Response to steroids predicts response to rituximab in pediatric chronic immune thrombocytopenia

Pediatric refractory immune thrombocytopenia: A systematic review

Pediatric immune thrombocytopenia (ITP) is an acquired disorder associated with autoimmune destruction and impairment of platelet production in children. Some children exhibit poor or transient response to ITP-directed treatments and are referred to as having refractory ITP (rITP). There is currently no consensus on the definition of rITP, nor evidence-based treatment guidelines for patients with rITP. After a survey of pediatric ITP experts demonstrated lack of consensus on pediatric rITP, we pursued a systematic review to examine the reported clinical phenotypes and treatment outcomes in pediatric rITP. The search identified 253 relevant manuscripts; following review, 11 studies proposed a definition for pediatric rITP with no consensus amongst them. Most definitions included suboptimal response to medical management, while some outlined specific platelet thresholds to define this suboptimal response. Common attributes identified in this study should be used to propose a comprehensive definition, which will facilitate outcome comparisons of future rITP studies.

Thrombopoietin receptor agonists and rituximab for treatment of pediatric immune thrombocytopenia: A systematic review and meta-analysis of prospective clinical trials

BACKGROUND

Children with immune thrombocytopenia (ITP) may require second-line ITP therapies. The high remission rate in pediatric patients, need for extended-duration use of thrombopoietin receptor agonists (TPO-RAs), drug adherence, potential side effects, monitoring, and cost effectiveness are factors that should be considered in decision-making about second-line therapies. Rituximab (RTX) has been used off-label for years to treat ITP but there are limited studies about its efficacy and safety in children. To date, no studies have directly compared TPO-RAs with RTX for the treatment of childhood ITP.

METHODS

This systematic review analyzed the overall platelet response, durability of treatment effect, and safety for RTX use in comparison to TPO-RAs in pediatric ITP. MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through December 2020 and meta-analysis was conducted using proportions of success/failure for each intervention in the selected studies.

RESULTS

The proportion of participants achieving the primary endpoint of a platelet response above 50,000 was similar for TPO-RAs (proportion = 0.71, 95% CI: 0.63-0.78) and RTX (proportion = 0.68, 95% CI: 0.53-0.82). However, considerable variation was found between the two groups with regards to the sustainability of the response and other secondary outcomes such as need for rescue and adverse events. RTX was associated with higher rates of rescue therapy.

CONCLUSIONS

In this analysis of prospective pediatric ITP studies, RTX and TPO-RAs had similar rates of overall platelet response but differed in other important measures. Prospective comparative studies are needed to better characterize second-line treatments for pediatric ITP.

Response to rituximab in children and adults with immune thrombocytopenia (ITP)

BACKGROUND

Rituximab is a monoclonal anti-CD20 antibody used as a second-line treatment for immune thrombocytopenia (ITP). As additional treatments for ITP emerge, identifying the most appropriate patients and optimal timing for rituximab are important but challenging without established predictors of response to therapy.

OBJECTIVES

The purpose of this study was to describe demographic, clinical, and laboratory characteristics of pediatric and adult patients with ITP to identify differences in evaluation before rituximab administration and correlates of platelet response.

METHODS

This is a retrospective cohort study describing the characteristics of patients with ITP treated with rituximab from 2010 to 2020 at two academic tertiary care centers.

RESULTS

A total of 64 patients met criteria for inclusion. Complete rituximab response (56%) was not significantly different between children (58%, n = 24) and adults (55%, n = 40). Response rate was similar in those with primary versus secondary ITP (53% vs 62%). Among patients treated with rituximab, Evans Syndrome was more common in children than adults (42% vs 18%). Immunologic labs assessed before rituximab varied by age and were more commonly evaluated in children (lymphocyte subsets 88% vs 22%). Immunologic markers, including antinuclear antibody, direct antiglobulin testing, immunoglobulin levels, and lymphocyte subsets, did not predict response to rituximab in pediatric or adult patients with ITP.

