The Kasabach-Merritt phenomenon (KMP) in kaposiform hemangioendothelioma (KHE) is characterized by life-threatening thrombocytopenia and consumptive coagulopathy. This study compared the efficacy and safety of sirolimus plus prednisolone vs sirolimus monotherapy as treatment strategies for KHE with KMP in the largest cohort to date. Participants were randomized to receive either sirolimus in combination with a short course of prednisolone or sirolimus monotherapy for at least 12 months. The primary outcome was defined as achievement of a durable platelet response (platelet count >100 × 109/L) at week 4. Participants completed efficacy assessments 2 years after the initial treatment. At week 4, a durable platelet response was achieved by 35 of 37 patients given sirolimus and prednisolone compared with 24 of 36 patients given sirolimus monotherapy (difference 27.9%; 95% confidence interval, 10.0-44.7). Compared with the sirolimus monotherapy group, the combination treatment group showed improvements in terms of measures of durable platelet responses at all points during the initial 3-week treatment period, median platelet counts during weeks 1 to 4, increased numbers of patients achieving fibrinogen stabilization at week 4, and objective lesion responses at month 12. Patients receiving combination therapy had fewer blood transfusions and a lower total incidence of disease sequelae than patients receiving sirolimus alone. The frequencies of total adverse events and grade 3-4 adverse events during treatment were similar in both groups. The responses seen in patients with KHE with KMP were profound and encouraging, suggesting that sirolimus plus prednisolone should be considered a valid treatment of KHE with KMP. This trial was registered at www.clinicaltrials.gov as #NCT03188068.

中文翻译：

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西罗莫司加泼尼松龙对比西罗莫司单药治疗卡波西样血管内皮瘤：一项随机临床试验。

卡波西样血管内皮瘤 (KHE) 中的 Kasabach-Merritt 现象 (KMP) 以危及生命的血小板减少症和消耗性凝血病为特征。本研究在迄今为止最大的队列中比较了西罗莫司加泼尼松龙与西罗莫司单药治疗 KHE 和 KMP 的疗效和安全性。参与者被随机分配接受西罗莫司联合短期泼尼松龙或西罗莫司单药治疗至少 12 个月。主要结果定义为在第 4 周实现持久的血小板反应（血小板计数 > 100 × 109/L）。参与者在初始治疗 2 年后完成了疗效评估。在第 4 周，接受西罗莫司和泼尼松龙治疗的 37 名患者中有 35 人获得了持久的血小板反应，而接受西罗莫司单药治疗的 36 名患者中有 24 人获得了持久的血小板反应（差异 27.9%；95% 置信区间，10.0-44.7）。与西罗莫司单药治疗组相比，联合治疗组在最初 3 周治疗期间的所有时间点的持久血小板反应测量、第 1 至 4 周的中位血小板计数、达到纤维蛋白原稳定的患者数量增加第 4 周和第 12 个月的客观病变反应。与单独接受西罗莫司的患者相比，接受联合治疗的患者输血更少，疾病后遗症的总发生率更低。两组在治疗期间的总不良事件发生率和 3-4 级不良事件发生率相似。KMP 合并 KHE 患者的反应是深刻且令人鼓舞的，这表明西罗莫司联合泼尼松龙应被视为 KMP 合并 KHE 的有效治疗方法。该试验在 www.clinicaltrials.gov 注册为#NCT03188068。