Risk of thromboembolism with thrombopoietin receptor agonists in adult patients with thrombocytopenia: Systematic review and meta-analysis of randomized controlled trials

The immune thrombocytopenia paradox: Should we be concerned about thrombosis in ITP?

Despite the predisposition to bleeding, patients with immune thrombocytopenia (ITP) may also have an increased risk of arterial and venous thrombosis, which can contribute to significant morbidity. The risk of thrombosis increases with age and the presence of cardiovascular risk factors. This narrative review explores the multifactorial nature of thrombosis in ITP, focusing on new pathological mechanisms, emerging evidence on the association between established treatments and thrombotic risk, the role of novel treatment approaches, and the challenges in assessing the balance between bleeding and thrombosis in ITP. The review also explores the challenges in managing acute thrombotic events in ITP, since the platelet count does not always reliably predict either the risk of bleeding or thrombosis and antithrombotic strategies lack specific guidelines for ITP. Notably, second-line therapeutic options, such as splenectomy and thrombopoietin receptor agonists (TPO-RAs), exhibit an increased risk of thrombosis especially in older individuals or those with multiple thrombotic risk factors or previous thrombosis, emphasizing the importance of careful risk assessment before treatment selection. In this context, it is important to consider second-line therapies such as rituximab and other immunosuppressive agents, dapsone and fostamatinib, which are not associated with increased thrombotic risk. In particular, fostamatinib, an oral spleen tyrosine kinase inhibitor, has promisingly low thrombotic risk. During the current era of the emergence of several novel ITP therapies that do not pose additional risks for thrombosis, it is critical to outline evidence-based strategies for the prevention and treatment of thrombosis in ITP patients.

Aplastic Anemia With Thrombosis Following the Administration of Immunosuppressant and Thrombopoietin Receptor Agonist (TPO-RA)

Thrombopoietin receptor agonist (TPO-RA) is effective for aplastic anemia (AA) and idiopathic thrombocytopenic purpura (ITP). However, the risk of thrombosis during ITP treatment with TPO-RA is higher than without TPO-RA. It is unclear whether TPO-RA increases the risk of thrombosis in patients with AA. We report a case of a 66-year-old female with severe AA having paroxysmal nocturnal hemoglobinuria (PNH) clones in the peripheral blood who developed ischemic colitis after three days of starting eltrombopag. Contrast-enhanced computed tomography showed ischemic colitis and contrast enhancement defect in the left atrial appendage, which indicated a thrombus in the heart. Stopping eltrombopag and providing supportive care improved her symptoms, and her blood cell counts gradually increased. Thrombosis should be considered when TPO-RA is administered during the immunosuppressive treatment of AA.

Treatment patterns and outcomes among adults with immune thrombocytopenia receiving pharmaceutical second-line therapies: a retrospective cohort study using administrative claims data

OBJECTIVES

To describe and compare real-world treatment patterns and clinical outcomes among individuals with immune thrombocytopenia (ITP) receiving second-line therapies (rituximab, romiplostim, or eltrombopag).

METHODS

A retrospective cohort study was conducted using a large administrative claims database (January 2013-May 2020) among continuously enrolled patients ≥18 years prescribed second-line ITP therapies. The index date was the date of the first claim of the study medications. Treatment patterns and outcomes were measured during the 12-month follow-up period. Inverse probability of treatment weighting (IPTW) was used to balance covariates across treatment groups. Multivariable logistic regression was used to compare treatment patterns and bleeding risk outcomes.

RESULTS

A total of 695 patients were included (rituximab, N = 285; romiplostim, N = 212; eltrombopag, N = 198). After IPTW, all baseline covariates were balanced. Compared to eltrombopag, patients in the rituximab cohort were 57% more likely to receive other ITP therapies (systematic corticosteroids or third-line therapies) during the follow-up period (odds ratio [OR] = 1.571, p = .030). There was no significant difference in the odds of receiving a different second-line therapy or experiencing a bleeding-related episode among three groups (p > .050). Patients in the romiplostim cohort were 69% more likely to receive rescue therapy compared to those in the rituximab cohort (OR = 1.688, p = .025).

CONCLUSION

Patients with ITP receiving rituximab were more likely to need other ITP therapies but did not experience higher risk of bleeding compared to those receiving eltrombopag or romiplostim. Benefits, risks, cost-effectiveness, and patient preference should all be considered in optimizing second-line therapy for ITP.

Primary Immune Thrombocytopenic Purpura (ITP) and ITP Associated with Systemic Lupus Erythematosus: A Review of Clinical Characteristics and Treatment Modalities

Immune thrombocytopenic purpura (ITP) is an immune-mediated disorder characterized by the destruction of platelets and megakaryocytes due to autoantibodies against the platelet surface proteins. ITP without any apparent cause of thrombocytopenia is defined as primary ITP, and ITP in the setting of SLE is secondary ITP, which can be diagnosed after excluding other causes of thrombocytopenia by history, physical examination, and laboratory testing. Patients with ITP associated with SLE have higher median platelet count and less bleeding manifestations compared to the patients with primary ITP. It can be very challenging to diagnose primary ITP in SLE patients as other causes of thrombocytopenia including drug-induced thrombocytopenia, antiphospholipid syndrome, and thrombotic microangiopathic process should be ruled out. Corticosteroids are the main modality of treatment. IVIG can be used in severe cases. Splenectomy was found to be less effective in ITP associated with SLE compared to primary ITP. Control of disease activity with immunosuppressive therapy can be helpful in some cases associated with active disease flares in SLE patients.