CONCLUSIONS

Pre-rituximab immunologic evaluation varied significantly between adults and children, which could represent institution-specific practice patterns or a more general practice difference. If the latter, underlying immunodeficiency in adults with ITP may be underrecognized. Standardized guidance for pre-rituximab immunologic evaluation is needed.

Efficacy and safety of rituximab for minors with immune thrombocytopenia: a systematic review and meta-analysis

Objective

We reviewed relevant research on rituximab (RTX) treatment for pediatric immune thrombocytopenia (ITP) to elucidate the efficacy and safety of RTX.

Methods

Prospective clinical trials of RTX for the treatment of pediatric ITP were collected by searching the PubMed, Cochrane Library, Web of Science, and OVID: EMBASE databases and ClinicalTrials.gov. We examined rates of overall response (OR), complete response (CR), partial response (PR), sustained response (SR), relapse (R), and adverse drug reaction (ADR). The Methodological Index for Nonrandomized Studies scale was used, and sensitivity analyses were performed.

Results

For five studies, including 100 patients, the pooled OR, CR, PR, SR, R, and ADR rates were 52% (95% CI: 0.36–0.77, I² = 78%), 52% (95% CI: 0.41–0.67, I² = 45%), 18% (95% CI: 0.10–0.33, I² = 33%), 43% (95% CI: 0.29–0.63, I² = 0%), 25% (95% CI: 0.06–0.96, I² = 52%), and 30% (95% CI: 0.15–0.58, I² = 64%), respectively.

Conclusion

There is evidence, albeit low quality, that RTX may be a better second-line therapy than splenectomy for children with ITP; however, its efficacy and safety need to be validated by further high-quality clinical trials, such as randomized controlled trials.

Risk factors and predictors of treatment responses and complications in immune thrombocytopenia

Management of adult patients with immune thrombocytopenia (ITP) is often unsatisfactory, due to variable efficacy of treatment, risk of life-threatening bleeding if disease control is poor, and side effects associated with treatment. Lack of data on the platelet count threshold associated with bleeding and infection risk associated with ITP treatment limits risk/benefit clinical decision making. We reviewed medical records of all ITP patients who were admitted to our hospital between 2012 and 2017 to evaluate the platelet count threshold for bleeding, infection burden associated with treatment, and real-world efficacy of second-line treatment. We demonstrated fair discrimination between platelet count and occurrence of bleeding, with 15 × 10⁹/L being the optimal cut-off for predicting any bleeding while 20 × 10⁹/L had the highest negative predictive value for severe bleeding. In multivariable analyses, patients who were treated with corticosteroids for at least 2 months were 5.3 times as likely to have an infection. In addition, rituximab response was strongly associated with response to frontline corticosteroids and infection was associated with older age ≥ 65 years and corticosteroid dependence. If corticosteroids are initiated, physicians should aim for the shortest duration of treatment before switching to effective second-line agents for hemostatic platelet counts.

American Society of Hematology 2019 guidelines for immune thrombocytopenia

BACKGROUND

Despite an increase in the number of therapies available to treat patients with immune thrombocytopenia (ITP), there are minimal data from randomized trials to assist physicians with the management of patients.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the management of ITP.

METHODS

In 2015, ASH formed a multidisciplinary guideline panel that included 8 adult clinical experts, 5 pediatric clinical experts, 2 methodologists with expertise in ITP, and 2 patient representatives. The panel was balanced to minimize potential bias from conflicts of interest. The panel reviewed the ASH 2011 guideline recommendations and prioritized questions. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including evidence-to-decision frameworks, to appraise evidence (up to May 2017) and formulate recommendations.

RESULTS

The panel agreed on 21 recommendations covering management of ITP in adults and children with newly diagnosed, persistent, and chronic disease refractory to first-line therapy who have non-life-threatening bleeding. Management approaches included: observation, corticosteroids, IV immunoglobulin, anti-D immunoglobulin, rituximab, splenectomy, and thrombopoietin receptor agonists.

CONCLUSIONS

There was a lack of evidence to support strong recommendations for various management approaches. In general, strategies that avoided medication side effects were favored. A large focus was placed on shared decision-making, especially with regard to second-line therapy. Future research should apply standard corticosteroid-dosing regimens, report patient-reported outcomes, and include cost-analysis evaluations.

