Thrombopoietin receptor agonists regulate myeloid-derived suppressor cell-mediated immunomodulatory effects in ITP.

TPO receptor agonists (TPO-RAs) are a class of clinical second-line regimens for the treatment of primary immune thrombocytopenia (ITP). It can promote megakaryocyte maturation and increase platelet production, but its effect on immunosuppressive cells in patients with ITP has not been explored. Sixty-two ITP patients and 34 healthy controls (HCs) were included in this study. The proportion and functions of myeloid-derived immunosuppressive cells (MDSCs) in ITP patients and HCs were investigated. We found that the proportion and function of MDSCs in ITP patients treated with TPO-RAs were significantly higher than those treated with glucocorticoids (GCs), which was correlated with the clinical efficacy. The proportion and function of cytotoxic Th1 cells and CD8+T cells decreased, while the proportion and immunosuppressive function of Treg cells increased in ITP patients treated with TPO-RAs. We further proved, through MDSC depletion tests, that the inhibitory effect of MDSCs on Th1 cells and the promotion of Treg cells in the original immune micro-environment of GCs-treated ITP patients were impaired; however, these MDSCs' functions were improved in TPO-RAs-treated patients. Finally, we found that the KLF9 gene in MDSCs cells of ITP patients treated with TPO-RAs was down-regulated, which contribute to the higher mRNA expression of GADD34 gene and improved function of MDSCs. These results demonstrate a novel mechanism of TPO-RAs for the treatment of ITP through the assessment of MDSCs and their subsequent impact on T cells, which provides a new basis for TPO-RAs as first-line treatment approach to the treatment of ITP.

Face validity of the Kids' ITP Tools (KIT) in the era of thrombopoietin receptor agonists.

The Kids' ITP Tools (KIT) is a questionnaire to assess quality of life of children with immune thrombocytopenia (ITP). The aim of this study was to update this previously validated tool to align with changes in clinical practice, specifically, treatment with thrombopoietin receptor agonists (TPO-RAs). Children aged 1-18 with ITP and/or their families were recruited to participate in interviews to review the KIT. Twenty-six interviews were conducted. Based on interview data from children and families, current guidelines, and expert opinion, five changes were made to the KIT in order to improve its face validity.

Thrombopoietin Receptor Agonists and Other Second-Line Therapies for Immune Thrombocytopenia: A Narrative Review With a Focus on Drug Access in Canada.

INTRODUCTION: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by low platelet counts and increased risk of bleeding. After corticosteroids with or without intravenous immune globulin (first-line treatment), second-line treatment options include rituximab, splenectomy, thrombopoietin receptor agonists (TPO-RAs), and fostamatinib. In Canada, the choice of second-line therapy is influenced by access to medications. The goals of this narrative review are to 1) summarize the evidence for the use of TPO-RAs and other second-line therapies in ITP and 2) highlight differences in public funding criteria for TPO-RAs across provinces and territories in Canada. METHODS: We conducted a literature review of second-line therapies for ITP. We solicited information on public funding programs for TPO-RAs in Canada from health care providers, pharmacists, and provincial ministries of health. RESULTS: Head-to-head trials involving TPO-RAs, rituximab, splenectomy, and fostamatinib are lacking. There is substantial evidence of effect for TPO-RAs in improving platelet count levels, health-related quality of life, bleeding, and fatigue from placebo-controlled trials and observational studies; however, access to TPO-RAs through provincial funding programs in Canada is variable. Splenectomy failure is a prerequisite for the funding of TPO-RAs in Ontario, Manitoba, and Saskatchewan, but not in Alberta or Quebec. Other provinces either do not have access to public funding or funding is provided on a case-by-case basis. DISCUSSION: TPO-RAs are effective second-line therapies for the treatment of ITP; however, access is variable across Canada, which results in health disparities and poor uptake of international treatment guidelines.

Recommendations for the future management of thrombocytopenia in patients with liver cirrhosis: A modified RAND/UCLA appropriateness method.