Thrombopoietin receptor agonists use and risk of thrombotic events in patients with immune thrombocytopenic purpura: A systematic review and meta‑analysis of randomized controlled trials

Thrombopoietin receptor agonists (TPO-RAs) have a role in second-line immune thrombocytopenic purpura (ITP) treatment, binding to and activating thrombopoietin receptors on megakaryocyte membranes in the bone marrow. This promotes megakaryocyte maturation and increases platelet production. Despite a 2-6% incidence of thrombotic events during TPO-RA treatment, it remains uncertain whether TPO-RAs elevate thrombosis rates. A comprehensive search of electronic databases was conducted using the relevant search criteria. To assess the risk of bias, the included studies were assessed using the revised Cochrane Risk of Bias Assessment Tool 2.0, and a meta-analysis was performed using RevMan 5.4.1. A total of 1,698 patients with ITP were included from randomized controlled trials (RCTs). There were 26 thromboembolic events in the TPO-RAs group and 4 in the control group. However, there was no significant difference in the incidence of thrombotic events between the two groups [odds ratio (OR)=1.76, 95% confidence interval (CI): 0.78-4.00, P=0.18], even if the duration of treatment was >12 weeks (OR=2.46, 95% CI: 0.81-7.43, P=0.11). Subgroup analysis showed that none of the four drugs significantly increased the incidence of thrombotic events (romiplostim: OR=0.92, 95% CI: 0.14-6.13, P=0.93; eltrombopag: OR=2.32, 95% CI: 0.64-8.47, P=0.20; avatrombopag: OR=4.15, 95% CI: 0.20-85.23, P=0.36; and hetrombopag: OR=0.76, 95% CI: 0.03-18.76, P=0.87). There was also no significant difference in the results of the double-blinded placebo-controlled RCTs (OR=1.21, 95% CI: 0.41-3.58, P=0.73). Compared to patients with ITP who did not receive TPO-RA treatment, those receiving TPO-RA treatment did not exhibit a significantly increased risk of thrombotic events.

EULAR recommendations for the management of systemic lupus erythematosus: 2023 update

OBJECTIVES

To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence.

METHODS

An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item.

RESULTS

The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease.

CONCLUSION

The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.

Hyperlipidemia in immune thrombocytopenia: a retrospective study

BACKGROUND

Immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disease characterized by low platelet count and bleeding manifestations. However, some patients also suffered from atherosclerosis or even infarction. Apart from activated platelets, lipid metabolism takes a large part in the formation of atherosclerosis and metabolic syndrome. The lipid metabolic state in ITP patients is still unknown.

METHODS

We retrospectively reviewed 302 hospitalized ITP patients in our cohort, comparing their blood lipids, bleeding symptoms, metabolic diseases and treatment responses.

RESULTS

We found a high proportion of ITP patients suffered from hyperlipidemia, and other metabolic diseases including cardiovascular or cerebral atherosclerosis or infarction, hypertension, and type 2 diabetes. Hyperlipidemia was associated with severe bleeding and treatment refractoriness in ITP. Statins could alleviate thrombocytopenia and bleeding severity, and facilitate ITP treatment, while improving hyperlipidemia in ITP patients.

CONCLUSIONS

Our present study demonstrated that lipid metabolism might play an indispensable role in ITP pathogenesis and development.

Fostamatinib or Thrombopoietin for the Treatment of Chronic Immune Thrombocytopenia in Adult Patients: A Real-World Assessment of Safety, Effectiveness and Cost

INTRODUCTION

Chronic immune thrombocytopenia purpura (ITP) in adults is a serious autoimmune disease in which platelets are prematurely destroyed, leaving the patient vulnerable to bruising and bleeding. Initial treatment starts with corticosteroids. In patients who become resistant or intolerant to corticosteroids, the thrombopoietic agents (TPOs), consisting of romiplostim (ROM), eltrombopag (ELT), and avatrombopag (AVA), or the spleen tyrosine kinase inhibitor fostamatinib (FOS), are appropriate next lines of therapy. In this study, the comparative safety, effectiveness, and cost of care between fostamatinib and the TPOs were evaluated in a real-world setting.

METHODS

A retrospective analysis of 17 community hematology practices across the USA was conducted to identify adult ITP patients who received one of the four agents. Data collection consisted of patient demographics, disease characteristics, as well as number and type of prior treatments. From the first day until the end of treatment, data were also collected on platelet (PLT) counts, adverse events, the use of rescue IVIG, platelet transfusions, and corticosteroids. Multivariable logistic regression analysis was used to compare PLT-related endpoints between agents.

RESULTS

A sample of 179 ITP patients who had received at least one of the four agents was identified. This resulted in a final sample of 51, 87, 127, and 44 patients who received FOS, ELT, ROM, or AVA, respectively. At month six, there were no significant differences between FOS and the TPOs in terms of the proportion of patients with the PLT count being ≥30 × 103/μL, ≥50 × 103/μL as well as the proportion of patients whose PLT levels doubled relative to baseline. The frequency of thromboembolic events (TEs) was 3.9% in FOS patients compared to 9.2%, 4.7%, and 11.4% in the ELT, ROM, and AVA groups. The mean cost per patient with FOS was $99,209 (95% CI: $59,595-$115,074), compared to $92,426 (95% CI: $68,331-$115,519), $108,482 (95% CI: $84,782-$132,182), and $131,050 (95% CI: $83,327-$179,897) for ELT, ROM, or AVA, respectively.

CONCLUSIONS

In this real-world analysis, FOS was comparable to the TPOs in maintaining PLTs at clinically beneficial levels. Given these findings, the choice of therapy should be based on overall patient safety, preexisting risk factors for TEs, and cost effectiveness.

Immune thrombocytopenia and cerebral thrombophlebitis in a patient on eltrombopag: A rare complication

Thrombopoietin receptor analogs (TPO-RAs) are indicated for splenectomized immune thrombocytopenia refractory to corticosteroids or immunoglobulins, intravenous, or as second-line therapy when splenectomy is contraindicated. Herein, we report a case of left transverse and superior sagittal sinus thrombophlebitis in a 49-year-old woman with chronic immune thrombocytopenia who received 10 days of eltrombopag treatment. Etiologic assessment ruled out acquired thrombophilia and antiphospholipid syndrome. Pharmacovigilance investigation confirmed causality between eltrombopag and the cerebral events, necessitating the definitive discontinuation of the drug. The patient was treated with anticoagulants and anticonvulsants. This evolution was marked by clinical recovery and significant radiological improvement of the thrombotic event. Cerebral venous thrombophlebitis within TPO-RA treatment remains rare, and without codified recommendations, a strict assessment of patients at risk of thrombotic events remains necessary prior to TPO-RA initiation.

