[Efficacy and safety of romiplostim N01 for refractory aplastic anemia: a retrospective single-center study]

Romiplostim N01 (QL0911) is a novel thrombopoietin receptor agonist (TPO-RA) ; however, clinical data regarding its efficacy and safety in patients with refractory aplastic anemia (AA) who have failed multiple prior lines of therapy are limited. This retrospective single center study analyzed the clinical outcomes of 32 patients with refractory AA who received romiplostim N01 at Peking Union Medical College Hospital between May 2024 and December 2024. All patients had previously failed to respond to full dose cyclosporine and at least two oral TPO-RA administered for adequate treatment durations and had been treated with romiplostim N01 for ≥3 months and followed for ≥6 months. The median age of the cohort was 62 years (range, 24-79 years) , and 11 patients (34.4% ) were male. Thirty patients had transfusion-dependent non-severe AA (TD-NSAA) , and 2 had severe AA (SAA) . The median duration of romiplostim N01 treatment was 5 months (range, 3-10 months) , and the median follow-up time was 6 months (range, 6-10 months) . The overall response rates (ORR) at 3 months, 6 months, and the last follow-up were 71.9% , 75.0% , and 75.0% , respectively, and the complete response rates (CRR) were 28.1% , 28.1% , and 31.2% , respectively. The median time to hematologic response was 1 month (range, 1-4 months) , and the median time to complete response was 3 months (range, 1-4 months) , indicating a rapid onset of action even in this refractory population. A total of 14 patients (43.8% ) experienced adverse events, all of which were grade 1 and improved with symptomatic management; no dose reductions or treatment discontinuations were required, and no treatment related liver dysfunction, thrombotic events, or deaths were observed. During follow-up, relapse occurred in 3 patients who had previously responded (3/26, 11.5% ) , and newly detected myelodysplastic syndrome (MDS) -related gene mutations were identified in 2 patients (6.3% ) . No new or expanding paroxysmal nocturnal hemoglobinuria (PNH) clones were detected. These findings suggest that romiplostim N01 can induce rapid and high hematologic response rates with a favorable safety profile in patients with refractory AA who have failed full-dose cyclosporine A and multiple oral TPO-RA; no obvious short-term signals of clonal evolution were observed.