Survival In Severe Aplastic Anemia Research Articles

Optimized Rabbit Antithymocyte Globulin Protocol Plus Sequential Cyclosporine and Levamisole Regimen for Newly Diagnosed Severe Aplastic Anemia: A Single-Arm, Single-Centre, Prospective, Phase 2 Trial

Background The inferior effect of rATG is due to the early fatal blow caused by the more potent immunosuppression. In order to retain its sustainable immunosuppression while weakening the early fatal blow. We explored a modifying schedule of administration of rATG by prolonging the course of rATG administration based on the equality of total dose, and then reported the better response and survival in severe aplastic anemia (SAA). And previously, we reported the encouraging effectiveness of cyclosporine alternately combined with levamisole (CSA and LMS regimen) in moderate AA, refractory or relapsed SAA, and SAA. We aim to establish whether the optimized rATG protocol plus sequential CSA and LMS regimen could improve SAA outcomes. Methods We conducted a single-arm, prospective, phase 2 trial at The Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College (CAMS & PUMC). Patients aged 6 years or older with confirmed, newly diagnosed SAA were eligible. Patients received optimized rATG administration (1.97 mg/kg/d for 9 days) based on the equality of total does with standard protocol (3.55 mg/kg/d for 5 days). And then CSA and LMS were alternatively administrated every other day from day 14. The initial dose of CSA was 3mg/kg/day in adults and 5mg/kg/day in children (6-18 years old). Oral LMS was alternatively administrated at a dose of 150 mg per day in adults and 2.5 mg/kg per day in children (< 40 kg) in three divided doses. The primary endpoint was overall response rate at 6 months. The trial is registered at www.clinicaltrials.gov as NCT02203396. Results: Between Aug 1, 2014 and Sep 30, 2017, 40 patients with newly diagnosed SAA were treated (median age 24 years [range 7-57 years]; 19 [47.5%] male; 18 [45%] VSAA; 1[2.5%] post-hepatitis). All of these patients were transfusion dependent. Demographic data and clinical characteristics of these patients are outlined in Table 1. The 3-month overall response rates (ORRs) was 40.0%, including 2.5% CR and 37.5% PR. The ORRs increased to 60% (15% CR and 45% PR) at 6 months and 72.5% (42.5% CR and 30% PR) at 12 months. With a median follow-up of 77 months (range 0.1-97 months), estimated 8-year OS rate and event-free survival rate were 84.9% (95% CI, 69.35-92.9%) and 66.5 (95%CI, 49.1-79.1%), respectively. No patient discontinued therapy because of treatment-related toxicity. There were two deaths-one due to infection and another due to cerebral hemorrhage. In this cohort, 4/40 patients (5.7%) evolved to clonal disorders. Of the 4 patients, 1 patients progressed to overt PNH, 2 MDS and 1 acute myeloid leukemia (AML). Cytogenetic abnormalities involved chromosome 7 occurred in one cases with AML. A total of 2 (7.1%) patients relapsed at 33 and 79 months after initial response. Both of the 2 relapsed patients acquired response again with the administration of CSA. Conclusions: Front-line sequential optimized rATG protocol with CSA and LMS regimen resulted in encouraging long-term survival. Future randomized studies should evaluate the optimized IST regimen in the treatment of patients with SAA.

Optimizing outcomes for haploidentical hematopoietic stem cell transplantation in severe aplastic anemia with intensive GVHD prophylaxis: a review of current findings

ABSTRACT Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has resulted in increased levels of disease-free survival in severe aplastic anemia (SAA). Haploidentical transplantation (haplo-SCT) was previously not recommended due to unacceptable incidences of graft-versus-host disease (GvHD) and graft failures. With the advent of intensive GvHD prophylaxis strategies, the outcomes obtained with haplo-SCT for SAA have gradually improved. Areas covered: A comprehensive search considered PubMed reported articles before 1 February 2021, presented abstracts, and clinical trials pertaining to haplo-HSCT for SAA. This manuscript covers modern approaches with intensive GvHD prophylaxis in haplo-SCT for SAA. The representative methods consist of granulocyte colony stimulating factor (G-CSF) plus ATG-based and posttransplantation cyclophosphamide (PT-Cy)-based protocols. Expert opinion: Currently, haplo-SCT has become a feasible option for treating SAA. The G-CSF/ATG-based protocol included the largest sample size and reported comparable survival rates with identical siblings. The PT-Cy protocol resulted in a relatively lower incidence of GvHD and seemingly poorer but continuously improved engraftment with augmented conditioning. The optimized outcomes are constantly updated with the modification of the conditioning regimen, donor selection, graft source and GvHD prophylaxis. In the future, we should pay more attention to quality of life in addition to survival, and personalized haplo-SCT may improve outcomes.

