Rituximab and three dexamethasone cycles provide responses similar to splenectomy in women and those with immune thrombocytopenia of less than two years duration

Rituximab versus Splenectomy in Chronic Primary ITP: Experience of a Single Hematology Clinic

Background

Immune thrombocytopenia (ITP) is an acquired immune-mediated disease that lacks an underlying etiology. Steroids are the main first-line treatment of ITP, while the second-line treatment consists primarily of splenectomy and rituximab. This study aimed to assess and compare the response to rituximab and splenectomy.

Methods

This retrospective comparative study reviewed ITP patients treated at a single private hematology clinic from 2007 to 2019. Seventy-four ITP patients were recruited, 27 were on rituximab, and 47 had undergone splenectomy. The initial platelet counts and bleeding symptoms were recorded, and initial and long-term responses to treatment were evaluated based on the American Society of Hematology guidelines.

Results

The mean age of the patients was 42.1 years with a male-to-female ratio of 1:1.8. The initial mean platelet count was comparable between the rituximab and splenectomy groups (p = 0.749). The initial complete response (CR) differed significantly between the rituximab and splenectomy groups (44.4% versus 83%, p = 0.002). The five-year response rate was significantly higher in the splenectomy than in the rituximab group (74% versus 52%, log-rank 0.038). Splenectomy was the only significant predictive factor for long-term response (OR = 0.193, p = 0.006).

Conclusion

The overall response revealed that splenectomy appeared superior to rituximab as a second-line treatment of ITP. Splenectomy was the only positive prognostic indicator of sustained response.

Efficacy and safety of two rituximab biosimilars for treating immune thrombocytopenia: a reference-product matched study

The emergence of rituximab biosimilars offers the prospect of significant savings to the healthcare system. However, these drugs have never been evaluated for treating immune thrombocytopenia (ITP). This was an observational, matched study. We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from the historic ITP-ritux registry. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. Response status was defined according to international criteria. We included 107 patients; 55 receiving Rixathon™ and 52 Truxima™. Three months after the first infusion of rituximab biosimilars, the overall response rate was 47/74 (63.5%) versus 76/142 (53.5%) for the matched controls receiving the reference product (p = .13). The 3-month overall response rate was 76.5% for Rixathon™ versus 51.5% for the matched control group (p = .01) and 21/40 (52.5%) for Truxima™ versus 41/74 (55.4%) for the matched controls (p = .81). For non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. Rituximab biosimilars seemed safe and effective for ITP treatment.

Recommendations for the Clinical Approach to Immune Thrombocytopenia: Spanish ITP Working Group (GEPTI)

Primary immune thrombocytopenia (ITP) is a complex autoimmune disease whose hallmark is a deregulation of cellular and humoral immunity leading to increased destruction and reduced production of platelets. The heterogeneity of presentation and clinical course hampers personalized approaches for diagnosis and management. In 2021, the Spanish ITP Group (GEPTI) of the Spanish Society of Hematology and Hemotherapy (SEHH) updated a consensus document that had been launched in 2011. The updated guidelines have been the reference for the diagnosis and management of primary ITP in Spain ever since. Nevertheless, the emergence of new tools and strategies makes it advisable to review them again. For this reason, we have updated the main recommendations appropriately. Our aim is to provide a practical tool to facilitate the integral management of all aspects of primary ITP management.

Early immunomodulation in immune thrombocytopenia-A report of the ICIS meeting in Lenzerheide, Switzerland 2022

The only way to prevent immune thrombocytopenia (ITP) from becoming refractory would be to restore tolerance to platelets at an early phase of the disease. Numerous immune alterations probably accumulate in chronic ITP; thus, the chances of cure decrease significantly with time. Currently, sustained remission off treatment (SROT) is a clinical definition describing patients who can discontinue their ITP treatment without risk and maintain a state of remission. Different treatment strategies are presently being evaluated with the goal of attaining SROT, mostly combining drugs targeting the innate and/or the adaptive immune system, the inflammation state, so as increasing the platelet load. In this sense, thrombopoietin receptor agonists (TPO-RAs) have shown promising results if used as upfront treatment. TPO-RAs seem to exhibit immunomodulation and immune tolerance properties, increasing not only the platelet antigen mass but also increasing the transforming growth factor-β concentration, and stimulating regulatory T and B lymphocytes. However, more immunological studies are needed to establish accurate molecular alterations in ITP that are potentially reversed with treatments.

Adolescents and young adults with newly diagnosed primary immune thrombocytopenia

Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with an initial platelet counts of <100×109/L. Patients with secondary ITP or non-immune thrombocytopenia (n=57) and pregnant women (n=10) were excluded. Of the 656 cases of AYAS with primary ITP registered from 2004 up to 2021, 12-month follow-up data were available for 72%. The initial median platelet count was 12×109/L. In 109 patients (17%), the diagnosis was incidental, without documented bleeding. Apart from gynecological bleeding, the clinical and therapeutical characteristics of females and males were similar. Platelet-enhancing drugs were reported in 66%, 45%, and 30% of patients at diagnosis, 1-6 months, and 6-12 months after diagnosis, respectively. Corticosteroids were the preferred treatment at all time points. At 12 months, 50% of all patients developed chronic ITP. In the subgroup of patients with initial severe thrombocytopenia (<20×109/L), those receiving frontline treatment had a higher remission rate at 1 year than those who followed an initial watch-and-wait strategy (53% and 32%; P<0.05). Our analysis indicates that the remission rate at 1 year may be associated with the initial treatment strategy. This hypothesis must be confirmed in prospective studies.

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.

Older Adults and Immune Thrombocytopenia: Considerations for the Clinician

Many epidemiological studies have shown that the incidence of immune thrombocytopenia (ITP) increases after age 60 years and peaks in patients over age 80 years. Therefore, ITP is a concern for physicians taking care of older patients, especially regarding its diagnosis and management. The diagnostic work-up should exclude other causes of thrombocytopenia and secondary ITP, including myelodysplastic syndrome and drug-induced ITP. The treatment decision is influenced by an increased risk of bleeding, infectious diseases and thrombosis in this population and should take into account comorbidities and concomitant medications such as anticoagulant drugs. First-line treatment is based on short corticosteroids courses and intravenous immunoglobulin, which should be reserved for patients with more severe bleeding complications, with their higher risk of toxic effects as compared with younger patients. Second-line treatment should be tailored to the patient's history, comorbidities and preferences. Preferred second-line treatments are thrombopoietin receptor agonists for most groups and guidelines given their good efficacy/tolerance ratio, but the thrombotic risk is increased in older people. Other second-line options that can be good alternatives depending on the clinical context include rituximab, dapsone, fostamatinib or immunosuppressive drugs. Splenectomy is less often performed but remains an option for fit patients with chronic refractory disease. Emerging treatments such as Syk or Bruton tyrosine kinase inhibitors and FcRn antagonists are becoming available for ITP and may modify the treatment algorithm in the near future. The aim of this review is to describe the particularities of the diagnosis and treatment of ITP in older people, including the response and tolerance to the currently available drugs. We also discuss some situations related to co-morbidities that can frequently lead to adapt the management strategy in older patients.

