Optimal management of chemotherapy-induced thrombocytopenia with thrombopoietin receptor agonists

Chemotherapy-induced thrombocytopenia: modern diagnosis and treatment

Chemotherapy-induced thrombocytopenia (CIT) is a common clinical problem in patients with solid tumour malignancies. Unlike nadir CIT which often resolves by the start of the following chemotherapy cycle, persistent CIT results in unacceptably low platelet counts at the beginning of a cycle lasting throughout multiple chemotherapy cycles, resulting in bleeding as well as chemotherapy treatment delays, dose reductions and discontinuation. Persistent CIT can be managed with thrombopoietin receptor agonist support in the context of a clinical trial or off-label use of romiplostim if a trial is not available.

Application of thrombopoietic agents in cancer therapy-induced thrombocytopenia: A comprehensive review

Cancer therapy-induced thrombocytopenia (CT-IT) is one of the most common hematological toxicities of anti-cancer therapy, often leading to treatment dose reduced, postponed, or treatment plans altered or even discontinued. Thrombopoietin (TPO) is the only key regulatory factor in platelet production, and TPO receptor is considered an ideal target for the treatment of thrombocytopenia. Thrombopoietic agents, including recombinant human thrombopoietin (rhTPO) and thrombopoietin receptor agonists (TPO-RAs), bind to different regions of the TPO receptor, activating downstream signaling pathways to increase platelet levels. In recent years, numerous studies have demonstrated the effectiveness of thrombopoietic agents in the management of CT-IT. These agents can reduce bleeding risk, decrease platelet transfusions, and maintain relative dose intensity (RDI) of anti-cancer treatments. This article provides a review of the current progress in the application of thrombopoietic agents for CT-IT management.

Effect and safety of recombinant human thrombopoietin on haematopoietic reconstitution after allogeneic haematopoietic cell transplantation

Delayed platelet engraftment (DPE) and thrombocytopenia are common complications following myeloablative conditioning in the advanced stage of allogeneic haematopoietic cell transplantation (allo-HCT), and they are associated with transplantation-related mortality and poor prognosis. Therefore, promoting haematopoietic reconstitution after allo-HCT plays a key role in improving patient outcomes. The aim of this retrospective study was to assess the effectiveness and safety of recombinant human thrombopoietin (rhTPO) in promoting haematopoietic reconstruction after allo-HCT. The study included 210 patients who underwent transplantation, with 158 in the rhTPO group and 52 in the control group. Of the total patient population, 120 were males and 90 were females, with a median age of 31 years (range=6 to 59 years). The results showed that the rhTPO group had a median platelet engraftment time that was 14.1 days shorter than that of the control group (14.1 days vs. 21.9 days; P < 0.001). The time for platelet count recovery to 50 × 10^9/L was also shorter in the rhTPO group than in the control group (21.7 days vs. 30.3 days; P < 0.001). Additionally, the granulocyte engraftment time was shorter in the rhTPO group (14.3 days vs. 18.2 days; P < 0.001). There was no significant difference in overall survival (OS) between the rhTPO group and the control group at 2 years after transplantation (77.2% vs. 65.4 %; P = 0.08). Furthermore, there were no significant differences in the amount of platelet transfusions, the rate of platelet engraftment, the rate of DPE, or the incidence of Grade 4 haemorrhage between the groups. Moreover, no adverse reactions were found in the rhTPO group. This study demonstrated that rhTPO administration after allo-HCT effectively reduced the time required for platelet and granulocyte engraftment and was safe.

A second chance for avatrombopag in chemotherapy-induced thrombocytopenia

Chemotherapy-induced thrombocytopenia (CIT) remains a common complication of cancer therapy with no approved available treatments in most of the world. Although a prior clinical trial of avatrombopag for CIT did not meet its primary end-point, a report from Galamaga and colleagues raises prospects for a second chance for avatrombopag in CIT, highlighting the differences between nadir and persistent CIT and the importance of patient selection in CIT treatment. Commentary on: Galamaga et al. Avatrombopag for the treatment of patients with chemotherapy-induced thrombocytopenia: a case series. Br J Haematol 2025; 206:272-278.

Let It Grow: The Role of Growth Factors in Managing Chemotherapy-Induced Cytopenia

Chemotherapy-induced cytopenia (CIC) is characterized by neutropenia, anemia, and thrombocytopenia, which are common and serious complications in cancer treatment. These conditions affect approximately 60% of patients undergoing chemotherapy and can significantly impact quality of life, treatment continuity, and overall survival. The use of growth factors, including granulocyte colony-stimulating factors (GCSFs), erythropoietin-stimulating agents (ESAs), and thrombopoietin receptor agonists (TPO-RAs), has emerged as a promising strategy for managing CIC. However, the use of these growth factors must be approached with caution. This review provides an overview of the mechanisms, efficacy, and safety of growth factors in the management of CIC. Additionally, we discuss predictive markers for treatment response, potential risks, and highlight areas for future research.

Use of Eltrombopag to Improve Thrombocytopenia and Tranfusion Requirement in Anti-CD19 CAR-T Cell-Treated Patients

Background/Objectives: Immune effector cell-associated hematotoxicity (ICAHT) is a frequent adverse event after chimeric antigen receptor (CAR)-T cell therapy. Grade ≥ 3 thrombocytopenia occurs in around one-third of patients, and many of them become platelet transfusion-dependent. Eltrombopag is a thrombopoietin receptor agonist (TPO-RA) able to accelerate megakaryopoiesis, which has been used successfully in patients with bone marrow failure and immune thrombocytopenia (ITP). Its role in managing thrombocytopenia and other cytopenias in CAR-T cell-treated patients has been scarcely addressed. Our aim was to report the safety and efficacy of this approach in patients included in the Spanish Group for Hematopoietic Transplantation and Cellular Therapy (GETH-TC) registry. Methods: This is a retrospective, multicenter, observational study. Patients who developed platelet transfusion dependence subsequently to CAR-T cells and received eltrombopag to improve platelet counts were recruited in 10 Spanish hospitals. Results: Thirty-eight patients were enrolled and followed up for a median (interquartile range [IQR]) of 175 (99, 489) days since CAR-T cell infusion. At the moment eltrombopag was indicated, 18 patients had thrombocytopenia and another severe cytopenia, while 8 patients had severe pancytopenia. After 32 (14, 38) days on eltrombopag, 29 (76.3%) patients recovered platelet transfusion independence. The number of platelet units transfused correlated with the time needed to restore platelet counts higher than 20 × 109/L (Rho = 0.639, p < 0.001). Non-responders to eltrombopag required more platelet units (58 [29, 69] vs. 12 [6, 26] in responders, p = 0.002). Nineteen out of twenty-three (82.6%) patients recovered from severe neutropenia after 22 (11, 31) days on eltrombopag. Twenty-nine out of thirty-five (82.9%) patients recovered red blood cell (RBC) transfusion independence after 29 (17, 44) days. Seven patients recovered all cell lineages while on treatment. No thromboembolic events were reported. Only two transient toxicities (cholestasis, hyperbilirubinemia) were reported during eltrombopag treatment, none of which compelled permanent drug withdrawal. Conclusions: Eltrombopag could be safely used to manage thrombocytopenia and accelerate transfusion independence in CAR-T cell-treated patients.

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.