Activity of eltrombopag in severe aplastic anemia

Efficacy and safety of immunosuppressive therapy combined with eltrombopag for severe aplastic anemia: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Immunosuppressive therapy (IST) is the first choice for severe aplastic anemia (SAA) patients with hematopoietic stem cell transplantation (HSCT) limitation, and the main factor limiting its efficacy is too few residual hematopoietic stem/progenitor cells (HSPC). Eltrombopag (EPAG), as a small molecule thrombopoietin receptor agonist, can stimulate the proliferation of residual HSPC and restore the bone marrow hematopoietic function of patients. In recent years, many studies have observed the efficacy and safety of IST combined with EPAG in the treatment of SAA, but the results are still controversial. The aim of this study is to systematically evaluate the efficacy and safety of IST combined with or without EPGA in the treatment of SAA.

METHODS

We conducted a systematic review of all relevant literature published up to January 19, 2024. Pooled odds ratio (OR) was calculated to compare the rates, along with 95% confidence intervals (CI) and p value to assess whether the results were statistically significant by Review Manager 5.4.1. The p values for the interactions between each subgroup were calculated by Stata 15.1. The Newcastle-Ottawa Scale and the Cochrane bias risk assessment tools were respectively used to evaluate the quality of the literature with cohort studies and randomized controlled trials. The Review Manager 5.4.1 and Stata 15.1 were used to assess bias risk and perform the meta-analysis.

RESULTS

A total of 16 studies involving 2148 patients were included. The IST combined with the EPAG group had higher overall response rate (ORR) than the IST group at 3 months (pooled OR = 2.10, 95% CI 1.58-2.79, p < 0.00001) and 6 months (pooled OR = 2.13, 95% CI 1.60-2.83, p < 0.00001), but the difference between the two groups became statistically insignificant at 12 months (pooled OR = 1.13, 95% CI 0.75-1.72, p = 0.55). The results of complete response rate (CRR) (pooled OR at 3 months = 2.73, 95% CI 1.83-4.09, p < 0.00001, 6 months = 2.76, 95% CI 2.08-3.67, p < 0.00001 and 12 months = 1.38, 95% CI 0.85-2.23, p = 0.19) were similar to ORR. Compared with the IST group, the IST combined with the EPAG group had better overall survival rate (OSR) (pooled OR = 1.70, 95% CI 1.15-2.51, p = 0.008), but there were no statistically significant differences in event-free survival rate (EFSR) (pooled OR = 1.40, 95% CI 0.93-2.13, p = 0.11), clonal evolution rate (pooled OR = 0.68, 95% CI 0.46-1.00, p = 0.05) and other adverse events between the two groups. The results of subgroup analysis showed that different ages were a source of heterogeneity, but different study types and different follow-up times were not. Moreover, all p-values for the interactions were greater than 0.05, suggesting that the treatment effect was not influenced by subgroup characteristics.

CONCLUSION

EPAG added to IST enables patients to achieve earlier and faster hematologic responses with a higher rate of complete response. Although it had no effect on overall EFSR, it improved OSR and did not increase the incidence of clonal evolution and other adverse events.

Single-cell analysis highlights a population of Th17-polarized CD4+ naïve T cells showing IL6/JAK3/STAT3 activation in pediatric severe aplastic anemia