Rituximab for treating inhibitors in people with inherited severe hemophilia

BACKGROUND

Hemophilia A and B are inherited coagulation disorders characterized by a reduced or absent level of factor VIII or factor IX respectively. The severe form is characterized by a factor level less than 0.01 international units (IU) per milliliter. The development of inhibitors in hemophilia is the main complication of treatment, because the presence of these antibodies, reduces or even nullifies the efficacy of replacement therapy, making it very difficult to control the bleeding. People with inhibitors continue to have significantly higher risks of morbidity and mortality, with considerable treatment costs. Given the wide 'off-label' use of rituximab for treating people with hemophilia and inhibitors, its efficacy and safety need to be evaluated. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the efficacy and safety of rituximab for treating inhibitors in people with inherited severe hemophilia A or B.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, complied from electronic database searches and handsearching of journals and conference abstract books. We searched the reference lists of relevant articles and reviews and also searched for ongoing or unpublished studies. We also undertook further searches of other bibliographic databases and trial registries. Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 19 March 2020.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials investigating the efficacy and safety of rituximab for treating inhibitors in people with hemophilia.

DATA COLLECTION AND ANALYSIS

No randomized controlled trials matching the selection criteria were eligible for inclusion.

MAIN RESULTS

No randomized controlled trials on rituximab for treating inhibitors in people with hemophilia were identified.

AUTHORS' CONCLUSIONS

We were unable to identify any relevant trials on the efficacy and safety of rituximab for treating inhibitors in people with hemophilia. The research evidence available is from case reports and case series. Randomized controlled trials are needed to evaluate the efficacy and safety of rituximab for this condition. However, prior to the publication of any possible future randomized controlled trials, meta-analysis of case reports and case series may provide some evidence.

Genetic variants in toll-like receptor 4 are associated with lack of steroid-responsiveness in pediatric ITP patients

Although the most common front-line therapies for immune thrombocytopenia (ITP) have been in use for decades, it is still not possible to predict an individual patient's clinical course and response to therapy. Patients are managed with a trial-and-error approach and often suffer side effects of therapies which could have been avoided if response prediction were possible. Corticosteroids are the most frequently used upfront therapy for adults and children with ITP. Our group performed whole exome sequencing on a cohort of pediatric ITP patients, and identified two missense single nucleotide variants (SNV) in Toll-like receptor 4 (TLR4). These coding variants in TLR4 had an increased frequency in Caucasian patients with poor response to upfront steroid therapy. Both TLR4 (D299G; rs4986790) and TLR4 (T399I; rs4986791) had a minor allele frequency (MAF) of 20.7% in those patients unresponsive to steroids, but were present at lower allele frequencies of 2.3% and 3.4% in responders respectively (P < .001). These findings were consistent with the trend identified in an independent cohort of pediatric ITP patients treated with corticosteroids who underwent direct genotyping for both SNVs. This study identified two candidate genetic variants in two unique cohorts of ITP patients which may contribute to steroid response and have prognostic implications for treatment response in ITP.

Clinical effect and safety evaluation of different dosage of Rituximab combined with Cyclophosphamide in treatment of refractory immune Thrombocytopenia

Objective:

To discuss clinical effect of different dosage of rituximab combined with cyclophosphamide in treatment of refractory immune thrombocytopenia (rITP).

Method:

This study was conducted at Department of Hematopathology in XX Hospital from January 2016 to January 2018. In this study. Seventy-eight patients with rITP were selected as the objects, divided into observation group (39 cases) and control group (39 cases) according to random number table. Patients in the control group were treated with conventional rituximab and cyclophosphamide, while the observation group received low-dose rituximab. The same amount of cyclophosphamide was used in the two groups. The statistics of clinical effect, recurrence rate, untoward effect and Laboratory inspection of both groups were made before and after the treatment.

Results:

Compared with the control group, the total occurrence rate of side effects in the observation group decreased significantly; the level of IgM and CD20⁺ in the observation group also decreased significantly, while. The level of IgA, IgG, CD3+ and CD4+ rose significantly (P<0.05). The differences in the level of Th1, TNF-a, IL-18 and Sc5b-9 had statistical significance before and after the treatment (P<0.05).