An obvious antinomy, superior sagittal sinus thrombosis in a patient with immune thrombocytopenia: Case report and a review of literatures

RATIONALE

Immune thrombocytopenia (ITP) is an autoimmune disease with an increased risk of bleeding. However, in recent years, it has been reported that patients with this hemorrhagic disease have the risk of thrombosis and embolism.

PATIENT CONCERNS AND DIAGNOSIS

The patient, in this case, was a young female who was diagnosed with ITP. When the platelet count was low, she had skin, mucosa, internal organs, and intracranial hemorrhage. In the process of ITP and hemostatic treatment, superior sagittal sinus thrombosis occurred when she was still bleeding.

INTERVENTIONS

She was given treatments for reducing intracranial pressure and controlling epilepsy.

OUTCOMES

And then the embolectomy operation failed. It was suggested in this case that ITP patients with severe thrombocytopenia and bleeding tendency also have a risk of having thrombotic disease. We reviewed literatures regarding the mechanism of the simultaneous occurrence of 2 antinomy diseases and cerebral venous thrombosis.

LESSONS

There are many factors for ITP patients to have thrombosis involving ITP itself, its treatment and the patients' constitution, medical history, and former medication. ITP is not only a hemorrhagic disease but also a thrombotic disease. Clinicians should be alert to the risk of thrombotic diseases in ITP treatment. Therefore thrombus monitoring and screening should be carried out, and early prevention or appropriate anticoagulant treatment should be selected, especially for patients with high risk.

Current approaches for the diagnosis and management of immune thrombocytopenia

Immune thrombocytopenia (ITP), is an acquired autoimmune disorder characterized by the destruction of platelets and megakaryocytes, resulting in thrombocytopenia (platelet count <100 × 10⁹/L). This review focuses on the diagnosis and current management of ITP. The diagnosis of ITP is based principally on the exclusion of other causes of isolated thrombocytopenia using patient history, physical examination, blood count, and evaluation of the peripheral blood film. The clinical treatment goals should be to resolve bleeding events and to prevent severe bleeding episodes. The platelet count should be improved to attain a minimum of > 20-30 × 10⁹/L. Therapy should be given as an inpatient in newly diagnosed ITP with a platelet count of > 20 × 10⁹/L or if there is active bleeding. Corticosteroids are considered the standard initial treatment for newly diagnosed patients. Subsequent medical therapies with robust evidence include thrombopoietin receptor agonists (TPO-RAs), rituximab and fostamatinib. Surgical therapy with splenectomy may be considered for patients failing medical therapy. The choice between therapy options is highly dependent upon patient values and preferences.

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.

Risk of Thromboembolism With Eltrombopag: A Case Report of Deep Vein Thrombosis and Bilateral Pulmonary Embolism

Eltrombopag is a second-line therapy for refractory thrombocytopenia from immune thrombocytopenic purpura (ITP). The medication is generally well tolerated but can lead to adverse thromboembolic complications in rare instances. We present a case of lower extremity deep vein thrombosis with bilateral pulmonary embolism in an ITP patient receiving eltrombopag. The patient underwent catheter-directed thrombolysis for pulmonary embolism. Eltrombopag was stopped on discharge, considering the potential cause of venous thrombosis.

Risk of thrombosis with thrombopoietin receptor agonists for ITP patients: a systematic review and meta-analysis

One possible side effect of thrombopoietin receptor agonists in immune thrombocytopenia is thrombosis. Our aim is to systematically review whether patients with ITP that were treated with a TPO-RA have an increased risk for thrombosis as compared to ITP patients without TPO-RA. Patients in the intervention group were required to receive TPO-RA therapy. The primary outcome was the incidence of thromboembolic events. Eleven studies were included in the pooled analysis. More thromboembolic events were noted in the TPO-RA group than in the control group: 25 compared to 4. Ten out of 11 studies showed a relative risk greater than 1. However, none of these individual risk ratios was statistically significant. The meta-analysis showed a RR of 1.82 [95% CI 0.78-4.24]. Our findings indicate there is a non-significant higher chance of thrombosis in ITP patients with TPO-RA treatments versus ITP patients without TPO-RA treatment.

Recombinant Human Thrombopoietin Accelerates the Recovery of Platelet in Patients With Lower-Risk Myelodysplastic Syndrome: A Proof-of-Concept Study

Aim

The effect of recombinant human thrombopoietin (rhTPO) is largely unknown in lower-risk myelodysplastic syndrome (LR-MDS). This study aimed at investigating the safety and efficacy of rhTPO in patients with LR-MDS.

Methods

LR-MDS patients receiving stanozolol (2 mg, t.i.d.) and supportive care alone (non-rhTPO) or additional rhTPO were enrolled in this study prospectively. rhTPO was given at 15,000 U (q.d.) for 7 days/month for at least 3 months. Patients stopped rhTPO if the platelet count was higher than 50 × 10⁹/L or had no effects after 3 months of treatment. The overall response (OR), complete response (CR), platelet response, side effects, clone evolution, and clinical outcome were evaluated.

Result

Thirty-five patients were enrolled: 20 (57.1%) patients in the rhTPO group and 15 (42.9%) patients in the non-rhTPO group. The demographic and baseline characteristics were balanced between the two groups. Platelet response was higher at 1 and 2 months as compared with that in the non-rhTPO group (p = 0.006 and p = 0.001, respectively). Meanwhile, the rhTPO group had a shorter time to achieve a platelet transfusion-free state compared with the non-rhTPO group (p = 0.034). Hematologic response was higher at 1 and 2 months compared with that in the non-rhTPO group (p = 0.006 and p = 0.001, respectively). There was no significant difference in the overall response or complete response at 1, 2, 3, 6, and 12 months between the two groups. One patient in the rhTPO group evolved into higher-risk MDS at 9 months. No significant difference in disease progression, infection, gastrointestinal disorders, or drug-related liver/renal injuries was found between the two groups (p > 0.05).