Acquired aplastic anemia (AA) is recognized as an immune-mediated disorder resulting from active destruction of hematopoietic cells in bone marrow (BM) by effector T lymphocytes. Bulk genomic landscape analysis and transcriptomic profiling have contributed to a better understanding of the recurrent cytogenetic abnormalities and immunologic cues associated with the onset of hematopoietic destruction. However, the functional mechanistic determinants underlying the complexity of heterogeneous T lymphocyte populations as well as their correlation with clinical outcomes remain to be elucidated. To uncover dysfunctional mechanisms acting within the heterogeneous marrow-infiltrating immune environment and examine their pathogenic interplay with the hematopoietic stem/progenitor pool, we exploited single-cell mass cytometry for BM mononuclear cells of severe AA (SAA) patients pre- and post-immunosuppressive therapy, in contrast to those of healthy donors. Alignment of BM cellular composition with hematopoietic developmental trajectories revealed potential functional roles for non-canonically activated CD4⁺ naïve T cells in newly-diagnosed pediatric cases of SAA. Furthermore, single-cell transcriptomic profiling highlighted a population of Th17-polarized CD4⁺CAMK4⁺ naïve T cells showing activation of the IL-6/JAK3/STAT3 pathway, while gene signature dissection indicated a predisposition to proinflammatory pathogenesis. Retrospective validation from our SAA cohort of 231 patients revealed high plasma levels of IL-6 as an independent risk factor of delayed hematopoietic response to antithymocyte globulin-based immunosuppressive therapy. Thus, IL-6 warrants further investigation as a putative therapeutic target in SAA.

Modern management of Fanconi anemia

In this review, we present a clinical case report and discussion to outline the importance of long-term specific Fanconi anemia (FA) monitoring, and we discuss the main aspects of the general management of patients with FA and clinical complications. While several nontransplant treatments are currently under evaluation, hematopoietic stem cell transplantation (HSCT) remains the only therapeutic option for bone marrow failure (BMF). Although HSCT outcomes in patients with FA have remarkably improved over the past 20 years, in addition to the mortality intrinsic to the procedure, HSCT increases the risk and accelerates the appearance of late malignancies. HSCT offers the best outcome when performed in optimal conditions (moderate cytopenia shifting to severe, prior to transfusion dependence and before clonal evolution or myelodysplasia/acute myeloid leukemia); hence, an accurate surveillance program is vital. Haploidentical HSCT offers very good outcomes, although long-term effects on malignancies have not been fully explored. A monitoring plan is also important to identify cancers, particularly head and neck carcinomas, in very early phases. Gene therapy is still experimental and offers the most encouraging results when performed in early phases of BMF by infusing high numbers of corrected cells without genotoxic effects. Patients with FA need comprehensive monitoring and care plans, coordinated by centers with expertise in FA management, that start at diagnosis and continue throughout life. Such long-term follow-up is essential to detect complications related to the disease or treatment in this setting.

[Hematologic responses to avatrombopag switch in TPO-RA refractory aplastic anemia]

Objective: Short-term efficacy and safety of afatrombopag conversion therapy in patients with aplastic anemia (AA) who were previously ineffectively treated with intense immunosuppressive therapy (IST) combined with TPO receptor Agonist (TPO-RA) or who were unable to tolerate the side effects of TPO-RA. Methods: Analysis of patients with severe aplastic anemia (SAA) treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College from January 2021 to December 2021 who received IST combined with TPO-RA (eltrombopag/hatrombopag) for at least 6 months, but was ineffective for at least 3 months or patients who cannot continue to use TPO-RA due to side effects, and switched from TPO-RA to avatrombopag (APAG) , and treated for at least 6 months. This study analyzed its short-term efficacy and evaluated its safety. Results: The median age was 54 (14-68) years old among the 16 patients with AA (8 male and eight female) . A total of ten patients (refractory group) who did not respond to IST combined with TPO-RA were converted to APAG median therapy for 6 (6-10) months. Only seven patients (70% ) obtained trilineage HR [four cases of complete treatment response (CTR) , one case of good treatment response (GPR) , and two cases of partial treatment response (PR) ], all of which began to take effect at 3 months of APAG treatment. There were six patients with TPO-RA intolerance, and APAG was treated for 6 (2 to 8) months. About four patients (67% ) received HR (three GPR cases and one PR case) , of which two patients received PR at 3 months and four patients received HR at 6 months of APAG treatment. No APAG-related grade 2 or more adverse events occurred during the APAG therapy, no thrombotic events occurred, no fibrologic tissue hyperplasia was found in the bone marrow pathology reexamination at 6 months of treatment, and none of the patients discontinued the drug due to adverse events. Conclusion: APAG may be a better switching treatment option for patients with AA who are refractory or are intolerant to TPO-RA.

