Tapering and Sustained Remission of Thrombopoietin Receptor Agonists (TPO-RAs): Is it Time for Paediatric ITP?

Thrombopoietin receptor agonists (TPO-Ras; romiplostim/eltrombopag/avatrombopag) have demonstrated high efficacy rates (59-88%) and a good safety profile in clinical trials with adult patients with immune thrombocytopenia (ITP). Similar efficacy and safety results have been observed with romiplostim and eltrombopag in paediatric cohorts. Continuous treatment with TPO-RAs has shown durable responses with long-term use, up to 3 years. The effect of TPO-RAs was generally considered transient, as platelet counts tended to drop to baseline values after a short period of time (about 2 weeks), unless treatment was maintained. Several groups have reported successful discontinuation of TPO-RAs without the need for concomitant treatments. This is referred to as sustained remission off treatment (SROT). Both short- and medium-term treatment with TPO-RAs may reduce costs to our healthcare systems and, more importantly, may reduce the potential side effects that may be associated with continuous TPO-RA treatment. The issue of tapering and discontinuation of TPO-RAs in paediatric patients with ITP has received little attention to date. Given that paediatric ITP has much higher rates of spontaneous remission than ITP in adults, we consider that the possibility of SROT of TPO-RAs in paediatric patients with ITP is a neglected but very relevant issue in this subtype of the disease.

Romiplostim in chemotherapy-induced thrombocytopenia: A review of the literature.

Chemotherapy-induced thrombocytopenia (CIT) is a common challenge of cancer therapy and can lead to chemotherapy dose reduction, delay, and/or discontinuation, affecting relative dose intensity, and possibly adversely impacting cancer care. Besides changing anticancer regimens, standard management of CIT has been limited to platelet transfusions and supportive care. Use of the thrombopoietin receptor agonist romiplostim, already approved for use in immune thrombocytopenia, has shown promising signs of efficacy in CIT. In a phase 2 prospective randomized study of solid tumor patients with platelet counts <100 × 109/L for ≥4 weeks due to CIT, weekly romiplostim corrected the platelet count to >100 × 109/L in 93% (14/15) of patients within 3 weeks versus 12.5% (1/8) of untreated patients (p < 0.001). Including patients treated with romiplostim in an additional single-arm cohort, 85% (44/52) of all romiplostim-treated patients responded with platelet count correction within 3 weeks. Several retrospective studies of CIT have also shown responses to weekly romiplostim, with the largest study finding that poor response to romiplostim was predicted by tumor invasion of the bone marrow (odds ratio, 0.029; 95% CI: 0.0046-0.18; p < 0.001), prior pelvic irradiation (odds ratio, 0.078; 95% CI: 0.0062-0.98; p = 0.048), and prior temozolomide treatment (odds ratio 0.24; 95% CI: 0.061-0.96; p = 0.043). Elsewhere, lower baseline TPO levels were predictive of romiplostim response (p = 0.036). No new safety signals have emerged from romiplostim CIT studies. Recent treatment guidelines, including those from the National Comprehensive Cancer Network, now support consideration of romiplostim use in CIT. Data are expected from two ongoing phase 3 romiplostim CIT trials.

Immune thrombocytopenia and pregnancy: challenges and opportunities in diagnosis and management.

INTRODUCTION: Immune thrombocytopenia (ITP) affecting pregnancy is a diagnostic and often a therapeutic challenge. AREAS COVERED: We review the current diagnostic criteria for ITP in pregnancy and the potential utility of laboratory tests. We discuss the impact of ITP on pregnancy outcomes and the effects of pregnancy on patients living with chronic ITP.  We describe the criteria for intervention, the evidence supporting first-line treatment approaches and the therapeutic decisions and challenges in cases refractory to steroids and IVIG. We review the evidence supporting the potential use of thrombopoietin receptor agonists for refractory thrombocytopenia. Finally, we describe the diagnostic, prognostic, and treatment approaches to neonatal ITP and considerations regarding breastfeeding. We searched the terms 'immune thrombocytopenia' and 'pregnancy' on PubMed to identify the relevant literature published before 31 December 2023, including within cited references. EXPERT OPINION: Decreased platelet production may play a role in pregnancy-related ITP exacerbation. Putative mechanisms include placental hormones, such as inhibin. Although IVIG and prednisone usually suffice to achieve hemostasis for delivery, second-line agents are sometimes required to allow for neuraxial anesthesia. There is growing evidence supporting the use of romiplostim during pregnancy; however, its risk of venous thromboembolism warrants further evaluation.