OBJECTIVE: The lack of consensus and specific guidelines, and the introduction of new treatments in thrombocytopenia management in liver cirrhosis patients, required a series of recommendations by experts to improve knowledge on this disease. This study's aim was to improve the knowledge around thrombocytopenia in liver cirrhosis patients, in order to contribute to the generation of future evidence to improve the management of this disease. PATIENTS AND METHODS: A modified version of the RAND/UCLA appropriateness method was used. The scientific committee, a multidisciplinary team of 7 experts in managing thrombocytopenia in liver cirrhosis patients, identified the expert panel, and participated in elaborating the questionnaire. Thirty experts from different Spanish institutions were invited to answer a 48-item questionnaire covering 6 areas on a nine-point Likert scale. Two rounds were voted. The consensus was obtained if >77.7% of panelists reached agreement or disagreement. RESULTS: A total of 48 statements were developed by the scientific committee and then voted by the experts, resulting in 28 defined as appropriate and completely necessary, relating to evidence generation (10), care circuit, (8), hemorrhagic risk assessment, decision-making and diagnostic tests (14), professionals' role and multidisciplinary coordination (9) and patient education (7). CONCLUSIONS: This is the first consensus in Spain on the management of thrombocytopenia in liver cirrhosis patients. Experts indicated several recommendations to be carried out in different areas that could help physicians make better decisions in their clinical practice.

Treatment of immune thrombocytopenia during pregnancy with thrombopoietin receptor agonists.

The introduction of thrombopoietin receptor agonists (TPO-RAs) led to a paradigm shift in the management of immune thrombocytopenia (ITP). However, TPO-RAs are not approved for use during pregnancy due to the absence of evidence and concerns for possible effects on the fetus due to their expected transplacental transfer. This comprehensive review examines the safety and efficacy of TPO-RA in 45 pregnancies of women with ITP (romiplostim n = 22; eltrombopag n = 21; both in the same pregnancy n = 2). Mothers experienced failure of the median of three treatment lines during pregnancy prior to TPO-RA administration. A platelet response (>30 × 109 /L) was seen in 86.7% of cases (including a complete response >100 × 109 /L in 66.7%) and was similar between eltrombopag and romiplostim (87.0% and 83.3%, p = 0.99). The maternal safety profile was favourable, with no thromboembolic events encountered. Neonatal thrombocytopenia was noted in one third of cases, with one case of ICH grade 3, and neonatal thrombocytosis was observed in three cases. No other neonatal adverse events attributable to TPO-RAs were seen. This review suggests that the use of TPO-RA during pregnancy is associated with a high response rate and appears safe. Nevertheless, TPO-RA should not be routinely used in pregnancy and should be avoided in the first trimester until further evidence is accumulated.

The role of T cells and myeloid-derived suppressor cells in refractory immune thrombocytopenia.

Immune thrombocytopenia (ITP) is characterized by a dysregulated immune response against platelets, affecting both their destruction and production. A role for an abnormal T-cell compartment has been established in ITP pathogenesis and treatments that increase platelet counts in patients with ITP have shown improvements in T-cell profiles. On the other hand, patients who were refractory to treatment appear to retain the T-cell abnormalities as before. Myeloid-derived suppressive cells (MDSCs) are also emerging as key contributors to the immune pathology of ITP and response to treatment. In this review, we will discuss how various treatments affect the T-cell and MDSC compartments in ITP. The review will focus on studies that have examined the underlying mechanisms and/or genetic basis responsible for refractoriness to a given treatment and highlight remaining challenges in identifying factors and mechanisms to predict response to treatment.

Use of thrombopoietin receptor agonists in adults with immune thrombocytopenia: a systematic review and Central European expert consensus.