Should dexamethasone alone or in combination be the initial steroid for adult ITP: Still a relevant question

Corticosteroids are used in first-line treatment in newly diagnosed immune thrombocytopenia. The goal of treatment is primarily to decrease autoantibody-mediated platelet clearance. Ideally initial treatment would not just increase the platelet count but also provide a long-term sustained remission. While many clinicians use prednisone (PDN) as their first choice of corticosteroid, others prefer dexamethasone. The controversy is the subject of debates. Short courses of higher-dose corticosteroids were first reported by the Andersen study in 1994. The study posited high-dose dexamethasone as a 'cure' for all ITP patients. Later, studies addressed the number of dexamethasone cycles, indications to repeat cycles and timing between cycles, with varied long-term results. The results with dexamethasone were compared to PDN in some studies: the four-day cycles of dexamethasone work faster in increasing platelet counts and appear to reduce the occurrence of severe adverse events. Therefore, it is probably a better option for patients with low platelet counts and bleeding diathesis; however, curative superiority, the initial reason to administer it, compared to PDN is not well demonstrated. Across the studies, treatment with high-dose dexamethasone seems to be safer, with lower incidence of all adverse events compared to PDN, which might be a reflection of shorter treatment duration and possibly also lower cumulative steroid dose. Dexamethasone in combination with rituximab in first-line treatment produced higher response rates with better long-term results compared to high-dose dexamethasone alone and is a particularly good option in younger women.

Secondary rituximab-associated versus primary immunodeficiencies: The enigmatic border

Rituximab (RTX), a chimeric monoclonal antibody targeting CD20-positive cells, is a valuable treatment option for malignant and benign immune-related disorders. The rationale of targeting the CD20 antigen relies on depletion of both healthy and autoreactive/malignant CD20-espressing cells, but normal B-cell reconstitution is expected within months after treatment. Nevertheless, a number of recent studies have documented prolonged B-cell deficiency associated with new-onset hypogammaglobulinemia in patients receiving RTX. Awareness of post-RTX hypogammaglobulinemia has become wider among clinicians, with a growing number of reports about the increased incidence, especially in children. Although these patients were previously regarded as affected by secondary/iatrogenic immunodeficiency, atypical clinical and immunological manifestations (e.g., severe or opportunistic infections; prolonged B-cell aplasia) raise concerns of delayed manifestations of genetic immunological disorders that have been unveiled by B-cell perturbation. As more patients with undiagnosed primary immune deficiency receiving RTX have been identified, it remains the challenge in discerning those that might display a higher risk of persistent RTX-associated hypogammaglobulinemia and need a tailored immunology follow-up. In this review, we summarize the principal evidence regarding post-RTX hypogammaglobulinemia and provide a guideline for identifying patients at higher risk of RTX-associated hypogammaglobulinemia that could harbor an inborn error of immunity.

A New Immunosuppressive Therapy for Very Severe Aplastic Anemia in Children with Autoantibodies

OBJECTIVE

At present, a number of very severe aplastic anemia (VSAA) patients cannot receive hematopoietic stem cell transplantation (HSCT) or standard immunosuppressive therapy (IST) due to the high cost of therapy, shortage of sibling donors, and lack of resources to support the HSCT. In addition, some VSAA patients with autoantibodies have no life-threatening infections or bleeding at the time of initial diagnosis. Considering the disease condition, economics and other factors, the present study designed a new and relatively mild treatment strategy: cyclosporine A plus pulsed high-dose prednisone (CsA+HDP).

METHODS

The present study retrospectively analyzed 11 VSAA patients, who were treated with CsA+HDP in our hospital from August 2017 to August 2019.

RESULTS

The median follow-up time for these patients was 24.9 months. The overall response rate was 54.5% (6/11) at six months after the initiation of IST and 81.8% (9/11) at deadline. Five patients achieved complete remission and four patients met the criteria for partial response at the last follow-up. The median time to response for responders was 110 days. Three patients underwent HSCT due to the poor effect of CsA+HDP or to find a suitable transplant donor. Recurrence and clonal evolution were not found in any of these patients. The estimated 3-year overall survival rate and 3-year failure-free survival rate were 100.0% and 72.7%, respectively. In addition, the results revealed that the cyclosporine-prednisone-associated toxicity was mild and well-tolerated by most patients.

CONCLUSION

The novel CsA+HDP regimen has good therapeutic effect and safety for VSAA patients with autoantibodies, who have no serious life-threatening infections or bleeding at the time of initial diagnosis.

Case Report: Crossing a rugged road in a primary immune regulatory disorder

Over the last decades, Inborn Errors of Immunity (IEI) characterized by an immune dysregulatory picture, isolated or combined with infections, have been increasingly identified and referred as Primary Immune Regulatory Disorders (PIRD). PIRD diagnosis may be difficult due to heterogeneity of time onset, sequence of clinical manifestations and laboratory abnormalities. Moreover, the dissection of a PIRD vs. a secondary immunodeficiency (SID) might be a real challenge since the same indications for immunosuppressant treatments might represent per se a PIRD clinical expression. Here we report a female patient with a history of recurrent respiratory and urinary tract infections since early infancy and a diagnosis of Rheumatoid Arthritis in adulthood. After poor response to several biologicals she was treated with Rituximab and sent to immunology referral for a severe hypogammaglobulinemia. Clinical and immunological features matched a diagnosis of common variable immunodeficiency and when IgG replacement therapy and antibiotic prophylaxis were added a good infectious control was obtained. Next generation sequencing analysis has revealed a novel heterozygous VUS in the IKBKB gene (c.1465A > G; p.Ser489Gly). Functional analysis has shown a reduced capacity of B lymphocytes and CD4 positive T cells in inducing IκBα degradation, with negative impact on NF-kB pathway. Due to recurrent infections attributed to a common condition in childhood and to an exclusive autoimmunity-centered approach in adulthood, both diagnosis and suitable treatment strategies have suffered a significant delay. To reduce the diagnostic delay, pediatricians, general practitioners and specialists should be aware of IEI and the challenges to differentiate them from SID. Furthermore, genetic characterization and functional analysis may contribute to a personalized approach, in a perspective of targeted or semi-targeted therapy.