Novel therapeutic choices in immune aplastic anemia.

Aplastic anemia (AA) in its severe form has historically been associated with high mortality. With limited supportive care and no effective strategy to reverse marrow failure, most patients diagnosed with severe AA (SAA) died of pancytopenia complications. Since the 1970s, hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) have changed SAA's natural history by improving marrow function and pancytopenia. Standard IST with horse anti-thymocyte globulin plus cyclosporine produces a hematologic response rate of 60 to 70%. In the long term, about one-third of patients relapse, and 10 to 15% can develop cytogenetic abnormalities. Outcomes with either HSCT or IST are similar, and choosing between these modalities relies on age, availability of a histocompatible donor, comorbidities, and patient preference. The introduction of eltrombopag, a thrombopoietin receptor agonist, improved SAA outcomes as both salvage (second-line) and upfront therapy combined with IST. As a single agent, eltrombopag in doses up to 150 mg daily improved cytopenias in 40 to 50% in those who failed initial IST, which associated with higher marrow cellularity, suggesting a pan-stimulatory marrow effect. When eltrombopag was combined with IST as upfront therapy, overall (about 90%) and complete responses (about 50%) were higher than observed extensively with IST alone of 65% and 10%, respectively. Not surprisingly, given the strong correlation between hematologic response rates and survival in SAA, most (>90%) were alive after a median follow-up of 18 months. Longer follow-up and real-word data continue to confirm the activity of this agent in AA. The use of eltrombopag in different combinations and doses are currently being explored. The activity of another thrombopoietin receptor agonist in AA, romiplostim, suggests a class effect. In the coming years, the mechanisms of their activity and the most optimal regimen are likely to be elucidated.

Manejo infectológico de la aplasia medular severa en pacientes pediátricos

La aplasia medular es una enfermedad poco frecuente en pediatría, siendo el tratamiento de elección en las formas severas el trasplante de células progenitoras hematopoyéticas (TCPH). Gracias a los avances en TCPH, los nuevos tratamientos inmunosupresores y al adecuado tratamiento de sostén, se ha logrado en las últimas décadas una franca disminución de la mortalidad asociada a esta patología. Es por ello que uno de los principales desafíos consiste en prevenir la aparición de infecciones asociadas a la neutropenia severa y prolongada que padecen estos pacientes, siendo actualmente las infecciones bacterianas y fúngicas una de las principales causas de morbimortalidad. Por otra parte, la mayoría de las guías de manejo y tratamiento de sostén se basan en recomendaciones de expertos, siendo la evidencia escasa, más aún en pediatría. Gran parte de las recomendaciones de tratamiento empírico se basan en guías de neutropenia febril de pacientes hemato-oncológicos. A su vez, existe gran variabilidad, de acuerdo al centro de atención, en cuanto al uso de antimicrobianos para profilaxis primaria, debiéndose tener en cuenta la mayor propensión a presentar infecciones invasivas por hongos filamentosos y, en el caso de pacientes con linfopenia marcada, de enfermedad por P jirovecii a la hora de valorar la indicación de profilaxis de estos pacientes.Se detallarán a continuación las principales recomendaciones sobre manejo de prevención de infecciones y tratamiento precoz de pacientes pediátricos con aplasia medular severa.

Evaluation of a Machine Learning-Based Prognostic Model for Unrelated Hematopoietic Cell Transplantation Donor Selection

The survival of patients undergoing hematopoietic cell transplantation (HCT) from unrelated donors for acute leukemia exhibits considerable variation, even after stringent genetic matching. To improve the donor selection process, we attempted to create an algorithm to quantify the likelihood of survival to 5 years after unrelated donor HCT for acute leukemia, based on the clinical characteristics of the donor selected. All standard clinical variables were included in the model, which also included average leukocyte telomere length of the donor based on its association with recipient survival in severe aplastic anemia, and links to multiple malignancies. We developed a multivariate classifier that assigned a Preferred or NotPreferred label to each prospective donor based on the survival of the recipient. In a previous analysis using a resampling method, recipients with donors labeled Preferred experienced clinically compelling better survival compared with those labeled NotPreferred by the test. However, in a pivotal validation study in an independent cohort of 522 patients, the overall survival of the Preferred and NotPreferred donor groups was not significantly different. Although machine learning approaches have successfully modeled other biological phenomena and have led to accurate predictive models, our attempt to predict HCT outcomes after unrelated donor transplantation was not successful.