There are currently three thrombopoietin receptor agonists (TPO-RAs) approved in Europe for treating patients with immune thrombocytopenia (ITP): romiplostim (Nplate®), eltrombopag (Revolade®), and avatrombopag (Doptelet®). However, comparative clinical data between these TPO-RAs are limited. Therefore, the purpose of this study was to perform a literature review and seek expert opinion on the relevance and strength of the evidence concerning the use of TPO-RAs in adults with ITP. A systematic search was conducted in PubMed and Embase within the last 10 years and until June 20, 2022. A total of 478 unique articles were retrieved and reviewed for relevance. The expert consensus panel comprised ITP senior hematologists from eight countries across Central Europe. The modified Delphi method, consisting of two survey rounds, a teleconference and email correspondence, was used to reach consensus. Forty articles met the relevancy criteria and are included as supporting evidence, including five meta-analyses analyzing all three European-licensed TPO-RAs and comprising a total of 31 unique randomized controlled trials (RCTs). Consensus was reached on seven statements for the second-line use of TPO-RAs in the management of adult ITP patients. In addition, the expert panel discussed TPO-RA treatment in chronic ITP patients with mild/moderate COVID-19 and ITP patients in the first-line setting but failed to reach consensus. This work will facilitate informed decision-making for healthcare providers treating adult ITP patients with TPO-RAs. However, further studies are needed on the use of TPO-RAs in the first-line setting and specific patient populations.

A cost-utility analysis of thrombopoietin receptor agonists for treating pediatric immune thrombocytopenia purpura after failure of first-line therapies.

BACKGROUND: Thrombopoietin receptor agonists (TPO-RAs) have emerged as a recommended treatment for children with persistent and/or chronic immune thrombocytopenic purpura (ITP). The purpose of this study was to evaluate the cost-effectiveness of TPO-RAs relative to treatment without TPO-RAs (non-TPO-RAs/usual care) for ITP in children who do not respond to first-line therapy and in whom splenectomy is not recommended in Ontario, Canada, from a hospital payer perspective. PROCEDURE: A 2-year Markov model with an embedded decision tree was used. Data on medications used, dose, response rate, bleeding, and emergency treatment events were collected from the Hospital for Sick Children in Toronto. The health outcomes were described in quality-adjusted life-years (QALYs). Health-state utilities were derived from the peer-reviewed literature. Scenario analyses, deterministic, and probabilistic sensitivity analyses were conducted. Economic costs were measured in 2021 Canadian dollars ($1.00 = US$0.80) RESULTS: TPO-RAs are estimated to result in an increased cost of $27,118 and a QALY gain of 0.21 compared to non-TPO-RAs over a 2-year horizon, resulting in an incremental cost-effectiveness ratio (ICER) of $129,133. In a 5-year scenario analysis, the ICER fell to $76,403. In the probabilistic sensitivity analysis, TPO-RAs exhibit a 40.0% probability of being cost-effective at a conventional ($100,000) willingness-to-pay threshold per QALY gained. CONCLUSIONS: Further assessment of the long-term efficacy of TPO-RAs is warranted to obtain more precise long-term estimates. As the costs of TPO-RAs decline with the introduction of generic formulations, TPO-RAs may be increasingly cost-effective.

Efficacy and Incidence of Treatment-Related Adverse Events of Thrombopoietin Receptor Agonists in Adults with Immune Thrombocytopenia: A Systematic Review and Network Meta-Analysis of Randomized Controlled Study.

INTRODUCTION: The aim of the study was to conduct a network meta-analysis to assess the efficacy and incidence of treatment-related adverse events (TRAEs) of eltrombopag, romiplostim, avatrombopag, recombinant human thrombopoietin (rhTPO), and hetrombopag for adult immune thrombocytopenia (ITP). METHODS: Randomized controlled trials (RCTs) of the five therapies from inception to June 1, 2022, were included. The efficacy outcome was the rate of platelet response, defined as the achievement of platelet counts above 50 × 109/L. Pairwise odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The surface under the cumulative ranking (SUCRA) was used to rank the included therapies for each outcome. RESULTS: In total, 1,360 participants were analyzed in 14 eligible RCTs. All of the therapies showed a significantly better platelet response than the placebo, and avatrombopag (OR, 7.42; 95% CI: 1.74-31.69) and rhTPO (OR, 3.86; 95% CI: 1.62-9.18) were better than eltrombopag. Regarding TRAEs, no significant differences were found between patients receiving eltrombopag, romiplostim, and avatrombopag. Avatrombopag carried the highest platelet response rate with SUCRA value of 87.5, and carried the least TRAEs risk with SUCRA value of 37.0. CONCLUSIONS: These findings indicated that avatrombopag appeared to be the optimal choice as the second-line therapy for adult ITP.

