Effective treatment of refractory aplastic anemia with romiplostim after failure of multiple thrombopoietin receptor agonists: a single-center retrospective study.

Background: Romiplostim (ROM), a second-generation thrombopoietin receptor agonist (TPO-RA), has shown promising results in patients with refractory aplastic anemia (AA); however, its optimal dosage, efficacy, and safety in patients with refractory AA who experienced treatment failure with immunosuppressive therapy (IST) and other types of TPO-RAs remain unclear. In the present study, we aimed to retrospectively assess the efficacy and safety of high-dose ROM in these patients.

Patients And Methods: Patients who received ROM consecutively for at least 3 months between 8 April 2023 and 23 October 2023, and were followed up for at least 6 months after therapy were analyzed. All enrolled patients had failed to respond and stopped the previous treatments for at least 3 months before receiving ROM.

Results: Eleven patients were followed up for at least 6 months; all experienced treatment failure with IST and at least two types of other TPO-RAs. They had a median age of 54 years (range: 27-77 years), and eight (72.7%) were women. The patients' initial and maximal ROM dose was 20 μg/kg per week. At a median follow-up of 8 months (range, 6-8 months), 72.7% (8/11) of the patients reached the response criteria at a median of 1 month (range: 1-3 months). Of these patients, 54.5% (6/11) met the criteria for a complete response at a median of 2.5 months (range: 1-3 months), and 27.3% (3/11) achieved a trilineage response. No severe ROM-related adverse events that led to treatment discontinuation or dosage reduction were observed. Notably, 12.5% (1/8) of the responders relapsed at 5 months after stopping ROM for 2 months.

Conclusion: High-dose ROM with an initial dosage of 20 μg/kg per week is effective and safe for patients with refractory AA who experienced treatment failure with IST and multiple oral TPO-RAs, exerting a rapid response.