Long-term follow-up study of porcine anti-human thymocyte immunoglobulin therapy combined with cyclosporine for severe aplastic anemia.

Immunosuppressive therapy with antithymocyte immunoglobulin (ATG) and cyclosporine A is the first treatment option for severe aplastic anemia (SAA) patients without transplantation. Horse ATG is not marketed in China. Because the price of porcine ATG (pATG) is only about one-third of the price of rabbit ATG (rATG), long-term follow-up studies of pATG's efficacy will help provide valuable insights into the treatment of SAA. Retrospective studies were performed to analyze the clinical information of 102 SAA patients treated with pATG and cyclosporine A from 1999 to 2014 in Peking Union Medical College Hospital. The median age was 29 years old (range 12-72). Median follow-up time was 59.6 months (0.2-176.8). The overall response rate was 74.5% (CR 42.1%, PR 32.4%). The recurrence rate was 9.9%. The mortality rate was 16.7%. The median survival time has not been reached, and the 5-year survival rate was 81.8%. Other hematologic abnormalities were observed in 7.8% of patients, including symptomatic PNH, MDS, and AML. Multivariate analysis revealed there was no significant effect on survival by factors such as gender, age, severity of disease, treatment time, and PNH clone (P > 0.05). These data have indicated pATG therapy combined with cyclosporine A has significant long-term efficacy and high overall survival in SAA.

Rabbit antithymocyte globulin as first-line therapy for severe aplastic anemia

Rabbit antithymocyte globulin (rATG) was proven effective as salvage therapy for refractory aplastic anemia (AA), or for relapse after initial therapy with horse ATG (hATG). Several clinical trials were performed to assess the efficiency of rATG as a first-line therapy for AA patients; however, their results were variable. The aim of the present study was to assess hematologic response and survival in severe AA (SAA) and very severe AA (VSAA) patients treated with rATG and cyclosporin A (CsA) in our center. The factors involved in these outcomes were also explored. A total of 292 patients with newly diagnosed, acquired SAA or VSAA received a combination of rATG and CsA as first-line therapy, and the results were retrospectively assessed. The median age was 18 years (range = 2-73 years). The early death rate was 5.5%, and the total response rates were 49.0% (143 responders), 60.3% (176 responders), 65.8% (192 responders), and 68.5% (200 responders) at 3, 6, 9, and 12 months, respectively, after immunosuppressive therapy. In multivariate analysis, initial response to granulocyte colony-stimulating factor (G-CSF) was the predictive factor for response to therapy at 12 months. Median follow-up of surviving patients was 34 months (range = 0-117 months). Five-year overall survival was 83.2%, and the 5-year, event-free survival was 67.2%. Independent prognostic factors for overall survival were neutrophil count and achievement of any response following rATG therapy. Our results indicate that rATG/CsA is a safe and effective first-line treatment for SAA/VSAA.

Increasing peripheral blood neutrophils after G-CSF treatment is a predictor of early response to immunosuppressive therapy in severe aplastic anemia

To testify whether absolute neutrophil count (ANC) response to preimmunosuppressive-therapy (pre-IST) granulocyte-stimulating factor (G-CSF) treatment could predict early response to IST in severe aplastic anemia (SAA). Clinical data and hematologic response of 125 SAA patients treated with antithymocyte globulin (r-ATG) combined with cyclosporine were retrospectively analyzed. Correlation of ANC response to pre-IST G-CSF treatment and early response to IST were statistically analyzed, and receiver operating characteristic (ROC) curve was used to estimate the value of increased ANC (∆ANC) in predicting early IST response. The hematologic response (HR) rate to IST in ANC reponded patients was significantly higher than non-responded group (3-month HR 49.0% vs 28.9%, P=0.023; 6-month HR 61.2% vs 40.8%, P=0.026). With ∆ANC≥0.5×10⁹/L as cutoff level, the best point to predict early IST response was 10 days after G-CSF (d 10). Response of ANC to pre-IST G-CSF treatment at d 10 was among the independent factors of predicting 3-month (P=0.004), but not for 6-month response to IST. The overall 5-year survival rate was 92.8% and 69.5% in ANC responded and non-responed groups, respectively (P=0.025). Responding to pre-IST G-CSF treatment reflected the residual bone marrow hematopoiesis, and could act as a convenient and practical predictor to early IST response as well as long-term survival in SAA.