Eltrombopag modulates the phenotypic evolution and potential immunomodulatory roles of monocytes/macrophages in immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease. Loss of immune tolerance plays a crucial role in the pathogenesis of ITP. Monocytes and macrophages play an indispensable role in the pathophysiology of hematopoietic malignancies and have been implicated as key players in platelet destruction. Approximately 80% of adult patients with ITP exhibit corticosteroid treatment failure or become dependent, requiring novel therapy. Thrombopoietin (TPO) receptor agonists (TPO-RAs) have been used clinically to manage ITP effectively, however, little is known about the effect of TPO-RAs on monocyte and macrophage modulation in adult ITP. In this study, we investigated the phenotypic evolution and potential immunomodulatory roles of monocytes/macrophages in ITP patients receiving eltrombopag therapy. Results showed that the peripheral monocyte count positively correlated with IFN-γ/IL-4 ratio in ITP patients. Moreover, numerous phenotype-associated genes in ITP macrophages exhibited diverse responses, and ITP macrophages exhibited more M1-related characteristics. After eltrombopag therapy, the peripheral monocyte count and IFN-γ/IL-4 ratio significantly decreased in ITP patients. M1-related characteristics of ITP macrophages were partially reversed by eltrombopag. Therefore, this study revealed eltrombopag restored the monocyte dynamics and the associated Th1/Th2 imbalance, and partially reversed the M1-related characteristics of the ITP macrophages, which suggest the potential vital roles of TPO-RAs in regulating the monocyte/macrophage plasticity in ITP.

What is the context? Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease. Loss of immune tolerance plays a crucial role in the pathogenesis of ITP.Monocytes and macrophages play an indispensable role in the pathophysiology of hematopoietic malignancies and have been implicated as key players in platelet destruction.Approximately 80% of adult patients with ITP exhibit corticosteroid treatment failure or become dependent, requiring novel therapy. Thrombopoietin (TPO) receptor agonists (TPO-RAs) have been used clinically to manage ITP effectively, however, little is known about the effect of TPO-RAs on monocyte and macrophage modulation in ITP.What is new?In this study, we investigated the phenotypic evolution and potential immunomodula-tory roles of monocytes/macrophages in ITP patients receiving eltrombopag therapy.The expansion of peripheral monocytes positively correlated with IFN-γ/IL-4 ratio in ITP patients.ITP macrophages exhibited more M1-related characteristics.After eltrombopag therapy, the peripheral monocyte count and IFN-γ/IL-4 ratio significantly decreased in ITP patients.M1-related characteristics of ITP macrophages were partially reversed by eltrombopag.What is the impact?This study provides evidence that the potential vital roles of TPO-RAs in regulating the monocyte/macrophage plasticity in ITP.

European Delphi panel to build consensus on tapering and discontinuing thrombopoietin receptor agonists in immune thrombocytopenia.

To establish pan-European consensus on tapering and discontinuing thrombopoietin receptor agonists (TPO-RAs) in patients with immune thrombocytopenia (ITP), we applied a three-step Delphi technique consisting of a one-to-one interview round and two online survey rounds. Three healthcare professionals (HCPs) from Italy, Spain, and the United Kingdom formed the Steering Committee (SC), which advised on study design, panelist selection, and survey development. A literature review also informed the development of the consensus statements. Likert scales were used to collect quantitative data on panelists' level of agreement. Twelve hematologists representing nine European countries assessed 121 statements spanning three categories: (1) patient selection; (2) tapering and discontinuation strategies; (3) post-discontinuation management. Consensus was reached on approximately half of the statements in each category (32.2%; 44.6%; 66%). Panelists agreed on patients' main selection criteria, patients' involvement in decision-making, tapering strategies, and follow-up criteria. Areas not reaching consensus were risk factors and predictors of successful discontinuation, monitoring intervals, and rates of successful discontinuation or relapse. This lack of consensus signals knowledge and practice gaps among European countries and suggests the need for the development of clinical practice guidelines that outline a pan-European, evidence-based approach to tapering and discontinuing TPO-RAs.

