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Single Center Evaluation of Romiplostim in Prolonged Thrombocytopenia after Allogeneic Hematopoietic Cell Transplantation

Year: 2025

Type: article

Abstract: Introduction Prolonged thrombocytopenia after allogeneic hematopoietic cell transplantation (alloHCT) can lead to significant morbidity and mortality. The etiology of post-alloHCT thrombocytopenia is multifactorial ranging from malignant disease relapse, impaired thrombopoiesis , and/or platelet (PLT) consumption. Thrombopoietin receptor agonists (TPO-RAs) have been increasingly used in this population; however, there are limited data regarding the use and efficacy of romiplostim for prolonged thrombocytopenia after alloHCT. This study aimed to assess use of romiplostim in patients with prolonged thrombocytopenia post alloHCT at our institution. Methods We retrospectively reviewed patients treated with romiplostim within 200 days of alloHCT between 01/2020 to 04/2024. Patients were excluded if they received romiplostim on a protocol or were enrolled in a clinical trial for GVHD prophylaxis. The primary objective was to determine the median dose to achieve a response, defined as PLTs >50k without transfusion for 7 days (Mahat et al., BBMT 2020). Results A total of 72 patients were analyzed ( Table ). Most patients received an unrelated donor peripheral blood stem cell allograft and half had PTCy for GVHD prophylaxis. The indications for romiplostim included ITP, poor graft function, graft failure , medication induced thrombocytopenia, etc. A total of 39 patients (54%) responded to romiplostim. Median time from alloHCT to romiplostim initiation was 64 days, with a median starting dose of 2 mcg/kg (IQR 2-3). PLT response occurred at a median of 28 days from initiation after a median of 4 doses (IQR 2-7). The median dose at PLT response was 5 mcg/kg (IQR 3-8). Most patients (n=65, 90%) stopped romiplostim without a taper. Thrombosis occurred in 5 (6.9%) patients including 4 DVTs and 1 PE. Six (8.3%) patients switched to eltrombopag due to romiplostim failure. Conclusion We observed that romiplostim was effective in half of our patients treated for thrombocytopenia with varying indications after alloHCT. Treatment response was observed at a median dose of 5 mcg/kg at a median of 28 days after 4 doses. Thrombosis was the main complication but not at higher than expected rates. Thus, our observations support the use of romiplostim for the treatment of thrombocytopenia post alloHCT. However, larger studies are needed to elucidate the role of TPO-RAs after alloHCT. Future analyses include evaluation of treatment response per etiology and optimization of the starting dose.

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.jtct.2025.01.207