitations to ATG use in developing countries include cost, horse ATG availability and the reduced number of hospital beds in hematology treatment centers are frequent. Alemtuzumab, a humanized anti-CD52 mAb, might be active in SAA because of its lymphocytotoxic properties. Subcutaneous alemtuzumab have about ORR 66% and is available in Brazil through a compassionate use program. Methods: Fourteen consecutive transplant-ineligible SAA patients were treated. Alemtuzumab was administered subcutaneously in a single at escalating dose of 3-10-30-(30)-(30) mg. Premedication included intravenous steroid, antihistamine and oral acetaminophen. The total dose was 103 mg for 14 patients, and 43 mg for one elderly frail patient. Low dose (1 mg/kg) oral cyclosporine was started on day 7, and then adjusted according to plasma levels (targeting 100-200 ng/ml using a monoclonal assay) at the time of immune reconstitution. Anti-infectious prophylaxis included oral acyclovir and trimethoprim-sulphametoxazole, weekly monitoring of CMV viraemia, and oral quinolone and fluconazole in case of severe neutropenia (<0.5x 109/L). Results: Fifteen SAA patients were treated. Primary outcome was hematologic response at 3months. Median age was 48 years, and 9 (60%) were male. Eight patients were treatment-naive, and 7 (46%) were relapsed-refractory. Eight patients presented PNH clone at the initial investigation, with a size clone between 0.001 to 55 in granulocytes and 0.001 to 98 in monocytes. Median time between SAA diagnosis and alemtuzumab treatment was 9 months (range 1-300). No treatment-related serious adverse events due were observed. Infectious complications were rare. The overall response rate was 66% (60% with PR, 40% CR). The median follow-up is about 29 months (range 5-69). The 3-year overall survival was 73%. Conclusion: The combination of subcutaneous alemtuzumab + cyclosporine appears to be effective and sufficiently safe in transplant-ineligible SAA patients. Moreover, it is feasible in a scenario of limited resources and low accessibility to ATG. DisclosuresNo relevant conflicts of interest to declare.

Outcomes of Combination of HLA-Haploidentical Hematopoietic SCT with an Unrelated Cord Blood Unit for 127 Patients with Acquired Severe Aplastic Anemia

Haploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) is an alternative treatment method for severe aplastic anemia (SAA) patients lacking suitable identical donors and those who are refractory to immunosuppressive therapy (IST). Studies have evaluated the feasibility of upfront haploidentical HSCT in SAA patients. We previously conducted a single-arm prospective study in 50 patients who received the combination of HID-HSCT and an unrelated umbilical cord blood unit for the treatment of hematological malignancies. To the best of our knowledge, there is no combination of HID-HSCT and an unrelated umbilical cord blood unit for SAA. Now, we report the outcomes of combination of HID-HSCT with an unrelated cord blood unit for 127 patients with SAA in our center from September 2011 to April 2017. The clinical data of 127 SAA patients, including 74 male patients and 53 female patients, 65 very severe aplastic anemia (vSAA), the median age was 23.5 years (range 3.0-54.0). 39 patients of failure to IST as salvage therapy, 88 patients underwent upfront transplantation. The median interval from SAA diagnosis to SCT was 2.0 months (range 0.5-180.0). Cord blood units were selected based on the results of HLA typing and cell doses evaluated before freezing. Units with at least 4/6 matched HLA loci became the candidates, and HLA matching was prioritized over cell dose. At the same level of typing, the richest UCB units were chosen. The conditioning regimen was modified BU/CY-based regimen. Prophylaxis for graft-versus host disease (GVHD): cyclosporine (CsA), mycophenolate mofetil (MMF) plus short-term methotrexate (MTX). The median values of absolute nucleated cell counts were 10.87 (3.61-24.00)×108/kg in the haploidentical grafts and 2.22 (1.10-7.30)×107/kg in the cord blood units. The median doses of CD34+ cells infused were 3.49(1.02-8.89)×106/kg and 0.56 (0.16-2.27)×105/kg, respectively. One patient occurred primary graft failure. All surviving patients attained complete haploidentical engraftment. The median time for myeloid engraftment was 11 (range, 9-28) days and 15 (range, 9-330) days for platelets, with a cumulative platelet engraftment incidence of 96.1%. With a median follow-up of 20.5(4.0-60.0) months, the incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 24.8%, moderate-severe chronic GVHD was 14.4%, 4-year estimated overall survival (OS) was 78.5% ± 4.3%. In conclusion, combination of HID-HSCT and an unrelated umbilical cord blood unit is a feasible choice for SAA with favourable outcomes. DisclosuresNo relevant conflicts of interest to declare.

Full Dose Cyclophosphamide with the Addition of Fludarabine for Matched Sibling Transplants in Severe Aplastic Anemia

The recommended therapy for severe aplastic anemia (SAA) in younger patients with a matched sibling donor (MSD) is allogeneic hematopoietic cell transplantation (allo-HCT). A number of conditioning regimens and protocols have been used for these patients. Here we report a homogeneous cohort of SAA patients receiving a uniform transplantation protocol. This study is a retrospective analysis of 82 consecutive patients with SAA who underwent MSD allo-HCT at a single center. The median duration of follow-up for survivors was 100 months, the 10-year overall survival (OS) was 87.5%, and the 10-year event-free survival was 75.3%. The OS was 97.4% for "mobilized" bone marrow (BM) graft recipients and 78.9% for "nonmobilized" BM graft recipients (P=.01. The cumulative incidence of acute graft-versus-host disease (GVHD) was 25.6%, that of chronic GVHD was 27.16%, and that of graft failure was 16.2%. Recipient age ≥30 years and transplantation at >6 months after SAA diagnosis were associated with a increased risk of events. In the presence of a fully matched sibling donor, allo-HCT with a mobilized BM graft and fludarabine-cyclophosphamide conditioning is an efficacious and safe approach. Early transplantation is associated with a better outcome, emphasizing the importance of not delaying transplantation in these patients. Prospective trials are needed to determine the optimal regimen.

