All-trans retinoic acid plus high-dose dexamethasone as first-line treatment for patients with newly diagnosed immune thrombocytopenia: a multicentre, open-label, randomised, controlled, phase 2 trial

The many facets of immune-mediated thrombocytopenia: Principles of immunobiology and immunotherapy

Immune thrombocytopenia (ITP) is a rare autoimmune condition, due to peripheral platelet destruction through antibody-dependent cellular phagocytosis, complement-dependent cytotoxicity, cytotoxic T lymphocyte-mediated cytotoxicity, and megakaryopoiesis alteration. This condition may be idiopathic or triggered by drugs, vaccines, infections, cancers, autoimmune disorders and systemic diseases. Recent advances in our understanding of ITP immunobiology support the idea that other forms of thrombocytopenia, for instance, occurring after immunotherapy or cellular therapies, may share a common pathophysiology with possible therapeutic implications. If a decent pipeline of old and new agents is currently deployed for classical ITP, in other more complex immune-mediated thrombocytopenic disorders, clinical management is less harmonized and would deserve further prospective investigations. Here, we seek to provide a fresh overview of pathophysiology and current therapeutical algorithms for adult patients affected by this disorder with specific insights into poorly codified scenarios, including refractory ITP and post-immunotherapy/cellular therapy immune-mediated thrombocytopenia.

Efficacy and safety of azathioprine plus prednisone versus prednisone alone as first-line treatment for antinuclear antibody-positive immune thrombocytopenia: a retrospective cohort study

OBJECTIVE

Antinuclear antibody (ANA)-positive immune thrombocytopenia (ITP) patients have an unsatisfactory prognosis due to the more severe conditions of these patients and poor response to first-line glucocorticoids (GCs). The current study intended to compare the efficacy and safety of AZA plus prednisone and prednisone alone as first-line treatment in ANA-positive ITP patients.

METHODS

Fifteen ANA-positive ITP patients receiving AZA plus prednisone (AZA + GC group) and eighteen ANA-positive ITP patients receiving prednisone alone (GC group) as first-line treatment were retrospectively enrolled.

RESULTS

The complete response (CR) rate (60.0% versus 22.2%) (P = 0.038) was increased in the AZA + GC group versus the GC group, while the overall response rate (86.7% versus 55.6%) (P = 0.070) only showed an increasing trend that did not achieve statistical significance. In addition, multivariate analysis revealed that AZA + GC (versus GC) (odds ratio = 31.331, P = 0.018) was independently associated with a higher possibility of achieving CR. Additionally, accumulating relapse-free duration was prolonged in the AZA + GC group versus the GC group (median: 7.8 months versus 3.4 months) (P = 0.038). Additionally, the multivariate analysis suggested that AZA + GC (versus GC) (hazard ratio = 0.306, P = 0.007) was independently correlated with longer accumulating relapse-free duration. The incidence of adverse events did not differ between the two groups (all P > 0.05), and the common adverse events in the AZA + GC group were pneumonia (13.3%), anemia (13.3%), cough (13.3%), nausea (6.7%), and granulocytopenia (6.7%), which were all tolerable and manageable.

CONCLUSION

First-line AZA plus prednisone realizes a better hematological response and relapse-free duration with acceptable adverse events compared to prednisone alone in ANA-positive ITP patients.

Efficacy and Safety Analysis of Combination Therapy Consisting of Intravenous Immunoglobulin and Corticosteroids versus Respective Monotherapies in the Treatment of Relapsed ITP in Adults

