FDA 批准每周注射 Klygefa 治疗全身型重症肌无力：260人试验第26周日常生活评分改善差1.6分，带脑膜炎球菌感染黑框警告
美国食品和药物管理局（FDA）于11月13日批准 Alexion Pharmaceuticals 的 Klygefa（gefurulimab-gaks）上市，用于抗乙酰胆碱受体抗体阳性的全身型重症肌无力成人患者。该药为每周一次的皮下注射，经培训后可由患者自行注射或由照护者注射，先给予负荷剂量，之后按体重每周给药。
FDA 说明书记载的26周试验共纳入260名成人，131人使用 Klygefa，129人使用安慰剂，患者可继续以稳定剂量使用原有重症肌无力药物。主要指标为疾病对日常生活干扰程度的评分，满分24分，分数越高表示困难越大。第26周时，Klygefa 组评分经调整平均改善4.2分，安慰剂组改善2.6分，两组相差1.6分，差异具有统计学意义；一项肌肉无力指标的改善幅度也大于安慰剂组。
Klygefa 通过阻断免疫系统的补体 C5 发挥作用，其标签带有严重甚至危及生命的脑膜炎球菌感染黑框警告，接种疫苗后风险仍然升高。标签要求治疗前接种脑膜炎球菌疫苗，一般至少在首剂前两周完成，并对必须紧急开始治疗的情况作出规定。该药只能通过受限安全计划提供，处方者须登记加入。安慰剂对照研究中最常见的不良反应是注射部位反应，Klygefa 组发生率为12%，安慰剂组为3%。标签同时说明，该药在儿童中的安全性和有效性尚未确立。
FDA Approves Weekly Klygefa Injection for Generalized Myasthenia Gravis: 260-Person Trial Shows 1.6-Point Advantage on Daily-Living Scores at Week 26, With Boxed Warning for Meningococcal Infection
The U.S. Food and Drug Administration approved Alexion Pharmaceuticals' Klygefa (gefurulimab-gaks) on November 13 for adults with generalized myasthenia gravis who test positive for anti-acetylcholine receptor antibodies. The medicine is a once-weekly injection under the skin that patients can give themselves, or a caregiver can give, after training, following an initial loading dose, with the weekly amount based on body weight.
The FDA prescribing information describes a 26-week trial of 260 adults, with 131 people assigned to Klygefa and 129 to placebo, while patients could continue their existing myasthenia gravis medicines at stable doses. The main measure was a score of how much the disease interfered with daily activities, running from zero to 24, with higher numbers meaning greater difficulty. At 26 weeks, scores had improved by an adjusted average of 4.2 points with Klygefa and 2.6 points with placebo, a statistically significant difference of 1.6 points. A separate measure of muscle weakness also improved more with Klygefa than with placebo.
Klygefa blocks complement C5, part of the immune system. Its label carries a boxed warning for serious and life-threatening meningococcal infections, and patients remain at increased risk even after vaccination. The label calls for meningococcal vaccination before treatment, generally at least two weeks before the first dose, and sets out precautions when treatment must begin urgently. The drug is available only through a restricted safety program, and prescribers must enroll. Injection-site reactions were the most common adverse reactions in the placebo-controlled study, occurring in 12 percent of Klygefa patients compared with 3 percent on placebo. The label says safety and effectiveness in children have not been established.
来源：美国食品和药物管理局
发布：GSM·美国（发布链接）
图片来源：图：Alexion Pharmaceuticals 总部大楼，Klygefa 由该公司研发。来源：ajay_suresh，Wikimedia Commons，CC BY 2.0。 / Photo: The Alexion Pharmaceuticals headquarters building; Klygefa was developed by the company. Source: ajay_suresh, Wikimedia Commons, CC BY 2.0.
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