Transplant-associated thrombotic microangiopathy in pediatric patients: pre-HSCT risk stratification and prophylaxis

AbstractTransplant-associated thrombotic microangiopathy (TA-TMA) is an endothelial injury syndrome that complicates hematopoietic stem cell transplant (HSCT). Morbidity and mortality from TA-TMA remain high, making prevention critical. We describe our retrospective single-center experience of TA-TMA after pediatric allogeneic HSCT and present a novel pre-HSCT risk-stratification system and prophylaxis regimen. From January 2012 through October 2019, 257 patients underwent 292 allogeneic HSCTs. Prospective risk stratification was introduced in December 2016. High-risk (HR) patients were treated with combination prophylaxis with eicosapentaenoic acid and N-acetylcysteine. The 1-year cumulative incidence of TA-TMA was 6.3% (95% confidence interval [CI], 3.2-9.4). Age ≥10 years, myeloablative conditioning with total body irradiation, HLA mismatch, diagnosis of severe aplastic anemia or malignancy, prior calcineurin inhibitor exposure, and recipient cytomegalovirus seropositivity were found to be pre-HSCT risk factors for development of TA-TMA. Before routine prophylaxis, TA-TMA rates were significantly different between the HR and standard-risk groups, at 28.2% (95% CI, 0-12.7) vs 3.2% (0.1-6.3), respectively (P < .001). After introduction of prophylaxis, the 1-year cumulative incidence of TA-TMA in the HR group decreased to 4.5% (95% CI, 0-13.1; P = .062, compared with the incidence before prophylaxis). Multicenter pediatric studies are needed to validate these risk criteria and to confirm the efficacy of the prophylactic regimen.

Incidence, Management, and Prognosis of Graft Failure and Autologous Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation.

BackgroundThis study presents outcomes of management in graft failure (GF) after allogeneic hematopoietic stem cell transplantation (HCT) and provides prognostic information including rare cases of autologous reconstitution (AR).MethodsWe analyzed risk factors and outcomes of primary and secondary GF, and occurrence of AR in 1,630 HCT recipients transplanted over period of 18 years (January 2000–September 2017) at our center.ResultsPrimary and secondary GF occurred in 13 (0.80%), and 69 patients (10-year cumulative incidence, 4.5%) respectively. No peri-transplant variables predicted primary GF, whereas reduced intensity conditioning (RIC) regimen (relative risk [RR], 0.97–28.0, P < 0.001) and lower CD34+ cell dose (RR, 2.44–2.84, P = 0.002) were associated with higher risk of secondary GF in multivariate analysis. Primary GF demonstrated 100% mortality, in the secondary GF group, the 5-year Kaplan-Meier survival rate was 28.8%, relapse ensued in 18.8%, and AR was observed in 11.6% (n = 8). In survival analysis, diagnosis of aplastic anemia (AA), chronic myeloid leukemia and use of RIC had a positive impact. There were 8 patients who experienced AR, which was rarely reported after transplantation for acute leukemia. Patient shared common characteristics such as young age (median 25 years), use of RIC regimen, absence of profound neutropenia, and had advantageous survival rate of 100% during follow period without relapse.ConclusionPrimary GF exhibited high mortality rate. Secondary GF had 4.5% 10-year cumulative incidence, median onset of 3 months after HCT, and showed 5-year Kaplan-Meier survival of 28.8%. Diagnosis of severe AA and use of RIC was both associated with higher incidence and better survival rate in secondary GF group. AR occurred in 11.6% in secondary GF, exhibited excellent prognosis.

Pediatric Patients with Severe Aplastic Anemia Treated with Combined Immunosuppressive Therapy, Eltrombopag and Eculizumab and Their Clinical Course to Stem Cell Transplant

Acquired aplastic anemia (AA) in children is a rare disorder characterized by pancytopenia and hypocellular bone marrow. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoetic stem cell (HCT) disorder characterized by complemented-mediated hemolysis, thrombosis and bone marrow failure secondary to deficiency of glycosylphosphatidylinositol-anchored proteins (GPI-AP) on hematopoetic stem cells. PNH and acquired AA are closely related; up to 50% of patients with AA have detectable PNH-clones at the time of diagnosis and small percentage of them can have clonal expansion throughout their disease course requiring close monitoring. Current standard therapy for severe aplastic anemia (SAA) patients without matched related donor (MRD) is immunosuppressive therapy (IST) regimen with anti-thymoglobulin (ATG), cyclosporine (CSA), and recent addition of eltrombopag. Eculizumab is a recombinant humanized monoclonal antibody that blocks complement protein C5 and prevents cell lysis. While it has been shown to be effective in children with PNH, concomitant treatment with IST for patients with SAA is unknown. To our knowledge, there has been no pediatric data on combined IST, eltrombopag and eculizumab treatment for children with AA with clinically significant PNH clones. Here we retrospectively reviewed three pediatric patients with SAA with PNH clones treated with IST, eltrombopag and eculizumab and their unique clinical courses. Two out of three patients had high PNH clone size and were started on eculizumab prior to IST with improvement in transfusion intervals. Of the two, one had decrease in PNH clone size after IST but the other patient's clone size continued to increase despite two courses of IST. Finally, the third patient had a minor PNH clone and was not started on eculizumab prior to IST. He remained asymptomatic for over a year until he developed symptomatic PNH with large clone size and aplastic bone marrow. His clone size continued to increase with no improvement in transfusion frequency despite being started on eculizumab. However, steroids were started based on anecdotal literature and his transfusion frequency decreased subsequently. All three patients are in the process of going through matched unrelated donor stem cell transplants. Several studies have reported the presence of a minor PNH clone at the time of AA diagnosis was associated a favorable response to IST. In this case series, the patient with the smallest PNH clone size at the time of diagnosis of SAA had the best response to IST compared to the other two patients who had larger PNH clone populations. These findings suggest that even though minor PNH population may lead to better response to IST compared to absence of the clone, the correlation between clone size and prognosis is unclear. Further study with larger sample size is needed to investigate this relationship. However, regardless of the population size, all three patients were able to prolong transfusion intervals using eculizumab without significant side effects. As the adoption of eltrombopag with standard IST is evolving with ongoing study, the efficacy of incorporating eculizumab to decrease transfusion frequency in patients with PNH-clone in addition to eltrombopag/IST regimen should be further investigated. Disclosures No relevant conflicts of interest to declare.