Objective  In this study, we aimed to evaluate the efficacy and safety of combination therapy, consisting of intravenous immunoglobulin (IVIg) and corticosteroids, in comparison to respective monotherapies in the treatment of relapsed immune thrombocytopenia (ITP) in adults. Methods  A retrospective analysis of clinical data was conducted on 205 adult patients with relapsed ITP who received first-line combination therapy or monotherapy in multiple centers across China from January 2010 to December 2022. The study evaluated the patients' clinical characteristics, efficacy, and safety. Results  We found that the proportion of patients with platelet counts in complete response was significantly higher in the combination group (71.83%) compared with the IVIg group (43.48%) and the corticosteroids group (23.08%). The mean PLT _max in the combination group (178 × 10 ⁹ /L) was significantly higher than that in the IVIg group (109 × 10 ⁹ /L) and the corticosteroids group (76 × 10 ⁹ /L). Additionally, the average time for platelet counts to reach 30 × 10 ⁹ /L, 50 × 10 ⁹ /L, and 100 × 10 ⁹ /L in the combination group was significantly shorter than in the monotherapy groups. The proportion curves for reaching these platelet counts during treatment were also significantly different from those in the monotherapy groups. However, there were no significant differences in the effective rate, clinical characteristics, and adverse events among the three groups. Conclusion  We concluded that combining IVIg and corticosteroids was a more effective and faster treatment for relapsed ITP in adults than using either therapy alone. The findings of this study provided clinical evidence and reference for the use of first-line combination therapy in the treatment of relapsed ITP in adults.

All-trans retinoic acid added to treatment of primary immune thrombocytopenia: a systematic review and meta-analysis

All-trans retinoic acid (ATRA) application is a novel treatment approach for primary immune thrombocytopenia (ITP). This study aimed to evaluate the efficacy and safety of ATRA in the treatment of ITP. The databases of PubMed (MEDLINE), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and China National Knowledge Internet were searched on August 5, 2022, to find randomized controlled trials (RCTs) and observational studies. Five observational studies and four RCTs from China were included, and 760 Chinese patients were analyzed. In the five observational studies, the pooled overall response rate (ORR) and complete response rate (CRR) were 59.5% (95% confidence interval [CI], 52.4-66.4%) and 20.6% (95% CI, 14.3-27.6%), respectively. In the selected four RCTs, the pooled odds ratios for sustained response rate, ORR, and CRR were 3.00 (95% CI, 1.97-4.57; P < 0.01), 3.21 (95% CI, 2.15-4.78; P < 0.01), and 2.12 (95% CI, 1.17-3.86; P = 0.01), respectively. ATRA was associated with a reduction in relapse rate and salvage treatment rate (odds ratio, 0.30; 95% CI, 0.18-0.50; P < 0.01; 0.36; 95% CI, 0.23-0.56; P < 0.01, respectively). The pooled odds ratios for grade 1-2 dry skin, headache (or dizziness), and rash acneiform were 49.99 (95% CI, 16.05-155.67; P < 0.01), 1.75 (95% CI, 0.98-3.12; P = 0.06), and 0.37 (95% CI, 0.10-1.34; P = 0.13), respectively. This study suggests that ATRA may significantly improve the initial and long-term response of patients with ITP.

Recent progress in ITP treatment

In this review, the recently approved drugs avatrombopag and fostamatinib, which were not extensively covered within 2019 international recommendations for ITP, will be discussed in some detail. Avatrombopag appears more convenient than eltrombopag as it does not require dietary restrictions or subcutaneous administration like romiplostim. However, data on quality of life (QoL) are lacking and the rate of thromboembolic events in exposed patients is not negligible. Efficacy of fostamatinib, an inhibitor of macrophagic activity, is supported by placebo-controlled trials in patients refractory to several therapies, including TPO-RA. While hypertension and diarrhea have been reported, only one minor thrombotic event occurred in 146 exposed patients. In addition, several new treatment combinations and new agents entered clinical investigation in recent years. In a UK trial, combining mycophenolate mofetil with corticosteroids as first line therapy was more effective than corticosteroids alone, but at the cost of worse QoL. No combination, including oseltamivir or all-trans retinoic acid or danazol, resulted in convincing evidence of superior efficacy and safety when used in first or later lines of treatment. Agents targeting specific mechanisms are also discussed: sutimlimab (complement inhibitor); rilzabrutinib (BTK inhibitor) and efgartigimod (modified Fc fragment inhibiting FcRn). Only efgartigimod has completed phase 3 investigation.