A modified regimen of low-dose rituximab therapy for patients with refractory immune thrombocytopenia associated with systemic lupus erythematosus

Background:

Severe and refractory immune thrombocytopenia (ITP) affects the life expectancy of patients with systemic lupus erythematosus (SLE) and poses a challenge in their clinical management. This intervention study employed a small sample size to evaluate the efficacy and safety of a modified low-dose rituximab (RTX) regimen in patients with SLE-associated refractory ITP.

Methods:

Eight patients with severe SLE-associated refractory ITP were enrolled in this intervention study. They received an infusion of intravenous RTX (200 mg) on days 1 and 15. The dose of corticosteroids (prescribed previously) was gradually tapered, and immunosuppressants were withdrawn. Patients were followed up at 1, 3, 6, and 12 months; platelet counts, other laboratory indicators, and side effects were recorded. We used intention-to-treat analysis to calculate the response rate.

Results:

Seven participants (87.5%) completed the study. At 1 month, two patients (25.0%) achieved partial response (PR); the PR rate increased to 87.5% at 3 months. At 6 months, three patients (37.5%) achieved complete response (CR). However, the CR rate dropped to 25.0% at 12 months. The overall responses (ORs) were 25.0% (2/8), 87.5% (7/8), 75.0%(6/8), and 75.0%(6/8) at 1, 3, 6, and 12 months, respectively. Two patients developed a mild infusion reaction and one discontinued the study due to herpes zoster virus infection and an allergic reaction 2 weeks after the first dose of RTX.

Conclusion:

Modified low-dose RTX therapy (two infusions of 200 mg every 2 weeks) could be a promising new option for patients with SLE-associated refractory ITP with a satisfactory response rate.

Immune thrombocytopenia

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a low platelet count (<100 × 10⁹/L) with an increased risk of bleeding. Recent (2019) guidelines from the International Consensus Report (ICR) expert panel and the American Society of Hematology (ASH) provide updated recommendations for the diagnosis and management of ITP.

AREAS COVERED

The 2019 ICR and ASH guidelines are reviewed, and differences and similarities highlighted. Clinical approaches to the treatment of ITP are discussed, including the role of fostamatinib which is an approved treatment option in adult patients who are refractory to other treatments.

EXPERT OPINION

The 2019 ICR and ASH guidelines reflect recent changes in the management of ITP. Current treatment approaches for ITP are more rational and evidence-based than in the past. Patients should be treated based on their needs rather than on disease stage, and patient-specific outcomes, (e.g. quality of life) should be considered. Whilst corticosteroids are the mainstay of initial ITP treatment their use should be limited. For subsequent treatment, the use of thrombopoietin receptor agonist (TPO-RA) agents, fostamatinib and rituximab in adults is supported by robust evidence. Rituximab and recently approved fostamatinib offer viable alternatives to splenectomy.

The Efficacy and Safety of Different Dosages of Rituximab for Adults with Immune Thrombocytopenia: A Systematic Review and Meta-Analysis

Background

Rituximab has been frequently used as a second-line treatment for patients with immune thrombocytopenia (ITP). The optimal dose and course of rituximab are uncertain.

Methods

A comprehensive search for randomized controlled trials reporting the use of low-dose (100 mg) or standard-dose (375 mg/m²) rituximab in ITP treatment was conducted. Meta-analyses were performed on CRR (complete response rate), ORR (overall response rate), PRR (partial response rate), SRR (sustained response rate), infection rate, SB (significant bleeding) rate, and SAE (serious adverse event) rate.

Results

A total of 12 studies were included, comprising 869 patients. Compared to the control group, rituximab treatment resulted in an obvious increase in CRR (P < 0.00001), ORR (P < 0.0001), and SRR at month 6 and 12 (P = 0.0007, P = 0.0003), without increasing the infection rate (P = 0.12) and SAE rate (P = 0.11). No significant differences in CRR (RR 1.61 vs. 1.42, P = 0.45), ORR (RR 1.26 vs. 1.49, P = 0.28), PRR (RR 1.25 vs. 1.00, P = 0.11), SRR at month 12 (RR 2.00 vs. RR 1.64, P = 0.54), infection rate (RR 0.85 vs. 1.46, P = 0.36), and SB rate (RR 0.14 vs. 1.19, P = 0.17) were found in subgroups of low dose and standard dose.

Conclusion

Rituximab was effective and safe for adult patients with ITP. A low-dose rituximab regimen might be an effective alternative to the standard-dose regimen in ITP, as it showed similar CRR, ORR, and SRR at month 12 and was relatively safer with a lower cost.

Consensus guidelines for the management of adult immune thrombocytopenia in Australia and New Zealand

Introduction

The absence of high quality evidence for basic clinical dilemmas in immune thrombocytopenic purpura (ITP) underlines the need for contemporary guidelines relevant to the local treatment context. ITP is diagnosed by exclusions, with a hallmark laboratory finding of isolated thrombocytopenia.

Main recommendations

Bleeding, family and medication histories and a review of historical investigations are required to gauge the bleeding risk and possible hereditary syndromes. Beyond the platelet count, the decision to treat is affected by individual bleeding risk, disease stage, side effects of treatment, concomitant medications, and patient preference. Treatment is aimed at achieving a platelet count > 20 × 10⁹/L, and avoidance of severe bleeding. Steroids are the standard first line treatment, with either 6‐week courses of tapering prednisone or repeated courses of high dose dexamethasone providing equivalent efficacy. Intravenous immunoglobulin can be used periprocedurally or as first line therapy in combination with steroids.

Changes in management as a result of this statement

There is no consensus on choice of second line treatments. Options with the most robust evidence include splenectomy, rituximab and thrombopoietin receptor agonists. Other therapies include azathioprine, mycophenolate mofetil, dapsone and vinca alkaloids. Given that up to one‐third of patients achieve a satisfactory haemostatic response, splenectomy should be delayed for at least 12 months if possible. In life‐threatening bleeding, we recommend platelet transfusions to achieve haemostasis, along with intravenous immunoglobulin and high dose steroids.