SAT-335 New Onset Adult Idiopathic Primary Hypoparathyroidism Concomitant with Severe Aplastic Anemia

Introduction: Primary hypoparathyroidism is a relatively rare cause of hypocalcemia with cases of primary hypoparathyroidism in the US estimated at 24–37 per 100,000 with 75% being due to neck surgery and 25% due to non-surgical causes. The clinical presentation depends on the acuity of development of hypocalcemia and the absolute level of serum calcium. Here is a case of severe hypocalcemia secondary to hypoparathyroidism of unknown etiology followed by the development of severe aplastic anemia.Case report: A 60-year-old Caucasian male presented to our ED with fatigue, tingling, numbness in extremities and was found to have severe hypocalcemia at 6.8 mg/dl and decreased PTH at 11 pg/mL. Calcium levels 8 months prior to presentation were normal. No history of neck surgery, radiation exposure or family history of autoimmune disorders. Initial workup included creatinine, magnesium and TSH were normal. Autoimmune panel (including PTH Abs and CaSR Abs), HIV test, hepatitis panel, serum protein electrophoresis were also negative. Infiltrative causes of hypoparathyroidism including hemochromatosis, malignancy and granulomatous diseases like sarcoidosis were ruled out with tissue sampling and lab workup. Sestamibi scan obtained showed no parathyroid activity in all four glands. Patient was initially treated with IV calcium to improve serum calcium to more than 7.5mg/L and then switched to oral calcium carbonate 500mg TID and calcitriol 0.5mcg BID until the calcium level was brought up to the lower limit of normal. Patient was seen in follow up and was doing well without any adverse effects. Consequently, the patient developed severe aplastic anemia which was treated with steroids and interestingly, has caused a gradual but consistent increase in PTH levels.Discussion: Idiopathic hypoparathyroidism (IHP) is a rare condition with an incidence of 0.02%. IHP can occur sporadically or as part of a familial condition with autosomal dominant, recessive and X-linked recessive patterns. Certain autosomal forms of hypoparathyroidism have mutations in the PTH gene and Calcium-Sensing Receptor (CaSR) gene. The challenging nature of this case is due to the subacute nature of the patient’s presentation along with the lack of a definitive etiology. The patient’s negative family history and older age makes genetic causes less likely, and Abs against PTH and CaSr were also negative. The patient’s diagnosis of severe aplastic anemia has made the case more fascinating, especially since its management with steroids has causes an improvement in the patient’s PTH status. Regardless of etiology, primary hypoparathyroidism is treated with lifelong supplementation of calcium and calcitriol to a goal serum calcium level at the lower limit of normal. Reference: Abate EG,Clarke BL. Review of Hypoparathyroidism. Front Endocrinol (Lausanne). 2017; 7:172. Published 2017 Jan 16

Burden of illness among patients with severe aplastic anemia who have had insufficient response to immunosuppressive therapy: a multicenter retrospective chart review study.

This study assessed treatment patterns and healthcare resource utilization (HRU) of patients with severe aplastic anemia (SAA) with insufficient response to immunosuppressive therapy (IST). A retrospective chart review was conducted at Dana-Farber Cancer Institute (DFCI), United States, and Hôpital Saint-Louis (HSL), France. Eligible patients were ≥ 18 years old, diagnosed with acquired SAA between January 1, 2006, and July 31, 2016, had insufficient response to IST, and had ≥ 12 months of follow-up post-diagnosis. Overall survival (OS) was estimated using the Kaplan-Meier method. Among the 40 patients, mean age at diagnosis was 44 years and 53% were women. Median follow-up time after SAA diagnosis was 48.3 months. Ninety-five percent of patients received antithymocyte globulin (ATG) as primary therapy prior to hematopoietic stem cell transplant (HSCT). Most common secondary SAA therapies prior to HSCT were eltrombopag (28%) and androgens (15%). Seventy-five percent of patients received HSCT. Prior to HSCT, patients received an average of 2.7 red blood cell (RBC) and 3.3 platelet transfusions per month; patients had 0.9 hospitalizations, 0.4 emergency room visits, and 12.8 office visits per year. Five-year OS was 75%, with infection as the primary cause of death. Additionally, this study provides information on the subgroup of patients receiving eltrombopag which was the most common secondary therapy. This study quantified transfusion and HRU burden associated with SAA and demonstrated high 5-year survival in a recently treated cohort.

Low-Dose Total Body Irradiation (TBI) Use As Part of Pre-Transplant Conditioning Regimen Is Associated with Worse Outcomes in Patients with Severe Aplastic Anemia (SAA) Treated with Allogeneic Hematopoietic Stem Cell Transplantation (HCT)