Immune thrombocytopenia (ITP) is a condition that may cause extensive bruising and excessive bleeding. Another sign is a pattern of small reddish-purple dots resembling a rash. ITP is treated with a class of medications known as thrombopoietin receptor agonists (TPO-RAs), which include eltrombopag, avatrombopag, and romiplostim. Sometimes the beneficial effects of the medication last even after the patient stops taking it, which means that some patients can be tapered off it. This paper presents the results of a Delphi panel­a method of research that gathers insights from experts­about tapering and discontinuing TPO-RAs. There were 12 physicians from nine European countries on the Delphi panel, all practicing hematologists with expertise in tapering and discontinuing TPO-RAs in patients with ITP. Panelists were presented with a total of 130 statements over three survey rounds. At the end of Round Three, 52 statements (40%) achieved consensus (response pattern of ≥80% "Agree"), and six statements (4.6%) achieved dissensus (response pattern of ≥80% "Disagree"). Consensus was achieved on the appropriateness of tapering the dose of the TPO-RA for two to three months prior to attempting discontinuation. The panel also reached consensus on considering tapering in a slower fashion (six to 12 months) for patients showing suboptimal response to TPO-RAs. More than half the survey's statements did not achieve consensus or dissensus. This signals that knowledge gaps exist and highlights the importance of conducting prospective, real-world evidence studies to identify best practices and develop pan-European guidelines for tapering and discontinuing TPO-RAs.

Complement activation negatively affects the platelet response to thrombopoietin receptor agonists in patients with immune thrombocytopenia: a prospective cohort study.

Increased platelet destruction is central in the pathogenesis of immune thrombocytopenia. However, impaired platelet production is also relevant and its significance underlies the rationale for treatment with thrombopoietin receptor agonists (TPO-RAs). Previous studies have associated enhanced complement activation with increased disease severity. Additionally, treatment refractoriness has been demonstrated to resolve by the administration of complement-targeted therapeutics in a subset of patients. The association between complement activation and the platelet response to TPO-RA therapy has previously not been investigated. In this study, blood samples from patients with immune thrombocytopenia (n = 15) were prospectively collected before and two, six and 12 weeks after the initiation of TPO-RA therapy. Plasma levels of complement degradation product C4d and soluble terminal complement complexes were assessed. Patients with significantly elevated baseline levels of terminal complement complexes exhibited more often an inadequate platelet response (p = .04), were exclusively subjected to rescue therapy with intravenous immunoglobulin (p = .02), and did not respond with a significant platelet count increase during the study period. C4d showed a significant (p = .01) ability to distinguish samples with significant terminal complement activation, implying engagement of the classical complement pathway. In conclusion, elevated levels of complement biomarkers were associated with a worse TPO-RA treatment response. Larger studies are needed to confirm these results. Biomarkers of complement activation may prove valuable as a prognostic tool to predict which patients that potentially could benefit from complement-inhibiting therapy in the future.

What is the context?Primary immune thrombocytopenia (ITP) is a potentially serious illness associated with an increased risk of bleeds. Manifestations range from confined skin bruising to life-threatening intracranial hemorrhages.It is an acquired immune disorder characterized by increased destruction and impaired production of platelets.Treatments aim at suppressing the destruction and supporting the production of platelets.Thrombopoietin receptor agonists (TPO-RA) are medically approved platelet growth factors that contribute to the generation of new platelets.The complement system is an evolutionary preserved part of innate immunity.Previous studies have indicated that complement activation may be an important contributor to disease and that the administration of complement-inhibiting therapy improves the platelet count in a subset of patients with primary ITP.What is new? The potential association between complement activation and a poor platelet response to TPO-RA therapy in primary ITP has not been previously studied.In fifteen patients with primary ITP starting TPO-RA therapy, we prospectively followed the platelet response and levels of complement biomarkers for 12 weeks.We showed that patients with high levels of complement biomarkers exhibited a worse treatment response during the study period.What is the impact?Our results suggest that levels of complement biomarkers may be valuable to predict which patients with treatment-refractory ITP that potentially could benefit from complement-inhibiting therapy in the futureLarger studies are needed to confirm our results.