Romiplostim for treatment of thrombocytopenia in dogs: A retrospective assessment and clinical outcomes.

BACKGROUND: Romiplostim, a thrombopoietin analog, is commonly used to treat immune-mediated thrombocytopenia (ITP) in humans, but its use in dogs remains limited. OBJECTIVES: Evaluate the effects and adverse events of romiplostim administration in dogs with thrombocytopenia caused by various underlying diseases. ANIMALS: Forty-two client-owned dogs with naturally occurring thrombocytopenia at 2 referral animal hospitals. METHODS: Retrospective, multi-institutional analysis to evaluate the outcomes of romiplostim treatment in dogs. RESULTS: Among the dogs treated with romiplostim, 27 experienced an increase in platelet count and 26 maintained a platelet count within the reference range. Platelet count improvement was observed in various conditions: primary ITP (90%, n = 18/20), pancytopenia of unknown etiology (42.9%, n = 3/7), chemotherapy-induced thrombocytopenia (50%, n = 3/6), babesiosis (100%, n = 1/1), radiotherapy-induced thrombocytopenia (0%, n = 0/1), and disseminated intravascular coagulopathy (33.3%, n = 2/6). The median time for platelet recovery (>50 000/µL) after romiplostim administration was 4 days, and the median time for platelet count normalization was 7 days. Median hospitalization time for the improvement group (I) was 5 days. The survival-to-discharge rates were 85%, 40%, and 28.6% for dogs with primary ITP, secondary thrombocytopenia, and thrombocytopenia of unknown etiology, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Romiplostim is a well-tolerated and promising treatment for primary ITP in dogs, suggesting its potential as a valuable therapeutic option for dogs with thrombocytopenia caused by various underlying conditions. These findings emphasize the need for further research to optimize romiplostim dosing and understand its role in treating secondary thrombocytopenia and pancytopenia of unknown etiology.

Romiplostim use in immune thrombocytopenia: Experience in Cuenca, Ecuador / Uso de romiplostim en trombocitopenia inmunitaria: experiencia en Cuenca (Ecuador)

Introduction. The international consensus and the American Society of Hematology guidelines from 2019 established thrombopoietin analogues as the second-line therapy for primary immune thrombocytopenia cases. Objectives. To describe romiplostim usefulness in patients with immune thrombocytopenia in a third-level hospital in Cuenca, Ecuador. Materials and methods. We conducted a descriptive and retrospective study in patients with immune thrombocytopenia treated with romiplostim. We evaluated the following variables: age, gender, previous therapies to romiplostim, dose, frequency, complications, change of thrombopoietin analogue, and treatment discontinuation. Results. We included 21 patients with immune thrombocytopenia treated with romiplostim, with a median age of 49 years. All patients received corticosteroids as first-line treatment. Three patients required longer administration intervals (over a week), with weekly doses lower than those recommended (< 1 µg/kg). Due to lack of efficacy, six patients replaced elthrombopag with romiplostim. Of the total, three suffered thrombotic complications: two had portal venous thrombosis, and one had pulmonary thromboembolism; five of the patients discontinued romiplostim scheme without resuming it. Conclusions. Romiplostim constitutes a convenient second-line therapy in immune thrombocytopenia. Despite the small sample size, romiplostim early use can minimize toxicities and infectious risks.