Conclusion

Adding short-term rhTPO can accelerate the early platelet response and decrease platelet transfusion, with no obvious side effects.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04324060?cond=NCT04324060&draw=2, identifier NCT04324060

Eltrombopag treatment of patients with secondary immune thrombocytopenia: retrospective EHR analysis

Immune thrombocytopenia (ITP) may occur in isolation (primary) or in association with a predisposing condition (secondary ITP [sITP]). Eltrombopag is a well-studied treatment for primary ITP, but evidence is scarce for sITP. We evaluated real-world use of eltrombopag for sITP using electronic health records. Eligible patients had diagnoses of ITP and a qualifying predisposing condition, and eltrombopag treatment. We described patient characteristics, treatment patterns, platelet counts, and thrombotic and bleeding events. We identified 242 eligible patients; the most common predisposing conditions were hepatitis C and systemic lupus erythematosus. Average duration of eltrombopag treatment was 6.1 months. Most (81.4%) patients achieved a platelet count ≥ 30,000/µL at a mean of 0.70 months, 70.2% reached ≥ 50,000/µL at a mean of 0.95 months, and 47.1% achieved a complete response of > 100,000/µL at a mean of 1.43 months after eltrombopag initiation. At eltrombopag discontinuation, 105 patients (43%) experienced a treatment-free period for a mean 3.3 months. Bleeding events occurred with similar frequency before and during eltrombopag treatment whereas thrombotic events were less frequent during eltrombopag treatment. Our results suggest similar rates of platelet response with eltrombopag in patients with sITP as compared with primary ITP. In addition, a treatment-free period is possible for a substantial minority of patients.

Eltrombopag-related renal vein thromboembolism in a patient with immune thrombocytopenia: A case report

BACKGROUND

Eltrombopag is an orally administered thrombopoietin receptor agonist linked to a heightened risk of treatment-related thromboembolism. Both venous and arterial thromboses have been documented in the medical literature.

CASE SUMMARY

In the absence of nephropathy, a 48-year-old patient receiving eltrombopag for immune thrombocytopenia (ITP) developed renal vein thrombosis and pulmonary embolism. The renal vein thrombus spontaneously resolved during subsequent anticoagulant treatment, restoring venous circulation.

CONCLUSION

A rapid upsurge in platelets, rather than their absolute number, may trigger thrombotic events in this setting. For patients at high thrombotic risk, individualized eltrombopag dosing and vigilance in platelet monitoring are perhaps needed during treatment of ITP.

High-dose dexamethasone plus recombinant human thrombopoietin vs high-dose dexamethasone alone as frontline treatment for newly diagnosed adult primary immune thrombocytopenia: A prospective, multicenter, randomized trial

We conducted a prospective, multicenter, randomized, controlled clinical trial to compare the efficacy and safety of high-dose dexamethasone (HD-DXM) plus recombinant human thrombopoietin (rhTPO), vs HD-DXM alone in newly diagnosed adult immune thrombocytopenia (ITP) patients. Enrolled patients were randomly assigned to receive DXM plus rhTPO or DXM monotherapy. Another 4-day course of DXM was repeated if response was not achieved by day 10 in both arms. One hundred patients in the HD-DXM plus rhTPO arm and 96 patients in the HD-DXM monotherapy arm were included in the full analysis set. So, HD-DXM plus rhTPO resulted in a higher incidence of initial response (89.0% vs 66.7%, P < .001) and complete response (CR, 75.0% vs 42.7%, P < .001) compared with HD-DXM monotherapy. Response rate at 6 months was also higher in the HD-DXM plus rhTPO arm than that in the HD-DXM monotherapy arm (51.0% vs 36.5%, P = .02; sustained CR: 46.0% vs 32.3%, P = .043). Throughout the follow-up period, the overall duration of response was greater in the HD-DXM plus rhTPO arm compared to the HD-DXM monotherapy arm (P = .04), as estimated by the Kaplan-Meier analysis. The study drugs were generally well tolerated. In conclusion, the combination of HD-DXM with rhTPO significantly improved the initial response and yielded favorable SR in newly diagnosed ITP patients, thus could be further validated as a frontline treatment for ITP. This study is registered as clinicaltrials.gov identifier: NCT01734044.

Severe thrombocytopaenia secondary to COVID-19

The SARS-CoV-2 infection has caused a pandemic with a case rate of over 290 000 lab-confirmed cases and over 40 000 deaths in the UK. There is little evidence to inform the optimal management of a patient presenting with new or relapsed acute idiopathic thrombocytopaenic purpura with concurrent SARS-CoV-2 infection. We present a case of severe thrombocytopaenia complicated by subdural haematoma and rectal bleed associated with COVID-19. A 67-year-old man, admitted with a non-productive cough and confusion, was found to be positive for COVID-19. Ten days after admission, his platelets decreased from 146×109/L to 2×109/L. His platelets did not increase despite receiving frequent platelet transfusions. He was non-responsive to corticosteroids and intravenous immunoglobulins. Romiplostim and eltrombopag were given and after 9 weeks of treatment, his platelet count normalised. He was deemed medically fit with outpatient follow-up in a haematology clinic.

Romiplostim and Eltrombopag in Immune Thrombocytopenia as a Second-Line Treatment

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by platelet count less than 100×10⁹/L and an increased risk of bleeding. The risk of bleeding increases in proportion with the degree of thrombocytopenia. Although several medications are used for primary thrombocytopenia treatment, refractoriness remains a concern. Romiplostim and eltrombopag, two relatively new drugs, have been shown to be successful in ITP treatment after standard treatment failure. The current guidelines recommend their use as a second-line treatment. In this article, we have tried to compare which of these two medications is the best option considering clinical effectiveness, cost-effectiveness, adverse effects, and the possibility of switching between them in case of ineffectiveness. The studies used in this article were found in the PubMed database. All the studies are limited to adults. Based on these studies, both medications seem to be a largely effective, safe option. Romiplostim appears to have slightly fewer adverse effects and higher costs. Switching between thrombopoietin receptor agonists (TRAs) is a successful way to overcome adverse effects and inadequacy according to the currently available literature. We believe that more detailed studies are needed to determine which of these drugs should be considered the first choice, to report long term efficacy and adverse effects, and to determine if treatment guidelines can change regarding the use of TRAs as first-line treatment.

