Course Of Antithymocyte Globulin Research Articles

Horse antithymocyte globulin test doses and infusion reactions in adults with aplastic anemia: A multicenter retrospective experience

Introduction Horse antithymocyte globulin carries a black box warning for life-threatening anaphylactic reactions, and prescribing information recommends test doses to identify patients at highest risk of this adverse effect. The predictive value of such test doses is not well validated, and practicality of use is unclear. Methods This was a planned secondary analysis of a multicenter, retrospective cohort study in adults with severe aplastic anemia being managed with horse antithymocyte globulin as part of their treatment regimen. Qualitative and quantitative descriptions of test doses and infusion reactions are summarized, alongside key institutional administration practices. Results Of 49 patients who received intradermal test doses, two experienced positive reactions and went onto receive their full horse antithymocyte globulin course through prolonged infusion time or desensitization. Infusion reaction rate in patients with negative test doses was 61%, corresponding to a negative predictive value of 39%. Premedication, infusion time, and infusion reaction management were similar across institutions. Conclusion Horse antithymocyte globulin has a high risk of infusion reactions that must be monitored and managed closely. However, test doses do not consistently predict who will experience an infusion reaction, and their practicality may be limited with current administration practices.

Comparison of hematopoietic stem cell transplantation and repeated intensified immunosuppressive therapy as second-line treatment for relapsed/refractory severe aplastic anemia.

The optimal treatment for patients with severe aplastic anemia (SAA) who fail an initial course of antithymocyte globulin (ATG) plus cyclosporine has not yet been established. We compared the effectiveness of allogeneic hematopoietic stem cell transplantation (allo-HSCT) (n = 36) with repeated immunosuppressive therapy (IST) (n = 33) for relapsed/refractory SAA between 2007 and 2022. In the IST group, patients were retreated with ATG (n = 16) or high-dose cyclophosphamide (n = 17). The overall response rate was 57.6% at 6 months and 60.6% at 12 months. In the allo-HSCT group, patients received a transplant from a matched sibling donor (n = 6), matched unrelated donor (n = 7), or haploidentical donor (n = 23). All patients achieved neutrophil engraftment, and there were no cases of primary graft failure. The cumulative incidences (CIs) of grades II-IV and III-IV acute graft-versus-host disease (GVHD) were 36.1% ± 0.7% and 13.9% ± 0.3% at day +100, respectively. The 4-year CI of chronic GVHD (cGVHD) was 36.2% ± 0.7%, with moderate to severe cGVHD at 14.9% ± 0.4%. Compared with IST, HSCT recipients showed much higher hematologic recovery rate at 3, 6, and 12 months (63.9%, 83.3%, and 86.1%, respectively, p < 0.001). The estimated 4-year overall survival (OS) (79.8% ± 6.8% vs. 80.0% ± 7.3%, p = 0.957) was similar; however, the failure-free survival (FFS) was significantly better in the HSCT group (79.8% ± 6.8% vs. 56.6% ± 8.8%, p = 0.049). Of note, children in the HSCT cohort were all alive without treatment failures, exhibiting superior OS (100% vs. 50.0% ± 17.7%, p = 0.004) and FFS (100% vs. 50.0% ± 17.7%, p = 0.004) than children in the IST cohort. Subgroup analysis revealed that younger patients (age ≤ 35 years), especially children, and those with refractory SAA benefited more from HSCT. Therefore, for these patients, salvage HSCT may be more preferable than a second course of IST.

Mass cytometric analysis unveils a disease-specific immune cell network in the bone marrow in acquired aplastic anemia.

Idiopathic acquired aplastic anemia (AA) is considered an immune-mediated syndrome of bone marrow failure since approximately 70% of patients respond to immunosuppressive therapy (IST) consisting of a course of anti-thymocyte globulin (ATG) followed by long-term use of ciclosporin. However, the immune response that underlies the pathogenesis of AA remains poorly understood. In this study, we applied high-dimensional mass cytometry on bone marrow aspirates of AA patients pre-ATG, AA patients post-ATG and healthy donors to decipher which immune cells may be implicated in the pathogenesis of AA. We show that the bone marrow of AA patients features an immune cell composition distinct from healthy donors, with significant differences in the myeloid, B-cell, CD4+ and CD8+ T-cells lineages. Specifically, we discovered that AA pre-ATG is characterized by a disease-specific immune cell network with high frequencies of CD16+ myeloid cells, CCR6++ B-cells, Th17-like CCR6+ memory CD4+ T-cells, CD45RA+CCR7+CD38+ CD8+ T-cells and KLRG1+ terminally differentiated effector memory (EMRA) CD8+ T-cells, compatible with a state of chronic inflammation. Successful treatment with IST strongly reduced the levels of CD16+ myeloid cells and showed a trend toward normalization of the frequencies of CCR6++ B-cells, CCR6+ memory CD4+ T-cells and KLRG1+EMRA CD8+ T-cells. Altogether, our study provides a unique overview of the immune landscape in bone marrow in AA at a single-cell level and proposes CCR6 as a potential new therapeutic target in AA.

