Eltrombopag for the treatment of refractory thrombocytopenia associated with connective tissue disease

Effectiveness and safety of eltrombopag in connective tissue disease patients with refractory immune thrombocytopenia: a retrospective study

Objectives

We aimed to investigate the safety and effectiveness of eltrombopag for adult patients with refractory immune thrombocytopenia (ITP) secondary to connective tissue disease (CTD).

Methods

This is a single-centre, retrospective cohort and propensity score-matched study. Data from CTD-ITP patients treated with eltrombopag between January 2019 and January 2023 were retrospectively analysed. Baseline characteristics and follow-up information were recorded. CTD patients without ITP were matched to identify the risk factors associated with CTD-ITP performed by Logistic regression analysis.

Results

Twenty patients were enrolled, including 5 systemic lupus erythematosus (SLE), 9 Sjögren's syndrome (SS) and 6 undifferentiated connective tissue disease (UCTD). Nineteen (95%) patients were female, and the median age was 59 years. Logistic regression analysis showed that anaemia (OR = 8.832, P = 0.007) was associated with increased risk of ITP, while non-erosive arthritis (OR = 0.045, P = 0.001) and interstitial lung disease (OR = 0.075, P = 0.031) were associated with reduced risk. Fourteen patients (70%) achieved a complete response (CR) and one (5%) achieved a partial response (PR). The median response time was 14 days. The median platelet count was 8.5 × 109/l at baseline of eltrombopag and increased to 122 × 109/l after 4 weeks. No adverse events were observed.

Conclusions

Eltrombopag appears to be effective, safe and well-tolerated in refractory ITP patients with CTD; larger studies are needed to confirm the generalizability of these findings.

Sirolimus for the treatment of patients with refractory connective tissue disease-related thrombocytopenia: a pilot study

OBJECTIVE

CTD-related immune thrombocytopenia (CTD-ITP) represents an unmet medical need because the drugs that are available are only partly effective and have considerable side-effects. The aim of this study was to assess the efficacy and safety of sirolimus in refractory CTD-ITP patients.

METHODS

We did a single-arm, open-label, pilot study of sirolimus in patients with CTD-ITP unresponsive to, or intolerant of, conventional medications. Patients received oral sirolimus for 6 months at a starting dose of 0.5-1 mg per day, with dose adjusted according to tolerance and to maintain a therapeutic range of 6-15 ng/ml. The primary efficacy end point was changes in platelet count, and overall response assessed according to the ITP International Working Group Criteria. Safety outcomes included tolerance as assessed by the occurrence of common side-effects.

RESULTS

Between November 2020 and February 2022, 12 consecutively hospitalized patients with refractory CTD-ITP were enrolled and prospectively followed. Of these, six patients (50%) achieved complete response, two (16.7%) achieved partial response, and four (33.3%) were no response under therapy. Three of four patients with primary Sjögren's syndrome and two of three patients with systemic lupus erythematosus achieved overall response. One of two patients with overlapping Sjögren's syndrome and systemic lupus erythematosus achieved complete response at 6 months. No severe drug-related toxicities were observed.

CONCLUSION

Our results do support sirolimus as an alternative regimen for refractory CTD-ITP patients, including systemic lupus erythematosus and primary SS.

A review on the role of RNA methylation in aging-related diseases

Senescence is the underlying mechanism of organism aging and is robustly regulated at the post-transcriptional level. This regulation involves the chemical modifications, of which the RNA methylation is the most common. Recently, a rapidly growing number of studies have demonstrated that methylation is relevant to aging and aging-associated diseases. Owing to the rapid development of detection methods, the understanding on RNA methylation has gone deeper. In this review, we summarize the current understanding on the influence of RNA modification on cellular senescence, with a focus on mRNA methylation in aging-related diseases, and discuss the emerging potential of RNA modification in diagnosis and therapy.

Refractory Acquired Amegakaryocytic Thrombocytopenia with Rapid Progression to Aplastic Anaemia in SLE

Acquired amegakaryocytic thrombocytopenia (AAMT) is a rare cause of thrombocytopenia seen in systemic lupus erythematosus (SLE) that is frequently misdiagnosed as immune thrombocytopenic purpura (ITP). Often patients do not respond to standard ITP treatment. Prompt bone marrow biopsy and further workup should ensue as it is a diagnosis of exclusion. While no standard guidelines exist, the mainstay of treatment is immunosuppressive therapy. Some cases are refractory and should have a follow-up biopsy, typically showing worsening disease. The exact pathogenesis is unclear; multiple mechanisms may be involved, suggesting AAMT may be a syndrome of various aetiologies rather than a distinct pathology. A common complication is aplastic anaemia, and the patient may need a haematopoietic stem cell transplant (HSCT). We present a young man with severe refractory AAMT in the setting of SLE that progressed to aplastic anaemia and required an HSCT. We then discuss and interpret the literature on AAMT.