The promise and perils of immunotherapy

Advances in understanding the ways in which the immune system fails to control tumor growth or prevent autoimmunity have led to the development of powerful therapeutic strategies to treat these diseases. In contrast to conventional therapies that have a broadly suppressive effect, immunotherapies are more akin to targeted therapies because they are mechanistically driven and are typically developed with the goal of "drugging" a specific underlying pathway or phenotype. This means that their effects and toxicities are, at least in theory, more straightforward to anticipate. The development of functionalized antibodies, genetically engineered T cells, and immune checkpoint inhibitors continues to accelerate, illuminating new biology and bringing new treatment to patients. In the following sections, we provide an overview of immunotherapeutic concepts, highlight recent advances in the field of immunotherapies, and discuss controversies and future directions, particularly as these pertain to hematologic oncology or blood-related diseases. We conclude by illustrating how original research published in this journal fits into and contributes to the overall framework of advances in immunotherapy.

Efficacy, safety and immunological profile of combining rituximab with belimumab for adults with persistent or chronic immune thrombocytopenia: results from a prospective phase 2b trial

B-cell activating factor may be involved in the failure of B-cell depleting therapy with rituximab in immune thrombocytopenia (ITP) by promoting the emergence of splenic long-lived plasma cells. From results obtained in mouse models, we hypothesized that combining rituximab with sequential injections of belimumab could increase the rate of response at one year in patients with persistent or chronic ITP by preventing the emergence of these long-lived plasma cells. The study was a single-center, single arm, prospective phase 2b trial (RITUX-PLUS, NCT03154385) investigating the safety and efficacy of rituximab given at a fixed dose of 1,000 mg, two weeks apart, combined with five infusions of belimumab, 10 mg/kg at week 0 (W0)+2 days, W2+2 days, W4, W8 and W12 for adults with primary persistent or chronic ITP. The primary endpoint was the total number of patients achieving an overall response (complete response + response) at W52 according to a standard definition. In total, 15 non-splenectomized adults, nine (60%) with persistent IPT and six (40%) with chronic ITP, were included. No severe adverse event, infection, or severe hypogammaglobulinemia was observed. Thirteen patients achieved an initial overall response. At W52, 12 (80%) patients achieved an overall response, including ten (66.7%) with complete response. When compared with a cohort of patients receiving rituximab alone, the kinetics of B-cell repopulation appeared similar, but the number of circulating T follicular helper cells was significantly decreased with belimumab combination therapy. Combining rituximab and belimumab seems a promising strategy in ITP, with high efficacy and acceptable safety.

How I treat primary ITP in adult patients who are unresponsive to or dependent on corticosteroid treatment

Approximately 80% of adult patients with immune thrombocytopenia (ITP) have treatment failure with corticosteroids or become dependent on them and require second-line therapy. Several new and effective therapies have been introduced during the past decade and our understanding of disease burden and its effect on quality of life has expanded. It is now recommended that splenectomy, the standard second-line therapy for decades, be delayed for at least 12 to 24 months, allowing for more patients to achieve remission on medical therapies before considering surgery. It is highly recommended that medical therapies be used that have abundant clinical trial evidence, such as the thrombopoietin receptor agonists (TPO-RAs) rituximab and fostamatinib. Unfortunately, there are no reliable biomarkers that help in treatment selection. These therapeutic medical options have variable efficacy, safety profiles, mechanisms of action, and modes of administration. This enables and mandates an individualized approach to treatment, where patient involvement, preferences and values have become central to the process of choosing the appropriate therapy. Both TPO-RAs and fostamatinib are maintenance therapies, whereas rituximab is given for a limited number of doses. Although the response is usually maintained while receiving a TPO-RA or fostamatinib therapy, half of rituximab responders will no longer respond 1 to 2 years after administration and require retreatment or other therapy.

Emerging Therapies in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a rare autoimmune disorder caused by peripheral platelet destruction and inappropriate bone marrow production. The management of ITP is based on the utilization of steroids, intravenous immunoglobulins, rituximab, thrombopoietin receptor agonists (TPO-RAs), immunosuppressants and splenectomy. Recent advances in the understanding of its pathogenesis have opened new fields of therapeutic interventions. The phagocytosis of platelets by splenic macrophages could be inhibited by spleen tyrosine kinase (Syk) or Bruton tyrosine kinase (BTK) inhibitors. The clearance of antiplatelet antibodies could be accelerated by blocking the neonatal Fc receptor (FcRn), while new strategies targeting B cells and/or plasma cells could improve the reduction of pathogenic autoantibodies. The inhibition of the classical complement pathway that participates in platelet destruction also represents a new target. Platelet desialylation has emerged as a new mechanism of platelet destruction in ITP, and the inhibition of neuraminidase could dampen this phenomenon. T cells that support the autoimmune B cell response also represent an interesting target. Beyond the inhibition of the autoimmune response, new TPO-RAs that stimulate platelet production have been developed. The upcoming challenges will be the determination of predictive factors of response to treatments at a patient scale to optimize their management.

Real-world Experience of Rituximab in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a relapsing-remitting disease often requiring more than one line of therapy. Rituximab is a recommended second-line therapy, but the real-world data on its efficacy and safety from resource constraint settings is limited. We aimed to analyze the safety and efficacy of rituximab in ITP. This is a single-center, retrospective study. This study was conducted at a tertiary care hospital in Northern India from 2005 to 2019. On audit of medical records, all patients of ITP (n-513) who had received rituximab (n-81) were screened for inclusion. Patients whose response assessment was not possible were excluded. Finally, 66 patients were analyzed using statistical packages of Python v3.7. The cumulative incidence of overall response on day 20 was 30.61%, and day 30 was 51.72%. The median time to response was 28 day (range 21-51 day). Cumulative incidence of complete response was 16.67%, and partial response 37.88%. After a median follow-up of 789 day (range 181-5260 day), the cumulative incidence of relapse was 30.32%, 36.12%, and 56.57% at 1, 2, and 5 years respectively. There was no effect of age, sex, duration of disease, lines of therapy received, and platelet count on either cumulative incidence of overall response or relapse. ANA positivity was significantly related to the better cumulative incidence of overall response (p = 0.012), but not with relapse. Infusion-related reactions were the commonest adverse event noted (n-4, grade ≥ 3 CTCAEv4). Rituximab and its generic version are safe and effective second line agent in ITP with a good overall response and sustained response.