<h3>Introduction</h3> Allogeneic HCT is a potentially curative strategy for SAA. In combination with fludaribine, anti-thymocyte globulin (ATG) or alemtuzumab, low-dose (2 Gy) total body irradiation (TBI) has been incorporated in the conditioning regimen for matched unrelated donors (MUD) for SAA, with the intention of reducing the cyclophosphamide dose and rate of graft failure. Progressive telomeric shortening in SAA can theoretically increase the risk of radiation injury in affected patients. Outcomes between TBI and non-TBI containing conditioning regimens in SAA have not been systematically compared. <h3>Methods</h3> After regulatory approval, clinical and outcomes data for patients with SAA treated with allogeneic HCT from 1998-2018 were collected, and compared between TBI and non-TBI groups. <h3>Results</h3> Fifty seven patients were included in the study, median age 25 (range: 1-63) years; 23 (40%) < 18 years, 44 (77%) < 40 years and 29 (51%) patients were male. Forty five (80%) patients received prior immunosuppressive therapy (IST); 19 (68%) horse ATG; 2 (7%) rabbit ATG. Median time from SAA diagnosis to transplant was <6 months in 18 (32%) patients, and >12 months in 28 (49%) patients. Graft source was bone marrow (BM) in 48 (84%) patients, followed by peripheral blood in 8 (14%), and cord blood in 1 patient. Twenty-nine (51%) patients were transplanted with matched sibling donors (MSD), followed by 20 (35%) MUD, and 13 (23%) others (cord/mismatch/haplo). TBI-containing regimens were used in 30 (53%) patients [MUD-20 (67%), mismatch-5 (17%)], while non-TBI regimens were used in 27 (47%) patients [MSD-24 (89%), mismatch-3 (11%)]. Although the rate of RBC (<i>P</i> = 0.02) and platelet transfusion dependence (<i>P</i> = 0.04) was higher in the TBI group, presence of clinically significant HLA alloantibodies prior to transplant (MFI>1000) was not different (<i>P</i> = 0.07). At a median follow-up of 77 (95% CI 63-95) months, there were 11 (19%) deaths [TBI-8 (27%), non-TBI-3 (11%), p=0.1]. Median overall survival (OS) was lower in the TBI group among MSD donors (163 mo v/s median NR, <i>P</i> = 0.01), and MSD+MUD donors (93 mo v/s NR, <i>P</i> = 0.0002, figure 1). The two groups did not significantly differ in terms of rates of graft failure (<i>P</i> = 0.7), acute (<i>P</i> =0.2), and chronic GVHD (<i>P</i> =0.6), and documented infections (<i>P</i> =0.5). Based on prior knowledge of adverse prognostic factors in SAA and limited events, a Cox proportional hazard model was designed with three variables; age at transplant, donor source and TBI-use. Only TBI use was independently associated with poor OS (HR 6, 95% CI 1-33, <i>P</i> = 0.05). <h3>Conclusion</h3> In our limited series, low-dose TBI use as part of pre-transplant conditioning regimen for SAA was associated with poor overall survival, despite no significant differences in rates of post-transplant graft failure, GVHD, and infections. Prospective validation of this finding in larger cohorts is needed.

Genome-Wide Association Study Identifies an Immune-Related Etiology for Severe Aplastic Anemia

Introduction. Acquired severe aplastic anemia (SAA) is a life-threatening disorder characterized by severe progressive pancytopenia and hypocellular bone marrow. The etiology of acquired SAA is not understood but believed to be related to abnormal immune responses to environmental exposures. We conducted a genome-wide association study (GWAS) to identify common germline variants associated with SAA. Methods. We identified 895 patients with SAA who underwent related or unrelated hematopoietic cell transplant (HCT) with clinical data and pre-HCT blood samples available in the Center for International Blood and Marrow Transplant Research (CIBMTR) database and biorepository. Pre-HCT DNA was extracted from blood of patients with SAA and genome-wide genotyping was conducted using the Illumina OmniExpress array. We excluded 93 inherited bone marrow failure cases. The SAA cases were grouped cases into discovery and validation sets based on time of batch sample receipt. Analyses were limited to patients of European ancestry based on principal component analyses to minimize the potential effect of population stratification. Controls were genomically matched and selected from previously scanned cancer-free subjects at the Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, NCI. The final analysis included 534 acquired SAA cases (359 in the discovery set and 175 in the validation set), and 2,455 controls (1,396 in the discovery set, and 1,059 in the validation set). Results. Patients with SAA in this study received HCT between 1989-2015 at a median age of 21 years, 56% were male, and the median time between SAA diagnosis and HCT was 11 months. Strong genome-wide association signals were identified across the human leukocyte antigen (HLA) genes encoded at the major histocompatibility complex (MHC) on chromosome 6p21 (Figure 1). The top SNP was located in the P4 binding pocket of the HLA class II gene HLA-DPB1(rs1042151A&gt;G, p.Met105Val, pooled-odds ratio [OR]=1.75, 95% confidence interval [CI]=1.50-2.03, p=1.94x10-13). The expression of HLA-DP in CD19+ cells from 175 healthy donors was significantly different by rs1042151 A&gt;G genotype (p=2.04x10-6) (Figure 2). A second SNP near HLA-B, rs28367832G&gt;A, also reached genome-wide significance (pooled-OR=1.49, 95% CI=1.22-1.78, p=7.27x10-9). Copy-number variant analysis and next generation sequencing also identified somatic, clonal copy-neutral loss-of-heterozygosity affecting class I HLA genes in 8.6% of the SAA cases and none of the controls. Conclusion. This SAA GWAS identified strong association signals between common germline genetic variants in HLA class I and II genes and SAA. The main SNP is associated with changes in HLA-DP expression suggesting a key role for this locus in SAA etiology. This study adds further evidence to the connection between SAA and immune dysregulation. Disclosures Cerhan: Janssen: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; Celgene: Research Funding. Lee:Incyte: Research Funding; Syndax: Research Funding; Amgen: Research Funding; Novartis: Research Funding; Takeda: Research Funding; Kadmon: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; AstraZeneca: Research Funding.