Conclusion:

Rituximab combined with cyclophosphamide has the definite curative effect on rITP. The small dosage of rituximab combined with cyclophosphamide has higher clinical safety in the treatment.

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.

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.

Rituximab for treating inhibitors in people with inherited severe hemophilia

BACKGROUND

Hemophilia A and B are inherited coagulation disorders characterized by a reduced or absent level of factor VIII or factor IX respectively. The severe form is characterized by a factor level less than 0.01 international units (IU) per milliliter. The development of inhibitors in hemophilia is the main complication of treatment, because the presence of these antibodies, reduces or even nullifies the efficacy of replacement therapy, making it very difficult to control the bleeding. People with inhibitors continue to have significantly higher risks of morbidity and mortality, with considerable treatment costs. Given the wide 'off-label' use of rituximab for treating people with hemophilia and inhibitors, its efficacy and safety need to be evaluated. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the efficacy and safety of rituximab for treating inhibitors in people with inherited severe hemophilia A or B.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, complied from electronic database searches and handsearching of journals and conference abstract books. We searched the reference lists of relevant articles and reviews and also searched for ongoing or unpublished studies. We also undertook further searches of other bibliographic databases and trial registries.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 16 February 2017.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials investigating the efficacy and safety of rituximab for treating inhibitors in people with hemophilia.

DATA COLLECTION AND ANALYSIS

No randomized controlled trials matching the selection criteria were eligible for inclusion.

MAIN RESULTS

No randomized controlled trials on rituximab for treating inhibitors in people with hemophilia were identified.

AUTHORS' CONCLUSIONS

We were unable to identify any relevant trials on the efficacy and safety of rituximab for treating inhibitors in people with hemophilia. The research evidence available is from case reports and case series. Randomized controlled trials are needed to evaluate the efficacy and safety of rituximab for this condition. However, prior to the publication of any possible future randomized controlled trials, meta-analysis of case reports and case series may provide some evidence.

When and how to treat childhood immune thrombocytopenia

Childhood immune thrombocytopenia is an autoimmune process resulting in an isolated thrombocytopenia that puts the child at risk for bleeding and can negatively impact quality of life. Pharmacologic intervention aims to stabilize the platelet count, with the goal of achieving hemostasis and maximizing health-related quality of life.

Rituximab for treating inhibitors in people with inherited severe hemophilia

BACKGROUND

Hemophilia A and B are inherited coagulation disorders characterized by a reduced or absent level of factor VIII or factor IX respectively. The severe form is characterized by a factor level less than 0.01 international units (IU) per milliliter. The development of inhibitors in hemophilia is the main complication of treatment, because the presence of these antibodies, reduces or even nullifies the efficacy of replacement therapy, making it very difficult to control the bleeding. People with inhibitors continue to have significantly higher risks of morbidity and mortality, with considerable treatment costs. Given the wide 'off-label' use of rituximab for treating people with hemophilia and inhibitors, its efficacy and safety need to be evaluated.

OBJECTIVES

To assess the efficacy and safety of rituximab for treating inhibitors in people with inherited severe hemophilia A or B.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, complied from electronic database searches and handsearching of journals and conference abstract books. We searched the reference lists of relevant articles and reviews and also searched for ongoing or unpublished studies.Date of last search: 27 January 2015.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials investigating the efficacy and safety of rituximab for treating inhibitors in people with hemophilia.

DATA COLLECTION AND ANALYSIS

No randomized controlled trials matching the selection criteria were eligible for inclusion.

MAIN RESULTS

No randomized controlled trials on rituximab for treating inhibitors in people with hemophilia were identified.

AUTHORS' CONCLUSIONS

We were unable to identify any relevant trials on the efficacy and safety of rituximab for treating inhibitors in people with hemophilia. The research evidence available is from case reports and case series. Randomized controlled trials are needed to evaluate the efficacy and safety of rituximab for this condition. However, prior to the publication of any possible future randomized controlled trials, meta-analysis of case reports and case series may provide some evidence.

