Objective: To evaluate the efficacy and safety of maintenance therapy with reduced dose of rhTPO in the patients with primary immune thrombocytopenia (ITP) who attained stable platelet (PLT) counts after daily administration of rhTPO. Methods: Treatment was started with a daily administration of rhTPO (300 U/kg) for 2 consecutive weeks. Patients who attained stable PLT≥50×10(9)/L were enrolled to maintenance therapy starting with every other day administration of rhTPO, then adjusted dose interval to maintain platelet count (30-100) ×10(9)/L. Results: A total of 91 eligible patients were enrolled. Fourteen patients discontinued the study due to noncompliance (12/14) and investigator decision (2/14) . Among 77 patients who completed the study, 38 patients with the administration of rhTPO at every other day or less could maintain PLT≥30×10(9)/L for 12 weeks. The percentage of patients with a platelet response (PLT≥30×10(9)/L) at 4(th) week, 8(th) week and 12(th) week of maintain therapy was 92.6% (63/68) , 82.7% (43/52) and 85.0% (34/40) , respectively. Median platelet counts remained in the range of (70-124) ×10(9)/L. The overall incidence of rhTPO-related adverse events was 7.7%. All the adverse events were generally mild. Conclusion: Extending the dose interval of rhTPO is feasible to maintain stable platelet count in the patients with ITP, but the optimal dose interval is uncertain and might vary with individuals.
目的： 评价重组人血小板生成素（rhTPO）减量维持治疗对于原发免疫性血小板减少症（ITP）的有效性和安全性。 方法： ITP患者接受连续2周的rhTPO治疗（300 U·kg(-1)·d(-1)），PLT ≥ 50×10(9)/L者进入维持治疗。入组者初始给予隔日用药方案，根据血小板计数调整rhTPO给药间隔，维持PLT （30~100）×10(9)/L，维持治疗共12周。 结果： 在91例rhTPO治疗有效的患者中，14例退出研究（12例依从性欠佳，2例经研究者决定换用其他治疗方案）。77例患者完成研究，其中38例在12周维持治疗中始终维持治疗有效（PLT≥30×10(9)/L）。在维持治疗第4、8、12周时，治疗有效率分别为92.6%（63/68）、82.7%（43/52）、85.0%（34/40）。所有接受治疗患者的中位血小板计数波动于（70~124）×10(9)/L。rhTPO相关不良反应发生率为7.7%，均为轻度。 结论： 延长给药间隔的减低剂量rhTPO维持治疗可使绝大多数ITP患者的血小板计数维持于安全水平，但给药间隔差异较大，需进行个体化调整。.
Keywords: Drug toxicity; Recombinant human thrombopoietin; Thrombocytopenia; Treatment outcome.