Treatment lines of childhood chronic ITP: A retrospective single-center analysis

Immune thrombocytopenia (ITP) is the most common cause of thrombocytopenia in children. Approximately 20–25% of children develop a chronic course of the disease. Many treatment options are available, including chronic use of first-line therapies, e.g., corticosteroids, intravenous immunoglobulin or anti-Rh-D, and second-line therapies, including dexamethasone, high-dose methylprednisolone, intensive immunosuppressants, rituximab, thrombopoietin receptor agonists (TPO-RAs), splenectomy, and many others; however, none of these treatments have been determined to be the best. In this study, we retrospectively reviewed the course, response to different treatment lines and outcome of children with chronic ITP over a period of ten years to compare the efficacy of different treatment options, aiming to determine a scale of priority for selecting the most costeffective treatment. A retrospective study was conducted and included children diagnosed with chronic ITP from January 2008 until December 2018 who were followed at the Pediatric Hematology Unit of Mansoura University Children Hospital, Mansoura, Egypt. The study proposal was approved on February 14, 2017 (approval No 17.02.59) by the Institutional Review Board (IRB) of the Faculty of Medicine, Mansoura University, Egypt. All research steps were conducted according to the Declaration of Helsinki. The diagnosis of chronic ITP was based upon the persistence of thrombocytopenia lasting for more than 1 year with or without therapy. Bone marrow aspiration was performed for all patients to confirm the diagnosis of chronic ITP and exclude other causes of thrombocytopenia. Data relevant to chronic ITP patients diagnosed from 2008 to 2018 were retrieved from the Electronic Data System of Hospital Management of Mansoura University Children Hospital, including age, sex, diagnosis date, duration of chronicity, treatment given during the chronic phase and response. Treatment regimen was immune modulatory therapies (high-dose dexamethasone, IV rituximab or low-dose dexamethasone + azathioprine), thrombopoietin receptor agonists (TPO-RAs) (eltrombopag or romiplostim). Out of 405 newly diagnosed ITP patients in a period of 10 years in our center, 103 progressed to chronic disease, of whom 29 were lost to follow-up, while 74 patients were followed at the hematology outpatient clinic and enrolled in the current study (32 males and 42 females, median age – 10 years, median initial platelet count – 16 × 109 /l). Approximately one-third of patients (25~33.8%) were managed conservatively; of them, 19 patients achieved sustained remission, and 6 patients needed another treatment line. Forty-six (62%) patients received immunomodulatory therapies. Twentyeight patients (37.8%) were treated with TPO-RAs. No differences were observed between the 3 types of immunomodulatory therapies regarding relapse-free survival and duration of remission (р value: 0.7). Additionally, no differences were noted according to relapse-free survival among those treated with eltrombopag and romiplostim (р value: 0.7). The number of male children who had a sustained response was significantly higher than that of female children among patients receiving immunomodulatory therapies (71.4% vs 28.6%, respectively) (р value 0.01). There were significantly more patients on TPO-RA with a sustained response than patients on immune modulators, and consequently, the number of patients who relapsed on immunomodulators was higher than that of those on TPO-RA (67.9% vs 30.4% compared to 69.9% vs 32.1%, р value 0.01). Many of our patients who received immunomodulators and failed to achieve or lost a response before 2015 were switched to TPO-RAs with comparable efficacy apart from sustainability, which was in favor of the latter. Additionally, among the types of immunomodulators, rituximab did not show superior efficacy compared to other types, with lower costs for the latter, leading to the abandonment of its use, particularly in limited resource countries such as ours.

More about the combination of rituximab, cyclosporine and dexamethasone in the treatment of chronic ITP. A useful option on an environment with limited resources

Treatment of chronic primary immune thrombocytopenia (ITP) is challenging especially with limited resources and therapy-related complications. This prospective interventional study assessed the efficacy and safety of triple therapy(TT4); a combination treatment of oral dexamethasone 40 mg for days1-4, oral cyclosporine A 2-3 mg/kg daily for 28 consecutive days and intravenous rituximab 100 mg for days7,14,21 and 28 among 40 patients with ITP who failed previous 2 or more treatment options. Our aim was to maintain platelet count ≥ 30 X 10⁹/L without any obvious bleeding at any point in the study. Platelet counts were assessed weekly for a month then monthly for 2 years to evaluate the long-term response. TT4 was well tolerated and induced a good response with a significant increase in the mean platelet count after the 1^st, 2^nd, 3^rd, and 4^thweek compared to the baseline. Patients with mean platelet count ≥ 30 X 10⁹/L at the 6^th month were 75% (30/40 patients). Treatment free survivals (TFS) at 12 and 24 months were 93.3% (28/30 patients) and 80% (24/30 patients) respectively. TT4 is an effective treatment option that maintained platelet count in the desired level and induced a higher sustained response, especially in an environment with limited resources.

[Immune thrombocytopenia: From pathogenesis to treatment]

Immune thrombocytopenia (ITP) is a rare autoimmune disease due to an immune peripheral destruction of platelets and an inappropriate platelet production. The pathogenesis of ITP is now better understood: it involves a humoral immune response which dependents on the stimulation of B cells by specific T cells called T follicular helper cells, leading to their differentiation into plasma cells that produce antiplatelet antibodies thus promoting the phagocytosis of platelets mainly by splenic macrophages. The deciphering of ITP pathogenesis has led to a better understanding of the inefficiency of treatments such as rituximab, although it has not provided yet the determination of biological predictive factor of response to treatments. Moreover, new therapeutic perspectives have been opened in the last few years with the development of molecules targeting Fcγ receptor signalling such as Syk inhibitor, or molecules increasing the clearance of pathogenic autoantibodies such as inhibitors of the neonatal Fc receptor (FcRn).

Rituximab and immune thrombocytopenia in adults: The state of knowledge 20 years later

Rituximab has been used for immune thrombocytopenia (ITP) for almost 20 years and is now considered a valid off-label second-line treatment. About 60% to 70% of patients with ITP show initial response to rituximab, but in half of these patients, the disease will eventually relapse. Therefore, in 30% of patients with persistent or chronic ITP, one course of rituximab at 375 mg/m²/week for 4 weeks or 2 fixed 1000-mg rituximab infusions allows for a sustained response rate at 5 years. Unfortunately, to date, no robust predictor of long-term sustained response has been found to assist the physician in deciding to treat with rituximab on an individual basis, and the choice of rituximab or another second-line treatment must be individualized and shared with the patient. Retreatment with rituximab has been found efficient, with a similar or higher magnitude and duration of response in most patients. Rituximab is usually well tolerated, with mainly mild and easily manageable infusion-related adverse events. Severe infections are uncommon, including in the long-term, and occur in patients with at least another contributing factor in more than two thirds. Several issues remain to be resolved. Indeed, head-to-head comparisons with other and new treatments in ITP and robust predictors of long-term response are urgently needed to better determine the position of rituximab in the therapeutic armamentarium for adult ITP. Additionally, the place of combination therapies, maintenance therapy with rituximab and rituximab in newly-diagnosed ITP deserve additional studies.