Introducción: El consenso internacional y la guía del 2019 de la American Society of Hematology, establecieron a los análogos de la trombopoyetina como medicamentos de segunda línea para tratar la trombocitopenia inmunitaria primaria. En Ecuador, se comercializan dos trombomiméticos: romiplostim y eltrombopag OBJETIVOS: Describir el uso de romiplostim en pacientes con trombocitopenia inmunitaria, en un hospital de tercer nivel en Cuenca (Ecuador). Materiales y métodos. Se adelantó un estudio descriptivo y retrospectivo en pacientes con trombocitopenia inmunitaria y tratamiento con romiplostim. Se evaluaron las siguientes variables: edad, sexo, tratamientos previos a romiplostim, dosis, frecuencia, complicaciones, cambio de análogo de trombopoyetina y discontinuación de la terapia. RESULTADOS: Veintiún pacientes con trombocitopenia inmunitaria fueron tratados con romiplostim, con una mediana de 49 años. Todos recibieron corticoides como tratamiento de primera línea. Tres precisaron de intervalos más prolongados que el semanal, con dosis semanales menores de las recomendadas (< 1 µg/kg). Por falta de eficacia, en seis pacientes se reemplazó la terapia con eltrombopag por romiplostim. Tres pacientes padecieron complicaciones trombóticas: dos, trombosis venosa portal, y uno, tromboembolia pulmonar. En cinco, se discontinuó el tratamiento con romiplostim, sin necesidad de reanudarlo. CONCLUSIONES: Romiplostim constituye un tratamiento de segunda línea para la trombocitopenia inmunitaria primaria. A pesar del reducido tamaño de la muestra, se observó que la administración temprana del medicamento puede minimizar toxicidades y riesgos infecciosos.

Recombinant human thrombopoietin improves platelet engraftment after autologous hematopoietic stem cell transplantation in patients with aggressive lymphoma.

BACKGROUND: To explore the efficiency and safety of recombinant human thrombopoietin (TPO) on the platelet engraftment after autologous stem cell transplantation (ASCT) in patients with aggressive lymphoma. PATIENTS AND METHODS: Forty patients were enrolled in a single-center, retrospective clinical trial from July 2019 with rhTPO administration when the platelet count ≤ 75 × 109/L after the reinfusion of stem cells. The hematopoietic reconstitution, platelet transfusion dependence, the cost and length of hospitalization, side effects and survival benefit were compared between the rhTPO group and the control group of 25 historic patients without rhTPO. RESULTS: The cumulative incidence of platelet engraftment in the rhTPO group was significantly higher since d+ 13 post-transplantation. But no difference of neutrophil engraftment was found. rhTPO was considered to influence the platelet engraftment independently by multivariate analysis. Subgroup analysis demonstrated that when the patients were older than 45 years old, male, at stage-IV as diagnosed and obtained PR after previous treatment, rhTPO was more recommended to facilitate platelet early engraftment after ASCT. Although rhTPO didn't relieve the dependency of platelet transfusion, patients had the shorter length of hospitalization. And better OS was shown in the rhTPO group. CONCLUSION: rhTPO improved platelet engraftment after ASCT with aggressive lymphoma, especially the ones older than 45 years old, male, at stage-IV as diagnosed and obtained PR after previous treatment. Although rhTPO didn't lessen platelet transfusion dependence, the length and medical cost of hospitalization were reduced when rhTPO was involved. rhTPO was efficacy and safety which could be recommended after ASCT.

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

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

Update on the Use of Thrombopoietin-Receptor Agonists in Pediatrics.