Iron chelation of hetrombopag in aplastic anemia: a post hoc analysis of a phase II study

Hetrombopag is the only CFDA-approved thrombopoietin (TPO) receptor agonist for severe aplastic anemia (SAA) in China. Its chemical structure has an iron chelation domain. To explore the iron chelation effect of hetrombopag, we performed a post hoc analysis of the phase II clinical trial (NCT03557099). Thirty-five immunosuppressive therapy (IST)-refractory SAA patients were enrolled in the study, and the longitudinal changes of serum ferritin (SF) were assessed. At 18 weeks post-hetrombopag initiation, 51.4% of patients showed decreased SF levels by a median of 49.0 (18.1-95.5) % from baseline (median ΔSF decrease value, 917.2 ng/ml, range from 104.0 to 7030.0 ng/ml). A decrease in SF was found in 75.0% of hematologic responders and 31.6% of non-responders. Among the 24 patients with iron overload, 12 had decreased SF levels by up to 51% of the baseline. Patients with normal SF levels also showed decreased SF levels, and iron deficiency occurred in two patients. In conclusion, hetrombopag showed a powerful and rapid iron chelation effect.

Epstein–Barr-virus-associated hepatitis with aplastic anemia: A case report

ABSTRACT

BACKGROUND

Hepatitis-associated aplastic anemia (HAAA) is a rare condition. Patients with HAAA usually present with acute hepatitis, jaundice and significantly increased transaminase. After 1–2 mo, hepatitis gradually improves, but progressive hemocytopenia, bone marrow hematopoietic failure, and severe or extremely severe aplastic anemia are manifest. Most cases of HAAA are fulminant and usually lethal if left untreated. The literature on Epstein–Barr virus (EBV)-associated HAAA is sparse.

CASE SUMMARY

We report a 30-year-old man who was admitted to our hospital because of pale yellow urine and skin with a simultaneous decrease in peripheral blood ternary cells. We made a diagnosis of EBV-associated HAAA. The treatment strategy for this patient included eltrombopag, an immunosuppressive regimen of rabbit anti-human thymocyte immunoglobulin, cyclosporine, and supportive care. The patient was discharged in normal physical condition after five months. A hemogram performed on follow-up revealed that he had achieved a complete response.

CONCLUSION

Eltrombopag plus anti-thymocyte globubin and cyclosporine may be a therapeutic option for EBV-associated HAAA.Larger studies are warranted to confirm.

Case Report: Successful Avatrombopag Treatment for Two Cases of Anti-PD-1 Antibody-Induced Acquired Amegakaryocytic Thrombocytopenia

Background: Anti-PD-1/PD-L1 immunotherapy has achieved impressive responses in multiple types of malignancies in recent years. However, immune-related adverse events (irAEs) occur and limit their continuous clinical use. Among these irAEs, acquired amegakaryocytic thrombocytopenia (AAT) is rare but often clinically serious, life-threatening and refractory to multiple treatment approaches.

Case summary: We reported for the first time the successful treatment of avatrombopag in two cases of anti-PD1 antibody-induced AAT (in particular, one case had progressed to aplastic anemia), which was refractory or intolerant to glucocorticoids, ciclosporin, intravenous immunoglobulin (IVIG), recombinant human thrombopoietin (rh-TPO) and even TPO receptor agonist (TPO-RA) eltrombopag. To date, the two cases manifested as normal platelet counts and are independent of transfusion.

Conclusion: Anti-PD1 antibody-induced AAT occurs with low frequency but is often serious and difficult to manage, for which this study proposed vatrombopag as a potential curative and safe approach.