Long-term follow-up of children with refractory immune thrombocytopenia treated with rituximab

Data on long-term outcomes of children with refractory immune thrombocytopenia (ITP) treated with rituximab are limited. We retrospectively analyzed the long-term effect of rituximab on 22 pediatric ITP patients (11 boys and 11 girls). Compete response (CR) (platelet count ≥100 × 10(9)/L) and partial response (PR) (platelet count 30-99 × 10(9)/L) were achieved in nine (41 %) and two (9 %) patients, respectively. Of the 11 responders, eight subsequently relapsed 2-26 months after initial rituximab treatment. The 5-year relapse-free rate was 14 % (3/22, 95 % confidence interval: 0-27 %) with a median follow-up period of 6.4 years. Five initial responders with subsequent relapse and one non-responder received multiple rituximab treatments of nine courses; all patients responded to the second rituximab therapy without any significant toxicity. All eight patients who relapsed after an initial response and six of 11 non-responders achieved CR or PR with subsequent treatment, including repeated courses of rituximab, splenectomy, steroids, and other immunomodulating agents. Our findings indicated that the sustained effect of rituximab on children with refractory ITP is low, but that the long-term outcome of ITP itself is not poor. Furthermore, repeated rituximab administration may be a promising therapy for those who relapse after an initial response.

Clinical practice: immune thrombocytopenia in paediatrics

Immune thrombocytopenia (ITP) is a disease affecting both children and adults. It is defined as acquired isolated thrombocytopenia caused by the autoimmune production of anti-platelet antibodies. Childhood ITP most frequently occurs in young children who have been previously well, although a viral respiratory tract infection often precedes thrombocytopenia. A benign and self-limiting course is common, but major bleeding complications such as intracranial haemorrhage may occur. Yet one cannot predict which child will have a prolonged course of thrombocytopenia and who will develop an intracranial haemorrhage. In children without atypical characteristics, only minimal diagnostic investigations are needed, and most paediatric ITP patients do not need platelet-enhancing therapy even though various treatment options are available. A "watch and wait" strategy should be considered in paediatric patients with mild disease. Steroids, intravenous immunoglobulin G or anti-D immunoglobulin are the current first-line therapeutic measures for children at risk for severe bleeding. When life-threatening bleeding occurs, a combination of therapies is needed. In this review, we summarise the current knowledge on primary ITP in children and adolescents.

Diagnosis and management of autoimmune cytopenias in childhood

The diagnosis and management of children with autoimmune cytopenias can be challenging. Children can present with immune-mediated destruction of a single-cell lineage or multiple cell lineages, including platelets (immune thrombocytopenia [ITP]), erythrocytes (autoimmune hemolytic anemia), and neutrophils (autoimmune neutropenia). Immune-mediated destruction can be primary or secondary to a comorbid immunodeficiency, malignancy, rheumatologic condition, or lymphoproliferative disorder. Treatment options generally consist of nonspecific immune suppression or modulation. This nonspecific approach is changing as recent insights into disease biology have led to targeted therapies, including the use of thrombopoietin mimetics in ITP and sirolimus for cytopenias associated with autoimmune lymphoproliferative syndrome.

ITP in children: pathophysiology and current treatment approaches

Primary immune thrombocytopenia (ITP) is one of the most common bleeding disorders of childhood. In most cases, it presents with sudden widespread bruising and petechiae in an otherwise well child. Thought to be mainly a disorder of antibody-mediated platelet destruction, ITP can be self-limited or develop into a chronic condition. In this review, we discuss current concepts of the pathophysiology and treatment approaches to pediatric ITP.

Childhood immune thrombocytopenia: role of rituximab, recombinant thrombopoietin, and other new therapeutics

Childhood immune thrombocytopenia (ITP) is often considered a benign hematologic disorder. However, 30% of affected children will have a prolonged course and 5%-10% will develop chronic severe refractory disease. Until recently, the only proven therapeutic option for chronic severe ITP was splenectomy, but newer alternatives are now being studied. However, because immunosuppressive agents such as rituximab are not approved for use in ITP and the thrombopoietin receptor agonists are not yet approved in children, the decision to use alternatives to splenectomy needs to be considered carefully. This review describes the factors that should affect decisions to treat ITP at diagnosis and compares the options for the occasional child in whom ITP does not resolve within the first year.

