Thrombosomes are trehalose-stabilized, freeze-dried group O platelets with a 3-year shelf life. They can be stockpiled, rapidly reconstituted, and infused regardless of the recipient's blood type. Thrombosomes thus represent a potential alternative platelet transfusion strategy. The present study assessed the safety and potential early signals of efficacy of Thrombosomes in bleeding thrombocytopenic patients. We performed an open-label, phase 1 study of single doses of allogeneic Thrombosomes at three dose levels in three cohorts, each consisting of eight patients who had hematologic malignancies, thrombocytopenia, and bleeding. Adverse events, dose-limiting toxicities (DLTs), World Health Organization (WHO) bleeding scores, and hematology values were assessed. No DLTs were reported. The median age was 59 years (24–71). Most patients had AML (58%) or ALL (29%), followed by MDS (8%) and myeloproliferative neoplasm (4%). The WHO scores of 22 patients who were actively bleeding at a total of 27 sites at baseline either improved (n = 17 [63%]) or stabilized (n = 10 [37%]) through day 6. Twenty-four hours after infusion, 12 patients (50%) had a clinically significant platelet count increase. Of eight patients who received no platelet transfusions for 6 days after Thrombosomes infusion, 5 had a clinically significant increase in platelet count of ≥5000 platelets/μL and 2 had platelet count normalization. Thrombosomes doses up to 3.78 × 10⁸ particles/kg demonstrated safety in 24 bleeding, thrombocytopenic patients with hematological malignancies. Thrombosomes may represent an alternative to conventional platelets to treat bleeding. A phase 2 clinical trial in a similar patient population is underway.

中文翻译：

---

冻干血小板是血液系统恶性肿瘤出血性血小板减少患者的一种有希望的替代品

血栓体是海藻糖稳定的冻干 O 组血小板，保质期为 3 年。无论接受者的血型如何，它们都可以被储存、快速重组和输注。因此，血栓体代表了一种潜在的替代血小板输注策略。本研究评估了血栓体在出血性血小板减少患者中的安全性和潜在的早期疗效信号。我们在三个队列中对三个剂量水平的单剂量异基因血小板进行了开放标签的 1 期研究，每个队列由 8 名患有血液系统恶性肿瘤、血小板减少症和出血的患者组成。评估了不良事件、剂量限制毒性 (DLT)、世界卫生组织 (WHO) 出血评分和血液学值。没有报告 DLT。中位年龄为 59 岁（24-71 岁）。大多数患者患有 AML (58%) 或 ALL (29%)，其次是 MDS (8%) 和骨髓增生性肿瘤 (4%)。基线时共有 27 个部位活动性出血的 22 名患者的 WHO 评分有所改善（n  = 17 [63%]) 或稳定 ( n  = 10 [37%]) 至第 6 天。输注后 24 小时，12 名患者 (50%) 的血小板计数显着增加。在 Thrombosomes 输注后 6 天未接受血小板输注的 8 名患者中，5 名血小板计数临床显着增加≥5000 血小板/μL，2 名血小板计数正常化。高达 3.78 × 10 ⁸颗粒/kg 的血栓体剂量在 24 名患有血液系统恶性肿瘤的出血性血小板减少症患者中表现出安全性。血栓体可能代表传统血小板治疗出血的替代品。一项针对类似患者群体的 2 期临床试验正在进行中。