New insights into the epidemiology of immune thrombocytopenia in adult patients: Impact for clinical practice

New insights into immune thrombocytopenia (ITP) epidemiology in adult patients highlight three main outcomes of morbidity and mortality: bleeding, infection and thrombosis. This review depicts current evidence about incidence and risk factors of bleeding, infection and thrombosis as well as predictors of chronicity, and shows how this assessment impacts the choice of ITP second-line treatment at the individual-level basis.

Markers of endothelial cell activation and neutrophil extracellular traps are elevated in immune thrombocytopenia but are not enhanced by thrombopoietin receptor agonists

INTRODUCTION

Patients with immune thrombocytopenia (ITP) are at increased risk of thrombosis, which seems to be further enhanced by treatment with thrombopoietin-receptor-agonists (TPO-RAs). The underlying mechanisms of thrombosis in ITP are not fully understood. Endothelial cell activation and neutrophil extracellular traps (NETs) play important roles in thrombosis, however, their roles in ITP itself, or in TPO-RA-treatment, have not yet been fully explored. We aimed to investigate whether endothelial cell activation and NETs are involved in the hypercoagulable state of ITP, and whether TPO-RA-treatment enhances endothelial cell activation and NET formation.

MATERIAL AND METHODS

We measured markers of endothelial cell activation including intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1) and thrombomodulin in 21 ITP patients, and E-selectin in 18 ITP patients. Markers of NET formation, citrullinated histone H3-DNA (H3Cit-DNA) and cell-free DNA (cfDNA), were measured in 15 ITP patients. All markers were measured before, and 2 and 6 weeks after initiation of TPO-RA-treatment in ITP patients, and in matched controls.

RESULTS

Higher levels of ICAM-1, thrombomodulin, and H3Cit-DNA were found in ITP patients, both before and after TPO-RA-treatment, compared with controls. No differences were found for VCAM-1, E-selectin or cfDNA. TPO-RA-treatment did not further increase markers of endothelial cell activation or NET formation.

CONCLUSIONS

This study showed that ITP patients have increased endothelial cell activation and NET formation, both of which may contribute to the intrinsic hypercoagulable state of ITP. TPO-RA-treatment, however, did not further increase endothelial cell activation or NET formation indicating that other drug-associated prothrombotic mechanisms are involved.

Platelet activation and neutrophil extracellular trap (NET) formation in immune thrombocytopenia: is there an association?

No biological predictors for the increased risk of thrombosis in patients with immune thrombocytopenia (ITP) have been identified. The aim of the study was to investigate platelet and neutrophil activation as well neutrophil extracellular trap (NET) formation in 63 ITP patients and 30 healthy volunteers. Platelet and neutrophil activation was assessed during steady state using flow cytometry analysis, and NETs were evaluated by quantitation of cell free DNA (cfDNA), and citrullinated histone-3-DNA (CitH3-DNA). Patient platelets and neutrophils showed increased CD62 and CD11b expression compared to controls (p = .038, and p = .022, respectively). In patients, platelet activation inversely correlated with platelet count and platelet size (p < .001), and positively correlated with neutrophil degranulation (p = .024). More NET formation, both CitH3-DNA (p = .025) and cfDNA(p < .001), were present in ITP patients compared to controls. CitH3-DNA inversely correlated with CD62 expression on platelets (p = .042), but higher levels of cfDNA were observed in individuals with classical cardiovascular risk factors for thrombosis, and in those with a previous history of thrombotic events. In this disease, the increased platelet activation and plasma NET levels seem to be separable processes that associate (either positively or inversely in the case of CitH3-DNA or platelet degranulation, respectively) to platelet mass.

Recurrent Coronary Thrombus in a Patient with Chronic Immune Thrombocytopenia with Treatment Using Eltrombopag

Background

Eltrombopag, a nonpeptide thrombopoietin receptor agonist (TPO-RA), has been reported to be an effective therapy for chronic immune thrombocytopenia (ITP). However, a higher incidence of arterial and venous thromboembolic events was reported after using eltrombopag.

Case Presentation

A 67-year-old man, treated with eltrombopag due to chronic ITP, was admitted due to acute coronary syndrome (ACS). Although coronary angiography revealed no occlusion, cardiac magnetic resonance imaging suggested a myocardial infarction in the territory of the left circumflex coronary artery. Three months after the ACS event, the obtuse marginal branches exhibited significant stenosis; hence, a percutaneous coronary intervention (PCI) was performed to implant a zotarolimus-eluting stent under the treatment of a dual antiplatelet therapy. However, stent thrombosis occurred 3 hours after PCI and required three other PCIs during the eltrombopag treatment.

Conclusion

We present a case of an ITP patient, who experienced repeated coronary and stent thrombosis during the treatment with eltrombopag. We propose that the risk of ACS and consequent coronary stent thrombosis should be considered before the introduction of eltrombopag.

Avatrombopag for the treatment of immune thrombocytopenia

INTRODUCTION

Thrombopoietin-receptor agonists (TPO-RAs) are the only American Society of Hematology (ASH) guideline-advocated, second-line treatment for immune thrombocytopenia (ITP) that have been validated by randomized, controlled trials with a placebo comparator. Avatrombopag is a new candidate in this class that has been investigated as a treatment option for the treatment of ITP. Areas covered: In this Drug Profile, we provide a review of the clinical data of avatrombopag, which was approved in May 2018 by the United States Food and Drug Administration (FDA) for the treatment of thrombocytopenia in patients with chronic liver disease undergoing an invasive procedure, and an opinion of its potential place in the current evidence-based ITP treatment landscape. Expert commentary: Avatrombopag induces doubling of platelet counts, increasing them to above 50 X 10⁹/L, and prevents the need for platelet transfusions while minimizing the need for rescue medications. Treatment-emergent adverse events (TEAEs) are comparable to placebo. Oral delivery, a 5-day dosing schedule and good tolerability (<1% discontinuation rate) with no clinically significant hepatoxicity make it a promising entrant as a potential second-line treatment for ITP. Further, data from a phase 3 study in patients with ITP supports its utility in the treatment of patients with ITP.