A Plant Pathogen in a Human Host! A Case Report and a Review of Literature

In this case report, we present a renal transplant recipient who developed an infection due to a plant pathogen – Pantoea agglomerans. This pathogen is a rare organism with no case reports in a renal transplant recipient from India so far. A 50-year-old renal transplant recipient presented with fever for 20 days associated with productive cough and upper back pain. She had received her graft kidney 8 months earlier in a deceased donor program in her local state. In the immediate postoperative period, she had one episode of a mixed rejection, which required a course of antithymocyte globulin and plasmapheresis. On examination, tenderness was noted in her upper back over the cervical and thoracic vertebrae. Her computed tomography scan showed a collection over the cervical vertebrae and consolidation in the lung. Blood culture grew P. agglomerans. P. agglomerans is a rare plant pathogen usually occurring after trauma involving organic debris being deposited within the body. Spontaneously occurring infection is seen only in special situations such as immunocompromised states, malignancy, or excessive antacid use. It has been known to cause lung infections, bone and joint infections, and fever with systemic signs. Spontaneously occurring infections like in this patient are very rare with a handful of case reports worldwide. In an immunocompromised host, a multitude of infections can occur. This case report highlights the importance of removing unnecessary medication from our transplant recipients and optimizing immunosuppression while pursuing the underlying microbiologic cause of infection aggressively.

S3207 Vanishing Tacrolimus Syndrome

Introduction: Cellular rejection is common and therapeutic IS levels are needed to minimize this risk. This case stresses the need to fully explore, and potentially reexplore common causes of subtherapeutic IS levels. Case Description/Methods: A 38-year-old man with history of alcohol related cirrhosis and liver transplant in 2019. followed by 2 episodes of acute rejection, presented with significantly abnormal liver tests. Tacrolimus levels were undetectable and liver biopsy showed moderate rejection. After a course of IV steroid, he was started on prednisone, sirolimus, and increased doses of tacrolimus. Tacrolimus levels remained undetectable despite escalating doses, and addition of fluconazole– used for cytochrome (CYP) inhibition. Liver tests worsened after initial improvements, and repeat biopsy showed changes of chronic rejection. He was treated with a 5-day course of anti-thymocyte globulin, steroids, and maintained on increased immunosuppression (IS). Drug levels for tacrolimus, sirolimus, and mycophenolate were undetectable. He reported medication adherence, and undetectable tacrolimus levels were thought to be due to CYP metabolism. With this concern, he was started on azathioprine and belatacept infusions for IS. He was readmitted with abdominal pain and chronic 10-15 stools daily. Physical exam was notable for abdominal pain, no jaundice or asterixis. Labs showed WBC 5.7, INR 1.03, total bilirubin 11.9, AST 784, ALT 714, Alkaline phosphatase 538, albumin 3.5, negative serology for EBV, CMV, and HSV, and tacrolimus level < 1.0. Lab testing for diarrhea was negative for viral and bacterial causes. With concern for malabsorption, IV tacrolimus was started. EGD and colonoscopy with biopsies were negative for malabsorptive pathology. He was started on pancreatic enzymes for concerns of pancreatic insufficiency, and fecal elastase obtained after was elevated. After 24 hours of IV tacrolimus, serum level was 22.7, and continued to rise even after reduction of dosing suggesting malabsorption as cause of subtherapeutic IS. Discussion: Therapeutic IS levels are vital for transplant success, with an understanding that this needs effective absorption and metabolism. Our patient failed to have therapeutic levels since shortly after his transplant– despite previous negative lab and endoscopic evaluations for malabsorption. We used tactics focused on abnormal metabolism, however, resultant drug levels after IV tacrolimus shows the importance of considering malabsorption as barriers to achieving therapeutic IS.

Romiplostim in patients with refractory aplastic anaemia previously treated with immunosuppressive therapy: a dose-finding and long-term treatment phase 2 trial