Evaluation of children with chronic immune thrombocytopenic purpura and Evans syndrome treated with rituximab

The primary objective was to evaluate the response rate of rituximab therapy for children with chronic immune thrombocytopenic purpura (ITP) and Evans syndrome (ES) and immune reconstitution of these children after rituximab therapy. Eleven patients with chronic ITP and 2 with ES between 6 and 18 years of age and platelet count less than 20 × 10(9)/L received rituximab. Overall response (OR) was defined as an increase in platelet count above 50 × 10(9)/L. The mean age of 13 children (9 girls, 4 boys) was 11.2 ± 3.8 years (6-18). One of the patients with ES had been splenectomized; others were not. The patients mean follow-up time was 10.3 ± 9.3 months after rituximab therapy. Two patients achieved complete response, 4 patients achieved partial response, and OR rate was 46% (6 of 13) after therapy. Seven patients have no response. In conclusion, rituximab may be considered prior to splenectomy in children with chronic ITP and ES with an acceptable toxicity profile.

Management of children and adolescents with primary immune thrombocytopenia: controversies and solutions

The management including diagnostic procedures, prophylaxis, treatment and follow-up of patients with primary immune thrombocytopenia (ITP) in childhood is controversial due to limited clinical data, difficulties in the estimation of individual bleeding risk and heterogeneity of pathophysiology potentially causing various treatment responses. Advances in the management of children include increased international collaborations, improved quality of diagnosis and treatment, increased clinical data, refinement of consensus statements where clinical evidence is absent, new drugs and last but not least establishment of watch-and-wait strategies. The Intercontinental Cooperative ITP Study Group promotes international collaboration since more than 10 years based on a worldwide network and experience in registries. Future considerations include concentration of available resources, strengthening international collaboration, focusing on most important scientific and clinical questions, such as identification of the subgroup of patients that benefits most from prophylactic platelet-enhancing treatments and investigation of treatment endpoints other than concepts solely based on the platelet count, including bleeding symptoms, health-related quality of life and economical aspects of treatments.

Rituximab for children with immune thrombocytopenia: a systematic review

Background

Rituximab has been widely used off-label as a second line treatment for children with immune thrombocytopenia (ITP). However, its role in the management of pediatric ITP requires clarification. To understand and interpret the available evidence, we conducted a systematic review to assess the efficacy and safety of rituximab for children with ITP.

Methodology/Principal Findings

We searched MEDLINE, EMBASE, Cochrane Library, CBM, CNKI, abstract databases of American Society of Hematology, American Society of Clinical Oncology and Pediatric Academic Society. Clinical studies published in full text or abstract only in any language that met predefined inclusion criteria were eligible. Efficacy analysis was restricted to studies enrolling 5 or more patients. Safety was evaluated from all studies that reported data of toxicity. 14 studies (323 patients) were included for efficacy assessment in children with primary ITP. The pooled complete response (platelet count ≥100×10⁹/L) and response (platelet count ≥30×10⁹/L) rate after rituximab treatment were 39% (95% CI, 30% to 49%) and 68% (95%CI, 58% to 77%), respectively, with median response duration of 12.8 month. 4 studies (29 patients) were included for efficacy assessment in children with secondary ITP. 11 (64.7%) of 17 patients associated with Evans syndrome achieved response. All 6 patients with systemic lupus erythematosus associated ITP and all 6 patients with autoimmune lymphoproliferative syndrome associated ITP achieved response. 91 patients experienced 108 adverse events associated with rituximab, among that, 91 (84.3%) were mild to moderate, and no death was reported.

Conclusions/Significance

Randomized controlled studies on effect of rituximab for children with ITP are urgently needed, although a series of uncontrolled studies found that rituximab resulted in a good platelet count response both in children with primary and children secondary ITP. Most adverse events associated with rituximab were mild to moderate, and no death was reported.