A sticky situation: myocardial infarction in a young woman with immune thrombocytopenia on eltrombopag and a history of mediastinal radiation

More recent immune thrombocytopenia (ITP) treatment strategies enhance platelet production with the use of thrombopoietin receptor agonists (TPO-RA) such as eltrombopag. Patients receiving TPO-RA agents may be at an increased risk of thromboembolism, however the pathophysiology and common underlying risk factors are not well understood. We present the case of a young asplenic woman on eltrombopag for chronic ITP with acute myocardial infarction involving the right coronary artery. Past medical history was significant for remote mediastinal radiation for lymphoma and splenectomy for ITP. She had no other risk factors for coronary artery disease. She underwent coronary catheterization and balloon angioplasty to the culprit lesion, although stenting was deferred due to concerns with dual antiplatelet therapy. She was discharged from hospital on single antiplatelet therapy with acetylsalicylic acid. We believe that the patient's ITP, recent eltrombopag use, surgical asplenia and history of mediastinal radiation synergistically contributed to her myocardial infarction. The risks of bleeding and thromboembolism must be carefully weighed in patients receiving TPO-RA therapy.

Pharmacokinetic and Pharmacodynamic Evaluation of Different PEGylated Human Interleukin-11 Preparations in Animal Models

Treating thrombocytopenia induced by chemotherapy remains an unmet-medical need. The use of recombinant human interleukin-11 (rhIL-11) requires repeated injections and induces significant fluid retention in some patients. Modification of human interleukin-11 with chemically inert polyethylene glycol polymer (PEG) may extend the peripheral circulation half-life leading to an improved pharmacokinetic and pharmadynamic profile. In this study, a number of rhIL-11 PEG conjugates were created to determine the optimal approach to prolong circulating half-life with the most robust pharmacological effect. The lead candidate was found to be a single 40-kDa Y-shaped PEG linked to the N-terminus, which produced a long-lasting circulating half-life, enhanced efficacy and alleviated side effect of dilutional anemia in healthy rat models. This candidate was also shown to be effective in myelosuppressive rats in preventing the occurrence of severe thrombocytopenia while ameliorating dilutional anemia, compared to rats receiving daily administration of unmodified rhIL-11 at the same dose. These data indicated that a single injection of the selected modified rhIL-11 for each cycle of chemotherapy regimen is potentially feasible. This approach may also be useful in treating patients of acute radiation syndrome when frequent administration is not feasible in a widespread event of a major radiation exposure.

Eltrombopag versus romiplostim in treatment of adult patients with immune thrombocytopenia: A systematic review incorporating an indirect-comparison meta-analysis

Purpose

In absence of direct comparison randomized controlled trials (RCTs), indirect comparison was conducted to evaluate the efficacy and safety of thrombopoietin-receptor agonists (TPO-RAs) in treatment of adult immune thrombocytopenia (ITP).

Methods

We searched PubMed, Embase and Cochrane Library, Clinical Trials.gov, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database from their earliest records to May 2017. RCTs comparing the TPO-RAs with placebo in adult ITP were included. Primary outcomes were the overall response rate. Secondary outcomes included safety, durable response, overall or clinically significant bleeding, and the proportion of patients receiving rescue medication.

Results

Nine randomized placebo-controlled trials (786 participants) were included in this systematic review. Overall response [Risk Ratio(RR) = 0.59, 95%Confidence Interval(CI): 0.24–1.45], the incidence of adverse events (RR = 0.98, 95%CI: 0.79–1.21), durable response (RR = 0.47, 95%CI: 0.08–2.81), the incidence of overall bleeding (RR = 1.15, 95%CI: 0.52–2.57) and clinically significant bleeding (RR = 1.09, 95%CI: 0.37–3.24), and the proportion of patients receiving rescue treatment (RR = 0.95, 95%CI: 0.47–1.90) were similar between eltrombopag and romiplostim.

Conclusions

Eltrombopag and romiplostim might be equivalent in efficacy and safety for adult ITP, however, physicians should still take into account drug cost and comorbidities of the specific patient while making decisions on the treatment of ITP with TPO-RAs.

Registration

PROSPERO International Prospective Register of Systematic Review (PROSPERO 2017: CRD42017068661).

A Randomized Multicenter Trial Comparing Low-Dose Prednisolone Versus Observation for Prevention of Recurrences in Adult Immune Thrombocytopenia

Adult immune thrombocytopenia (ITP) commonly relapses after stopping treatments. This may be preventable by low-dose steroids. In this multicenter study, adult patients with ITP who had been responding to corticosteroids were randomized with the 2 strata of newly diagnosed and relapsed ITP to prednisolone 7.5 mg/d or observation for 6 months. Relapses were defined by a platelet count below 30 × 10⁹/L and/or clinical bleeding. There were 75 patients evaluable for the efficacy and 77 for safety. The recurrent ITP comprised 57.3%. During the median follow-up of 42 weeks, there were 20.5% (8/39) and 25% (9/36) of recurrences in the prednisolone and control groups (P = .643), with the hazard ratio (HR) of 0.75 (P = .549). The significant factor that could predict recurrences was relapsed ITP with the HR of 2.79 (95% confidence interval, 1.02-7.64, P = .037). Prednisolone showed a trend toward a benefit in the relapsed subgroup (P = .070). Adverse events were not different (P = .540) and mostly mild. In conclusion, prednisolone maintenance could not prolong relapse-free survival. Relapsed patients deserve further investigations for preventive measures.

Eltrombopag versus romiplostim in treatment of children with persistent or chronic immune thrombocytopenia: a systematic review incorporating an indirect-comparison meta-analysis

In absence of direct comparison, we conducted an indirect-comparison meta-analysis to evaluate the efficacy and safety of thrombopoietin-receptor agonists(TPO-RAs) in treatment of pediatric persistent or chronic immune thrombocytopenia(ITP). PubMed, Embase, Cochrane Library, Clinical Trials.gov, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database were searched from their earliest records to May 2017. Randomized controlled trials comparing the TPO-RAs with placebo in pediatric ITP were included. Outcomes included overall response rate(primary), durable response, overall or clinically significant bleeding, the proportion of patients receiving rescue medication, and safety. Five randomized placebo-controlled studies(N = 261) were analyzed. The overall response[Risk Ratio(RR) 0.57, 95% confidence interval(CI) 0.21–1.56], the incidence of adverse events (RR 0.96, 95%CI 0.66–1.39), durable response(RR 2.48, 95%CI 0.31–19.97), and the proportion of patients receiving rescue treatment(RR 0.73, 95%CI 0.20–2.73) were similar between eltrombopag and romiplostim group. Nevertheless, eltrombopag might have lower risk of overall bleeding(RR 0.43, 95%CI 0.23–0.80) and clinically significant bleeding(RR 0.33, 95%CI 0.12–0.89) than romiplostim. This meta-analysis suggests that eltrombopag might be similar to romiplostim in efficacy and safety, but seems to reduce the risk of bleeding compared to romiplostim. Furthermore, cost of the treatment, comorbidity of patients and drug compliance should also be considered in clinical decision making.