Aplastic anaemia is a rare, life-threatening condition, characterised by pancytopenia with hypocellular bone marrow. Haematopoietic stem cells and most progenitor cells express thrombopoietin receptor (c-MPL). Romiplostim is a peptibody with c-MPL agonist activity that stimulates endogenous thrombopoietin production and leads to promoting the proliferation and differentiation of megakaryocytes in the bone marrow. In this phase 2 trial we aimed to assess the activity and safety of romiplostim in patients with aplastic anaemia who were previously treated with immunosuppressive therapy. We did an open-label, phase 2 study including a randomised, parallel, dose-finding part followed by an extension part to evaluate long-term treatment at two clinical centres in Seoul, South Korea. Eligible patients were aged 19 years or older, and had aplastic anaemia confirmed by bone marrow and cytogenetic studies and thrombocytopenia (platelet count ≤30 × 109/L), an Eastern Cooperative Oncology Group performance status score of 2 or lower, and were previously treated with immunosuppressive therapy, including at least one course of antithymocyte globulin plus cyclosporin. In the dose-finding part, patients were randomly assigned to fixed dose cohorts (1, 3, 6, or 10 μg/kg) of subcutaneous romiplostim once weekly for 8 weeks, according to a static allocation procedure after stratification by platelet count. In the extension part of the study, patients continued romiplostim titrated every 4 weeks in single steps (1, 3, 6, 10, 13, 16, and 20 μg/kg once weekly), depending on platelet response and safety up to 1 year (weeks 9-52). Patients who had a platelet response during weeks 46-53 continued dose titration in single steps (3, 6, 10, 13, 16, and 20 μg/kg once weekly) for an additional 2 years (weeks 53-156). The primary endpoint was the proportion of patients achieving a platelet response at week 9 (after completion of the dose-finding part). Activity was assessed per-protocol in all patients evaluable for response at week 9 and safety was assessed in all patients who received at least one dose of romiplostim. This trial is registered with ClinicalTrials.gov, NCT02094417. Between April 14 and Nov 24, 2014, 35 patients were enrolled and randomly assigned to one of four dose cohorts: romiplostim 1 μg/kg (n=7), 3 μg/kg (n=9), 6 μg/kg (n=9), and 10 μg/kg (n=10). Data cutoff for this final analysis was on April 14, 2018. The median duration of treatment for all patients was 53 weeks (IQR 35-155). Ten (30%) of 33 evaluable patients achieved a platelet response at week 9, including seven (70%) of ten patients in the 10 μg/kg cohort, three (33%) of nine patients in the 6 μg/kg cohort, and no patients in both the 3 μg/kg and 1 μg/kg cohorts. During the extension study, 18 (55%) of 33 evaluable patients had a platelet response during weeks 46-53 and were eligible for continued treatment. Ten (30%) patients maintained a platelet response at 2 and 3 years, of whom nine had an erythroid response and five a neutrophil response, and completed protocol treatment. Treatment-related adverse events occurred in three (9%) of 35 patients, including grade 1 or 2 myalgia, fatigue, and dizziness. 17 (49%) of 35 patients had adverse events of grade 3 or higher; seven (20%) had serious adverse events (one event of febrile neutropenia, cataract, retinal detachment, macular fibrosis, inguinal hernia, appendicitis, cellulitis, tendon injury, and transfusion reaction); and one patient died from sepsis during treatment; none of these events were related to treatment. No patients developed clonal evolution. Romiplostim seems to be active and has a favourable safety profile in patients with refractory aplastic anaemia. 10 μg/kg once weekly might be used as a recommended starting dose in future studies. These findings warrant further investigation. Kyowa Hakko Kirin Korea.

Alternative donor transplants for severe aplastic anemia.

Allogeneic hematopoietic stem-cell transplantation remains the only curative treatment for patients with acquired severe aplastic anemia (SAA). When a matched sibling is not available, one can search for a matched unrelated donor or a cord blood unit (CB) in the international registries or, more recently, for an HLA haploidentical (HAPLO) family member. International guidelines call for a course of antithymocyte globulin (ATG) and cyclosporine before a patient with SAA receives a transplant from a donor other than an HLA identical sibling, but whether this is necessary for patients age <20 years is less clear. Here I will examine the rapid increase in HAPLO transplantations for SAA, showing encouraging early results both in children and young adults. Graft-versus-host disease prophylaxis remains of primary importance in patients with SAA, and in vivo T-cell depletion with either ATG or alemtuzumab offers a significant survival advantage. Finally, I will discuss the strong age effect, which is particularly evident at >40 and 50 years of age for reasons not entirely clear and which should be taken into account when designing a treatment strategy for a given patient.

The Effectiveness of Eltrombopag at the Different Stages of Aplastic Anemia and Probability of Clonal Expansion

Background. New insight into pathogenesis of aplastic anemia (AA) in conjunction with effectiveness of Eltrombopag allowes to recommend it for initial treatment of de novo AA. However, eltrombopag was an attractive option for patients at different stages of the therapy.Aim. In our study we present various application points of eltrombopag as a therapeutic option in patients (pts) at different stages of the disease.Materials and patients. We are presenting our single-center experience, that include 11 pts with acquired aplastic anemia (SAA/NSAA = 10/1) on different stages of the disease. All pts were divided into four groups. In the 1st group we included refractory pts after two (n=3) or three (n=2) lines of antithymocyte globulin (ATG) therapy. The 2nd group included two pts who received the second ATG course in combination with eltrombopag, after faild first ATG. In the 3rd group included 2 pts with refractoriness after 1 course of ATG, who couldn't receive the second ATG/CsA because of severe infections. The 4th group included two pts with one lineage thrombocytopenia but transfusion independent. The median time from the start of immunosuppressive therapy (IST) to beginning of eltrombopag was Me(min-max): 56(12-115), 51(8-94), 1(1-1), 69(37-100) months respectively. The daily dose of eltrombopag for pts was 100-150 mg.Results. Hematological response are present in 3 out of 5 pts in the 1st group. Median duration of eltrombopag treatment was 8,5 (3-12) months. It is necessary to note that responding pts were refractory to 2nd (n=1) or 3rd (n=2) ATG and transfusion dependence. All pts in the 2nd group achieve PR (Me duration eltrombopag treatment was 12 months). All pts from 3rd group achieved granulocytic response, that allowed to recover get out from infections and to hold the 2nd ATG. However in 1 pt monosomy 7 was detected by FISH in bone marrow after therapy. It was noted that before eltrombopag administration there were not cytogenetic aberrancies but there were myelodysplastic features by flow cytometry (low index of granularity in granulocytes, low HLA-DR expression of monocytes and high CD56 expression in both granulocytes and monocytes) and PNH-clone. After eltrombopag treatment and monosomy 7 detection we performed a FACS sorting and FISH-study for PNH+ and PNH- granulocytes. Monosomy 7 was found in PNH- but not in PNH+ granulocytes. From the 4th group thrombocytopenia resolved in 1 pt (11 months eltrombopag duration), in over case present threelineage relapse subsequently.Conclusion. Eltrombopag can be used in pts with long-term ineffective IST and as a bridge to the next step of IST. It is necessary to remain cautious about the earlier development of clonal complications, even in patients from the so-called favorable risk group with the PNH clone. DisclosuresNo relevant conflicts of interest to declare.