[Efficacy and safety analysis of eltrombopag and recombinant human thrombopoietin combined with immunosuppressive therapy for severe aplastic anemia]

Objective: To evaluate the efficacy and safety of combination therapy of eltrombopag, recombinant human thrombopoietin (rhTPO) , and standard immunosuppressive therapy (IST) for severe aplastic anemia (SAA) . Methods: A total of 16 cases with SAA treated with IST combined with eltrombopag and rhTPO were retrospectively analyzed. Results: At 3 months, the total response rate was 81.3%, and the complete hematological response rate was 37.5%. At 6 months, the total response rate was 87.5%, and the complete hematological response rate was 50.0%. The median time of platelet transfusion independence was 35 (16-78) days, the median time of red blood cell transfusion independence was 47.5 (15-105) days, the median platelet transfusion was 5.5 (3-20) U, and the median red blood cell transfusion was 6.5 (2-16) U. Conclusion: The combination of eltrombopag and rhTPO can improve the hematological response rate of IST for SAA and the quality of hematological remission with minimal toxic effects.

Efficacy and safety of immunosuppressive therapy with or without eltrombopag in pediatric patients with acquired aplastic anemia: A Chinese retrospective study

To determine the efficacy and safety of eltrombopag (E-PAG) combined with intensive immunosuppressive therapy (IST) for the treatment of pediatric patients with severe aplastic anemia (SAA). A total of 57 pediatric patients with newly diagnosed severe aplastic anemia were enrolled in this study. Thirty nine patients were treated with IST alone, consisting of porcine anti-human thymocyte globulin (30 mg/kg/day × 5 days) and cyclosporine A (CsA) (treated for 2 years, with a trough concentration maintained at 200-250 ng/mL), and 18 patients were treated with IST + E-PAG (12.5-50 mg/day, maintained for 6 months). We found no statistical difference between the response rates at 3 months for the two groups (CR: 12.8% vs. 22.2% p > 0.05, ORR: 56.4% vs. 77.7% p > 0.05). However, we found a statistical difference between the response rates at 6 months for the two groups (CR: 17.9% vs. 50% p < 0.05, ORR: 69.2% vs. 94.4% p < 0.05). The main side-effect during treatment with E-PAG was having a slightly to moderately elevated bilirubin level, which was temporary and controllable, accounting for approximately 66.6% (12/18) of patients in the IST + E-PAG group vs. 20.5% (8/39) of those in the IST group (p < 0.05). IST + E-PAG therapy appears to be more effective than IST alone for the treatment of pediatric SAA, with good tolerability and compliance. This approach deserves further exploration.

Unresponsive Severe Aplastic Anemia in a Young Patient: Case Report and Short Review of the Literature

Aplastic anemia or medullary aplasia is a medical condition characterized by pancytopenia and is associated with a high prevalence of morbidity and mortality. In patients in whom bone marrow transplantation cannot be attempted, an immunosuppressive regimen is considered to be the first-line therapy. Also, the addition of eltrombopag from the first day of immunosuppressive treatment seems to significantly increase response rate. Unfortunately, there are a small number of patients who remain unresponsive to all these therapies. Here we present the case of a young woman who was referred by the family doctor complaining of marked physical asthenia, new onset dyspnea, and dizziness. Apart from a severe pancytopenia, no further changes have been brought to light by paraclinical investigations. After multiple secondary causes were excluded, the patient was diagnosed with idiopathic aplastic anemia. Even if bone marrow transplant was the first-line therapy in this case, because of the severe leukopenia, it was not possible to determine the HLA type. Therefore, the patient was prescribed immunosuppressive treatment. Despite the three drug-associated therapy (horse anti-thymocyte globulin, cyclosporin A, and eltrombopag), the response was unsatisfactory, with the persistence of severe pancytopenia.