Management of newly diagnosed immune thrombocytopenia: can we change outcomes?

Immune thrombocytopenia resulting from antibody-mediated platelet destruction combined with impaired platelet production is a common cause of thrombocytopenia. The decision to treat newly diagnosed patients is based on several factors including ceasing hemorrhagic manifestations, increasing the platelet count, prevention of bleeding, and inducing remission. Current standard first-line therapy is a course of corticosteroids. Although this treatment paradigm increases the platelet count in the majority of patients, a high percentage relapse after discontinuation of corticosteroid therapy. For this reason, intensification of first-line therapy that results in superior long-term remission rates would be desirable. This manuscript focuses primarily on adults with idiopathic thrombocytopenic purpura (ITP), highlighting pediatric data and practice when applicable. The primary aim is to outline upfront strategies for treatment-naive patients with ITP to enhance remission rates, taking into account assessment of the risks and benefits of these approaches.

Effect of thrombopoietin receptor agonists on markers of coagulation and P-selectin in patients with immune thrombocytopenia

Thrombopoietin-receptor-agonists (TPO-RA) are effective treatments of immune thrombocytopenia (ITP). Previous long-term TPO-RA clinical trials have shown that thrombotic events occurred in 6% of TPO-RA-treated ITP patients. To explore the increased risk of thrombosis, the effects of TPO-RA on markers of coagulation and P-selectin were studied. The study comprised two ITP cohorts and controls. Cohort 1 included 26 patients with sequential samples acquired before and during treatment with TPO-RA. Cohort 2 included a single sample in 18 patients on TPO-RA for more than one year. Thrombin generation (endogenous thrombin potential (ETP)) prothrombin fragments 1 + 2 (F₁₊₂), D-dimer, and plasminogen-activator-inhibitor-1 (PAI-1) were measured as well as soluble P-selectin (sP-selectin). Sequential expression of encoding genes for P-selectin (SELP) and PAI-1 (SERPINE1) was determined in four patients in cohort 1. Significantly higher levels of F₁₊₂, D-dimer, and PAI-1 were found in ITP patients before TPO-RA treatment and in patients on long-term TPO-RA treatment than in controls. Pre-treatment levels of sP-selectin did not differ from controls. Analysis of longitudinal trends showed an increase in platelet count, sP-selectin, and PAI-1 after initiation of TPO-RA, followed by gradual decline. Platelet count and sP-selectin remained at higher levels throughout the study, whereas PAI-1 did not. Levels of other studied parameters did not show significant changes after initiation of treatment. Expression of SELP was up-regulated after initiation of TPO-RA, while the expression of SERPINE1 showed no significant changes. In conclusion, elevated pre-treatment levels of F₁₊₂, D-dimer and PAI-1 are compatible with ITP being an intrinsically pro-thrombotic condition. After TPO-RA treatment, there were no significant changes in markers of coagulation activation or fibrinolysis, except for an initial increase in PAI-1 and a significant increase in sP-selectin both of which may contribute to increased thrombotic risk associated with TPO-RA treatment in ITP.

Management of newly diagnosed immune thrombocytopenia: can we change outcomes?

Immune thrombocytopenia resulting from antibody-mediated platelet destruction combined with impaired platelet production is a common cause of thrombocytopenia. The decision to treat newly diagnosed patients is based on several factors including ceasing hemorrhagic manifestations, increasing the platelet count, prevention of bleeding, and inducing remission. Current standard first-line therapy is a course of corticosteroids. Although this treatment paradigm increases the platelet count in the majority of patients, a high percentage relapse after discontinuation of corticosteroid therapy. For this reason, intensification of first-line therapy that results in superior long-term remission rates would be desirable. This manuscript focuses primarily on adults with idiopathic thrombocytopenic purpura (ITP), highlighting pediatric data and practice when applicable. The primary aim is to outline upfront strategies for treatment-naive patients with ITP to enhance remission rates, taking into account assessment of the risks and benefits of these approaches.

Use of eltrombopag for secondary immune thrombocytopenia in clinical practice

Eltrombopag is a second-line treatment in primary immune thrombocytopenia (ITP). However, its role in secondary ITP is unknown. We evaluated the efficacy and safety of eltrombopag in secondary ITP in daily clinical practice. Eighty-seven secondary ITP patients (46 with ITP secondary to autoimmune syndromes, 23 with ITP secondary to a neoplastic disease subtype: lymphoproliferative disorders [LPDs] and 18 with ITP secondary to viral infections) who had been treated with eltrombopag were retrospectively evaluated. Forty-four patients (38%) had a platelet response, including 40 (35%) with complete responses. Median time to platelet response was 15 days (95% confidence interval, 7-28 days), and was longer in the LPD-ITP group. Platelet response rate was significantly lower in the LPD-ITP than in other groups. However, having achieved response, there were no significant differences between the durable response of the groups. Forty-three patients (49·4%) experienced adverse events (mainly grade 1-2), the commonest being hepatobiliary laboratory abnormalities. There were 10 deaths in this case series, all of which were related to pre-existing medical conditions. In routine clinical practice, eltrombopag is effective and well-tolerated in unselected patients with ITP secondary to both immune and infectious disorders. However, the response rate in LPD-ITP is low.