Report of a 'consensus' on the lines of therapy for primary immune thrombocytopenia in adults, promoted by the Italian Gruppo di Studio delle Piastrine

Despite the publication in 2009 of a paper on 'terms and definitions of immune thrombocytopenia' (ITP), some unresolved issues remain and are reflected by the disagreement in the treatment suggested for primary ITP in adults. Considering that these disagreements could be ascribed to non-shared goals, we generated a 'consensus' on some terms, definitions, and assertions useful for classifying the different lines of treatment for primary ITP in adults according to their indications and goals. Agreement on the appropriateness of the single assertions was obtained by consensus for the following indicators: 1. classification of four 'lines of therapy'; 2. acceptance of the expression 'sequences of disease' for the indications of the respective four lines of treatment; 3_I . practicability of splenectomy; 3_Ib . acceptance, with only some exceptions, of a 'timing for elective splenectomy of 12 months'; and 4_a-d . 'goals of the four lines of therapy.' On the basis of the consensus, a classification of four lines of treatment for primary ITP in adults was produced. In our opinion, this classification, whose validity is not influenced by the recently published new guidelines of the American Society of Hematology (ASH) and reviews, could reduce the disagreement that still exists regarding the treatment of the disease.

Management of immune thrombocytopenia in women: current standards and special considerations

Introduction: Immune thrombocytopenia (ITP) is an acquired autoimmune disorder, with an incidence rate of 20-40/million adults/year and an estimated prevalence in women of childbearing age of 24.5/million.Areas covered: Authors discuss management of ITP in pregnancy, treatment-related toxicity, delivery, neonatal thrombocytopenia and breastfeeding, and other women's specific issues. The search of papers published between January 1990 and December 2019 was done on PubMed using combinations of the keywords below. The distinction between ITP and other thrombocytopenias in pregnancy is of paramount importance. The current belief (at variance with the past) that ITP is a relatively benign disease pregnancy is emphasized.Expert opinion: The lack of randomized, prospective, controlled studies hampers evidence-based statements. Remarkably, ITP diagnosis is still one of exclusion, there are no clinical or laboratory criteria for prognosis and we still need more solid data on the risks related to neonatal thrombocytopenia. Corticosteroids and IVIG remain the mainstay of treatment, since rituximab, thrombopoietin-receptor agonists, fostamatinib may be toxic in pregnancy. Safety and efficacy of recombinant-human-thrombopoietin, available in China, require confirmation studies. Quality of life and women-related toxicity of treatments in young girls, adults, and elders are still an orphan area of investigation.

Long-term safety and efficacy of rituximab in 248 adults with immune thrombocytopenia: Results at 5 years from the French prospective registry ITP-ritux

Rituximab is a second-line option in adults with immune thrombocytopenia (ITP), but the estimated 5-year response rate, only based on pooled retrospective data, is about 20%, and no studies have focused on long-term safety. We conducted a prospective multicenter registry of 248 adults with ITP treated with rituximab with 5 years of follow-up to assess its long-term safety and efficacy. The median follow-up was 68.4 [53.7-78.5] months. The incidence of severe infections was only 2/100 patient-years. Profound hypogammaglobulinemia (<5 g/L) developed in five patients at 15 to 31 months after the last rituximab infusion. In total, 25 patients died at a median age of 80 [69.5-83.9] years, corresponding to a mortality rate of 2.3/100 patient-years. Only three deaths related to infection that occurred 12 to 14 months after rituximab infusions could be due in part to rituximab. At 60 months of follow-up, 73 (29.4%) patients had a sustained response. On univariate and multivariate analysis, the only factor significantly associated with sustained response was a previous transient response to corticosteroids (P = .022). Overall, 24 patients with an initial response and then relapse received retreatment with rituximab, which gave a response in 92%, with a higher duration of response in 54%. As a result of its safety profile and its sustained response rate, rituximab remains an important option in the current therapeutic armamentarium for adult ITP. Retreatment could be an effective and safe option.

Updated international consensus report on the investigation and management of primary immune thrombocytopenia

Over the last decade, there have been numerous developments and changes in treatment practices for the management of patients with immune thrombocytopenia (ITP). This article is an update of the International Consensus Report published in 2010. A critical review was performed to identify all relevant articles published between 2009 and 2018. An expert panel screened, reviewed, and graded the studies and formulated the updated consensus recommendations based on the new data. The final document provides consensus recommendations on the diagnosis and management of ITP in adults, during pregnancy, and in children, as well as quality-of-life considerations.

The efficacy and safety of low-dose rituximab in immune thrombocytopenia: a systematic review and meta-analysis

Rituximab has been frequently used as a second-line treatment for patients with immune thrombocytopenia (ITP). Recently, several studies have proposed low-dose (100 mg or 100mg/m² per week for 4 weeks) rituximab instead of the standard dose of 375mg/m² per week for 4 weeks to treat ITP patients. The aim of this review was to systematically evaluate the efficacy and safety of low-dose rituximab for patients with ITP. Pubmed, Web of Science, Cochrane Library and Embase were searched to identify the clinical studies published in full text or abstract that met the predefined inclusion criteria. Efficacy analysis was restricted to the studies enrolling five or more patients. While safety analysis was evaluated based on all the studies reported adverse events. Nine studies (329 patients) were included for effect assessment of low-dose rituximab treatment on the patients with ITP. The pooled overall response rate was 63% (95% CI, 0.54-0.71) while the pooled complete response was 44% (95% CI, 0.33-0.55). Thirty-one patients were reported to experience adverse effects associated with rituximab, among them 30 cases suffered mild to moderate side-effects (grade1-2). Only one patient developed into interstitial pneumonia (grade3). No death was reported. Low-dose rituximab exhibited a satisfactory efficacy and safety profile, indicating that this regimen is a promising therapy for ITP, and should be further investigated through randomized clinical trials with standard-dose rituximab.

Rituximab in the treatment of immune thrombocytopenia: what is the role of this agent in 2019?

The use of rituximab for the treatment of immune thrombocytopenia was greeted enthusiastically: it led to up to 60% response rates, making it, nearly 20 years ago, the main alternative to splenectomy, with far fewer side effects. However, long-term follow-up data showed that only 20-30% of patients maintained the remission. No significant changes have been registered using different dose schedules and timing of administration, while the combination with other drugs seemed promising. Higher response rates have been observed in young women before the chronic phase, but apart from that, other clinical factors or biomarkers predictive of response are still lacking. In this review we examine the historical and current role of rituximab in the management of immune thrombocytopenia, 20 years after its first use for the treatment of autoimmune diseases.

