Avatrombopag plus fostamatinib combination as treatment in patients with multirefractory immune thrombocytopenia.

Immune thrombocytopenia (ITP) refractory to multiple therapies may require a combination of drugs targeting different mechanisms and targets. In this retrospective, multicentre, international study, we report the safety and effectiveness of avatrombopag and fostamatininb in combination administered to 18 patients with multirefractory ITP. Overall, the combination response was achieved in 15 patients (83.3%), with a median time from combination start to best response of 15 days (IQR: 8-35 days). After a median follow-up of 256 days (IQR: 142.8-319), 5 patients relapsed (26.7%), all during tapering or stopping one drug. Adverse events were described in 6 of 18 patients (33%).

Efficacy of thrombopoietin receptor agonists versus rituximab in non-responsive immune thrombocytopenia-A single centre retrospective analysis.

Management of immune thrombocytopenia (ITP) beyond initial glucocorticoid therapy is challenging. In this retrospective single-centre cohort study, we compared all ITP patients relapsed or non-responsive to glucocorticoid therapy treated with either continuous TPO-RAs (n = 35) or rituximab induction (n = 20) between 2015 and 2022. While both groups showed high initial complete response rates (CR, 68.6 vs. 80.0%, ns), the overall rate of progression to the next therapy was higher after time-limited rituximab (75.0 vs. 42.9%), resulting in a lower relapse-free survival (median 16.6 vs. 25.8 months, log-rank; p < 0.05). We conclude that both treatments show similar initial efficacy and their ideal duration of therapy warrants further investigation.

Real-world use of thrombopoietin receptor agonists for the management of immune thrombocytopenia in adult patients in the United Kingdom: Results from the TRAIT study.

Few studies have reported the real-world use of both romiplostim and eltrombopag in immune thrombocytopenia (ITP). TRAIT was a retrospective observational study aimed to evaluate the platelet responses and adverse effects associated with the use of these thrombopoietin receptor agonists (TPO-RAs) in adult patients with ITP in the United Kingdom. Of 267 patients (median age at diagnosis, 48 years) with ITP (primary ITP [n = 218], secondary ITP [n = 49]) included in the study, 112 (42%) received eltrombopag and 155 (58%) received romiplostim as the first prescribed TPO-RA. A platelet count ≥30 × 109/L was achieved in 89% of patients with the first TPO-RA treatments, while 68% achieved a platelet count ≥100 × 109/L. Treatment-free response (TFR; platelet count ≥30 × 109/L, 3 months after discontinuing treatment) was achieved by 18% of the total patients. Overall, 61 patients (23%) switched TPO-RAs, most of whom achieved platelet counts ≥30 × 109/L with the second TPO-RA (23/25 who switched from eltrombopag to romiplostim [92%]; 28/36 who switched from romiplostim to eltrombopag [78%]). TFR was associated with secondary ITP, early TPO-RA initiation after diagnosis, the presence of comorbidity and no prior splenectomy or treatment with steroids or mycophenolate mofetil. Both TPO-RAs had similar efficacy and safety profiles to those reported in clinical studies.

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

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

Current Understanding of Immune Thrombocytopenia: A Review of Pathogenesis and Treatment Options.

The management of immune thrombocytopenia (ITP) and the prediction of patient response to therapy still represent a significant and constant challenge in hematology. ITP is a heterogeneous disease with an unpredictable evolution. Although the pathogenesis of ITP is currently better known and its etiology has been extensively studied, up to 75% of adult patients with ITP may develop chronicity, which represents a significant burden on patients' quality of life. A major risk of ITP is bleeding, but knowledge on the exact relationship between the degree of thrombocytopenia and bleeding symptoms, especially at a lower platelet count, is lacking. The actual management of ITP is based on immune suppression (corticosteroids and intravenous immunoglobulins), or the use of thrombopoietin receptor agonists (TPO-RAs), rituximab, or spleen tyrosine kinase (Syk) inhibitors. A better understanding of the underlying pathology has facilitated the development of a number of new targeted therapies (Bruton's tyrosine kinase inhibitors, neonatal Fc receptors, strategies targeting B and plasma cells, strategies targeting T cells, complement inhibitors, and newer TPO-RAs for improving megakaryopoiesis), which seem to be highly effective and well tolerated and result in a significant improvement in patients' quality of life. The disadvantage is that there is a lack of knowledge of the predictive factors of response to treatments, which would help in the development of an optimized treatment algorithm for selected patients.