How I treat refractory immune thrombocytopenia

This article summarizes our approach to the management of children and adults with primary immune thrombocytopenia (ITP) who do not respond to, cannot tolerate, or are unwilling to undergo splenectomy. We begin with a critical reassessment of the diagnosis and a deliberate attempt to exclude nonautoimmune causes of thrombocytopenia and secondary ITP. For patients in whom the diagnosis is affirmed, we consider observation without treatment. Observation is appropriate for most asymptomatic patients with a platelet count of 20 to 30 × 109/L or higher. We use a tiered approach to treat patients who require therapy to increase the platelet count. Tier 1 options (rituximab, thrombopoietin receptor agonists, low-dose corticosteroids) have a relatively favorable therapeutic index. We exhaust all Tier 1 options before proceeding to Tier 2, which comprises a host of immunosuppressive agents with relatively lower response rates and/or greater toxicity. We often prescribe Tier 2 drugs not alone but in combination with a Tier 1 or a second Tier 2 drug with a different mechanism of action. We reserve Tier 3 strategies, which are of uncertain benefit and/or high toxicity with little supporting evidence, for the rare patient with serious bleeding who does not respond to Tier 1 and Tier 2 therapies.

Alternatives, and adjuncts, to prophylactic platelet transfusion for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation

BACKGROUND

Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people with thrombocytopenia. Although considerable advances have been made in platelet transfusion therapy since the mid-1970s, some areas continue to provoke debate especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding.

OBJECTIVES

To determine whether agents that can be used as alternatives, or adjuncts, to platelet transfusions for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation are safe and effective at preventing bleeding.

SEARCH METHODS

We searched 11 bibliographic databases and four ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 4), MEDLINE (OvidSP, 1946 to 19 May 2016), Embase (OvidSP, 1974 to 19 May 2016), PubMed (e-publications only: searched 19 May 2016), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (searched 19 May 2016).

SELECTION CRITERIA

We included randomised controlled trials in people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation who were allocated to either an alternative to platelet transfusion (artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, recombinant activated factor VII, desmopressin (DDAVP), or thrombopoietin (TPO) mimetics) or a comparator (placebo, standard care or platelet transfusion). We excluded studies of antifibrinolytic drugs, as they were the focus of another review.

DATA COLLECTION AND ANALYSIS

Two review authors screened all electronically derived citations and abstracts of papers identified by the review search strategy. Two review authors assessed risk of bias in the included studies and extracted data independently.

MAIN RESULTS

We identified 16 eligible trials. Four trials are ongoing and two have been completed but the results have not yet been published (trial completion dates: April 2012 to February 2017). Therefore, the review included 10 trials in eight references with 554 participants. Six trials (336 participants) only included participants with acute myeloid leukaemia undergoing intensive chemotherapy, two trials (38 participants) included participants with lymphoma undergoing intensive chemotherapy and two trials (180 participants) reported participants undergoing allogeneic stem cell transplantation. Men and women were equally well represented in the trials. The age range of participants included in the trials was from 16 years to 81 years. All trials took place in high-income countries. The manufacturers of the agent sponsored eight trials that were under investigation, and two trials did not report their source of funding.No trials assessed artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin.Nine trials compared a TPO mimetic to placebo or standard care; seven of these used pegylated recombinant human megakaryocyte growth and differentiation factor (PEG-rHuMGDF) and two used recombinant human thrombopoietin (rhTPO).One trial compared platelet-poor plasma to platelet transfusion.We considered that all the trials included in this review were at high risk of bias and meta-analysis was not possible in seven trials due to problems with the way data were reported.We are very uncertain whether TPO mimetics reduce the number of participants with any bleeding episode (odds ratio (OR) 0.40, 95% confidence interval (CI) 0.10 to 1.62, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce the risk of a life-threatening bleed after 30 days (OR 1.46, 95% CI 0.06 to 33.14, three trials, 209 participants, very low quality evidence); or after 90 days (OR 1.00, 95% CI 0.06 to 16.37, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce platelet transfusion requirements after 30 days (mean difference -3.00 units, 95% CI -5.39 to -0.61, one trial, 120 participants, very low quality evidence). No deaths occurred in either group after 30 days (one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce all-cause mortality at 90 days (OR 1.00, 95% CI 0.24 to 4.20, one trial, 120 participants, very low quality evidence). No thromboembolic events occurred for participants treated with TPO mimetics or control at 30 days (two trials, 209 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed or quality of life.One trial with 18 participants compared platelet-poor plasma transfusion with platelet transfusion. We are very uncertain whether platelet-poor plasma reduces the number of participants with any bleeding episode (OR 16.00, 95% CI 1.32 to 194.62, one trial, 18 participants, very low quality evidence). We are very uncertain whether platelet-poor plasma reduces the number of participants with severe or life-threatening bleeding (OR 4.00, 95% CI 0.56 to 28.40, one trial, 18 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed, number of platelet transfusions, all-cause mortality, thromboembolic events or quality of life.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine if platelet-poor plasma or TPO mimetics reduce bleeding for participants with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation. To detect a decrease in the proportion of participants with clinically significant bleeding from 12 in 100 to 6 in 100 would require a trial containing at least 708 participants (80% power, 5% significance). The six ongoing trials will provide additional information about the TPO mimetic comparison (424 participants) but this will still be underpowered to demonstrate this level of reduction in bleeding. None of the included or ongoing trials include children. There are no completed or ongoing trials assessing artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin in people undergoing intensive chemotherapy or stem cell transplantation for haematological malignancies.

Role of romiplostim in splenectomized and nonsplenectomized patients with immune thrombocytopenia

Romiplostim is a thrombopoietin receptor agonist (TPO-RA) used for the treatment of adult primary immune thrombocytopenia (ITP). ITP is an autoimmune condition characterized by low platelet counts due to increased destruction and reduced platelet production. First-line interventions include corticosteroids, anti-D, and intravenous immunoglobulins, while second-line therapies comprise splenectomy, rituximab, cyclosporine A, and TPO-RAs. The recognition that compromised platelet production is a critical part of the pathogenesis of ITP prompted the development of therapeutic strategies based on the stimulation of the TPO receptor. TPO-RAs enhance megakaryocyte proliferation, increase platelet production, and lead to a reduction in bleeding episodes in ITP patients. This review will summarize current data on the TPO-RA romiplostim, with a particular focus on its relation to splenectomy.