Switching thrombopoietin receptor agonist treatments in patients with primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is a bleeding disorder that conventionally has been treated with steroids or other immunosuppressive treatments. The introduction of thrombopoietin receptor agonists (TPO-RAs), which increase platelet production, dramatically changed the treatment landscape for ITP by providing patients with well-tolerated, long-term treatment options. Two TPO-RAs, eltrombopag and romiplostim, have been approved in the United States and European Union for the treatment of ITP. Some patients do not benefit from the first TPO-RA they receive, so it is assumed that the alternate TPO-RA would have the same outcome. However, eltrombopag and romiplostim have distinct pharmacodynamic and pharmacokinetic properties and may have different tolerability and efficacy in individual patients with ITP. Published retrospective studies showed that >75% of patients who switched to the alternate TPO-RA maintained or achieved a response with the new treatment. Notably, most patients who switched due to lack of efficacy with the first TPO-RA responded to the alternate TPO-RA, which demonstrates an absence of cross-resistance between the two drugs. Therefore, switching to the alternate TPO-RA if the first TPO-RA fails to demonstrate a response should be considered before the use of a less-preferable option.

[The value of platelet count in predicting the efficacy of rituximab treatment in adult patients with chronic primary immune thrombocytopenia]

目的

探讨血小板计数水平在成人慢性原发免疫性血小板减少症（ITP）患者利妥昔单抗疗效预测中的价值。

方法

回顾性分析2011年1月1日至2014年12月31日期间接受利妥昔单抗治疗（100 mg每周1次，连用4次）慢性ITP患者的临床资料，计算利妥昔单抗治疗后不同随访时间截点血小板计数预测疗效的敏感性、特异性和阳性预测值、阴性预测值，并通过ROC曲线下面积得出最佳截断点。

结果

103例患者纳入研究，男46例，女57例，中位年龄30（18~67）岁。首剂利妥昔单抗后第1、5、7天，成功组（治疗后PLT≥50×10⁹/L且未接受其他药物治疗）与无效组（治疗后PLT<50×10⁹/L）中位血小板计数差异均无统计学意义（P>0.05）；利妥昔单抗治疗后第14天，成功组中位血小板计数高于无效组[41（8~384）×10⁹/L对23（0~106）×10⁹/L，P=0.003]；在随后的各随访截点，成功组中位血小板计数进一步回升并维持于正常水平，无效组中位血小板计数均低于正常水平。以ROC曲线获得的预测治疗反应的优化界限值血小板计数50×10⁹/L为基础，首剂妥昔单抗治疗后第14、30、60天血小板计数能够组成一个预后评估体系。

结论

利妥昔单抗治疗后第14、30、60天血小板计数能够组成一个疗效预测评估体系，有助于随访和制定治疗计划。

Efficacy and Safety of the Combination Treatment of Rituximab and Dexamethasone for Adults with Primary Immune Thrombocytopenia (ITP): A Meta-Analysis

Objective. To conduct a meta-analysis, assessing the efficacy and safety of the combination treatment of dexamethasone and rituximab for adults with ITP (primary immune thrombocytopenia). Methods. Randomized controlled trials that compared rituximab and dexamethasone combination treatment to dexamethasone monotherapy in the treatment of adults with ITP were collected by searching Pubmed, Embase, Cochrane, China National Knowledge (CNKI), Wanfang database, and Sino Med. We conducted pooled analyses on OR (overall response) rate, CR (complete response) rate, PR (partial response) rate, SR (sustained response) rate, R (relapse) rate, change in Treg cell count (mean [SD]), and AE (adverse event). GRADE pro scale was used to assess the quality of the evidence. Publication bias was assessed with Egger's test method. Results. A total of 11 randomized controlled trials were eligible for inclusion. The overall efficacy estimates favored combination arm in terms of OR rate at month 3, CR rate at week 4 and month 3, SR rate, and Treg cell count at week 2. Subgroup analysis showed that females obtained a higher OR rate than males did at week 4. No significant difference was found in pooled analysis of relapse rate between combination arm and monotherapy arm. The comparison of serious AE and other AEs showed no significant difference either. A total of 19 outcomes were assessed by GRADE pro software, of which 79% (15/19) was scaled as moderate-to-high level. Publication bias existed in studies on OR at week 4 (P=0.025), CR at week 4 (P=0.017), infection (P=0.006), and rash (P=0.028) of the AEs. Conclusion. Dexamethasone combined with rituximab can provide a better long-term response in the treatment of adults with ITP and will not increase the risk of adverse effects.

Eltrombopag-based combination treatment for immune thrombocytopenia

Immune thrombocytopenia (ITP) is a bleeding disorder caused by a decrease in platelet count resulting from increased destruction and insufficient production of platelets. Although impaired regulatory T-lymphocyte activity plays a critical role in platelet destruction, many other immunologic abnormalities are also likely to be involved. Importantly, patients with ITP appear to have defects in a thrombopoietin-mediated physiological mechanism that compensates for a decrease in platelet count by increasing platelet production. Thus, simultaneous treatment of multiple pathogenic pathways involved in ITP could potentially result in synergistic efficacy. While conventional treatments for ITP suppress or modulate the immune system to reduce platelet destruction, a unique class of ITP therapy, namely thrombopoietin receptor agonists (TPO-RAs), improves platelet production by activating the thrombopoietin pathway. As hypothesized, preliminary studies show that combinations of eltrombopag, an oral TPO-RA, with conventional treatments improve outcomes in both newly diagnosed and refractory patients. In this review, the clinical experience with eltrombopag-based combinations in patients with ITP is summarized and the implications of the available data are discussed.

Transitioning patients with immune thrombocytopenia to second-line therapy: Challenges and best practices

In patients with immune thrombocytopenia who do not adequately respond to first-line therapy, there is no clear consensus on which second-line therapy to initiate and when. This situation leads to suboptimal approaches, including prolonged exposure to treatments that are not intended for long-term use (eg, corticosteroids) and overuse of off-label therapies (eg, rituximab) while approved, more efficacious options exist. These approaches may not only fail to address symptoms and burden of disease, but may also worsen health-related quality of life. A better understanding of available second-line treatments may ensure best use of therapeutic options and thereby optimize patient outcomes.

Chinese guidelines for treatment of adult primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

Advances in chemical pharmacotherapy for the treatment of pediatric immune thrombocytopenia

INTRODUCTION

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder of heterogeneous pathophysiological mechanisms. Treatment endpoints include elevation of platelets and reduction of bleeding risk, elevation of quality of life, reduction of concomitant therapies and prevention from bleeding. Persistent and chronic ITP is more common in adults but occurs in children. Standard therapies include corticosteroids and immunoglobulins, both associated with side effects. There are new treatments, such as thrombopoietin-receptor agonists and promising investigational drugs.