This review summarizes the rationale and current data on the use of thrombopoietin receptor agonists (TPO-RAs) for treating severe thrombocytopenia in infants, children, and adolescents. It focuses on substances that have been approved by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) for pediatric patients. Romiplostim and eltrombopag are already established as second-line treatment for persistent or chronic immune thrombocytopenia (ITP). As in adults, TPO-RAs are currently also evaluated in severe aplastic anemia (SAA), chemotherapy-induced thrombocytopenia (CIT), myelodysplastic syndromes (MDS), and poor engraftment after hematopoietic stem cell transplantation in pediatric and adolescent patients. Moreover, studies on the implication of TPO-RA in treating rare inherited thrombocytopenias, such as Wiskott-Aldrich syndrome (WAS), congenital amegakaryocytic thrombocytopenia (CAMT), or MYH9-associated thrombocytopenia, deserve future attention. Current developments include testing of avatrombopag and lusutrombopag that are approved for the treatment of thrombocytopenia associated with chronic liver disease (CLD) in adult patients. In pediatric and adolescent medicine, we expect in the near future a broader use of TPO-RAs as first-line treatment in primary ITP, thereby considering immunomodulatory effects that increase the rate of sustained remission off-treatment, and a selective use in rare inherited thrombocytopenias based on current clinical trials.

Immune thrombocytopenia: Pathophysiology and impacts of Romiplostim treatment.

Immune thrombocytopenia (ITP) is an autoimmune bleeding disease caused by immune-mediated platelet destruction and decreased platelet production. ITP is characterized by an isolated thrombocytopenia (<100 × 109/L) and increased risk of bleeding. The disease has a complex pathophysiology wherein immune tolerance breakdown leads to platelet and megakaryocyte destruction. Therapeutics such as corticosteroids, intravenous immunoglobulins (IVIg), rituximab, and thrombopoietin receptor agonists (TPO-RAs) aim to increase platelet counts to prevent hemorrhage and increase quality of life. TPO-RAs act via stimulation of TPO receptors on megakaryocytes to directly stimulate platelet production. Romiplostim is a TPO-RA that has become a mainstay in the treatment of ITP. Treatment significantly increases megakaryocyte maturation and growth leading to improved platelet production and it has recently been shown to have additional immunomodulatory effects in treated patients. This review will highlight the complex pathophysiology of ITP and discuss the usage of Romiplostim in ITP and its ability to potentially immunomodulate autoimmunity.

Romiplostim for Treatment of Children and Young Adults With Severe Aplastic Anemia and Myelodysplastic Syndrome.

Thrombopoietin receptor agonists (TPO-RAs) induce trilineage hematopoiesis under conditions with acquired hematopoietic failure. We evaluated safety, tolerability, and preliminary efficacy of a TPO-RA, romiplostim (Nplate), with or without standard-of-care immunosuppressive therapy (±IST) for children (ages < 21 y) with newly diagnosed and relapsed/refractory severe aplastic anemia (SAA) and myelodysplastic syndrome (MDS). Data were collected from an observational study and a single arm interventional pilot study. The safety outcome was treatment-related adverse events (AEs). Efficacy was evaluated by complete hematopoietic response (CHR) at week 24. Romiplostim was commenced at 5 µg/kg/week, with dose escalation of 2.5 µg/kg/week (maximum, 20 µg/kg/dose) based on platelet response. Romiplostim was continued until CHR was observed. Ten subjects (SAA, 9 [IST, 4; without IST, 5]; MDS, 1) completed the study (median age: 9.2 y). Median romiplostim dose was 10 µg/kg/week (range: 5 to 17.5 µg/kg/week). The cumulative incidence of CHR was 70.4% (95% CI, 20.2%-92.6%). Among 21 AEs (Grade 1 to 3), 3 were attributed to romiplostim. At a median posttherapy follow-up of 10.9 months (range: 0.7 to 77.5), no clonal evolution, bone marrow fibrosis or mortality was reported. This proof-of-concept study provides data about short-term safety, tolerability, and preliminary efficacy of romiplostim (±IST) for treatment of pediatric SAA/MDS.

Eltrombopag can promote platelet implantation after allogeneic hematopoietic stem cell transplantation as safely and similarly to thrombopoietin.