Eltrombopag restores erythropoiesis in refractory adult acquired pure red cell aplasia

Acquired pure red cell aplasia is a rare condition characterized by normocytic normochromic anemia with severe reticulocytopenia. In refractory acquired pure red cell aplasia, the low response rate of immunosuppressive therapy also constitutes a challenge. We herein report the case of a 58-year-old male with refractory acquired pure red cell aplasia that was successfully treated by eltrombopag at a dose of 75 mg/day. After application of eltrombopag, the patient achieved complete remission and tolerated the treatment very well, with only mild bilirubin elevation. These preliminary findings showed that eltrombopag may be effective and well tolerated in adult patients with refractory acquired pure red cell aplasia.

[Efficacy and safety of eltrombopag in aplastic anemia: A multi-center survey in China]

目的

评估艾曲泊帕联合免疫抑制治疗（IST）在中国再生障碍性贫血（AA）患者中的疗效及安全性。

方法

调查分析2015年4月至2019年5月来自中国14个血液病治疗中心、连续应用艾曲泊帕治疗至少3个月的输血依赖非重型和重型AA患者临床资料。

结果

纳入19例IST初治及37例IST难治性AA患者，中位艾曲泊帕治疗时间为7（3~31）个月，中位艾曲泊帕最大稳定使用剂量为75（50~150）mg/d。10例应用艾曲泊帕联合标准IST一线治疗的SAA患者3个月血液学反应（HR）率为60%，完全HR（CR）率为30%；9例艾曲泊帕联合环孢素A（CsA）一线治疗SAA患者后3个月HR率为89%，CR率为44%。19例患者应用艾曲泊帕联合IST一线治疗，至调查随访时HR率为79%，CR率为52.6%。19例CsA±雄激素治疗无效的AA患者，艾曲泊帕开始治疗后3个月HR率为57.9%（11/19），最佳HR率为68.4%；标准IST治疗无效的难治性AA，艾曲泊帕治疗最佳HR率为44%。51%患者应用艾曲泊帕发生不同严重程度的不良反应，以胃肠道不适最为常见。

结论

艾曲泊帕治疗可加快HR的获得，改善HR质量；残存造血细胞较多的AA患者或可采用非抗胸腺细胞球蛋白免疫抑制联合艾曲泊帕治疗；艾曲泊帕可作为CsA±雄激素治疗无效AA的补救治疗；艾曲泊帕不良反应轻微，多可耐受。

Effectiveness and safety of tacrolimus with or without eltrombopag, as a part of immunosuppressive treatment of aplastic anemia in adults: a retrospective case series

First-line treatment of aplastic anemia(AA) and for AA patients ineligible for hematopoietic stem cell transplantation (HSCT) has consisted of antithymocyte globulin (ATG), the calcineurin inhibitor cyclosporine A (CsA), and more recently eltrombopag. However, at our institution, we have successfully substituted another calcineurin inhibitor, tacrolimus, as a part of immunosuppressive threatment (IST) for AA due to more favorable toxicity profile. Since there is limited data on the use of tacrolimus in aplastic anemia, we conducted a retrospective review of twenty patients treated with tacrolimus-based immunosuppressive therapy (IST) as a first- or second-line treatment. The overall response rate was comparable to that of patients treated with CsA (18 patients). However, there were no cutaneous side effects observed in patients receiving tacrolimus, a relatively common finding with CsA use. Our data suggest that tacrolimus-based IST is a potential option in AA and might have a more favorable toxicity profile compared to CsA.

Correlation of the Plasma Concentration of Eltrombopag With Efficacy in the Treatment of Refractory Aplastic Anemia: A Single-Centre Study in China

Background and purpose: Eltrombopag (ELT) can be effective in the treatment of relapse/refractory aplastic anemia (AA) patients. Responses and adverse drug reactions (ADRs) differed greatly among individuals treated at the same dosage of ELT.