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.

Eltrombopag for the treatment of aplastic anemia: current perspectives.

Aplastic anemia (AA) is a potential life-threatening hematopoietic stem cell (HSC) disorder resulting in cytopenia. The mainstays of treatment for AA are definitive therapy to restore HSCs and supportive measures to ameliorate cytopenia-related complications. The standard definitive therapy is HSC transplantation for young and medically fit patients with suitable donors and immunosuppressive therapy (IST) with antithymocyte globulin and cyclosporine for the remaining patients. A significant proportion of patients are refractory to IST or relapse after IST. Various strategies have been explored in these patients, including second course of antithymocyte globulin, high-dose cyclophosphamide, and alemtuzumab. Eltrombopag, a thrombopoietin mimetic, has recently emerged as an encouraging and promising agent for patients with refractory AA. It has demonstrated efficacy in restoring trilineage hematopoiesis, and this positive effect continues after discontinuation of the drug. There are ongoing clinical trials exploring the role of eltrombopag as a first-line therapy in moderate to severe AA and a combination of eltrombopag with IST in severe AA.

Antithymocyte globulin therapy for patients with recent-onset type 1 diabetes: 2year results of a randomised trial.

Aims/hypothesisType 1 diabetes results from T cell mediated destruction of beta cells. We conducted a trial of antithymocyte globulin (ATG) in new-onset type 1 diabetes (the Study of Thymoglobulin to ARrest T1D [START] trial). Our goal was to evaluate the longer-term safety and efficacy of ATG in preserving islet function at 2 years.MethodsA multicentre, randomised, double-blind, placebo-controlled trial of 6.5 mg/kg ATG (Thymoglobulin) vs placebo in patients with new-onset type 1 diabetes was conducted at seven university medical centres and one Children’s Hospital in the USA. The site-stratified randomisation scheme was computer generated at the data coordinating centre using permuted-blocks of size 3 or 6. Eligible participants were between the ages of 12 and 35, and enrolled within 100 days from diagnosis. Subjects were randomised to 6.5 mg/kg ATG (thymoglobulin) vs placebo in a 2:1 ratio. Participants were blinded, and the study design included two sequential patient-care teams: an unblinded study-drug administration team (for the first 8 weeks), and a blinded diabetes management team (for the remainder of the study). Endpoints assessed at 24 months included meal-stimulated C-peptide AUC, safety and immunological responses.ResultsFifty-eight patients were enrolled; at 2 years, 35 assigned to ATG and 16 to placebo completed the study. The pre-specified endpoints were not met. In post hoc analyses, older patients (age 22–35 years) in the ATG group had significantly greater C-peptide AUCs at 24 months than placebo patients. Using complete preservation of baseline C-peptide at 24 months as threshold, nine of 35 ATG-treated participants (vs 2/16 placebo participants) were classified as responders; nine of 11 responders (67%) were older. All participants reported at least one adverse event (AE), with 1,148 events in the 38 ATG participants vs 415 in the 20 placebo participants; a comparable number of infections were noted in the ATG and placebo groups, with no opportunistic infections nor difficulty clearing infections in either group. Circulating T cell subsets depleted by ATG partially reconstituted, but regulatory, naive and central memory subsets remained significantly depleted at 24 months. Beta cell autoantibodies did not change over the 24 months in the ATG-treated or placebo participants. At 12 months, ATG-treated participants had similar humoral immune responses to tetanus and HepA vaccines as placebo-treated participants, and no increased infections.Conclusions/interpretationA brief course of ATG substantially depleted T cell subsets, including regulatory cells, but did not preserve islet function 24 months later in the majority of patients with new-onset type 1 diabetes. ATG preserved C-peptide secretion in older participants, which may warrant further study.Trial registration:ClinicalTrials.gov NCT00515099Public data repository:START datasets are available in TrialShare www.itntrialshare.org Funding:National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH). The trial was conducted by the Immune Tolerance Network (ITN).Electronic supplementary materialThe online version of this article (doi:10.1007/s00125-016-3917-4) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

Guidelines for the diagnosis and management of adult aplastic anaemia.