Outcome of combination of HLA-haploidentical hematopoietic SCT with an unrelated cord blood unit for 127 patients with acquired severe aplastic anemia

目的评价单倍型造血干细胞移植（haplo-HSCT）联合第三方脐血干细胞移植治疗重型再生障碍性贫血（SAA）的疗效及安全性。方法对2011年9月至2017年4月间接受haplo-HSCT联合第三方脐血干细胞移植的127例SAA患者进行回顾性研究。结果全部127例SAA患者中，男74例，女53例，中位年龄23.5（3~54）岁，其中极重型再生障碍性贫血65例。诊断至移植中位时间2（0.5~180）个月。单倍型造血干细胞来源为骨髓+外周血。脐血均选用单份，HLA配型≥4/6相合。127例患者均接受改良Bu/Cy+ATG/ALG预处理方案（白消安+环磷酰胺+抗胸腺细胞球蛋白/抗淋巴细胞球蛋白）。以环孢素A、霉酚酸酯联合短程甲氨蝶呤预防GVHD。回输单倍型供者单个核细胞10.87（3.61~24.00）×108/kg，CD34+细胞3.49（1.02~8.89）×106/kg；回输脐血单个核细胞2.22（1.10~7.30）×107/kg，CD34+细胞0.56（0.16~2.27）×105/kg。127例患者中5例发生早期死亡。在可评估的122例患者中，1例发生原发植入失败，其余121例患者成功植入（均为单倍型造血干细胞植入）。中性粒细胞、血小板植入时间分别为11（9~28）d、15（9~330）d，5例患者发生血小板植入不良。移植过程中74例（58.27%）发生感染。存活患者中位随访20.5（4.0~60.0）个月，Ⅱ~Ⅳ度急性GVHD发生率为24.79%（30/121），中/重度慢性GVHD发生率为14.15%（15/106），预期4年总生存率为（78.5±4.3）%，无失败生存率为（77.4±4.3）%。结论haplo-HSCT联合第三方脐血干细胞移植治疗SAA疗效确切且安全性较好，在无全相合供者情况下可作为有价值的治疗选择。

PSY90 - Health Resource Burden Among Patients with Severe Aplastic Anemia who Have Had Insufficient Response to Immunosuppressive Therapy: A Retrospective Chart Review Study

To examine healthcare resource utilization (HRU) among patients with severe aplastic anemia (SAA) with insufficient response to immunosuppressive therapy (IST) in real-world practice. A retrospective chart review was conducted at Dana-Farber Cancer Institute, US (DFCI) and Hôpital Saint-Louis, France (HSL). Eligible patients were ≥18 years old, diagnosed with acquired SAA between 1/1/2006-7/31/2016, had insufficient response to ≥1 course of IST, and had ≥12 months follow-up post diagnosis. SAA-related HRU was summarized with incidence rates. Among the 40 patients (NDFCI=20; NHSL=20), mean age at diagnosis was 44.1 years and 52.5% of patients were women. During follow-up, 25.0% of patients died; median follow-up time after SAA diagnosis was 48.3 months. 95.0% of patients received antithymocyte globulin (ATG) in combination with cyclosporine or tacrolimus as primary therapy prior to hematopoietic stem cell transplant (HSCT). The most common secondary SAA therapies prior to HSCT were eltrombopag (27.5%) and androgens (15.0%). 75% of patients received ≥1 HSCT with a median time of 15.7 months after first IST. Prior to HSCT, the mean frequency of transfusions per patient per month (PPPM) was 2.7 red blood cell (RBC) and 3.3 platelet transfusions. The mean SAA-related HRU rates per patient per year (PPPY) were 0.9 hospitalizations, 0.4 emergency room visits, and 12.8 office visits. Among patients treated with eltrombopag (N=11), the mean number of RBC transfusions PPPM was reduced from 2.2 to 1.3 and platelet transfusions from 2.9 to 2.1 after eltrombopag treatment. Similarly, SAA-related HRU rates appeared lower after eltrombopag initiation (∆hospitalizations: -0.5; ∆emergency room visits: -1.0; ∆office visits: -10.2 PPPY). This study is among the first to quantify the transfusion and healthcare resource burden of SAA. In a subgroup of patients receiving eltrombopag, there was a trend toward a reduction in transfusion frequency and HRU following eltrombopag initiation.

Bone marrow failure may be caused by chromosome anomalies exerting effects on RUNX1T1 gene

BackgroundThe majority of the cases of bone marrow failure syndromes/aplastic anaemias (BMFS/AA) are non-hereditary and considered idiopathic (80–85%). The peripheral blood picture is variable, with anaemia, neutropenia and/or thrombocytopenia, and the patients with idiopathic BMFS/AA may have a risk of transformation into a myelodysplastic syndrome (MDS) and/or an acute myeloid leukaemia (AML), as ascertained for all inherited BMFS. We already reported four patients with different forms of BMFS/AA with chromosome anomalies as primary etiologic event: the chromosome changes exerted an effect on specific genes, namely RUNX1, MPL, and FLI1, leading to the disease.ResultsWe report two further patients with non-hereditary BM failure, with diagnosis of severe aplastic anaemia and pancytopenia caused by two different constitutional structural anomalies involving chromosome 8, and possibly leading to the disorder due to effects on the RUNX1T1 gene, which was hypo-expressed and hyper-expressed, respectively, in the two patients. The chromosome change was unbalanced in one patient, and balanced in the other one.ConclusionsWe analyzed the sequence of events in the pathogenesis of the disease in the two patients, including a number of non-haematological signs present in the one with the unbalanced anomaly. We demonstrated that in these two patients the primary event causing BMFS/AA was the constitutional chromosome anomaly. If we take into account the cohort of 219 patients with a similar diagnosis in whom we made cytogenetic studies in the years 2003–2017, we conclude that cytogenetic investigations were instrumental to reach a diagnosis in 52 of them. We postulate that a chromosome change is the primary cause of BMFS/AA in a not negligible proportion of cases, as it was ascertained in 6 of these patients.