RNA modification: mechanisms and therapeutic targets

RNA modifications are dynamic and reversible chemical modifications on substrate RNA that are regulated by specific modifying enzymes. They play important roles in the regulation of many biological processes in various diseases, such as the development of cancer and other diseases. With the help of advanced sequencing technologies, the role of RNA modifications has caught increasing attention in human diseases in scientific research. In this review, we briefly summarized the basic mechanisms of several common RNA modifications, including m6A, m5C, m1A, m7G, Ψ, A-to-I editing and ac4C. Importantly, we discussed their potential functions in human diseases, including cancer, neurological disorders, cardiovascular diseases, metabolic diseases, genetic and developmental diseases, as well as immune disorders. Through the "writing-erasing-reading" mechanisms, RNA modifications regulate the stability, translation, and localization of pivotal disease-related mRNAs to manipulate disease development. Moreover, we also highlighted in this review all currently available RNA-modifier-targeting small molecular inhibitors or activators, most of which are designed against m6A-related enzymes, such as METTL3, FTO and ALKBH5. This review provides clues for potential clinical therapy as well as future study directions in the RNA modification field. More in-depth studies on RNA modifications, their roles in human diseases and further development of their inhibitors or activators are needed for a thorough understanding of epitranscriptomics as well as diagnosis, treatment, and prognosis of human diseases.

Methyltransferase-like proteins in cancer biology and potential therapeutic targeting

RNA modification has recently become a significant process of gene regulation, and the methyltransferase-like (METTL) family of proteins plays a critical role in RNA modification, methylating various types of RNAs, including mRNA, tRNA, microRNA, rRNA, and mitochondrial RNAs. METTL proteins consist of a unique seven-beta-strand domain, which binds to the methyl donor SAM to catalyze methyl transfer. The most typical family member METTL3/METTL14 forms a methyltransferase complex involved in N6-methyladenosine (m6A) modification of RNA, regulating tumor proliferation, metastasis and invasion, immunotherapy resistance, and metabolic reprogramming of tumor cells. METTL1, METTL4, METTL5, and METTL16 have also been recently identified to have some regulatory ability in tumorigenesis, and the rest of the METTL family members rely on their methyltransferase activity for methylation of different nucleotides, proteins, and small molecules, which regulate translation and affect processes such as cell differentiation and development. Herein, we summarize the literature on METTLs in the last three years to elucidate their roles in human cancers and provide a theoretical basis for their future use as potential therapeutic targets.

The Outcomes and Adverse Drug Patterns of Immunomodulators and Thrombopoietin Receptor Agonists in Primary Immune Thrombocytopenia Egyptian Patients with Hemorrhage Comorbidity

Immune thrombocytopenia (ITP) treatment has evolved recently. However, none of the treatments have only benefits without drawbacks. This study aimed to compare the clinical outcomes and adverse drug patterns of Eltrombopag, Romiplostim, Prednisolone + Azathioprine, High Dose-dexamethasone (HD-DXM) (control group), and Rituximab in primary ITP Egyptian patients. All patients were initiated with corticosteroids, HD-DXM, as a first-line treatment for the first month immediately following diagnosis. Four hundred sixty-seven ITP patients were randomly assigned to five groups. The outcome measures were judged at baseline, at the end of treatment (6 months), and after an additional 6-month free treatment period. The follow-up period for which relapse is noted was 6 months after the end of treatment. Eltrombopag and Romiplostim resulted in a significantly higher incidence of sustained response than Rituximab, HD-DXM, and Prednisolone + Azathioprine (55.2% and 50.6% vs. 29.2%, 29.1%, and 18%, respectively; p-value < 0.001). More patients on immunomodulators (Prednisolone+ Azathioprine, HD-DXM, and Rituximab) relapsed than those on Romiplostim and Eltrombopag (81.9%, 70.8%, and 70.7% vs. 49.3%, and 44.7%, respectively; p-value < 0.01). We also describe 23 reports of pulmonary hypertension with Prednisolone+ Azathioprine and 13 reports with HD-DXM. The thrombotic events occurred in 16.6% and 13% of patients who received Eltrombopag and Romiplostim treatment, respectively. Most patients had at least one or two risk factors (92.8% of cases). Corticosteroids are effective first-line therapy in primary ITP patients. However, relapse is frequent. Eltrombopag and Romiplostim are safer and more effective than Prednisolone, HD-DXM, and Rituximab. They might be reasonable beneficial options after a one-month HD-DXM regimen.