Sally B. Killick (Writing Group Chair), Nick Bown, Jamie Cavenagh, Inderjeet Dokal, Theodora Foukaneli, Peter Hillmen, Robin Ireland, Austin Kulasekararaj, Ghulam Mufti, John A Snowden, Sujith Samarasinghe, Anna Wood (BCSH Task Force Member), Judith C.W. Marsh on behalf of the British Society for Standards in Haematology. The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust, Bournemouth, Northern Genetics Service, Newcastle upon Tyne, St Bartholomew’s Hospital, Barts Health NHS Trust, London, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Barts Health NHS Trust, London, Addenbrooks Hospital, University of Cambridge, Cambridge, Leeds Teaching Hospitals, Leeds, Kings College Hospital NHS Foundation Trust, London, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Great Ormond Street Hospital for Children NHS Foundation Trust, London, West Hertfordshire NHS Trust, Watford.

Immune Intervention for Type 1 Diabetes, 2012–2013

Immune Intervention for Type 1 Diabetes, 2012–2013

Management of the refractory aplastic anemia patient: what are the options?

Refractory aplastic anemia (AA) is defined as a lack of response to first-line immunosuppressive therapy (IST) with antithymocyte globulin and cyclosporin and is manifested as persistence of severe cytopenias at 6 months after IST. Although supportive care is critical for AA patients, it is of paramount importance for refractory disease in view of the longer duration of pancytopenia and susceptibility to life-threatening infections due to IST. Improvements in supportive care have largely contributed to better outcome over the past 2 decades, with 5-year overall survival reaching 57% during 2002 to 2008 for patients with AA unresponsive to initial IST. Exclusion of hypocellular myelodysplastic syndrome and constitutional BM failure masquerading as apparent idiopathic AA should be done in conjunction with centers of excellence. Hematopoietic stem cell transplantation is indicated if refractory AA patients are fit and have a suitably matched donor, either a sibling (>40-50 years) or unrelated donor. Patients lacking a fully matched donor should be considered for a second course of antithymocyte globulin plus cyclosporin, although response in the refractory setting is only ∼30% to 35%. Response may also occur with alemtuzumab or the thrombopoietin mimetic eltrombopag in refractory AA. The emerging data for alternate donor (cord or haploidentical) transplantation in AA has provided additional therapeutic choices to consider in refractory disease.

Genetic Characterization Of Aplastic Anemia Patients By Targeted Sequencing

IntroductionAplastic anemia (AA) is a rare but life-threatening bone marrow failure syndrome, which is diagnosed based on cytopenias in peripheral blood and hypocellularity in the bone marrow. The distinction between AA and hypocellular myelodysplastic syndrome (MDS) is often difficult, and AA evolves into MDS at a 10-year cumulative incidence of 4-10%. As AA patients often respond to immunosuppressive therapy, an immune pathophysiology is widely assumed. However, the evolution of clonal cytogenetic aberrations in hematopoietic cells and the association with clonal paroxysmal nocturnal hemoglobinuria (PNH) suggest that at least some patients have a clonal hematopoietic disease. Walter et al. reported that 74% of MDS patients harbour a mutation in at least one of 94 genes (Walter et al. Leukemia 2013). We hypothesized that mutations that are found in MDS patients may also be present in AA patients. AimTo evaluate the mutation profile of 41 myelodysplasia-related genes in AA patients. MethodsBone marrow or peripheral blood was collected from 39 patients with moderate (n=11), severe (n=12), or very severe (n=16) AA before allogeneic transplantation (n=23) or when the patient was cytopenic in at least one blood lineage (non-transplanted patients, n=16, median time from diagnosis to sample harvest 2 years). The coding region of 33 genes was amplified by PCR and sequenced on the SOLiDTM sequencing system. The sequences were analyzed using the DNAnexus software and an in-house pipeline of bioinformatics software. All candidate SNPs were validated by Sanger sequencing and only those confirmed are reported. Eight additional genes were only sequenced by Sanger sequencing. Confirmed mutations were also sequenced using DNA from hair follicles as germline control. Telomere length was evaluated by monochrome multiplex quantitative PCR-based method in peripheral blood leukocytes of 13 AA patients and 20 healthy volunteers. ResultsThe median age of AA patients at diagnosis was 30 years (range 9-79). Four patients (10%) had abnormal cytogenetics. In seven patients (18%), a GPI-deficient clone suggesting PNH/AA overlap syndrome was present. Twenty-three patients underwent allogeneic or syngeneic transplantation. The median follow-up from diagnosis of patients alive was 7.1 years. 36 of 39 patients were alive at last follow-up. Telomeres in peripheral blood leukocytes were significantly shorter in AA patients than in age matched healthy controls (P<.001). Next generation sequencing yielded an average coverage of 2015 reads per amplicon. In total, 6 mutations were identified in 5 patients (12.8%). One patient had a missense germline mutation in MYBL2, who developed trisomy 8 in the course of the disease; one patient had a missense germline mutation in TET2, another patient with very severe AA had a somatic missense TET2 mutation besides deletion of chromosome 5 (del5[q14q13]); one patient had a somatic missense mutation in SLIT1, and one patient with severe AA had two somatic mutations, i.e. one missense mutation in SETPB1 (D868N) and one frameshift mutation in ASXL1 (G646fs). This patient was diagnosed with severe AA at age 14 and received 4 courses of immunosuppressive therapy. Eleven years after diagnosis treatment with SCF and G-CSF was started, which induced a partial remission with signs of multilineage dysplasia. Two years later the patient received an allogeneic transplantation due to progressive thrombocytopenia. The current analysis was performed on cells harvested shortly before transplantation, and suggests that the patient had progressed to MDS. The patient with a SLIT1 mutation had very severe AA and responded well to the second course of anti-thymocyte globulin (ATG) and cyclosporine (CSA). The patient with a MYBL2 mutation is in remission after 2 courses of ATG/CSA for 16.8 years since diagnosis. The other two patients with mutations received an allogeneic or syngeneic transplant and are in remission 5.9 and 7.1 years after transplantation, respectively. ConclusionsThe frequency of MDS-related mutations is low in AA. We therefore suggest that mutation analysis of myelodysplasia-related genes may help to distinguish AA from MDS in ambiguous cases and may identify patients who are at risk for MDS-progression. Disclosures:No relevant conflicts of interest to declare.

