2018年4月17日，美国食品和药品监管局批准Crysvita(burosumab)，第一被批准药物治疗成年和儿童年龄1岁和以上有x-连接的低磷血症(XLH)，a一种罕见，遗传形式的佝偻病. XLH致在血中磷的低水平。它导致被损害的骨生长和发育在儿童和青少年和患者终生至始至终骨矿物质问题。
  FDA的药品评价和研究中心中药品评价III办公室主任Julie Beitz，M.D说“XLH不同于其他形式的佝偻病在于维生素D治疗是无效，” “这是第一个 FDA-批准的药物为XLH治疗的药物和一个真正突破对那些有这种严重疾病活着的患者。”
  XLH是一种严重的疾病影响大约3,000儿童和12,000成年在美国。大多数有XLH 儿童有经受弓样弯曲或弯腿，身材矮小，骨痛和严重牙痛。有些成年XLH经受持续不适或并发症，例如关节痛，运动受损，牙脓肿和听力丧失。
  在四项临床试验中研究Crysvita的安全性和疗效。在安慰剂-对照试验，94%成年接受Crysvita一月一次实现正常磷水平，与之比较接受安慰剂为8%。在儿童中，94至100%用Crysvita每两周治疗患者实现正常磷水平。在儿童和成年两者，X-线发现伴随XLH用Crysvita治疗改善。结果与自然史队列的比较提供对Crysvita有效性的支持。
  在成年中服用Crysvita最常见不良反应为背痛，头痛，静坐不适综合证，减低维生素D，眩晕和便秘。在儿童中最常见不良反应为头痛，注射部位反应，呕吐，减低的维生素D和发热。
  Crysvita被授予突破性治疗指定，在它下FDA提供强指导对公司有效药物开发，和加速它的药物审评是意向治疗严重条件其中临床证据显示药物可能一种实质上改善超过其他可得到的治疗。  Crysvita还接受孤儿药物指定，它提供鼓励帮助和鼓励对罕见疾病药物的开发。
承办单位正在在一个程序意向鼓励新药和生物制品为预防和治疗罕见儿童疾病下接受一个罕见儿童疾病优先审评证件。一个证件可被履行在以后日期对一个不同产品的上市申请接受优先审评一个随后上市申请 优先审评。这是自程序开始FDA发出的第14个儿童疾病优先审评证件。
FDA 授权Crysvita的批准给予Ultragenyx Pharmaceutical Inc有限公司。
Crysvita(burosumab-twza)
CRYSVITA Rx
Generic Name and Formulations:
Burosumab-twza 10mg/mL, 20mg/mL, 30mg/mL; soln for SC inj; preservative-free.
Company:
Ultragenyx Pharmaceutical Inc.
Indications for CRYSVITA:
Treatment of X-linked hypophosphatemia in patients aged ≥1 year.
Adult:
Discontinue oral phosphate and active vitamin D analogs 1 week prior to treatment start. Give as SC inj (eg, upper arms, upper thighs, buttocks, abdomen quadrant); rotate sites. Round to nearest 10mg; max 1.5mL per inj site. ≥18yrs: 1mg/kg every 4 weeks; max 90mg. Assess fasting serum phosphorous every 4 weeks, measured 2 weeks post-dose, for the first 3 months, 2 weeks after a dose adjustment, then thereafter as needed. Interrupt or reduce dose based on serum phosphorous level; do not adjust sooner than every 4 weeks (see full labeling).
Children:
Discontinue oral phosphate and active vitamin D analogs 1 week prior to treatment start. Give as SC inj (eg, upper arms, upper thighs, buttocks, abdomen quadrant); rotate sites. Round to nearest 10mg; max 1.5mL per inj site. <1yr: not established. 1–<18yrs: initially 0.8mg/kg every 2 weeks; max 90mg. Assess fasting serum phosphorous every 4 weeks for the first 3 months, 4 weeks after a dose adjustment, then thereafter as needed. Adjust dose based on serum phosphorous level, but not sooner than every 4 weeks (see full labeling).
Contraindications:
Concomitant oral phosphate and active vitamin D analogs. Serum phosphorous within or above normal range for age: do not initiate. Severe renal impairment or ESRD.
Warnings/Precautions:
Prior to initiation, confirm fasting serum phosphorous concentration below reference range for age. Discontinue if serious hypersensitivity or severe inj site reactions occur. Elderly. Pregnancy. Nursing mothers.
Pharmacological Class:
Fibroblast growth factor 23 (FGF23) blocking antibody.
Adverse Reactions:
Headache, inj site reaction, vomiting, pyrexia, extremity pain, vitamin D decreased, back pain, tooth infection, restless leg syndrome, dizziness, constipation, blood phosphorous increased; hypersensitivity, hyperphosphatemia, nephrocalcinosis.
Generic Availability:
NO
How Supplied:
Single-dose vial—1
https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm604810.htm