Catastrophic antiphospholipid syndrome in lupus-associated immune thrombocytopenia treated with eltrombopag A case series and literature review

BACKGROUND

Eltrombopag, a thrombopoietin receptor (TPO-R) agonist, is considered a second-line treatment for patients with refractory immune thrombocytopenia (ITP). Systemic lupus erythematosus (SLE) is frequently associated with ITP. In some cases, thrombocytopenia in SLE patients is attributed to concurrent antiphospholipid antibodies (APLA). Currently, data regarding treatment with TPO-R agonists for ITP in SLE or APLA patients are limited. The incidence of SLE flare or antiphospholipid syndrome while on TPO-R agonists has not been well-studied.

CASES

We report 2 cases of female patients with SLE and concurrent triple positive APLA, without thrombotic events in their medical history, in our rheumatology clinic, who were treated for refractory ITP with eltrombopag. Both developed catastrophic antiphospholipid syndrome a few weeks after beginning treatment with eltrombopag. They were admitted to the intensive care unit and treated with solumedrol, plasmapheresis, anticoagulation and rituximab.

CONCLUSIONS

We describe a severe possible side-effect of eltrombopag as a trigger of catastrophic antiphospholipid syndrome, a rare initial manifestation of antiphospholipid syndrome, in SLE patients with APLA. We suggest that APLA should be tested before initiating eltrombopag in patients with SLE-associated ITP. The safety of this treatment should be considered in these cases.

METTL3 from Target Validation to the First Small-Molecule Inhibitors: A Medicinal Chemistry Journey

RNA methylation is a critical mechanism for regulating the transcription and translation of specific sequences or for eliminating unnecessary sequences during RNA maturation. METTL3, an RNA methyltransferase that catalyzes the transfer of a methyl group to the N⁶-adenosine of RNA, is one of the key mediators of this process. METTL3 dysregulation may result in the emergence of a variety of diseases ranging from cancer to cardiovascular and neurological disorders beyond contributing to viral infections. Hence, the discovery of METTL3 inhibitors may assist in furthering the understanding of the biological roles of this enzyme, in addition to contributing to the development of novel therapeutics. Through this work, we will examine the existing correlations between METTL3 and diseases. We will also analyze the development, mode of action, pharmacology, and structure-activity relationships of the currently known METTL3 inhibitors. They include both nucleoside and non-nucleoside compounds, with the latter comprising both competitive and allosteric inhibitors.

Eltrombopag in severe immune thrombocytopenia secondary to connective tissue disease: a report of 17 patients and literature review

To assess the remission rate of eltrombopag in the treatment of severe immune thrombocytopenia (ITP) secondary to connective tissue disease (CTD) and to explore factors related to drug efficacy in the context of literature reports, seventeen CTD patients accompanied with severe ITP treated with eltrombopag between June 2019 and February 2021 were included, with their follow-up information recorded. Combined with literature review, patients were divided into two groups depending on whether the treatment was effective or not to determine efficacy-related factors. Totally, 7 patients with systemic lupus erythematosus, 6 with Sjögren's syndrome, and 4 with undifferentiated connective tissue disease were enrolled. The median duration of eltrombopag treatment was 8 weeks, and the median time to response was 4 weeks. Twelve (70.6%) patients responded to eltrombopag. Patients with higher serum white blood cell counts, lower serum triglyceride levels, or previously received multiple immunosuppressants achieved a better efficacy (p < 0.05), while those with megakaryocytopenia in bone marrow tended to have lower remission rate (p = 0.08). By using pooled data including literature reported cases, we demonstrated that evidence of leukopenia, megakaryocytopenia, and being treated with fewer prior immunosuppressants were still associated with poor remission (p < 0.05). Meanwhile, there was a trend indicating the primary disease might affect the treatment efficacy (p = 0.06). Eltrombopag is a viable option for treating severe ITP secondary to CTDs, yet it may be less effective for patients with leukopenia, megakaryocytopenia, and being treated with fewer prior immunosuppressants. Key Points • Eltrombopag provides an alternative to the current treatment of CTD-ITP. • White blood cell levels, bone marrow megakaryocyte counts, and prior use of immunosuppressants may affect the efficacy of eltrombopag.

