Gene Therapy for Rare Form of Blindness Approved in US
American health officials recently approved the first gene therapy treatment for an inherited disease – the type that can pass from parent to child.
The treatment improves the sight of patients suffering from a genetic mutation that destroys their ability to see. It is the first gene therapy approved where a corrective gene is given directly to patients.
People with the disease usually start losing their sight before they are 18. This often progresses to total blindness. The gene that causes the disease could suddenly appear when a child is born with a copy of the gene from both parents.
Only a few thousand people in the U.S. are thought to have the condition.
Patients receive the therapy, called Luxturna, through two injections, one for each eye. These replace the problem gene that prevents the retina, a tissue at the back of the eye, from changing light into electronic signals sent to the brain.
Mistie Lovelace received one of the early treatments. She said, "One of the best things I've ever seen since surgery are the stars. I never knew that they were little dots that twinkled."
Drugmaker Spark Therapeutics has not set the price for the treatment. Its own research, however, has put the value of the therapy at around $1 million.
The company says the reason for the high price is due to their prediction that Luxturna will be given only once, with lasting positive effects. To date, the company has researched patients in a study for as long as four years and has not seen their vision worsen.
The Food and Drug Administration has approved three gene therapies since August. The two other treatments are specially designed treatments for forms of blood cancer.
New success for difficult field
The approval marks an important growth for a field of study that has struggled with safety concerns.
In 1999, a patient treated for a rare metabolic disorder at the University of Pennsylvania died. In another case, patients treated for an immune disorder later developed leukemia.
Dr. David Valle said the excitement about the possibilities for genetic medicine create opportunities for research on individual diseases.
University of Pennsylvania researcher Dr. Jean Bennett said she and her husband, Dr. Albert Maguire, first imagined using genetic medicine to treat retinal blindness in the mid-1980s.
But it took many years to develop the science and technology. The first animal tests happened in 2000 and the first human tests in 2007.
"We didn't know what genes caused the disease, we didn't have animal models with those genes, we didn't have the ability to clone genes and deliver them to the retina — so it took time to develop all that," said Bennett.
I'm Phil Dierking.
1.gene therapy 基因疗法
It is far too early to make sweeping statements about gene therapy.
2.inherited disease 遗传性疾病
If the parent of a child has a inherited disease, the child would have the same disease.
3.born with 与生俱来
He was born with only one lung.
4.blood cancer 白血病
Multiple myeloma is a blood cancer that typically strikes much later in life.
5.To date, the company has researched patients in a study for as long as four years and has not seen their vision worsen.
To date 迄今为止
To date there is no evidence to support this theory.
Police have stressed that this is the most accurate description of the killer to date.
6.The approval marks an important growth for a field of study that has struggled with safety concerns.
struggled with 与...抗争
There were signs that she struggled with her attacker.
The cab driver struggled with her luggage, scraping a bag against the door as they came in.
该疗法可改善患者因基因突变导致的眼疾 。这是首个获得批准将修正基因直接赋予病人的基因疗法 。
这种疾病的患者通常在18岁之前会丧失视力，这往往会导致彻底失明 。当新生儿遗传了父母双方的基因时，这种致病基因可能会突然出现 。
患者接受Luxturna疗法时会进行两次注射，每只眼睛各注射一次 。这些基因会代替干扰视网膜的致病基因，视网膜是眼睛内部的一种组织，能够将光线转化为电子信号发送给大脑 。
米斯提·洛夫雷斯（Mistie Lovelace）接受了这种早期治疗 。她说：“术后我看到的最美好的事物就是星星 。我从来不知道星星原来是会闪烁的小点 。”
该药物的制造商Drugmaker尚未确定基因疗法的价格 。不过，该公司的研究所将这以疗法的价格设定在100万美元左右 。
该公司表示，考虑到Luxturna疗法可一次性带来持久的积极疗效，因此定下高昂的费用 。迄今为止，该公司对病人进行了长达4年的研究，病人的视力未出现恶化 。
自8月份以来，美国食品和药品管理局批准了三种基因疗法 。另外的两种疗法是针对白血病的基因疗法 。
1999年，一名在宾夕法尼亚大学接受罕见代谢紊乱疾病治疗的患者去世 。在另一起案例中，一位接受免疫疾病治疗的患者之后患上了白血病 。
戴维·瓦勒博士(Dr. David Valle)表示，遗传医学的可贵之处在于这种可能性为研究个体疾病创造了机会 。
宾夕法尼亚大学研究员吉恩·班纳特博士（Dr. Jean Bennett）表示，在上世纪80年代中期，她和丈夫艾伯特·马奎尔博士（Dr. Albert Maguire）最先设想到利用遗传医学治疗视网膜疾病引发的失明 。
但是研发这一科学技术耗时多年 。2000年进行了首次动物试验，2007年进行了首次人体试验 。