Yamaguchi Hiroki, Iino Masaki, Kowata Shugo, Yamamoto Ryusuke, Yamanouchi Jun, Imamura Yutaka, Kirito Keita, Yokoyama Kenji, Ito Tomoki, Ishikawa Tatsunori, Shiratsuchi Motoaki, Tomiyama Yoshiaki, Kamiya Harumi, Zhang Jessica, Jamieson Brian D
Department of Hematology, Nippon Medical School Hospital, Tokyo, Japan.
Department of Hematology and Hematopoietic Stem Cell Transplantation, Yamanashi Prefectural Central Hospital, Yamanashi, Japan.
Int J Hematol. 2025 May 20. doi: 10.1007/s12185-025-04001-4.
Avatrombopag is an oral thrombopoietin receptor agonist approved widely for the treatment of adults with chronic immune thrombocytopenia (ITP). However, data in Japanese patients are limited. This confirmatory phase 3, open-label study investigated avatrombopag (initial dose 20 mg/day) in Japanese adults (aged ≥ 18 years) with chronic ITP (≥ 12 months), insufficient response to prior treatment and an average of 2 platelet counts (PCs) < 30 × 10/L. The primary endpoint was the cumulative number of weeks of platelet response (PC ≥ 50 × 10/L) without rescue therapy for bleeding. Secondary endpoints included platelet response rate at Day 8 and safety. In total, 19 patients were enrolled into the 26-week core phase. The mean age was 56.0 years; 78.9% of patients were female. Mean cumulative number of weeks of platelet response was 13.5 (95% CI 9.1-17.8). Platelet response at Day 8 was achieved by 63.2% of patients. In the core phase, adverse events (AEs) occurred in 94.7% of patients and serious AEs in 15.8%. No thromboembolic events or deaths occurred in the core phase. Avatrombopag demonstrated a rapid and durable platelet response and was well tolerated in Japanese patients with chronic ITP. Long-term safety and efficacy are being assessed in the ongoing extension phase.
阿伐曲泊帕是一种口服血小板生成素受体激动剂，已被广泛批准用于治疗成人慢性免疫性血小板减少症（ITP）。然而，日本患者的数据有限。这项验证性3期开放标签研究调查了阿伐曲泊帕（初始剂量20mg/天）在年龄≥18岁、患有慢性ITP（≥12个月）、对先前治疗反应不足且平均2次血小板计数（PC）<30×10⁹/L的日本成人中的疗效。主要终点是无出血抢救治疗的血小板反应（PC≥50×10⁹/L）的累计周数。次要终点包括第8天的血小板反应率和安全性。共有19名患者进入了为期26周的核心阶段。平均年龄为56.0岁；78.9%的患者为女性。血小板反应的平均累计周数为13.5（95%CI 9.1-17.8）。63.2%的患者在第8天实现了血小板反应。在核心阶段，94.7%的患者发生了不良事件（AE），15.8%的患者发生了严重AE。核心阶段未发生血栓栓塞事件或死亡。阿伐曲泊帕在日本慢性ITP患者中显示出快速且持久的血小板反应，耐受性良好。正在进行的扩展阶段正在评估长期安全性和疗效。