Antithymocyte globulin treatment for patients with recent-onset type 1 diabetes: 12-month results of a randomised, placebo-controlled, phase 2 trial

Type 1 diabetes results from T-cell-mediated destruction of β cells. Findings from preclinical studies and pilot clinical trials suggest that antithymocyte globulin (ATG) might be effective for reducing this autoimmune response. We assessed the safety and efficacy of rabbit ATG in preserving islet function in participants with recent-onset type 1 diabetes, and report here our 12-month results. For this phase 2, randomised, placebo-controlled, clinical trial, we enrolled patients with recent-onset type 1 diabetes, aged 12-35 years, and with a peak C-peptide of 0.4 nM or greater on mixed meal tolerance test from 11 sites in the USA. We used a computer generated randomisation sequence to randomly assign patients (2:1, with permuted-blocks of size three or six and stratified by study site) to receive either 6.5 mg/kg ATG or placebo over a course of four days. All participants were masked and initially managed by an unmasked drug management team, which managed all aspects of the study until month 3. Thereafter, to maintain masking for diabetes management throughout the remainder of the study, participants received diabetes management from an independent, masked study physician and nurse educator. The primary endpoint was the baseline-adjusted change in 2-h area under the curve C-peptide response to mixed meal tolerance test from baseline to 12 months. Analyses were by intention to treat. This is a planned interim analysis of an on-going trial that will run for 24 months of follow-up. This study is registered with ClinicalTrials.gov, number NCT00515099. Between Sept 10, 2007, and June 1, 2011, we screened 154 individuals, randomly allocating 38 to ATG and 20 to placebo. We recorded no between-group difference in the primary endpoint: participants in the ATG group had a mean change in C-peptide area under the curve of -0.195 pmol/mL (95% CI -0.292 to -0.098) and those in the placebo group had a mean change of -0.239 pmol/mL (-0.361 to -0.118) in the placebo group (p=0.591). All except one participant in the ATG group had both cytokine release syndrome and serum sickness, which was associated with a transient rise in interleukin-6 and acute-phase proteins. Acute T cell depletion occurred in the ATG group, with slow reconstitution over 12 months. However, effector memory T cells were not depleted, and the ratio of regulatory to effector memory T cells declined in the first 6 months and stabilised thereafter. ATG-treated patients had 159 grade 3-4 adverse events, many associated with T-cell depletion, compared with 13 in the placebo group, but we detected no between-group difference in incidence of infectious diseases. Our findings suggest that a brief course of ATG does not result in preservation of β-cell function 12 months later in patients with new-onset type 1 diabetes. Generalised T-cell depletion in the absence of specific depletion of effector memory T cells and preservation of regulatory T cells seems to be an ineffective treatment for type 1 diabetes.

Antithymocyte Globulin and Cyclosporine in Children With Aplastic Anemia

Human leukocyte antigen-matched bone marrow transplant in the treatment of aplastic anemia is generally not feasible in developing countries due to lack of resources and expertise and immunosuppressive therapy (IST) has been used as an alternative. This study aims to report the long-term outcome of children with aplastic anemia treated with IST [antithymocyte globulin (ATG) and cyclosporine] in our hospital. Case files of children with aplastic anemia who received IST from January 2001 to November 2009 were reviewed. Thirty-five patients with aplastic anemia (14 very severe aplastic anemia; 21 severe aplastic anemia) were given IST. Seven patients expired within 3 months of therapy and were excluded. The analysis was done in 28 patients (24 male and 4 female; 12 very severe aplastic anemia and 16 severe aplastic anemia). The median age was 10 years (range, 5 to 12 y). Ten patients achieved partial response and 4 patients complete response at 1 year with overall response rate of 50%. Three nonresponders received a second course of ATG after 12 months out of which 2 responded. Hence, overall response including second course was 16 (57%). Three patients relapsed after a median interval of 23 months. The median duration of follow-up of 16 responders was 40 months (range, 15 to 119 mo). In the patients with long-term follow-up for >4 years (n = 7), all were surviving and independent of transfusions. In a developing country setting, IST with ATG and cyclosporine seems to be a good alternative treatment for aplastic anemia in children.

