Abstract Background and Significance: Autologous hematopoietic stem cell transplantation (ASCT) remains a cornerstone of consolidated or salvage therapy for malignant diseases, significantly improving patient survival. However, delayed platelet engraftment (DPE) defined as platelet recovery ≥ 20×109/L without tranfusion for 7 consecutive days beyond day +28 post-ASCT, is a common complication contributing to increased risks of severe infection, anemia and bleeding. Early Cytokine support post-transplant is critical to shorten myelosuppression duration and optimize transplant outcomes. Recombinant human thrombopoietin (rhTPO) and thrombopoietin receptor agonists (TPO-RAs) have demonstrated efficacy in shortening DPE duration (Qiu et al, Transfusion and Apheresis Science. 2024, PMID: 39013350). Notably, a single-center trial evaluating romiplostim (a TOP-RA) in ASCT recipients reported higher platelet counts at days +21 and +30 (Michael et al, Blood Advances. 2023, PMID: 36409612). Nevertheless, existing evidence is limited by the single-center designs and incomplete data collection (e.g., during the COVID-19 pandemic). Romiplostim N01, a long-acting TPO-RA developed and produced by Chinese pharmaceutical enterprise, is approved by the National Medical Products Administration (NMPA) for immune thrombocytopenia (ITP). This study evaluates its novel application in promoting platelet engraftment after ASCT. Study design and Methods: This investigator-initated, prospective, single-arm, open-label, multi-center trial (ChiCTR2500096999) was approved by institutional ethics Committees and conducted at four centers: The First Affiliated Hospital of Nanchang University, Jiangxi Provincial People's Hospital, Ganzhou People's Hospital and First Affiliated Hospital of Gannan Medical University. Fifty eligible patients include patients (age unrestricted) with hematological malignancy (multiple myeloma, lymphoma, or favorable-risk acute leukemia) scheduled for ASCT, weighting ≥ 30 kg, with Eastern Cooperative Oncology Group (ECOG) performance status ≤1, and adequate hematopoietic reserve/liver/kidney function. Exclusion criteria include severe organ dysfunction (e.g., cardiac, hepatic, renal, pancreatic) or uncontrolled comorbidities. Patients receive romiplostim N01 at an initial dose of 3 µg/kg subcutaneously once weekly, starting on day +3 post-ASCT, and continuing until platelet count sustains ≥ 70×10⁹/L. Dosing adjustments follow a predefined protocol based on platelet counts. No more than 4 doses will be administered, even if engraftment is delayed. The primary endpoint is time to platelet engraftment (days from ASCT to first of 7 consecutive days with platelet count ≥ 20×109/L without transfusion). Secondary endpoints include: (1) cumulative platelet engraftment rate by day +28; (2) 28-day cumulative platelet transfusion volume; (3) incidence and severity of bleeding events; (4) time to neutrophil engraftment (neutrophil count ≥ 0.5×109/L for ≥ 3 days without granulocyte colony-stimulating factor support); (5) progression-free survival (PFS) and overall survival (OS); and (6) safety (adverse events AEs, serious AEs SAEs). Enrollment began in February 2025. As of July 15, 2025, 23 of 50 planned patients have been enrolled. Recruitment and follow-up are ongoing.
Mingxing Zhong (Mon,) studied this question.