Current Concepts in the Diagnosis and Management of Adult Primary Immune Thrombocytopenia: Our Personal View.

Primary immune thrombocytopenia (ITP) is an acquired blood disorder that causes a reduction in circulating platelets with the potential for bleeding. The incidence of ITP is slightly higher in adults and affects more women than men until 60 years, when males are more affected. Despite advances in basic science, primary ITP remains a diagnosis of exclusion. The disease is heterogeneous in its clinical behavior and response to treatment. This reflects the complex underlying pathophysiology, which remains ill-understood. Platelet destruction plays a role in thrombocytopenia, but underproduction is also a major contributing factor. Active ITP is a proinflammatory autoimmune disease involving abnormalities within the T and B regulatory cell compartments, along with several other immunological abnormalities. Over the last several years, there has been a shift from using immunosuppressive therapies for ITP towards approved treatments, such as thrombopoietin receptor agonists. The recent COVID-19 pandemic has hastened this management shift, with thrombopoietin receptor agonists becoming the predominant second-line treatment. A greater understanding of the underlying mechanisms has led to the development of several targeted therapies, some of which have been approved, with others still undergoing clinical development. Here we outline our view of the disease, including our opinion about the major diagnostic and therapeutic challenges. We also discuss our management of adult ITP and our placement of the various available therapies.

Regulatory T cells are replenished in the splenic microenvironment of patients with immune thrombocytopenia by treatment with thrombopoietin receptor agonists.

Therapeutic management of patients with immune thrombocytopenia (ITP) remains challenging; however, thrombopoietin receptor agonists (TPO-RAs) have revolutionised the treatment landscape of ITP. It is increasingly hypothesised that TPO-RAs may have an immune modulatory role and Pizzi and colleagues provide evidence in support of this by demonstrating that TPO-RA treatment restores the decreased regulatory T cell (Treg) numbers in the splenic microenvironment of patients with ITP. Commentary on: Pizzi M, Vianello F, Binotto G, Vianelli N, Carli G, Auteri G, et al. Thrombopoietin receptor agonists increase splenic regulatory T-cell numbers in Immune Thrombocytopenia. Br J Haematol. 2022;198:916-922.

Immune thrombocytopenia with clinical significance in systemic lupus erythematosus: a retrospective cohort study of 90 patients.

OBJECTIVES: To describe the characteristics, treatment and outcome of patients with immune thrombocytopenia with clinical significance (ITPCS) associated with SLE. METHODS: This retrospective multicentre study included SLE patients who experienced ≥1 ITPCS (defined as ITP with attributable bleeding disorders and/or a platelet count <30×109/l). Other causes of secondary thrombocytopenia were excluded. Major bleeding event (MBG) was defined as Khellaf score >8 and/or WHO score >2. RESULTS: A total of 90 patients were included, the median (range) follow-up duration was 80 (6-446) months. ITP was diagnosed before SLE in 25 patients. They presented a high rate of autoimmune haemolytic anaemia (15%), antiphospholipid antibody (62%) and antiphospholipid syndrome (19%). The 25 (28%) patients who experienced MBG had significantly more bleedings at ITP diagnosis and higher bleeding scores, and serositis and thrombosis during follow-up. They required significantly more treatment lines, transfusions and hospitalizations. The 11 (12%) patients who experienced no bleeding event presented a significantly more restricted SLE phenotype (cutaneous and/or articular). Patients received a mean (range) of 4.2 (1-11) treatment lines. Corticosteroids and HCQ allowed ITPCS overall response in one-third of patients. The median relapse-free survival of rituximab (n = 34), AZA (n = 19), MMF (n = 8), thrombopoietin-receptor agonists (n = 16) and splenectomy (n = 19) were 53, 31.5, 61, 24.5 and 78 months, respectively. Four patients experienced thrombotic events after splenectomy and one occurred under thrombopoietin-receptor agonist treatment. CONCLUSION: SLE-ITCS patients displayed a high rate of haematological abnormalities and MBG patients exhibited higher morbidity. Management of thrombocytopenia was highly heterogeneous and many options seem viable.