Response to Immunosuppressive Therapy with Antithymocyte Globulin (ATG) In Older Patients with Aplastic Anemia

Abstract 4374Immunosuppressive therapy (IST) with antithymocyte globulin in combination with prednisolone and cyclosporine is the treatment of choice for patients with aplastic anemia who are ineligible for transplant either because of age or because of absence of a HLA identical donor. Limited data that exists on the role of immunosuppressive therapy in older patients with aplastic anemia suggest that responses were poorer. This retrospective analysis was aimed at determining whether older patients with aplastic anemia had an inferior response to IST compared with younger patients.Between October 1985 to December 2010, 322 adult patients (>12 years) were treated at our centre with antithymocyte globulin (ATG) in combination with prednisolone and with/without cyclosporine. Either ATGAM (Pharmacia Upjohn, USA) at 40 mg/kg/day × 4 days or Lymphoglobulin (Pasteur Merieux, France) at 15 mg/kg/day × 5 days was used. Prednisolone at 1 mg/kg in 3 divided doses were started one day after completion of ATG and tapered from Day +14 if there was no evidence of serum sickness. Cyclosporine at the dose of 6 mg/kg/day in 2 divided doses was started once steroids were tapered and then continued for 12 months and then tapered depending upon response. Patients were divided into 3 age groups - Ages 12 – 29 [n=116], ages 30 – 49 [n = 116] and > 50 years [n = 90]. The baseline characteristics are detailed in the table below – Thirty one patients were above the age of 60 years. The older age group had significantly higher % of males, more use of ATGAM compared with Lymphogloblin and a higher number was given Cyclosporine (CSA) post ATG. The severity of aplastic anemia (severe vs non-severe) and the median time from diagnosis to administration of ATG was not significantly different between the 3 groups. The number of patients who developed serum sickness was significantly lower in the older age group (21.1%) compared to the age group of 30 – 49 (35.3%) and 12 – 29 years (48.3%) [p = 0.000]. The overall response to ATG was similar in all 3 groups (63.8% in age 12 –29, 64.7% in ages 30 – 49 and 54.4% in age > 50 yrs) [p = 0.233]. The response in patients above the age of 60 years was 51.6%. Six patients received a second course of ATG while 3 patients underwent HLA identical sibling donor transplantation. At a median follow up of 32 months (range: 1 –145), 221 patients (68.6%) are alive. The overall survival is similar for the older age group compared with the younger age groups (66.7% with age>50 years, 68.1% with age 30–49 and 70.7% with age 12 –29) [p= 0.817]. In conclusion, immunosuppressive therapy with ATG has a reasonable outcome in older patients (> 50 years) with aplastic anemia.Table 1:Demographic characteristics and outcome of IST among the 3 age groupsVariables12 – 29 yrs (n = 116)30 – 49 yrs (n = 116)>50 yrs (n = 90)p valueMale84 (72.4%)87 (75%)52 (57.8%)Female32 (27.6%)29 (25%)38 (42.2%)0.019Severity of AA86 (74.1%)77 (66.4%)63 (70%)0.581VSAA + SAA30 (25.9%)39 (33.6%)27 (30%)NSAAType of ATG45 (38.8%)33 (28.4%)53 (58.9%)0.000ATGAM71 (61.2%)83 (71.6%)37 (41.1%)LymphoglobulinCSA used92 (79.3%)103 (88.8%)85 (94.4%)0.005Yes24 (20.7%)13 (11.2%)5 (5.6%)NoResponse74 (63.8%)75 (64.6%)49 (54.4%)0.233Overall response34 (29.3%)28 (24.1%)15 (16.7%)Complete response (CR)40 (34.5%)47 (40.5%)34 (37.8%)Partial response (PR)42 (36.2%)41 (35.3%)41 (45.6%)No response (NR)Overall survival82 (70.7%)79 (68.1%)60 (66.7%)0.817Alive34 (29.3%)37 (31.9%)30 (33.3%)Dead Disclosures:No relevant conflicts of interest to declare.

Alemtuzumab (Campath) Monotherapy for Severe Aplastic Anemia.