Combining thrombopoietin receptor agonists with immunosuppressive drugs in adult patients with multirefractory immune thrombocytopenia, an update on the French experience.

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21-96]), with a median ITP duration of 57 months [3-393] and a median platelet count at initiation of 10 × 109 /L [1-35]. The combination regimen was given for a median duration of 12 months [1-103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 109 /L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 109 /L during at least 3 months) with a median time to response of 30 days [7-270] and a median duration of response of 15 months [4-63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination.

Immunomodulation with romiplostim as a second-line strategy in primary immune thrombocytopenia: The iROM study.

Thrombopoietin receptor agonists (TPO-RAs) stimulate platelet production, which might restore immunological tolerance in primary immune thrombocytopenia (ITP). The iROM study investigated romiplostim's immunomodulatory effects. Thirteen patients (median age, 31 years) who previously received first-line treatment received romiplostim for 22 weeks, followed by monitoring until week 52. In addition to immunological data, secondary end-points included the sustained remission off-treatment (SROT) rate at 1 year, romiplostim dose, platelet count and bleedings. Scheduled discontinuation of romiplostim and SROT were achieved in six patients with newly diagnosed ITP, whereas the remaining seven patients relapsed. Romiplostim dose titration was lower and platelet count response was stronger in patients with SROT than in relapsed patients. In all patients, regulatory T lymphocyte (Treg) counts increased until study completion and the counts were higher in patients with SROT. Interleukin (IL)-4, IL-9 and IL-17F levels decreased significantly in all patients. FOXP3 (Treg), GATA3 (Th2) mRNA expression and transforming growth factor-ß levels increased in patients with SROT. Treatment with romiplostim modulates the immune system and possibly influences ITP prognosis. A rapid increase in platelet counts is likely important for inducing immune tolerance. Better outcomes might be achieved at an early stage of autoimmunity, but clinical studies are needed for confirmation.

Transient increase in platelet counts associated with COVID-19 infection during TPO-RA as the second-line treatment in children with ITP.

The thrombopoietin receptor agonists (TPO-RA) were recommended for primary immune thrombocytopenia (ITP) during the pandemic of COVID-19. However, the incidence of thrombocytosis and thrombosis was sporadically reported in the chronic immune thrombocytopenia (CITP) patients receiving TPO-RA during the COVID-19 infection. With the local prevalence of COVID-19 in December 2022 in the Beijing area, we got more powerful evidence about the change in platelet (Plt) counts associated with COVID-19 infection. A single-centre observational cohort study was performed from the beginning of December 2022 to the end of February 2023 to enrol CITP children treated with TPO-RA alone as the second-line treatment and suffering from the COVID-19 infection in December 2022. The Plt counts before, during and after COVID-19 infection were collected. In total, 67 (34 males and 33 females) patients with 8.10 (2.15, 15.70) years of age were enrolled. Sixty-three patients who had responded to the TPO-RA showed a transient increase in Plt counts after the infection of COVID-19. The time of starting to increase was on Day 3 (2, 7), and to the peak level on Day 14 (7, 19) of infection with the peak Plt count was 289 (88, 1974) × 109 /L. With at least 2 months observation period from COVID-19 infection, the Plt counts of 100% (63/63) patients declined to the baseline on Day 25 (14, 41). The phenomenon of transient increase in Plt counts has been shown in the CITP children who responded to TPO-RA when suffering from COVID-19 infection.

Evaluating the impact of thrombopoietin receptor agonist medications on patient outcomes and quality of life in paediatric immune thrombocytopenia through semi-structured interviews.