Application and investigation of thrombopoiesis-stimulating agents in the treatment of thrombocytopenia

Platelets, derived from a certain subpopulation of megakaryocytes, are closely related to hemostasis, coagulation, metastasis, inflammation, and cancer progression. Thrombopoiesis is a dynamic process regulated by various signaling pathways in which thrombopoietin (THPO)-MPL is dominant. Thrombopoiesis-stimulating agents could promote platelet production, showing therapeutic effects in different kinds of thrombocytopenia. Some thrombopoiesis-stimulating agents are currently used in clinical practices to treat thrombocytopenia. The others are not in clinical investigations to deal with thrombocytopenia but have potential in thrombopoiesis. Their potential values in thrombocytopenia treatment should be highly regarded. Novel drug screening models and drug repurposing research have found many new agents and yielded promising outcomes in preclinical or clinical studies. This review will briefly introduce thrombopoiesis-stimulating agents currently or potentially valuable in thrombocytopenia treatment and summarize the possible mechanisms and therapeutic effects, which may enrich the pharmacological armamentarium for the medical treatment of thrombocytopenia.

A bibliometric analysis of primary immune thrombocytopenia from 2011 to 2021

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia. This bibliometric analysis was applied to identify the characteristics of global scientific output, the hotspots, and frontiers of ITP over the past 10 years. We retrieved publications from 2011 to 2021 from the Web of Science Core Collection (WoSCC). Bibliometrix package, VOSviewer, and Citespace were used to analyse and visualize the trend, distribution, and hotspots of research on ITP. Altogether, there were 2084 papers, written by 9080 authors from 410 organizations in 70 countries/regions, published in 456 journals with 37 160 co-cited references. In the last decades, the most productive journal was British Journal of Haematology, China was the most productive country. and the most cited journal was Blood. Shandong University was the most productive institution in the field of ITP. NEUNERT C, 2011, BLOOD, CHENG G, 2011, LANCET, and PATEL VL, 2012, BLOOD were the top three most cited documents. "Thrombopoietin receptor agonist", "regulatory T cell" and "sialic acid" were three hotspots of the last decade. And "immature platelet fraction", "Th17", and "fostamatinib" would be research frontiers in the feature. The present study provided a novel insight for future research directions and scientific decision-making.

Efficacy and safety of treatments in newly diagnosed adult primary immune thrombocytopenia: A systematic review and network meta-analysis

BACKGROUND

Immune thrombocytopenia is an autoimmune disease characterised by decreased platelet count. In recent years, novel therapeutic regimens have been investigated in randomised controlled trials (RCTs). We aimed to compare the efficacy and safety of different treatments in newly diagnosed adult primary immune thrombocytopenia.

METHODS

We did a systematic review and network meta-analysis of RCTs involving treatments for newly diagnosed primary immune thrombocytopenia. PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases were searched up to April 31, 2022. The primary outcomes were 6-month sustained response and early response. Secondary outcome was grade 3 or higher adverse events. This study is registered with PROSPERO (CRD42022296179).

FINDINGS

Eighteen RCTs (n = 1944) were included in this study. Pairwise meta-analysis showed that the percentage of patients achieving early response was higher in the dexamethasone-containing doublet group than in the dexamethasone group (79.7% vs 68.7%, odds ratio [OR] 1.82, 95% CI 1.10-3.02). The difference was more profound for sustained response (60.5% vs 37.4%, OR 2.57, 95% CI 1.95-3.40). Network meta-analysis showed that dexamethasone plus recombinant human thrombopoietin ranked first for early response, followed by dexamethasone plus oseltamivir or tacrolimus. Rituximab plus prednisolone achieved highest sustained response, followed by dexamethasone plus all-trans retinoic acid or rituximab. Rituximab plus dexamethasone showed 15.3% of grade 3 or higher adverse events, followed by prednis(ol)one (4.8%) and all-trans retinoic acid plus dexamethasone (4.7%).

