US Approves Two Treatments for Sickle Cell Disease

US Approves Two Treatments for Sickle Cell Disease

美国批准两种镰状细胞病治疗方法

【原文听力】

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　　By Hai Do

　　11 December 2023

　　United States health officials last week approved two gene treatments for sickle cell disease. Doctors hope that the treatments will provide a cure for the painful genetic blood disorder.

　　The U.S. Food and Drug Administration (FDA) said the one-time treatments can be used for patients 12 and older with severe forms of the disease.

　　One treatment is made by Vertex Pharmaceuticals and CRISPR Therapeutics. The other is made by Bluebird Bio.

　　"Sickle cell disease is a... life-threatening blood disorder with significant unmet need," the FDA's Dr. Nicole Verdun said in a statement announcing the approvals. "We are excited to advance the field especially for individuals whose lives have been severely disrupted by the disease."

　　Sickle cell disease (or SCD) affects millions of people worldwide. The disease is common in places with high cases of malaria, like Africa and India. Scientists believe being a carrier of SCD helps protect against severe malaria.

　　It is more common among Black Americans, Africans, and Middle Easterners than other population groups. The World Health Organization said many children with the most severe form of the disease die before the age of five, usually from an infection or severe blood loss.

　　The new treatments

　　A genetic change, or mutation, causes blood cells to become defective in people with sickle cell disease. The unhealthy blood cells result in blockages, called blood clots. The clots cause pain and damage to bones and organs in the human body.

　　The Vertex treatment is called Casgevy. Its goal is to help the body go back to producing healthy blood cells that are present at birth. It uses CRISPR, the gene editing tool, to knock out a gene in stem cells collected from the patient.

　　Bluebird's treatment, called Lyfgenia, aims to add copies of a modified gene. The modified gene helps red blood cells to produce a protein that prevents or reverses unhealthy cells.

　　The two gene treatments are the first approved in the U.S. for sickle cell disease. Vertex is already approved in Britain and Bahrain.

　　The new treatments are costly. The cost for Bluebird Bio is $3.1 million and for Vertex, $2.2 million. To help cover the cost, the U.S. Centers for Medicare and Medicaid says it plans to create partnerships with state Medicaid agencies and drug companies.

　　Even with the high cost, many patients say they would consider the gene treatment because of the seriousness of the disease.

　　Jalen Matthews of Louisville, Kentucky, was diagnosed with sickle cell at birth. She had her first pain episode at age 9. Three years later, the disease led to a spinal cord stroke that left her with some paralysis in her left arm and leg.

　　"I had to learn how to walk again, feed myself, clothe myself, basically learn how to do everything all over again," said Matthews, who is now 26.

　　Today, she deals with the disease by having blood transfusions. About every two months, the treatment replaces five units of her blood with healthy cells. She said she plans to ask her doctor about the new treatments.

　　"This one-time kind of cure is very much needed," Matthews said.

　　Studies testing the treatments suggest they work well. Of 31 people treated in the Vertex study with enough follow-up, 29 were free of pain episodes for at least a year. In the Bluebird study, 28 of 32 patients had no severe pain or organ damage between six and 18 months after the treatment.

　　But doctors note there are possible side effects. They also say the long-term results are unknown. For both treatments, the required chemotherapy comes with risks such as infertility, hair loss and serious infections.

　　With the Bluebird treatment, blood cancer has happened. The FDA said it will include a "black box warning" about that risk.

　　With the Vertex therapy, some scientists worry that CRISPR brings the possibility of "off-target effects." These are unexpected changes to a person's genome.

　　I'm Anna Matteo.

　　Hai Do adapted this story for Learning English with reporting from The Associated Press and other sources.

