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【bio-news】拭目以待：FDA即将审核胚胎干细胞安全
FDA即将审核胚胎干细胞安全
US agency holds first public hearings to assess therapies.
美国举行第一次公众听证会对干细胞治疗的安全性进行评估
Investors, biotech companies and other stem-cell stakeholders are meeting in Gaithersburg, Maryland, this week for the US Food and Drug Administration’s (FDA’s) first public hearing on the safety of therapies that use human embryonic stem cells.
这周，投资人，生物工程公司，和其他干细胞的利益相关人士，聚集在马里兰州的盖士堡，为美国FDA第一次对人类胚胎干细胞治疗的安全性问题举行公众听证会.
The meeting is “a big deal”, says Michael Werner, former chief of policy at the Biotechnology Industry Organization in Washington DC. “It could provide clues about what the FDA is thinking in terms of product approvals.”
这个会议是个“大买卖”，华盛顿特区，前生物工程技术组织主管Michael Werne说，“能提示FDA在产品批准方面的引导方向。”
Stem cells derived from human fetal and adult tissues are already being used in clinical trials. But researchers want to use embryonic stem (ES) cells because they show greater capacity to proliferate and differentiate into other cell types. Cells derived from human ES cells have shown dramatic results in treating animal models of disease, but they have not yet been tested in patients, and there are fears that they may carry health risks.
干细胞可来源于人类胎儿或成人组织，已经进入临床试验。但是科学家希望使用胚胎干细胞因为它们具有更大的自我更新能力，和分化成其他细胞的能力。胚胎干细胞在动物的疾病模型上取得了极大的成功。但因为担心对健康造成风险，至今在病人身上还末进行过试验。
Geron, a biotech company based in Menlo Park, California, plans to start a trial in patients with acute spinal-cord injury this summer using oligodendroglial progenitor cells derived from ES cells. Two other California-based biotech companies, Novocell in San Diego and Advanced Cell Technology in Los Angeles, are also preparing to start human trials using ES-cell-derived products to treat (respectively) diabetes and visual impairment caused by macular degeneration.
Geron是一家加利福尼亚州Menlo Park 生物工程公司，计划今年夏天用胚胎干细胞来源的胶质细胞治疗急性脊髓损伤试验。另外两个在加利福尼亚州的生物工程公司，和圣地亚哥州Novocell洛杉矶的高级细胞技术公司（Advanced Cell Technology）也准备进行人体实验分别治疗糖尿病和黄斑点退化引起的视觉损害。
The FDA seems to be most concerned about the cells’ potential to cause tumours or to differentiate in dangerous ways, and whether the animal safety tests that have been carried out so far provide enough evidence to justify testing ES cells in people, according to FDA briefing documents seen by Nature. Another issue concerns how patients should be monitored for signs of problems. Members of the advisory committee have been asked not to speak to the press before the meeting.
根据在《自然》的简短文件表明，FDA对细胞的致瘤性或分化异常非常关注，是否动物试验安全性能为人体试验提供足够的依据。另外一个关心问题是患者应该怎样被监测可能出现问题的迹象。学术委员会的成员们被要求在会议前不在媒体前发表评论。
The FDA has been looking at these issues for a number of years, according to Michael West, head of BioTime, a biotech in Emeryville, California, and a former executive of Geron and Advanced Cell Technology. “The first time I met with them was in 2001 and they had given it a lot of thought back then,” he says.
Michael West,是位于加利福尼亚州，Emeryville ，BioTim公司的领导，前Geron t和 Advanced Cell Technology执行主管。根据Michael West，FDA关注这个问题有数年了，他说：“我第一次碰到他们是2001年，他们提供了很多支持干细胞的建议。”
Human trials will not administer actual ES cells, but cells derived from them, and one of the biggest issues is how to assess the final cell product. One question is how many partially differentiated or undifferentiated cells, if any, are acceptable, and whether undesirable cells can be reliably detected. “You might have cells destined for the spinal cord mixed in with precursor cells destined to make a wisdom tooth,” West says. “What happens when you put those cells into the spinal cord?” West says he’s not against clinical trials, but he points out that the FDA has a very difficult balance to strike.
人类试验不会应用真正的胚胎干细胞，但会应用从它们来源的细胞，最大的问题是如何评估最后的细胞分化结果。一个问题是多少部分分化或未分化细胞是可以接受的，是否不向目的方向分化的细胞可以可靠的检测到。因为有可能向脊髓定向分化细胞的细胞混合可分化为智齿的祖细胞，而我们不知道如果你把这些细胞同时导入脊髓里面会发生什么事情？ West说，他不反对临床试验，但也指出FDA很难作出平衡。
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作者:admin@医学,生命科学 2011-02-14 18:21
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