A Retrospective Chart Review to Assess Burden of Illness Among Patients with Severe Aplastic Anemia with Insufficient Response to Immunosuppressive Therapy

Background: Aplastic anemia (AA) is a rare disease, with an incidence of 1-2 new cases per million per year in Europe and North America. Primary therapies for AA for patients who do not have a sibling or matched unrelated donor or are unfit for allogeneic hematopoietic stem cell transplantation (HSCT) include immunosuppressive therapy (IST) with the combination of antithymocyte globulin (ATG) and calcineurin inhibitors. Therapeutic options beyond IST are limited and include eltrombopag, which was approved by the US FDA for use in patients with severe AA who fail to respond adequately to IST. The health economic burden of this rare and debilitating condition is poorly understood, especially for refractory cases.Objective: To examine health resource utilization associated with severe AA among patients with insufficient response to IST in real-world practice settings in a recent time period.Methods: We conducted a retrospective, longitudinal chart review of patients with severe AA treated at clinical centers in the US (Dana-Farber Cancer Institute [DFCI]) and France (Service d'Hématologie Greffe, Hôpital Saint-Louis [AGRAH]). Severe AA in this study was identified as having bone marrow cellularity <25%, or 25-50% with <30% residual hematopoietic cells; and at least two of the following laboratory findings: neutrophil count <500 cell/µL, platelets <20,000/µL, reticulocyte count <20,000/µL. Eligible patients were ≥18 years old, first diagnosed with severe AA between January 1, 2006 and January 31, 2016, had insufficient response to at least one course of IST following severe AA diagnosis, and had ≥12 months of medical data after first diagnosis with severe AA. Patients with congenital disorders of hematopoiesis were excluded. Kaplan-Meier method was used to analyze time from first IST to time of HSCT. Cumulative incidence and incidence rates were used to summarize frequency of blood transfusions and AA-related health care resource utilization. The study was approved by local IRB.Results: The study included 34 refractory severe AA patients (NDFCI=20; NAGRAH =14). Mean age at severe AA diagnosis was 43.3 (standard deviation [SD]: 16.8) years and 52.9% (18/34) of patients were women. Median follow-up time after severe AA diagnosis was 56.1 (range: 12.0-118.7) months. Thirty-three (97.1%) patients received ATG in combination with calcineurin inhibitor (cyclosporine or tacrolimus) with or without corticosteroid as primary therapy. Among patients treated with ATG, 51.5% (17/33) patients received only one course of ATG and 48.5% (16/33) patients received ≥2 courses of ATG. The most common secondary AA therapy included eltrombopag (17.6%, N=6) and androgens (8.8%, N=3). The median treatment duration for eltrombopag was 6.4 (range: 5.6-53.4) months. The average frequency of transfusions per patient per month was 2.8 (SD: 2.8) red blood cell (RBC) and 3.3 (SD: 3.5) platelet transfusions. The mean AA-related health care utilization rates per patient per year were 0.8 (95% confidence interval [CI]: 0.6, 1.0) for inpatient visits, 0.5 (95% CI: 0.4, 0.8) for emergency room visits, and 19.1 (95% CI: 17.9, 20.5) for office visits prior to undergoing HSCT. Among the subgroup of patients treated with eltrombopag, the mean number of RBC transfusions per patient per month was reduced from 2.4 (SD: 2.0) before to 0.9 (SD: 0.8) after eltrombopag treatment, and from 3.0 (SD: 2.3) to 1.3 (SD: 1.6) for platelet transfusions. Similarly, AA-related health care utilization rates were lower after eltrombopag initiation (∆inpatient visits: -0.3 (95% CI: -1.1, 0.5); ∆emergency room visits: -0.6 (95% CI: -1.5, 0.4); ∆office visits: -11.7 (95% CI: -16.2, -7.1) per patient per year). Thirty (88.2%) patients received HSCT with a median time of 12.9 (95% CI: 7.9, 17.3) months after first IST initiation. During the follow-up period, 29.4% (10/34) patients died; nine patients died after HSCT. Two (5.9%) patients transformed to myelodysplastic syndrome and/or acute myeloid leukemia.Conclusion: This is one of the first studies to quantify the transfusion and health resource burden of refractory severe AA. In a small subgroup of patients receiving eltrombopag, there was a trend toward reduction in blood transfusion frequency, AA-related hospitalization rate, and outpatient office and emergency room visits after eltrombopag initiation. DisclosuresPeffault De Latour:Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding; Amgen: Research Funding. Huynh:Novartis Pharmaceuticals Corporation: Research Funding. Ivanova:Novartis, GSK, Teva, Lilly: Research Funding. Totev:Novartis Pharmaceuticals Corporation, Shire Pharmaceuticals Inc.: Research Funding. Bilginsoy:Novartis Pharmaceuticals Corporation: Research Funding. Roy:Novartis: Employment, Equity Ownership. Duh:Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Research Funding; Novartis Pharmaceuticals Corporation: Research Funding.

Nationwide Survey on the Use of Eltrombopag in Patients with Severe Aplastic Anemia: Report on Behalf of the French Reference Center for Aplastic Anemia