Background: Eltrombopag has demonstrated efficacy in treating low platelet (PLT) levels, but it remains unclear whether eltrombopag can promote PLT engraftment after hematopoietic stem cell transplantation (HSCT). Methods: Forty-one HSCT patients received eltrombopag 50 mg/d from +1 day until PLT >50 × 109/L or 1 month after HSCT. Fifty-one patients in the same period received thrombopoietin (TPO) to promote PLT graft after HSCT and served as a control group. Results: A total of 51 patients who applied TPO during the same period were treated as a control. In the eltrombopag group, the median time to white blood cells (WBC) graft was 12 days (range, 10-17 days) and the PLT graft was 15 days (range, 10-30 days), whereas for the patients in the TPO group, the median time to WBC and PLT graft was 12 days (range, 9-23 days) and 15.5 days (range, 9-41 days), respectively. In the first month after HSCT, the median WBC count in the eltrombopag group was 4.41 × 109/L (range, 0.87-40.01 × 109/L) and the median PLT was 89x109/L (range, 30-401 × 109/L); the median WBC and PLT \counts in the TPO group were 4.65 × 109/L (range, 0.99-23.63 × 109/L) and 86 × 109/L (range, 5-512 × 109/L), respectively. Patients in the TPO or eltrombopag group did not experience serious side effects after drug administration, and the difference in side effects on liver and kidney function between the two groups was not statistically significant. Conclusion: Eltrombopag is safe and similarly promotes platelet engraftment to thrombopoietin after allogeneic HSCT.

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.

Recombinant Human Thrombopoietin Promotes Platelet Engraftment in Severe Aplastic Anemia Patients Following Treatment With Haploid Hematopoietic Stem Cell Transplantation using Modified Post-Transplantation Cyclophosphamide.

BACKGROUND: Recombinant human TPO (rhTPO) promotes platelet engraftment in patients after allogeneic HSCT (allo-HSCT). However, the effects of rhTPO on platelet recovery after Haplo-HSCT in patients with severe aplastic anemia (SAA) have not been intensively studied. OBJECTIVE: We aimed to evaluate the efficacy of rhTPO on platelet engraftment in patients with SAA who were treated with Haplo-HSCT using post-transplantation cyclophosphamide (PTCy). STUDY DESIGN: SAA patients who received Haplo-HSCT plus PTCy regimen were divided into the rhTPO group (with subcutaneous injection of rhTPO, n = 28) and Control group (no rhTPO administration, n = 27). The engraftment of platelet/neutrophil, platelet infusion amount, and transplant-related complications between the 2 groups were compared. RESULTS: All 55 patients showed successful hematopoietic reconstitution. The median time of platelet engraftment was 11 (9 to 29) days in the rhTPO group and 14 (9 to 28) days in the Control group (P = .003). The rhTPO group had a significantly reduced amount of infused platelets compared to the Control group (2 (1 to 11.5) versus 3 (1 to 14) therapeutic doses; P = .004). There was no significant difference between the 2 groups regarding median time of neutrophil engraftment, incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), incidence of cytomegalovirus or Epstein-Barr virus reactivation, 3-yr overall survival rate, and failure-free-survival rate. No obvious adverse reactions were observed in the rhTPO group. CONCLUSION: rhTPO promoted platelet engraftment, reduced the amount of transfused platelets, and demonstrated good safety profiles without evidence of adverse reactions in patients with SAA who received Haplo-HSCT using PTCy regimen.

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.

A real-world observation on thrombopoietic agents for patients with cancer treatment-induced thrombocytopenia in China: A multicenter, cross-sectional study.