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.

Eltrombopag improves refractory thrombocytopenia in patients with Sjögren's syndrome

INTRODUCTION

Eltrombopag, a kind of thrombopoietin (TPO) receptor agonist, plays the role on the megakaryocyte to activate the platelet production and rapidly increase the number of circulating platelets in patients with primary immune thrombocytopenia (ITP). Eltrombopag provides an opportunity for rapid tapering and/or cessation of corticosteroid therapy. However, it is not clear about the platelet response to Eltrombopag in ITP associated with Sjögren's Syndrome(SS).

METHODS

A retrospective research was conducted on the clinical course of three patients, each with ITP secondary to SS, and initially received therapy of corticosteroids or other immunomodulatory. They took this drug for bleeding diseases. Referring to the description, Eltrombopag was prescribed and adjusted with an initial dose of 25 mg daily, then weekly, then monthly according to the monitoring of platelet counts.

RESULTS

All patients maintained a satisfactory level of platelet counts (>100,000/mm3 for >2 years) following corticosteroid withdrawal. Meanwhile, Eltrombopag was well-tolerated, and there were no adverse effects, such as thrombotic events.

CONCLUSIONS

Eltrombopag is effective and safe for patients with ITP associated with SS during corticosteroid withdrawal. Thus it may be a crucial therapeutic strategy for reducing corticosteroid-related side effects in SS patients with ITP.

Eltrombopag as an Allosteric Inhibitor of the METTL3-14 Complex Affecting the m6A Methylation of RNA in Acute Myeloid Leukemia Cells

N⁶A-methyladenosine (m⁶A) post-transcriptional modification, the most abundant internal RNA modification, is catalyzed by the METTL3-14 methyltransferase complex. Recently, attention has been drawn to the METTL3-14 complex regarding its significant roles in the pathogenesis of acute myeloid leukemia (AML), attracting the potential of novel therapeutic targets for the disease. Herein, we report the identification and characterization of eltrombopag as a selective allosteric inhibitor of the METTL3-14 complex. Eltrombopag exhibited selective inhibitory activity in the most active catalytic form of the METTL3-14 complex by direct binding, and the mechanism of inhibition was confirmed as a noncompetitive inhibition by interacting at a putative allosteric binding site in METTL3, which was predicted by cavity search and molecular docking studies. At a cellular level, eltrombopag displayed anti-proliferative effects in the relevant AML cell line, MOLM-13, in correlation with a reduction in m⁶A levels. Molecular mechanism studies of eltrombopag using m⁶A-seq analysis provided further evidence of its cellular function by determining the hypomethylation of leukemogenic genes in eltrombopag-treated MOLM-13 cells and the overlapping of the pattern with those of METTL3-knockdown MOLM-13 cells. In conclusion, eltrombopag was first disclosed as a functional METTL3-14 allosteric inhibitor in AML cells, which could be utilized for the further development of novel anti-AML therapy.

Immune Thrombocytopenia in Antiphospholipid Syndrome: Is It Primary or Secondary?

Antiphospholipid syndrome (APS) is frequently associated with thrombocytopenia, in most cases mild and in the absence of major bleedings. In some patients with a confirmed APS diagnosis, secondary immune thrombocytopenia (ITP) may lead to severe thrombocytopenia with consequent major bleeding. At the same time, the presence of antiphospholipid antibodies (aPL) in patients with a diagnosis of primary ITP has been reported in several studies, although with some specific characteristics especially related to the variety of antigenic targets. Even though it does not enter the APS defining criteria, thrombocytopenia should be regarded as a warning sign of a “high risk” APS and thus thoroughly evaluated. The presence of aPL in patients with ITP should be assessed as well to stratify the risk of paradoxical thrombosis. In detail, besides the high hemorrhagic risk in secondary thrombocytopenia, patients with a co-diagnosis of APS or only antibodies are also at risk of arterial and venous thrombosis. In this narrative review, we discuss the correlation between APS and ITP, the mechanisms behind the above-reported entities, in order to support clinicians to define the most appropriate treatment strategy in these patients, especially when anticoagulant or antiplatelet agents may be needed.