▪ BACKGROUNDFew therapeutic options are currently available for patients (pts) with severe aplastic anemia (SAA) refractory to antithymocyte globulin (ATG) plus ciclosporine (CsA) and not eligible for allogeneic stem cell transplantation. It has recently been reported that eltrombopag (ELT), a TPO receptor agonist, is efficient to improve tri-lineage blood counts in this setting. However, real-life use of this drug is still largely unknown. In pts with SAA refractory to ATG, physicians can accede to ELT in France through a compassionate use program. We took advantage of this program to assess the efficacy and safety of ELT in SAA pts. PATIENTS AND METHODSThe French National Reference Center for Aplastic Anemia conducted this study in pts who received ELT for the treatment of SAA. Latest guidelines were used to define disease severity, treatment indication, and response rates (Marsh et al, BJH 2014). The diagnosis of SAA was confirmed by marrow biopsy and Camita criteria for all pts. Pts were eligible if they received at least 2 months of ELT alone or in combination with other treatment in case of relapsed/refractory disease or front-line therapy for pts not eligible to the association of ATG and CsA. Pts were identified through a national e-mailing on behalf of the French reference center for SAA and the French Society of Hematology. All data presented here were collected at the reference date of June 26th, 2016. The study was conducted according to Helsinki's Declaration. RESULTSForty-six pts (male, 54%) who received ELT between July 2012 and February 2016 were identified in 17 French centers. Indications for ELT were relapsed/refractory SAA in 35 pts (76%) after 1 (49%), 2 (29%) or 3 (9%) courses of CsA+ATG. Eleven pts considered unfit for ATG also received the drug as first line therapy. The characteristics of the pts according to ELT indications are shown in Table 1. Median age at time of ELT initiation was 61 years [IQR 40 to 70]. 44 pts had idiopathic SAA including 17 (37%) with a detectable PNH clone (median size 7%). Two pts (4%) with dyskeratosis congenita also received ELT. ELT was introduced 17 months [8-50] after the initial diagnosis of SAA and with a median of 6 months [3-14] after the last course of immunosuppressive therapy. The maximal dose was 150 mg/day [100-150] for a median duration time of 6 months [4-12]. At last follow-up 22(48%) pts were still on treatment, 4(9%) pts stopped because of good hematological response, 1(2%) and 15(33%) after limited toxicity and failure to improve hematological status. Before treatment, median neutrophils count was 790/mm3 [500-1215] and pts received a median number of 4 red blood cells packs [2-4] and 3 platelets apheresis units [2-4] every month. Neutrophils counts were 765 [515-1475], 1100 [600-1800], 1200 [670-1915] and 1200/mm3 [757-2300] at 1, 3, 6 months and at last follow-up respectively. The rates of transfusion independence for both red cells and platelets were 7%, 33%, 46% and 46% at 1, 3, 6 months and at last follow-up. In pts achieving transfusion independence, hemoglobin and platelets level improved of 3 gr/dL [1.4, 4.5] and 42 G/L [11, 100], respectively. The rate of transfusion independence was not different among first line and refractory pts (p=0,5). We did not observe any response in the 2 patients with dyskeratosis congenita. No factor associated with hematological response to ELT was identified.Liver toxicity (cytolysis) occurred in 11 pts (1 grade 3 that required withdrawal of the treatment and 10 grade 1 who responded to dose reduction). 2 pts had a grade 2 intestinal toxicity which improved after dose reduction. Other side effects where related to SAA (28% infections, 13% hemorrhages). Bone marrow karyotype analysis after ELT was done in twelve pts (26%) (median time 14 months [5-22] after ELT start). In 10 pts the karyotype was normal, in one, trisomy 8 was identified (already seen at SAA diagnosis), and karyotype was a failure in 1 pt. CONCLUSIONWe report here the first real-life multicenter study about the use of ELT in SAA. In a particular severe pts population with no other treatment possibility, we confirm a 40% rate of hematological improvement with transfusion independence. Some of the pts who were not eligible to ATG plus CsA (comorbidities) also received ELT first line with similar response rates. Elderly pts unfit for ATG may thus benefit from this treatment which at the best should be given through prospective clinical trials. [Display omitted] DisclosuresAdes:Celgene, Takeda, Novartis, Astex: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Terriou:Novartis: Consultancy; amgen: Consultancy. Peffault de Latour:Alexion: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding.

Efficacy and Safety of Unrelated Cord Blood Transplantation in Patients with Acquired Refractory Aplastic Anemia: A Phase II Study on Behalf of Eurocord and the Francophone Society of Bone Marrow Transplantation and Cellular Therapy

▪Background: While therapeutic outcomes in patients (pts) with acquired severe aplastic anemia (SAA) has greatly improved in recent years, results remain poor for pts who are refractory to first-line immunosuppressive therapy (IST) and lack a matched unrelated donor. We conducted a prospective multi-center phase II uncontrolled trial to assess the efficacy and safety of cord blood transplantation (CBT) in refractory SAA pts (NCT 01343953).Patients and methods: Pts with SAA refractory to IST with anti-thymocyte globuline (ATG) and ciclosporin (CsA) were eligible in case of no existing matched unrelated donor but available one or two unrelated CB units containing alone or both together more than 4 x 107/Kg frozen nucleated cells/Kg (no more than 2 out of 6 HLA mismatches allowed between each CB unit and the pts). Pts with isolated bone marrow cytogenetic abnormality (absence of morphologic evidence of myelodysplastic syndrome) were also eligible. The conditioning regimen consisted of fludarabine 30mg/m2 (D-6 to D-3), cyclophosphamide 30mg/kg (D-6 to D-3), ATG (thymoglobulin) 2.5mg/kg at D-3 and D-2 (5mg/Kg total dose) and total body irradiation (2 Gray) on D-2. All pts received one injection of anti-CD20 (150 mg/m2) to prevent EBV reactivation (D+5). CsA was given alone as prophylaxis for graft versus host disease (GVHD). The trial used the Fleming's Single Stage Phase II Design, with sample size computed to demonstrate an improved overall survival (OS) rate at one year from 20% up to 50%, with type I and type II error rates set at 0.05. A minimum sample of 25 pts was required, with a minimum number of 9 pts alive at one year needed to indicate treatment efficacy. Secondary endpoints included cumulative incidences (CumI) of engraftment, acute and chronic GVHD (aGVHD and cGVHD), infections, relapse and late cause of death.Results: 29 pts were included between June 2011 and October 2015. One pt was diagnosed with dyskeratosis congenita and a matched unrelated donor was identified for another pt between inclusion and anticipated date of CBT (exclusion criteria). One pt died before CBT due to a septic shock (D+4 after inclusion). Analyses were conducted in the remaining 26 pts. Median time between SAA diagnosis and CBT was 12 months (interquartile range (IQR) 8.7 to 17.8). All pts received at least one course of IST before CBT (2 courses, n=8). Twenty-three pts received 20 or more transfusions before CBT. BM karyotyping showed 2 pts respectively with monosomy 7 in 4 and 15 mitoses as well as one pt with trisomy 8 in 4 mitoses before CBT. Eight pts (31%) have a PNH clone (median 4.5% [IQR: 3.1-9.7]). Median age at time of CBT was 16 years (IQR 8.25 to 23) and median follow-up is 13.2 months (IQR 4.1 - 23.5). Three out of 26 pts incorrectly received twice the dose of ATG (10mg/Kg total dose) due to protocol violation. Sixteen pts received one CB and 10 received two CB units. Median number of nucleated cells infused was 3.7 x 107/Kg (IQR, 3-4.9) and CD34+ cells infused was 1.4 x 105/Kg (IQR, 1.0-1.9). Myeloid engraftment occurred in 23 pts, with a 60 day-CumI of neutrophil engraftment of 88.5% with full chimerism for all of them. Three pts did not engraft (2 deaths at D71 and D92 and one successful second HSCT). The 100 day-CumI of grade II-IV acute GVHD was 40% (95% CI, 20-60) (8 grade II; 0 grade III; 2 grade IV). Among the 23 pts alive at day 100, five developed cGVHD leading to a one-year CumI of cGVHD at 27% (95% CI, 7-47) (severe cGvHD in 2 pts). During follow-up, 8 pts experienced a total of 18 grade III infections with a 6-month CumI of 32% (95% CI, 13-51). None of the pts presented post-transplant EBV-related lymphoproliferative disorder. Immune reconstitution is shown in Figure 1. Three pts died before 1 year due to non-engraftment (n=2) and infection (n=1, one of those who received twice the dose of ATG). With 23 pts alive at 1 year, the primary objective of the study was thus reached. The one-year treatment related mortality (TRM) was 15% (95%CI, 4-35). One additional pt who had also received twice the dose of ATG died (severe cGvHD) after one year (at 13.6 months), resulting in a 14-month OS of 81% (95%CI, 66-100) (Figure 2).Conclusion: CBT with at least 4 x 107/Kg frozen nucleated cells/Kg after a FLU-CY-TBI-ATG conditioning regimen gave rise to very encouraging results in this particular high risk SAA refractory population. Pediatric and young adult SAA pts who are refractory to first-line IST should now be considered either way for matched unrelated donor or CBT. [Display omitted] [Display omitted] DisclosuresPeffault de Latour:Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Alexion: Consultancy, Honoraria, Research Funding; Amgen: Research Funding.

