Several controlled studies have evidenced good efficacy and short-term and mid-term safety profiles for hydroxyurea (HU), which has become the cornerstone for prevention of sickle-cell disease (SCD)-related vaso-occlusive crises. However, there are few large-scale reports on its long-term use and certain caregivers and patients have concerns about its safety. Following the licensing of HU in Europe for children and adults with severe forms of SCD, ESCORT-HU was designed as a Phase IV observational cohort study. It included 1906 participants, of whom 55% were adults. The most common hemoglobin (Hb) genotypes were HbSS (84.7%) and HbSβ+ (7.0%). The median duration of follow-up was 45 months, for a total of 7309 patient-years of observation. The dose of HU after 1 year was 20.6 mg/kg/d for children and 16.3 mg/kg/d for adults. There was a statistically significant decrease in the number of vaso-occlusive episodes lasting >48 h, acute chest syndrome episodes, hospitalizations, and the percentage of patients requiring blood transfusions within the first 12 months relative to the year before enrolment. Neutropenia and thrombocytopenia were the most commonly reported adverse effects. No new HU toxicity was identified. Overall, 125 pregnancies were reported in 101 women and no malformations were observed in the neonates. There were 12 pregnancies for partners of male patients treated with HU. One case of fatal myelodysplastic syndrome was reported, for which a causal association with HU could not be excluded. This cohort study of patients with SCD highlights the positive benefit-to-risk ratio of HU in children and adults.

中文翻译：

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镰状细胞病患者使用羟基脲的真实经验：前瞻性 ESCORT-HU 队列研究的结果

多项对照研究证明羟基脲 (HU) 具有良好的疗效和短期和中期安全性，已成为预防镰状细胞病 (SCD) 相关血管闭塞危象的基石。然而，关于其长期使用的大规模报道很少，某些护理人员和患者对其安全性存在担忧。在欧洲获得 HU 对患有严重 SCD 的儿童和成人的许可后，ESCORT-HU 被设计为一项 IV 期观察性队列研究。它包括 1906 名参与者，其中 55% 是成年人。最常见的血红蛋白 (Hb) 基因型是 HbSS (84.7%) 和 HbSβ+ (7.0%)。中位随访时间为 45 个月，总共观察了 7309 患者年。1 年后 HU 的剂量为儿童 20.6 mg/kg/d 和成人 16.3 mg/kg/d。与入组前一年相比，持续时间 > 48 小时的血管闭塞发作次数、急性胸部综合征发作次数、住院次数以及前 12 个月内需要输血的患者百分比均显着减少。中性粒细胞减少症和血小板减少症是最常见的不良反应。没有发现新的 HU 毒性。总体而言，101 名妇女报告了 125 次怀孕，新生儿中没有观察到畸形。接受 HU 治疗的男性患者的伴侣有 12 次怀孕。报告了 1 例致命的骨髓增生异常综合征，不能排除与 HU 的因果关系。这项针对 SCD 患者的队列研究强调了 HU 在儿童和成人中的正收益风险比。