Refractory primary immune thrombocytopenia (ITP): current clinical challenges and therapeutic perspectives.

Chronic primary immune thrombocytopenia (ITP) can today benefit from multiple therapeutic approaches with proven clinical efficacy, including rituximab, thrombopoietin receptor agonists (TPO-RA), and splenectomy. However, some ITP patients are unresponsive to multiple lines of therapy with prolonged and severe thrombocytopenia. The diagnosis of refractory ITP is mainly performed by exclusion of other disorders and is based on the clinician's expertise. However, it significantly increases the risk of drug-related toxicity and of bleedings, including life-threatening events. The management of refractory ITP remains a major clinical challenge. Here, we provide an overview of the currently available treatment options, and we discuss the emerging rationale of new therapeutic approaches and their strategic combination. Particularly, combination strategies may target multiple pathogenetic mechanisms and trigger additive or synergistic effects. A series of best practices arising both from published studies and from real-life clinical experience is also included, aiming to optimize the management of refractory ITP.

A multicentre double-blind, double-dummy, randomised study of recombinant human thrombopoietin versus eltrombopag in the treatment of immune thrombocytopenia in Chinese adult patients.

We performed a double-blind, double-dummy controlled study to compare the efficacy between recombinant human thrombopoietin (rhTPO) and eltrombopag in rapidly increasing the platelet counts in Chinese patients with immune thrombocytopenia (ITP). A total of 96 patients diagnosed with ITP for ≥6 months who had baseline platelet counts of <30 × 109 /l were randomly assigned (1:1 ratio) to receive eltrombopag 25 mg/day or rhTPO 300 u/kg for 2 weeks. Compared with the eltrombopag group, a significantly higher proportion of patients in the rhTPO group achieved platelet counts of ≥50 × 109 /l [75·00% (36/48) vs. 43·75% (21/48), P = 0·003] or complete response (64·58% vs. 25·00%) on day 15. Moreover, a higher proportion of patients in the rhTPO group either had platelet counts that rapidly increased to twice that of baseline and with platelet counts of ≥30 × 109 /l, or reached ≥50 × 109 /l at least once when analysed on day 9, 12, and 15. However, upon discontinuation of the treatment, the platelet counts reduced to the baseline within 1 week in the rhTPO group, but on the fourth week in the eltrombopag group. Adverse events were similar in patients given rhTPO and eltrombopag. To conclude, rhTPO is superior to eltrombopag at 25 mg/day in rapidly increasing platelet counts in patients with ITP (ClinicalTrials.gov Identifier: NCT03771378).

Risk factors of hospitalisation for thrombosis in adults with primary immune thrombocytopenia, including disease-specific treatments: a French nationwide cohort study.

We aimed to assess the risk factors of venous thrombosis (VT) and arterial thrombosis (AT) in adults with primary immune thrombocytopenia (ITP), particularly in relation to treatments. The population comprised all incident primary ITP adults in France between 2009 and 2017 (FAITH cohort; NCT03429660) built in the national health database. Outcomes were the first hospitalisation for VT and AT. Multivariable Cox regression models included baseline risk factors, time-varying exposure to ITP drugs, splenectomy and to cardiovascular drugs. The cohort included 10 039 patients. A higher risk of hospitalisation for VT was observed with older age, history of VT, history of cancer, splenectomy [hazard ratio (HR) 3·23, 95% confidence interval (CI) 2·26-4·61], exposure to corticosteroids (HR 3·55, 95% CI 2·74-4·58), thrombopoietin-receptor agonists (TPO-RAs; HR 2·28, 95% CI 1·59-3·26) and intravenous immunoglobulin (IVIg; HR 2·10, 95% CI 1·43-3·06). A higher risk of hospitalisation for AT was observed with older age, male sex, a history of cardiovascular disease, splenectomy (HR 1·50, 95% CI 1·12-2·03), exposure to IVIg (HR 1·85, 95% CI 1·36-2·52) and TPO-RAs (HR 1·64, 95% CI 1·26-2·13). Rituximab was not associated with an increased risk. These findings help to estimate the risk of thrombosis in adult patients with ITP and to select treatment.