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　　作者：Hai Do

　　2023年12月11日

　　美国卫生官员上周批准了两种针对镰状细胞病的基因治疗。医生们希望这些治疗方法能为这种痛苦的遗传性血液疾病提供治愈。

　　美国食品和药物管理局（FDA）表示，这些一次性治疗可以用于12岁及以上患有该病严重形式的患者。

　　其中一种治疗由Vertex Pharmaceuticals和CRISPR Therapeutics制造。另一种由Bluebird Bio制造。

　　"镰状细胞病是一种...威胁生命的血液疾病，目前还有许多未得到满足的需求，"美国食品和药物管理局（FDA）的Nicole Verdun博士在宣布批准新治疗方法的声明中说。"我们很高兴能推动这个领域的发展，特别是对那些生活被这种疾病严重打乱的人来说。"

　　镰状细胞病（或称SCD）影响着全球数百万人。这种疾病在疟疾病例高的地方，如非洲和印度，较为常见。科学家们认为，成为SCD的携带者有助于抵抗严重的疟疾。

　　在黑人美国人、非洲人和中东人中，这种疾病比其他人群更为常见。世界卫生组织表示，许多患有最严重形式疾病的儿童在五岁前死亡，通常是由于感染或严重的失血。

　　这些新的治疗方法...

　　镰状细胞病患者的血细胞会因为基因变异而变得有缺陷。这些不健康的血细胞会导致血液凝结，形成血栓。血栓会引发疼痛，并对人体的骨骼和器官造成损害。

　　Vertex的治疗方法被称为Casgevy。其目标是帮助身体恢复到出生时的健康血细胞生产状态。它使用基因编辑工具CRISPR，来关闭患者干细胞中的一个基因。

　　Bluebird的治疗方法被称为Lyfgenia，旨在增加修改过的基因的副本。这个修改过的基因帮助红细胞生产一种可以防止或逆转不健康细胞的蛋白质。

　　这两种基因治疗是美国首次批准用于治疗镰状细胞病的。Vertex已经在英国和巴林获得批准。

　　这些新的治疗方法费用高昂。Bluebird Bio的费用为310万美元，Vertex的费用为220万美元。为了帮助支付费用，美国医疗保险和医疗补助中心计划与各州的医疗补助机构和药品公司建立合作关系。

　　尽管费用高昂，但由于疾病的严重性，许多患者表示他们会考虑接受基因治疗。

　　肯塔基州路易斯维尔的Jalen Matthews在出生时就被诊断出患有镰状细胞病。她在9岁时首次出现疼痛症状。三年后，这种疾病导致了脊髓中风，使她的左臂和左腿部分瘫痪。

　　"我不得不重新学习走路，自己吃饭，自己穿衣，基本上是重新学习所有的事情，"现年26岁的Matthews说。

　　如今，她通过输血来应对这种疾病。大约每两个月，她会接受一次治疗，用健康的细胞替换掉五个单位的血液。她说她打算向医生询问这些新的治疗方法。

　　"这种一次性的治愈方式非常必要，"Matthews说。

　　测试这些治疗方法的研究表明，它们的效果很好。在Vertex的研究中，有足够随访的31名患者中，有29人在至少一年的时间里没有疼痛发作。在Bluebird的研究中，32名患者中有28名在治疗后的六到十八个月内没有严重的疼痛或器官损伤。

　　但医生们指出，可能会有副作用。他们还表示，长期结果尚不明确。对于这两种治疗方法，所需的化疗都有可能带来不孕、脱发和严重感染等风险。

　　在Bluebird的治疗中，有发生血液癌的情况。FDA表示，它将对此风险进行"黑框警告"。

　　在Vertex的治疗中，一些科学家担心CRISPR可能带来"非目标效应"。这些是对人的基因组的意外改变。

　　我是Anna Matteo。

　　Hai Do根据美联社和其他来源的报道，为英语学习者改编了这个故事。

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　　本故事中的词汇

　　advance - v. 向前移动

　　knock out - 短语动词，使某物停止工作

　　reverse - v. 返回到早期状态

　　episode - n. 疾病的短暂时间

　　paralysis - n.无法移动的状态

　　blood transfusion - n. 将某人的血液输入另一个人体内的医疗治疗