AbstractAbstract 1167Immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG) and cyclosporine (CsA) results in hematologic responses in 60–70% of severe aplastic anemia (SAA) patients and long-term survival among responders >80% (Young, Calado et al. 2006). With standard horse ATG (h-ATG) + CsA, success is limited because 1/3 of patients are unresponsive; 1/3 of responders relapse after achieving hematologic recovery; and clonal evolution to myelodysplasia occurs in 10–15% of cases. Retreatment success with rabbit ATG (r-ATG) in refractory patients has varied widely, from 30->70% (DiBona, Coser et al. 1999; Scheinberg, Nunez et al. 2006); for relapse, response to retreatment has been more consistent, at 50–60% (Schrezenmeier, Marin et al. 1993; Tichelli, Passweg et al. 1998; Scheinberg, Nunez et al. 2006). We hypothesized that the humanized anti-CD52 monoclonal antibody alemtuzumab (Campath) might be active in SAA due to its lymphocytotoxic properties and reported activity in various immune cytopenias (Willis, Marsh et al. 2001). At the Clinical Center of the National Institutes of Health, we tested alemtuzumab monotherapy in several research protocols for marrow failure. For refractory SAA, we conducted a prospective randomized study (starting in 2003) comparing r-ATG/CsA vs. alemtuzumab in patients unresponsive to initial h-ATG/CsA (www.clinicaltrials.govNCT00065260). Sample size was based on the primary endpoint, hematologic response at 6 months, through testing the proportions with 5% significance level and 80% power. A difference in response rate of 30% was hypothesized between these two regimens. Rabbit-ATG was administered at 3.5 mg/kg/day for 5 days with CsA to a trough of 200 – 400 ng/ml for 6 months, and alemtuzumab at 10 mg/d for 10 days, without CsA. In a recent interim analysis (25 patients in each arm), the response rate for each regimen was identical at 36% (95% CI, 15%-56%; p=1.00). The 1000-day survival was 86% (95% CI, 63%-95%) in the alemtuzumab arm and 65% (95% CI, 39%-82%) in the r-ATG arm (log-rank, p=0.25). Both regimens were well tolerated with no significant difference in serious adverse events between the two groups. Subclinical EBV and CMV reactivations commonly occurred after immunosuppressive therapy as described previously (Scheinberg, Fischer et al. 2007). Specific prophylactic or pre-emptive antiviral therapies were not instituted in any case. Based on this initial experience, we conducted a single arm open label trial investigating alemtuzumab in relapsed SAA (www.clinicaltrials.govNCT00195624). Sample size was calculated using a Two-Stage Minimax Design, based on the hypothesis that response to alemtuzumab would be >50%. After accruing 23 patients (first stage), hematologic response at 6 months (primary endpoint) was observed in 13 (56%; 95% CI, 37%-77%) and the study will proceed to the second stage. Based on the encouraging results in refractory and relapsed SAA, alemtuzumab was investigated in treatment-naïve patients in a study that randomized (1:1:1) among h-ATG/CsA, r-ATG/CsA, and alemtuzumab (www.clinicaltrials.govNCT00260689). After 16 patients were randomized to alemtuzumab, this arm of the study was discontinued at the recommendation of the DSMB as response was observed in only three patients and there were three early deaths. Alemtuzumab was also investigated in other settings in the context of these clinical trials. Of 13 patients unresponsive to r-ATG/CsA given as first line therapy, only one patient responded to rescue with alemtuzumab; and of 11 patients who were unresponsive to both h-ATG/CsA and r-ATG/CsA, response to alemtuzumab was observed in two (both responders had shown small but incremental improvement with each prior ATG course). Our results show that: 1) alemtuzumab is an active agent in SAA patients with relapsed or refractory SAA; 2) either r-ATG or alemtuzumab can rescue about 30% of patients unresponsive to initial h-ATG + CsA; 3) the response rate of alemtuzumab in relapsed SAA is comparable to the reported response rate of 50%-60% in this setting; 4) the salvage rate with alemtuzumab in those unresponsive to initial r-ATG/CsA appear low; and 6) alemtuzumab cannot be recommended as first line therapy of SAA outside of a clinical research protocol. Disclosures:Off Label Use: Alemtuzumab in severe aplastic anemia.

Epstein-Barr virus infections after allogeneic stem cell transplantation: a comparison between non-malignant and malignant hematological disorders

Hematological cancers and non-malignant hematological disorders are biologically diverse conditions and are treated differently. We compared the pattern of EBV infections following allogeneic stem cell transplantation between the above two groups of hematological disorders. Eighty-three transplants were evaluated over a consecutive 7-year period at a single center. No difference was found in the incidence of post-transplant EBV infections between the two groups, though a higher median peak viral load was noted in the non-malignant group (P=0·04). Pre-transplant immunosuppressive therapy with antithymocyte globulin (ATG) significantly increased the risk of post-transplant EBV infections (P=0·04) in the non-malignant group patients. No significance was found for prior cytotoxic chemotherapy among the malignant group of patients. Alemtuzumab based conditioning was not associated with an increased risk for EBV infections in either of the groups. Treatment with two or more courses of ATG was found to be significantly associated with post-transplant EBV-related PTLD (P=0·01). Post-transplant EBV infections did not influence overall survival (non-malignant, P=0·66; malignant, P=0·41) in either of the subgroups. There were no deaths directly attributable to EBV infections.