BACKGROUND: Studies on various thrombopoietic agents for cancer treatment-induced thrombocytopenia (CTIT) in China are lacking. This study aimed to provide detailed clinical profiles to understand the outcomes and safety of different CTIT treatment regimens. METHODS: In this retrospective, cross-sectional study, 1664 questionnaires were collected from 33 hospitals between March 1 and July 1, 2021. Patients aged >18 years were enrolled who were diagnosed with CTIT and treated with recombinant interleukin 11 (rhIL-11), recombinant thrombopoietin (rhTPO), or a thrombopoietin receptor agonist (TPO-RA). The outcomes, compliance, and safety of different treatments were analyzed. RESULTS: Among the 1437 analyzable cases, most patients were treated with either rhTPO alone (49.3%) or rhIL-11 alone (27.0%). The most common combination regimen used was rhTPO and rhIL-11 (10.9%). Platelet transfusions were received by 117 cases (8.1%). In multivariate analysis, rhTPO was associated with a significantly lower proportion of platelet recovery, platelet transfusion, and hospitalization due to chemotherapy-induced thrombocytopenia (CIT) than rhIL-11 alone. No significant difference was observed in the time taken to achieve a platelet count of >100 × 109/L and chemotherapy dose reduction due to CIT among the different thrombopoietic agents. The outcomes of thrombocytopenia in 170 patients who received targeted therapy and/or immunotherapy are also summarized. The results show that the proportion of platelet recovery was similar among the different thrombopoietic agents. No new safety signals related to thrombopoietic agents were observed in this study. A higher proportion of physicians preferred to continue treatment with TPO-RA alone than with rhTPO and rhIL-11. CONCLUSIONS: This survey provides an overview of CTIT and the application of various thrombopoietic agents throughout China. Comparison of monotherapy with rhIL-11, rhTPO, and TPO-RA requires further randomized clinical trials. The appropriate application for thrombopoietic agents should depend on the pretreatment of platelets, treatment variables, and risk of bleeding. PLAIN LANGUAGE SUMMARY: To provide an overview of the outcome of cancer treatment-induced thrombocytopenia in China, our cross-sectional study analyzed 1437 cases treated with different thrombopoietic agents. Most of the patients were treated with recombinant interleukin 11 (rhIL-11) and recombinant thrombopoietin (rhTPO). rhTPO was associated with a significantly lower proportion of platelet recovery and platelet transfusion compared with rhIL-11.

The problem of immune thrombocytopenia refractory to both eltrombopag and romiplostim.

Immune thrombocytopenia refractory to multiple thrombopoietin receptor agonists remains a challenging clinical problem. This commentary discusses and contextualizes the recent report on this entity from Moulis and colleagues, and how to move forward with these patients. Commentary on: Moulis et al. Difficult-to-treat primary immune thrombocytopenia in adults: Prevalence and burden. Results from the CARMEN-France Registry. Br J Haematol 2024;204:1476-1482.

Long-term treatment with rilzabrutinib in patients with immune thrombocytopenia.

ABSTRACT: Immune thrombocytopenia (ITP) is an autoimmune disease associated with autoantibody-mediated platelet destruction and impaired platelet production, resulting in thrombocytopenia and a predisposition to bleeding. The ongoing, global phase 1/2 study showed that rilzabrutinib, a Bruton tyrosine kinase inhibitor specifically developed to treat autoimmune disorders, could be an efficacious and well-tolerated treatment for ITP. Clinical activity, durability of response, and safety were evaluated in 16 responding patients who continued rilzabrutinib 400 mg twice daily in the long-term extension (LTE) study. At LTE entry, the median platelet count was 87 × 109/L in all patients, 68 × 109/L in those who had rilzabrutinib monotherapy (n = 5), and 156 × 109/L in patients who received concomitant ITP medication (thrombopoietin-receptor agonists and/or corticosteroids, n = 11). At a median duration of treatment of 478 days (range, 303-764), 11 of 16 patients (69%) continued to receive rilzabrutinib. A platelet count of ≥50 × 109/L was reported in 93% of patients for more than half of their monthly visits. The median percentage of LTE weeks with platelet counts ≥30 × 109/L and ≥50 × 109/L was 100% and 88%, respectively. Five patients discontinued concomitant ITP therapy and maintained median platelet counts of 106 × 109/L at 3 to 6 months after stopping concomitant ITP therapy. Adverse events related to treatment were grade 1 or 2 and transient, with no bleeding, thrombotic, or serious adverse events. With continued rilzabrutinib treatment in the LTE, platelet responses were durable and stable over time with no new safety signals. This trial is registered at www.clinicaltrials.gov as #NCT03395210 and www.clinicaltrialsregister.eu as EudraCT 2017-004012-19.