Methods: Patients diagnosed with nonsevere aplastic anemia (NSAA) between January 2018 and January 2019 in Peking Union Medical Colleague Hospital who were refractory to immunosuppressive therapy were treated with ELT and followed up for at least 6 months. Plasma concentrations of ELT were detected by high-performance liquid chromatography-mass spectrometry after at least two months of ELT treatment and treatment at the same dosage for at least 2 weeks. The dose-concentration, concentration-response and concentration-ADR relationships were evaluated.

Results: Among the 72 patients treated with ELT during the study period, 44 patients with complete data were enrolled. Six (13.6%) were males, and 38 were females (86.4%), with a median age of 54 years [interquartile range (IQR): 38.5–63]. At the time the ELT plasma concentration was detected, the median dosage of ELT was 75 (IQR 50–100) mg/d, the median time of total ELT exposure was 3 (IQR 2.0–6.0) months, and 37 (70.5%) patients had responded to ELT. The median concentration of ELT was 10.4 μg/ml (IQR 3.7–24.4 μg/ml). The concentration of ELT was positively correlated with the daily dose of ELT (r = 0.68, p < 0.001). Multivariate logistic regression analysis showed that the risk of inefficacy of ELT at a concentration between 11.2 and 15.2 μg/ml was 0.028-fold (95% CI: 0.001–0.864; p = 0.041) of that at a concentration between 3.2 and 7.2 μg/ml. The cutoff value for the concentration of ELT showing efficacy was 12.50 μg/ml according to the receiver operation characteristic curve. A higher risk of ADR was related to a longer total exposure to ELT (p = 0.012). Although the correlation was not significant, the odds ratio increased with the ELT concentration, suggesting that it was possible that an elevated risk of ADR was correlated with the ELT blood concentration.

Conclusion: ELT is effective for the treatment of NSAA and has acceptable side effects. The plasma concentration of ELT was correlated with the dose and the effects of ELT.

Mesenchymal Stem Cells in Aplastic Anemia and Myelodysplastic Syndromes: The "Seed and Soil" Crosstalk

There is growing interest in the contribution of the marrow niche to the pathogenesis of bone marrow failure syndromes, i.e., aplastic anemia (AA) and myelodysplastic syndromes (MDSs). In particular, mesenchymal stem cells (MSCs) are multipotent cells that contribute to the organization and function of the hematopoietic niche through their repopulating and supporting abilities, as well as immunomodulatory properties. The latter are of great interest in MDSs and, particularly, AA, where an immune attack against hematopoietic stem cells is the key pathogenic player. We, therefore, conducted Medline research, including all available evidence from the last 10 years concerning the role of MSCs in these two diseases. The data presented show that MSCs display morphologic, functional, and genetic alterations in AA and MDSs and contribute to immune imbalance, ineffective hematopoiesis, and leukemic evolution. Importantly, adoptive MSC infusion from healthy donors can be exploited to heal the "sick" niche, with even better outcomes if cotransplanted with allogeneic hematopoietic stem cells. Finally, future studies on MSCs and the whole microenvironment will further elucidate AA and MDS pathogenesis and possibly improve treatment.

Effective treatment of refractory acquired pure red blood cell aplasia with eltrombopag and sirolimus: a case report

Acquired pure red cell aplasia (aPRCA) is a kind of anemia characterized by severe reticulocytopenia and reduced bone marrow erythroblastic cells. For patients who are refractory to the first-line therapy (cyclosporin A with/without glucocorticoids), second-line therapy is considered less effective. We report on a patient with primary aPRCA who was refractory to cyclosporin A, glucocorticoids, and several second-line regimens. The patient was treated with sirolimus for 10 months with no improvement in hemoglobin but complete response was achieved after adding eltrombopag at a dosage of 25 mg/day. Eltrombopag was well tolerated with no evidence of clonal evolution at the end of follow up. This case provided a new attempt at treating patients with refractory/relapse aPRCA with eltrombopag, probably in combination with sirolimus.