Successful Resolution of Preretinal Haemorrhage with Intravitreal Ranibizumab

We would like to report two cases of preretinal haemorrhage from two different aetiology courses of bleeding being treated with intravitreal ranibizumab and its outcome. Our first case was a 39-year-old man with a diagnosis of severe aplastic anaemia that presented with bilateral premacular haemorrhages in both eyes. His right eye vision was 6/45 and it was counting finger in the left eye. He was treated with intravitreal ranibizumab once to the right eye and twice to the left eye. Right eye showed complete resolution of premacular haemorrhage and minimal residual premacular haemorrhage in the left eye at 3 months after initial presentation. Our second case was a 32-year-old healthy teacher that presented with preretinal haemorrhage at superotemporal region extending to macular area in left eye secondary to valsalva retinopathy. Her left vision was counting finger. She was treated with single intravitreal ranibizumab to the left eye. There was significant reduction of premacular haemorrhage and her left eye vision improved to 6/6 at 10 weeks after injection. Both cases had favourable outcome with intravitreal ranibizumab and can be considered as nonsurgical treatment option in treating premacular haemorrhage.

Molecular Classification of Bone Marrow Failure Syndromes: Protein Signatures As Surrogate Biomarker for Accurate Diagnosis of Severe Aplastic Anemia, Hypoplastic Myelodysplastic Syndrome and Paroxysmal Nocturnal Hemoglobinuria Patients

Background/Purpose: Bone marrow failure syndrome is an example of disease entity where accurate diagnosis of Severe Aplastic Anemia (SAA), Paroxysmal Nocturnal Hemoglobinuria (PNH) and Hypoplastic Myelodysplastic Syndrome (MDS) is very challenging. The aim of this study was to identify panels of disease-specific /disease-associated proteins biomarkers to be used for more objective diagnosis and better prediction of disease prognosis of patients presenting with features of bone marrow failure syndromes.Methodology:Bone marrow plasma (MBP) and peripheral blood plasma (PBP) samples from 20 patients with bone marrow hypoplasia; including AA/MDS/PNH were subjected to expression proteome analysis using label-free quantitative liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).Results: Approximately 300 unique protein species were identified of which 107 and 218 were significantly differentially expressed (> 2- ∞- fold change &p < 0.05) in BMP and PBP respectively. These protein fingerprints independently discriminates patients into three distinct clusters; AA/MDS/PNH. Furthermore, only approx. 25% of the proteins were common between the two datasets from BMP and PBP. Some of the identified proteins were filtered and mapped using Ingenuity Pathway Analysis, and were associated with five different networks. The top two of these networks involved cell-to-cell signaling interaction, hematological system development and function, and immune cell trafficking. Only three of the differentially expressed proteins were uniquely expressed in SAA and MDS but absent in PNH, thus making these proteins potential biomarkers.The probable diagnostic utility of these proteins would be validated in large archival clinical samples. Our data indicates the utility of multivariate analysis of quantitative proteome data as a means of discovery of disease related or disease specific biomarkers for bone marrow syndromes.Conclusions:We have identified protein signatures capable of objective classification of bone marrow failure syndromes patients. Our expression proteomics strategy is very promising for identification of clinically useful biomarkers. These proteins once validated, on a larger cohort of patients, might be valuable to complement the currently existing parameters for reliable and objective disease diagnosis, monitoring treatment response and clinical outcome of bone marrow failure syndrome patients. DisclosuresOwaidah:King abdulaziz city for science, Novo Nordisk, Bayer: Honoraria, Research Funding.