Over the last decade, treatment of immune thrombocytopenia (ITP) in children has advanced to include thrombopoietin receptor agonist (TPO-RA) medications. Concurrently, there has been an increased emphasis on patient-reported outcomes-especially quality of life-to guide treatment. Assessing the impact of TPO-RAs on quality of life in paediatric ITP is therefore a priority. In this single-centre integrative mixed-methods study, a cohort of children with ITP prescribed a TPO-RA was identified. These children and/or their caregivers were invited to participate in semi-structured interviews focussed on quality-of-life measures. Independently, a retrospective chart review collected ITP-related data (platelet count, bleeding events) and TPO-RA data (dosing, side effects). Among the 23 eligible patients, 20 were represented in interviews. On chart review, 11/20 patients responded to TPO-RA by meeting platelet count criteria of ≥50 × 109 /L for six or more weeks in the absence of rescue therapy. In interviews with these children and/or their parents, 19/20 expressed the TPO-RA had 'worked', with 11/20 reporting benefit to mood and 11/20 reporting increased participation in activities/sports. Concerns were raised in interviews about TPO-RA medication cost (17/20), medication administration (10/20) and potential side effects (10/20). In conclusion, this study suggests that TPO-RA use in children with ITP improves quality of life.

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

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

A decade of changes in management of immune thrombocytopenia, with special focus on elderly patients.

BACKGROUND: Ten years after their availability, thrombopoietin receptor agonists (TPO-RA) have heralded a paradigm shift in the treatment of immune thrombocytopenia (ITP). This study was aimed to analyze the implementation of current recommendations in the standard practice of adult ITP patients, and how age may influence those changes. METHODS: We included 121 adult patients (> 65 years, n = 54; younger individuals, n = 67) who initiated treatment with TPO-RA between January 2012 and December 2014. RESULTS: Patients older than 65 years treated with TPO-RA presented at diagnosis with significantly higher platelet counts, less bleeding, and a more prothrombotic profile than younger ones. The high efficacy rates of TPO-RA, preferentially used during the last decade in non-chronic phases, precluded from further therapies in the majority of ITP patients. Their administration was associated with a sharp decline in the last decade in the use of splenectomy and intravenous immunoglobulin, especially in younger ITP individuals. CONCLUSION: These results confirm (1) that there is a preferential use of TPO-RAs in elderly ITP patients with fewer bleeding complications but more unfavorable prothrombotic conditions than in younger individuals, and (2) that early use of these agents has been established as an effective therapeutic alternative to other second line therapies.

Thrombopoietin receptor agonists for the treatment of primary immune thrombocytopenia: a meta-analysis and systematic review.

Previous meta-analyses reported discordant results on the efficacy and safety of thrombopoietin receptor agonists (TPO-RA) as second-line treatment in patients with immune thrombocytopenia (ITP). We conducted a meta-analysis of primary ITP treatment with the TPO-RA Romiplostim, Eltrombopag and Avatrombopag, including additional studies and relevant endpoints. We searched MEDLINE, EMBASE and CENTRAL for randomized clinical trials (RCTs) and cohort studies on TPO-RA in ITP published until December 31, 2018. The primary endpoints were: risk ratio (RR) of treatment failure and bleeding of WHO grade ≥2; rate of remission after discontinuation of treatment. The principal safety outcome was RR and incidence of thrombotic events and liver damage. From 1044 identified records we selected 16 RCTs and 19 cohort studies. RCTs included 909 patients assigned to TPO-RA and 427 to the control arm. Treatment failure was observed in 21% TPO-RA-treated patients and 47% control arm patients (RR = 0.42, 95% CI 0.33-0.53) in RCTs during a median follow-up of 13 weeks, and in 29% TPO-RA-treated patients in cohort studies, during a median follow-up of 69 weeks. The incidence of remission after TPO discontinuation was 18% (5-36%). RR of WHO grade ≥2 bleeding was 0.58 (0.38-0.86) in TPO-RA-treated patients, compared to control arm patients. Adverse events were rare and not significantly different in the two groups of patients. All-cause mortality was significantly lower with TPO-RA (RR 0.21, 95% CI, 0.06-0.68). In conclusion, TPO-RA are effective and safe in patients with ITP, even in the long term.