INTERPRETATION

Our findings suggested that compared with monotherapy dexamethasone or prednis(ol)one, the combined regimens had better early and sustained responses. rhTPO plus dexamethasone ranked top in early response, while rituximab plus corticosteroids obtained the best sustained response, but with more adverse events. Adding oseltamivir, all-trans retinoic acid or tacrolimus to dexamethasone reached equally encouraging sustained response, without compromising safety profile. Although this network meta-analysis compared all the therapeutic regimens up to date, more head-to-head RCTs with larger sample size are warranted to make direct comparison among these strategies.

FUNDING

National Natural Science Foundation of China, Major Research Plan of National Natural Science Foundation of China, Shandong Provincial Natural Science Foundation and Young Taishan Scholar Foundation of Shandong Province.

How we treat primary immune thrombocytopenia in adults

Primary immune thrombocytopenia (ITP) is an immune-mediated bleeding disorder characterized by decreased platelet counts and an increased risk of bleeding. Multiple humoral and cellular immune abnormalities result in accelerated platelet destruction and suppressed platelet production in ITP. The diagnosis remains a clinical exclusion of other causes of thrombocytopenia. Treatment is not required except for patients with active bleeding, severe thrombocytopenia, or cases in need of invasive procedures. Corticosteroids, intravenous immunoglobulin, and anti-RhD immunoglobulin are the classical initial treatments for newly diagnosed ITP in adults, but these agents generally cannot induce a long-term response in most patients. Subsequent treatments for patients who fail the initial therapy include thrombopoietic agents, rituximab, fostamatinib, splenectomy, and several older immunosuppressive agents. Other potential therapeutic agents, such as inhibitors of Bruton's tyrosine kinase and neonatal Fc receptor, are currently under clinical evaluation. An optimized treatment strategy should aim at elevating the platelet counts to a safety level with minimal toxicity and improving patient health-related quality of life, and always needs to be tailored to the patients and disease phases. In this review, we address the concepts of adult ITP diagnosis and management and provide a comprehensive overview of current therapeutic strategies under general and specific situations.

Changing Paradigms in ITP Management: Newer Tools for an Old Disease

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by isolated thrombocytopenia that may be accompanied clinically by bleeding and reduced health-related quality of life (HRQoL). While corticosteroids, splenectomy, and various immunosuppressants (used off-label) have served as historical mainstays of ITP treatment, their use is associated with adverse effects and morbidity. Over the last 15 years, the advent of the thrombopoietin receptor agonists has revolutionized the management of chronic ITP with high response rates, durable responses, and minimal adverse effects in most patients. With four agents now FDA-approved to manage chronic ITP, there is a renewed emphasis on improving HRQoL and minimizing the toxicities associated with traditional therapies. Promising agents with diverse mechanisms of action, ranging from those targeting Bruton's Tyrosine Kinase to the neonatal Fc receptor, are currently under investigation. This review highlights recent landmark clinical trials which have made significant impacts on ITP management and ongoing drug development. In critically analyzing studies of relevance, we illustrate the changing paradigms of ITP management and how the field is advancing beyond traditional therapies.

Systemic lupus erythematosus-complicating immune thrombocytopenia: From pathogenesis to treatment

Immune thrombocytopenia (ITP) is a common hematological manifestation of systemic lupus erythematosus (SLE). The heterogeneity of its clinical characteristics and therapeutic responses reflects a complex pathogenesis. A better understanding of its pathophysiological mechanisms and employing an optimal treatment regimen is therefore important to improve the response rate and prognosis, and avoid unwanted outcomes. Besides glucocorticoids, traditional immunosuppressants (i.e. cyclosporine, mycophenolate mofetil) and intravenous immunoglobulins, new therapies are emerging and promising for the treatment of intractable SLE-ITP, such as thrombopoietin receptor agonists (TPO-RAs), platelet desialylation inhibitors(i.e. oseltamivir), B-cell targeting therapy(i.e. rituximab, belimumab), neonatal Fc receptor(FcRn) inhibitor, spleen tyrosine kinase(Syk) inhibitor and Bruton tyrosine kinase(BTK) inhibitor et al., although more rigorous randomized controlled trials are needed to substantiate their efficacy. In this review, we update our current knowledge on the pathogenesis and treatment of SLE-ITP.