AREAS COVERED

Experience from the management of adults is valuable for children with persistent and chronic symptomatic ITP. In this review first- and second-line therapies, but also investigational drugs for children with ITP are discussed.

EXPERT OPINION

Although time-consuming and based on experience, children with no or mild bleeding can be safely managed with a watch and wait strategy. Chronic symptomatic immune thrombocytopenia is an area of second-line treatments based on a highly individualized approach. Furthermore, there are investigational drugs, which may also be of benefit for children with chronic symptomatic ITP.

Splenectomy for immune thrombocytopenia: down but not out

Splenectomy is an effective therapy for steroid-refractory or dependent immune thrombocytopenia (ITP). With the advent of medical alternatives such as rituximab and thrombopoietin receptor antagonists, the use of splenectomy has declined and is generally reserved for patients that fail multiple medical therapies. Splenectomy removes the primary site of platelet clearance and autoantibody production and offers the highest rate of durable response (50% to 70%) compared with other ITP therapies. However, there are no reliable predictors of splenectomy response, and long-term risks of infection and cardiovascular complications must be considered. Because the long-term efficacy of different second-line medical therapies for ITP have not been directly compared, treatment decisions must be made without supportive evidence. Splenectomy continues to be a reasonable treatment option for many patients, including those with an active lifestyle who desire freedom from medication and monitoring, and patients with fulminant ITP that does not respond well to medical therapy. We try to avoid splenectomy within the first 12 months after ITP diagnosis for most patients to allow for spontaneous or therapy-induced remissions, particularly in older patients who have increased surgical morbidity and lower rates of response, and in young children. Treatment decisions must be individualized based on patients' comorbidities, lifestyles, and preferences. Future research should focus on comparing long-term outcomes of patients treated with different second-line therapies and on developing personalized medicine approaches to identify subsets of patients most likely to respond to splenectomy or other therapeutic approaches.

Treatment of Children with Persistent and Chronic Idiopathic Thrombocytopenic Purpura: 4 Infusions of Rituximab and Three 4-Day Cycles of Dexamethasone

OBJECTIVES

To assess initial and long-term outcome of children with persistent/chronic idiopathic thrombocytopenic purpura (ITP) treated with 4 infusions of rituximab and three 4-day cycles of dexamethasone (4R+3Dex) including cohorts with most benefit and/or treatment associated toxicity.

STUDY DESIGN

All pediatric patients with ITP at Weill-Cornell who received 4R+3Dex were included in this retrospective study. Duration was median time from first rituximab infusion to treatment failure. Patient cohort included 33 children ages 1-18 years with persistent/chronic ITP; 19 were female, 10 of whom were adolescents. Every patient had failed more than 1 and usually several ITP treatments.

RESULTS

Children were treated with rituximab, 375 mg/m² weekly for 4 weeks and three 4-day courses of dexamethasone 28 mg/m² (40 mg max). Average age of nonresponders was 7.75 years, and initial responders averaged 12.7 years (P = .0073); 30% maintained continuing response at 60 months or last check-up. Eight of the 10 patients who underwent remission were female with ITP <24 months prior to initiating 4R+3Dex. All responding male patients except 2 relapsed.

CONCLUSIONS

Durable unmaintained ITP remission after 4R+3Dex was seen almost exclusively in female adolescents with <24 months duration of ITP. This provides a new therapeutic paradigm for a subpopulation with hard-to-treat chronic ITP. The pathophysiology of ITP underlying this distinction requires further elucidation.

Safety and efficacy of long-term treatment of chronic/persistent ITP with eltrombopag: final results of the EXTEND study. Blood. 2017;130:2527-2536. [PMID: 29042367 DOI: 10.1182/blood-2017-04-748707]

In phase 2/3 trials, eltrombopag treatment of 6 months or less in patients with chronic/persistent immune thrombocytopenia (ITP) increased platelet counts and reduced bleeding. The open-label EXTEND study evaluated long-term safety and efficacy of eltrombopag in adults with ITP who had completed a previous eltrombopag study. For the 302 patients enrolled, median duration of eltrombopag treatment was 2.37 years (2 days-8.76 years). Median platelet counts increased to 50 × 10⁹/L or more by week 2 and were sustained throughout the treatment period. Overall, 259 patients (85.8%) achieved a response (platelet count ≥50 × 10⁹/L at least once in the absence of rescue), and 133 (52%) of 257 patients achieved a continuous response of 25 weeks or longer. Responses in patients with platelet counts lower than 15 × 10⁹/L, more previous therapies, and/or splenectomy were somewhat lower. Thirty-four (34%) of 101 patients receiving concomitant ITP medication discontinued 1 or more medication. In patients with assessments, bleeding symptoms (World Health Organization grades 1-4) decreased from 57% at baseline to 16% at 1 year. Forty-one patients (14%) withdrew because of adverse events. Hepatobiliary adverse events (n = 7), cataracts (n = 4), deep vein thrombosis (n = 3), cerebral infarction (n = 2), headache (n = 2), and myelofibrosis (n = 2) occurred in more than 1 patient; the remaining adverse events occurred only once. Rates of thromboembolic events (6%) and hepatobiliary adverse events (15%) did not increase with treatment duration past 1 year. EXTEND demonstrated that long-term use of eltrombopag was effective in maintaining platelet counts of 50 × 10⁹/L or more and reducing bleeding in most patients with ITP of more than 6 months' duration. Important adverse events (eg, thrombosis, hepatobiliary, and bone marrow fibrosis) were infrequent. (ClinicalTrials.gov:NCT00351468).

Pathogenesis and Therapeutic Mechanisms in Immune Thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is a complex autoimmune disease characterized by low platelet counts. The pathogenesis of ITP remains unclear although both antibody-mediated and/or T cell-mediated platelet destruction are key processes. In addition, impairment of T cells, cytokine imbalances, and the contribution of the bone marrow niche have now been recognized to be important. Treatment strategies are aimed at the restoration of platelet counts compatible with adequate hemostasis rather than achieving physiological platelet counts. The first line treatments focus on the inhibition of autoantibody production and platelet degradation, whereas second-line treatments include immunosuppressive drugs, such as Rituximab, and splenectomy. Finally, third-line treatments aim to stimulate platelet production by megakaryocytes. This review discusses the pathophysiology of ITP and how the different treatment modalities affect the pathogenic mechanisms.