Practical guidance for the management of adults with immune thrombocytopenia during the COVID-19 pandemic.

This document aims to provide practical guidance for the assessment and management of patients with thrombocytopenia, with a particular focus on immune thrombocytopenia (ITP), during the COVID-19 pandemic. The intention is to support clinicians and, although recommendations have been provided, it is not a formal guideline. Nor is there sufficient evidence base to conclude that alternative approaches to treatment are incorrect. Instead, it is a consensus written by clinicians with an interest in ITP or coagulation disorders and reviewed by members of the UK ITP forum.

Thrombopoietin receptor agonist (TPO-RA) treatment raises platelet counts and reduces anti-platelet antibody levels in mice with immune thrombocytopenia (ITP).

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder in which autoantibodies and/or autoreactive T cells destroy platelets and megakaryocytes in the spleen and bone marrow, respectively. Thrombopoietin receptor agonists (TPO-RA e.g. Romiplostim and Eltrombopag) have made a substantial contribution to the treatment of patients with ITP, which are refractory to first-line treatments and approximately 30% demonstrate sustained elevated platelet counts after drug tapering. How TPO-RA induce these sustained responses is not known. We analyzed the efficacy of a murine TPO-RA in a well-established murine model of active ITP. Treatment with TPO-RA (10 ug/kg, based on pilot dose escalation experiments) significantly raised the platelet counts in ITP-mice. Immunomodulation was assessed by measuring serum IgG anti-platelet antibody levels; TPO-RA-treated mice had significantly reduced IgG anti-platelet antibodies despite the increasing platelet counts. These results suggest that TPO-RA is not only an efficacious therapy but also reduces anti-platelet humoral immunity in ITP.

Efficacy and safety of thrombopoietin receptor agonists in children with chronic immune thrombocytopenic purpura: meta-analysis.

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder presenting with low platelet count <100 × 109/L. The condition affects both adults and children. Thrombopoietin receptor agonists (TPO-RAs) are second-line of therapy that includes Romiplostim and Eltrombopag, which stimulate the production of normally functioning platelets. Although the biological effect of these drugs is well established, there has not been a meta-analysis in children. To estimate the efficacy and safety of Romiplostim and Eltrombopag, we performed a systematic review and meta-analysis in children with chronic ITP. Systematic literature search was conducted in the following database: PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL). Review Manager 5.3 for Windows was used to analyze the data. Five randomized controlled trials with total of 261 pediatric patients from 1-17 years of age were included. The efficacy and safety analysis showed TPO-RA groups were superior over placebo, and there was no difference in adverse event occurrence between TPO-RA (Romiplostim and Eltrombopag) and placebo groups. The efficacy and safety of Eltrombopag did not differ significantly from those of Romiplostim. Both drugs were effective in treatment of children with chronic ITP. Our findings extend the currently available data on ITP treatment and is helpful for pediatric health providers and for the design of future clinical trials.

Emerging drugs for immune thrombocytopenia (ITP).

INTRODUCTION: Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by autoantibody production against platelets, increased platelet destruction, and, in some cases, impaired thrombopoiesis. The majority of affected patients have significant bleeding risks due to low platelet counts and require treatment. The etiology of ITP is an immunological labyrinth. Currently available treatment options are usually not only nonspecific, but are also associated with some risks. Areas covered: Several useful drugs for the treatment of ITP are currently available. Furthermore, ongoing trials with new drugs and preclinical development of additional drugs may help to improve and determine their value. Expert opinion: ITP is a heterogeneous complex requiring individualized treatment. None of the available drugs are specific, nor are they invariably safe and effective. Thus, the need for specific therapy is evident.

Megakaryocyte morphology and its impact in predicting response to steroid in immune thrombocytopenia.