Targeted therapies for immune thrombocytopenic purpura: a meta-analysis of randomized controlled trials.

Several targeted therapies have been approved in recent years for second-line treatment of immune thrombocytopenic purpura (ITP), providing an alternative to rituximab and splenectomy. The extent to which these drugs reduce bleeding risk has not been well defined. Targeted therapies recently approved for the treatment of ITP in adults were identified through a search of recently published professional guidelines. Randomized controlled trials (RCTs) supporting regulatory approval were identified through a search of drug labels on FDA@gov. Odds ratios (ORs) and associated 95% confidence intervals (CIs) were computed for pre-specified efficacy outcomes including platelet recovery to ≥ 50,000/µL, major and minor bleeding events, and survival. ORs for all adverse events were also computed. Four targeted therapies were identified, including three thrombopoietin receptor agonists and one tyrosine kinase inhibitor. Six RCTs, comprising 752 patients, were included in the meta-analysis. More patients treated with targeted therapies for ITP as compared to placebo achieved platelet counts over ≥ 50,000/µL (OR 8.29, 95% CI 5.59-12.29). Compared to placebo, targeted therapies for ITP were associated with significantly lower odds for major bleeding (OR 0.43, 95% CI 0.21-0.91), minor bleeding (OR 0.66, 95% CI 0.45-0.97), and with numerically lower mortality rates (OR 0.24, 95% CI 0.05-1.07). The odds for adverse events were comparable between the two arms (OR 1.43 95% CI 0.76-2.67). Compared to placebo, targeted therapies for ITP increase platelet counts, decrease bleeding events, and show a trend towards lower mortality, without increased toxicity. These findings support their use as a second-line ITP treatment.

Tapering and Discontinuation of Thrombopoietin Receptor Agonist Therapy in Patients with Immune Thrombocytopenia: Results from a Modified Delphi Panel.

BACKGROUND: Recent evidence suggests that in patients with immune thrombocytopenia (ITP) with a stable response on thrombopoietin receptor agonists, treatment may be tapered and/or discontinued. OBJECTIVES: The objective of this study was to provide a guide for tapering and discontinuation of TPO-RA therapy in patients with ITP, based on hematologist survey results, existing evidence, and expert consensus. PATIENTS/METHODS: UK hematologists completed a survey to characterize self-reported practice patterns related to TPO-RA tapering and discontinuation in patients with ITP. Using a modified Delphi panel approach, ITP experts developed consensus statements regarding the use of TPO-RA tapering and discontinuation. RESULTS: Survey respondents estimated that 30-34% of their patients were suitable for tapering or discontinuation and that 29-35% of these patients required treatment re-initiation after an average treatment-free interval of 86-106 days. No clear predictors of patient suitability or response to tapering or discontinuation were identified. The ITP expert consensus was that approximately 30% of patients are eligible for tapering and discontinuation, which may be considered after 6-12 months for patients demonstrating an adequate treatment response (platelet count >50,000/µL at ≥75% of assessments in the preceding 6 months). Treatment re-initiation may be considered if the platelet count decreases or if the patient becomes symptomatic. Individual differences need to be taken into account when considering TPO-RA tapering or discontinuation. CONCLUSIONS: Tapering and discontinuation of TPO-RA therapy may be considered for certain patients with ITP. Further study is needed to better predict patients likely to achieve sustained off-treatment responses after tapering and discontinuation.