Aplastic anemia: therapeutic updates in immunosuppression and transplantation

Abstract Advances in hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) have improved survival in severe aplastic anemia (SAA) from 10%-20% in the 1960s to 80%-90% today. A matched sibling HSCT is the treatment of choice in younger patients, whereas IST is often used in older patients or in those who lack a histocompatible sibling. Graft rejection, GVHD, and poor immune reconstitution (with associated infectious complications) limit the success of HSCT, whereas lack of response, relapse, and clonal evolution limit the success of IST. The historically high rate of graft rejection in SAA is now less problematic in the matched setting, but with greater rates observed with unrelated and umbilical cord donors. The correlation of increasing age with the risk of GVHD and the significant morbidity and mortality of this transplantation complication continue to affect the decision to pursue HSCT versus IST as initial therapy in adults with SAA. Outcomes with matched unrelated donor HSCT have improved, likely due to better donor selection, supportive care, and improved transplantation protocols. Results with mismatched unrelated donor and umbilical HSCT are not as favorable, with higher rates of graft rejection, GVHD, and infectious complications. Investigation of several upfront alternative IST protocols has not improved outcomes beyond horse antithymocyte globulin and cyclosporine. More recently, the role of alemtuzumab in SAA has been better defined and an oral thrombomimetic, eltrombopag, is showing promising activity in refractory cases. The most recent advances in HSCT and IST in SAA are discussed in this review.

Aplastic anemia: therapeutic updates in immunosuppression and transplantation.

Advances in hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) have improved survival in severe aplastic anemia (SAA) from 10%-20% in the 1960s to 80%-90% today. A matched sibling HSCT is the treatment of choice in younger patients, whereas IST is often used in older patients or in those who lack a histocompatible sibling. Graft rejection, GVHD, and poor immune reconstitution (with associated infectious complications) limit the success of HSCT, whereas lack of response, relapse, and clonal evolution limit the success of IST. The historically high rate of graft rejection in SAA is now less problematic in the matched setting, but with greater rates observed with unrelated and umbilical cord donors. The correlation of increasing age with the risk of GVHD and the significant morbidity and mortality of this transplantation complication continue to affect the decision to pursue HSCT versus IST as initial therapy in adults with SAA. Outcomes with matched unrelated donor HSCT have improved, likely due to better donor selection, supportive care, and improved transplantation protocols. Results with mismatched unrelated donor and umbilical HSCT are not as favorable, with higher rates of graft rejection, GVHD, and infectious complications. Investigation of several upfront alternative IST protocols has not improved outcomes beyond horse antithymocyte globulin and cyclosporine. More recently, the role of alemtuzumab in SAA has been better defined and an oral thrombomimetic, eltrombopag, is showing promising activity in refractory cases. The most recent advances in HSCT and IST in SAA are discussed in this review.

Current management of severe acquired aplastic anemia.

Overall survival in severe aplastic anemia has markedly improved in the past four decades due to advances in stem cell transplantation, immunosuppressive therapies and supportive care. Horse anti-thymocyte globulin plus cyclosporine is the standard immunosuppressive regimen in severe aplastic anemia, and often employed as initial therapy as most are not candidates for a matched related stem cell transplantation. With this regimen, hematologic response can be achieved in 60 to 70% of cases, but relapse is observed in 30 to 40% of responders and clonal evolution in 10 to 15% of patients. Efforts to improve outcomes beyond horse anti-thymocyte globulin plus cyclosporine have been disappointing, with no significant improvement in the critical parameter of hematologic response, which strongly correlates with long-term survival in severe aplastic anemia. Furthermore, rates of relapse and clonal evolution have also not improved with the development of three drug regimens or with more lymphocytotoxic therapies. Therefore, horse anti-thymocyte globulin plus cyclosporine remains the standard immunosuppression of choice as first therapy in severe aplastic anemia. Interestingly, survival has markedly improved over the years in large part due to better anti-infective therapy and more successful salvage therapies with immunosuppression and stem cell transplantation. In this review general aspects of diagnosis and management are discussed.