UNC13B Promote Arsenic Trioxide Resistance in Chronic Lymphoid Leukemia Through Mitochondria Quality Control

In clinical practice, arsenic trioxide can be used to treat a subset of R/R CML patients, but resistance tends to reappear quickly. We designed an experiment to study arsenic trioxide resistance in K-562 cells. Previously, we identified the UNC13B gene as potentially responsible for arsenic trioxide resistance in K-562 cells via gene chip screening followed by high-content screening. We aimed to investigate the role and mechanism of the UNC13B gene in K-562 cells, an arsenic trioxide-resistant chronic myeloid leukemia cell line. In vitro lentiviral vector-mediated UNC13B siRNA transfection was performed on K-562 cells. The roles of UNC13B in cell proliferation, apoptosis and cell cycle pathways, and colony formation were analyzed by CCK-8 assay, fluorescence-activated cell sorting, and soft agar culture, respectively. Gene chip screening was used to define the possible downstream pathways of UNC13B. Western blot was performed to further validate the possible genes mediated by UNC13B for arsenic trioxide resistance in patients with chronic myeloid leukemia. UNC13B downregulation significantly inhibited growth, promoted apoptosis, decreased colony formation, reduced the duration of the G1 phase, and increased the duration of the S phase of K-562 cells. Western blot results confirmed that UNC13B may modulate the apoptosis and proliferation of arsenic trioxide-resistant chronic myeloid leukemia cells through the mediation of MAP3K7, CDK4, and PINK1. UNC13B is a potential therapeutic target for patients with arsenic trioxide-resistant chronic myeloid leukemia.

Immune Cell Plasticity in Inflammation: Insights into Description and Regulation of Immune Cell Phenotypes

Inflammation is a life-saving immune reaction occurring in response to invading pathogens. Nonetheless, inflammation can also occur in an uncontrolled, unrestricted manner, leading to chronic disease and organ damage. Mechanisms triggering an inflammatory response, hindering such a response, or leading to its resolution are well-studied but so far insufficiently elucidated with regard to precise therapeutic interventions. Notably, as an immune reaction evolves, requirements and environments for immune cells change, and thus cellular phenotypes adapt and shift, leading to the appearance of distinct cellular subpopulations with new functional features. In this article, we aim to highlight properties of, and overarching regulatory factors involved in, the occurrence of immune cell phenotypes with a special focus on neutrophils, macrophages and platelets. Additionally, we point out implications for both diagnostics and therapeutics in inflammation research.

Alternatives for managing patients with newly diagnosed immune thrombocytopenia: a narrative review

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an acquired bleeding disorder. Conventionally, first-line ITP therapy aims to obtain a rapid response and stop or decrease the risk of bleeding by increasing the platelet count. At this point, the duration of the response, the tolerability, and the long-term safety of pharmacologic interventions are considered less of a priority. Combination treatments that simultaneously address multiple disease mechanisms are an attractive strategy to increase efficacy in acute ITP therapy. In this review, we discuss the treatment of newly diagnosed ITP patients, emphasizing the use of new combinations to benefit from their synergy.

AREAS COVERED

This article summarizes conventional treatment, recent and novel combinations, and COVID-19 management recommendations of newly diagnosed ITP patients.

EXPERT OPINION

The key areas for improvement consider the long-term effects of conventional first-line therapy, reducing relapse rates, and extending responses to achieve long-term remission. Although corticosteroids remain first-line therapy, restricting their use to avoid toxicity and the increasing use of rituximab and TPO-RAs in the first three months after diagnosis open the landscape for future interventions in frontline therapy for ITP. First-line therapy intensification or synergistic drug combination offers a potential and realistic shift in future treatment guidelines.