Pathogenetic mechanisms of primary immune thrombocytopenia (ITP) include antibody-mediated destruction of platelets; cell-mediated destruction and suppressed thrombopoiesis. Various morphological changes in megakaryocytes are reported in ITP patients, but never these were correlated with the response to various forms of therapy. In the present study, we intended to find out the impact of megakaryocytic abnormalities on the response to steroid, the first line of treatment. The mean age of patients (n = 33) was 28.9 ± 7.6 years. Male/female ratio was 1/1.8. The mean platelet count at presentation was 5.6 ± 4.4 × 10(9)/L. 63.6% (21/33) patients showed response to steroid. The non-responders were given 50 mg/d TPO-RA (eltrombopag) in addition to steroid, to which, 83.3% (10/12) responded. Two-third patients (66.7%, n = 22) had normal megakaryocyte morphology. Those with abnormal morphology commonly had hypolobated forms and micromegakaryocytes. Ninety-five percent of steroid responders had normal megakaryocytic morphology. Among steroid non-responders, most patients (n = 10, 83.3%) had abnormal megakaryocytic morphology. 80% steroid non-responders with abnormal morphology responded to the addition of eltrombopag. The findings suggest that the abnormal megakaryocyte morphology can be an evidence of dominant pathogenetic mechanism and thereby can help us in individualizing the treatment of ITP.

Is There a Correlation Between Immune Thrombocytopenia and Immunoglobulin G4-Related Disease?

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition causing organ swelling and fibrosis. Rarely, it coexists with primary immune thrombocytopenia (ITP), characterized by low platelet count (< 100 × 106/L) without an underlying cause. We present a case of a 56-year-old woman diagnosed with ITP in 2005, successfully treated with dexamethasone and intravenous immunoglobulins (IVIG). In 2011, she was diagnosed with IgG4-RD, type I autoimmune pancreatitis, initially treated with steroids then azathioprine with no response. ITP relapses were managed with prednisone/IVIG, rituximab, and thrombopoietin-receptor agonist therapy. Fostamatinib provided temporary relief, but platelet count dropped again in 2023. Combination therapy with small doses of prednisone and mycophenolate showed a partial response, maintaining platelet count over 50 × 106/L. Further investigation is warranted to explore any correlation between these two conditions, especially considering the patient's prolonged response to immunosuppressors.

Final Results from the First European Real-World Experience on Lusutrombopag Treatment in Cirrhotic Patients with Severe Thrombocytopenia: Insights from the REAl-World Lusutrombopag Treatment in ITalY Study.

Background and aims: Management of severe thrombocytopenia poses significant challenges in patients with chronic liver disease. Here, we aimed to evaluate the first real-world European post-marketing cohort of cirrhotic patients treated with lusutrombopag, a thrombopoietin receptor agonist, verifying the efficacy and safety of the drug. Methods: In the REAl-world Lusutrombopag treatment in ITalY (REALITY) study, we collected data from consecutive cirrhotic patients treated with lusutrombopag in 19 Italian hepatology centers, mostly joined to the "Club Epatologi Ospedalieri" (CLEO). Primary and secondary efficacy endpoints were the ability of lusutrombopag to avoid platelet transfusions and to raise the platelet count to ≥50,000/µL, respectively. Treatment-associated adverse events were also collected. Results: A total of 66 patients and 73 cycles of treatment were included in the study, since 5 patients received multiple doses of lusutrombopag over time for different invasive procedures. Fourteen patients (19%) had a history of portal vein thrombosis (PVT). Lusutrombopag determined a significant increase in platelet count [from 37,000 (33,000-44,000/µL) to 58,000 (49,000-82,000), p < 0.001]. The primary endpoint was met in 84% of patients and the secondary endpoint in 74% of patients. Baseline platelet count was the only independent factor associated with response in multivariate logistic regression analysis (OR for any 1000 uL of 1.13, CI95% 1.04-1.26, p 0.01), with a good discrimination power (AUROC: 0.78). Notably, a baseline platelet count ≤ 29,000/µL was identified as the threshold for identifying patients unlikely to respond to the drug (sensitivity of 91%). Finally, de novo PVT was observed in four patients (5%), none of whom had undergone repeated treatment, and no other safety or hemorrhagic events were recorded in the entire population analyzed. Conclusions: In this first European real-world series, lusutrombopag demonstrated efficacy and safety consistent with the results of registrational studies. According to our results, patients with baseline platelet counts ≤29,000/µL are unlikely to respond to the drug.