Supplementary Material for: Romiplostim Treatment in Adults with Immune Thrombocytopenia of Varying Duration and Severity

Romiplostim is recommended for the second- and third-line treatment of primary immune thrombocytopenia (ITP). We conducted a large, single-arm study (clinicaltrials.gov; NCT00508820) with broad entry criteria to evaluate the safety of romiplostim in adult ITP. Patients (n = 407) with ITP lasting 0.03-57.14 years and low platelet counts (median 14.0 × 10⁹/l) or uncontrolled bleeding received romiplostim for up to 4 years. The rates of treatment-related, serious adverse events, serious hemorrhage events, thromboembolic events and fatal events were similar to those reported in previous romiplostim trials (0.2, 0.4, 0.2 and 0.1/100 patient-weeks, respectively). Bone marrow reticulin was observed in 4 patients, but biopsies were not routinely performed so the true incidence of this event cannot be determined. Type I collagen (nonserious, unrelated) was reported in 1 patient who likely had myelodysplastic syndrome. No new class of adverse events was reported. Platelet responses were achieved by >90% of the patients, typically within 1-2 weeks of the initiation of romiplostim treatment. From week 8, median platelet counts were >100 × 10⁹/l; 47% of the patients received rescue medications (the use decreased over time). This study confirms and extends the tolerability/efficacy findings of previous romiplostim clinical studies. It was performed on a large ITP population, which is likely more representative of clinical practice.

罗米司亭（Romiplostim）被推荐用于原发性免疫性血小板减少症（primary immune thrombocytopenia, ITP）的二线及三线治疗。本研究开展了一项纳入宽泛入组标准的大型单臂临床试验（临床试验官网clinicaltrials.gov；编号NCT00508820），旨在评估罗米司亭在成人ITP患者中的安全性。本研究共纳入407名ITP病程为0.03~57.14年、血小板计数低下（中位数为14.0×10^9/L）或存在出血未控制情况的患者，给予罗米司亭治疗最长达4年。治疗相关性严重不良事件、严重出血事件、血栓栓塞事件及致死事件的发生率，与既往罗米司亭临床试验报告的数据相近，分别为0.2、0.4、0.2及0.1/100患者-周。4例患者观察到骨髓网状纤维异常，但因未常规开展骨髓活检，无法确定该事件的真实发生率。1名疑似骨髓增生异常综合征（myelodysplastic syndrome）的患者报告了I型胶原相关不良反应（非严重、与治疗无关）。本研究未发现新的不良事件类别。超过90%的患者达成了血小板应答，通常在罗米司亭治疗起始后的1~2周内即可观察到该应答。自第8周起，患者的血小板计数中位数高于100×10^9/L；47%的患者接受了解救治疗，且用药比例随时间推移逐渐降低。本研究证实并拓展了既往罗米司亭临床研究的耐受性与疗效相关结论。本次研究纳入了大样本ITP人群，其受试者特征更贴合临床实际诊疗场景。