Decreased Infection-Related Mortality and Improved Survival in Severe Aplastic Anemia in the Past Two Decades

Persistent neutropenia associated with severe aplastic anemia (SAA) is an important risk factor for development of life-threatening infections. Earlier studies underscored the high mortality associated with invasive fungal infections (IFIs) in SAA. However, little is known about the current patterns of infections and the impact of advances in anti-infective therapy on survival in SAA. We reviewed the records of 174 patients with SAA admitted to the Hematology Branch at NHLBI from 1989 to 2008 who were unresponsive to initial immunosuppressive therapy (IST) at 6 months. Three patient groups determined by IST protocol and time interval were compared: group 1 (43 patients; December 1989-October 1996), group 2 (51 patients; November 1996-October 2002), and group 3 (80 patients; November 2002-April 2008). Outcome variables included infections, patterns of resistance, survival, and infection-related mortality. During the past 2 decades, infection-related mortality decreased from 37% in group 1 to 11% in group 3 (P < .001), and the frequency of IFIs decreased from 49% in group 1 to 8% in group 3 (P < .001). Overall 5-year survival for all patients (n = 420) increased from 64% in group 1 to 79% in group 3 (P < .001). Among non-responders (n = 174), it increased from 23% in group 1 to 57% in group 3 (P < .001). In multivariate analysis, younger age, absolute neutrophil count > 200 cells/μL before IST, absence of IFIs, and use of voriconazole were independently predictive of survival. During the past 2 decades, there has been a significant decrease in IFIs, infection-related mortality, and overall mortality in patients with SAA unresponsive to initial IST.

Association of Telomere Length of Peripheral Blood Leukocytes With Hematopoietic Relapse, Malignant Transformation, and Survival in Severe Aplastic Anemia

Critically short telomeres produce apoptosis, cell senescence, and chromosomal instability in tissue culture and animal models. Variations in telomere length have been reported in severe aplastic anemia but their clinical significance is unknown. To investigate the relationship between telomere length and clinical outcomes in severe aplastic anemia. Single institution analysis of 183 patients with severe aplastic anemia who were treated in sequential prospective protocols at the National Institutes of Health from 2000 to 2008. The pretreatment leukocyte age-adjusted telomere length of patients with severe aplastic anemia consecutively enrolled in immunosuppression protocols with antithymocyte globulin plus cyclosporine for correlation with clinical outcomes were analyzed. Hematologic response, relapse, clonal evolution, and survival. There was no relationship between hematologic response and telomere length with response rates of 56.5% of 46 patients in the first, 54.3% of 46 in the second, 60% of 45 in the third, and 56.5% of 46 in the fourth quartiles. Multivariate analysis demonstrated that telomere length was associated with relapse, clonal evolution, and mortality. Evaluated as a continuous variable, telomere length inversely correlated with the probability of hematologic relapse (hazard ratio [HR], 0.16; 95% confidence interval [CI], 0.03-0.69; P = .01). The probability of clonal evolution was higher in patients in the first quartile (24.5%; 95% CI, 8.7%-37.5%) than in quartiles 2 through 4 (8.4%; 95% CI, 3.2%-13.3%; P = .009), and evolution to monosomy 7 or complex cytogenetics was more common in the first quartile (18.8%; 95% CI, 3.5%-31.6%) [corrected] than in quartiles 2 through 4 (4.5%; 95% CI, 0.5%-8.2%; P = .002) [corrected]. Survival between these 2 groups differed, with 66% (95% CI, 52.9%-82.5%) surviving 6 years in the first quartile compared with 83.8% (95% CI, 77.3%-90.9%) in quartiles 2 through 4 (P = .008). In a cohort of patients with severe aplastic anemia receiving immunosuppressive therapy, telomere length was unrelated to response but was associated with risk of relapse, clonal evolution, and overall survival.

Selection of Patients for Bone Marrow Transplantation in Severe Aplastic Anemia

Despite androgens and intensive supportive care, satisfactory survival in severe aplastic anemia remains at 20% or less. Histocompatible bone marrow transplantation can restore normal hematopoiesis in approximately 40% of similarly severe individuals. Delay of transplantation for 3 wk after diagnosis allows time for proper evaluation and for many spontaneous recoveries. Further delay increases risks of fatal complications and decreases chances for successful transplantation while the incidence of spontaneous remission declines. When available, early histocompatible bone marrow transplantation may be the treatment of choice for severe aplastic anemia.

Selection of patients for bone marrow transplantation in severe aplastic anemia

Despite androgens and intensive supportive care, satisfactory survival in severe aplastic anemia remains at 20% or less. Histocompatible bone marrow transplantation can restore normal hematopoiesis in approximately 40% of similarly severe individuals. Delay of transplantation for 3 wk after diagnosis allows time for proper evaluation and for many spontaneous recoveries. Further delay increases risks of fatal complications and decreases chances for successful transplantation while the incidence of spontaneous remission declines. When available, early histocompatible bone marrow transplantation may be the treatment of choice for severe aplastic anemia.