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11/10/2017

There’s gene therapy and there’s gene therapy

I’ve seen a number of different things described in the general press as “gene therapy.” But they are indeed different.  It’s important to be specific.

For one, there’s the situation where a set of mature human cells are obtained from the person to be treated and genetically altered outside the body to make them into a potentially useful treatment, then re-administered (by vein) to the patient.  Such is the case with so-called “CAR-T” therapy, which is well handled by current regulatory structures.  Main ethical issues: common human subject research concerns, regulation of the quality of the cells, and whether the treatment, which can be dramatically effective, is worth the high price.

Then there are situations where a diseased tissue is altered to make it normal, like the recent report of how a mutation in the skin of a boy was altered, and the repaired skin grafted back on, to spread over most of his body and replace the defective skin.  Again, way cool, well dealt with by current ethical and regulatory structures.

Or, similarly, Spark Therapeutics’ LUXTERNA, which is a gene injected into the eye to repair a defective gene causing blindness, literally restoring some sight, recently recommended for approval by an advisory committee to FDA.   Truly a gene made into a therapy.

Where the ethical issues get thorny is when one speaks of possibly editing a gene in a person–likely an unborn person very early in development; i.e., and embryo–in a way that can be inherited over generations.  I and others have discussed this recently on this blog.  See for example my post of last month (October 5).  Adherents say that there are serious diseases demanding cures, and that those who would counsel caution are obstructionists who fret too much about enhanced Olympic athletes.  (Example here, but subscription required.)  But the ethical issues are several: How safe and reliable will the technique be, and how much testing should be required before trying to birth “edited” babies?  How many embryos will have to be destroyed to perfect the approach?  How can we know whether there will be unforeseen long-term effects, after several generations?  How much should we care about that?  How will discrimination be avoided?  What are the implications for control of human reproduction–no more babies from sex? And who will decide and control that?

And–where, short of the Olympics, will it all end?  Should we try to edit genes that are known to increase cancer risk, to eliminate them from the human race?

The Hastings Center recently convened journalists to discuss some of the ethical issues with gene editing.  But even then, they are more concerned about whether there is a parental duty to “edit” the next generation.  Precautionary deliberations appeared to be limited to environmental concerns from the use of “gene drive” to spread genetic modifications rapidly through entire plant or animal species.  (Fair enough, but I’d extend the precautions to humans, where “gene drive” is not an issue.)  And, helpfully, the Hastings symposium did ask, will general press coverage necessarily be biased because reporters’ sources are the very scientists who tend to be enthusiasts?  In any event, the Center should not only do more public education events, but should make much more of the detailed content from such symposia available to the public for free, online, much as the Presidential bioethics commissions do.  As it is, we are left with their brief press releases, usually.  Thin gruel, IMHO.

This entry was posted in Genetics, Health Care and tagged , , , , . Posted by Jon Holmlund. Bookmark the permalink.

11/10/2017

There’s gene therapy and there’s gene therapy

I’ve seen a number of different things described in the general press as “gene therapy.” But they are indeed different.  It’s important to be specific.

For one, there’s the situation where a set of mature human cells are obtained from the person to be treated and genetically altered outside the body to make them into a potentially useful treatment, then re-administered (by vein) to the patient.  Such is the case with so-called “CAR-T” therapy, which is well handled by current regulatory structures.  Main ethical issues: common human subject research concerns, regulation of the quality of the cells, and whether the treatment, which can be dramatically effective, is worth the high price.

Then there are situations where a diseased tissue is altered to make it normal, like the recent report of how a mutation in the skin of a boy was altered, and the repaired skin grafted back on, to spread over most of his body and replace the defective skin.  Again, way cool, well dealt with by current ethical and regulatory structures.

Or, similarly, Spark Therapeutics’ LUXTERNA, which is a gene injected into the eye to repair a defective gene causing blindness, literally restoring some sight, recently recommended for approval by an advisory committee to FDA.   Truly a gene made into a therapy.

Where the ethical issues get thorny is when one speaks of possibly editing a gene in a person–likely an unborn person very early in development; i.e., and embryo–in a way that can be inherited over generations.  I and others have discussed this recently on this blog.  See for example my post of last month (October 5).  Adherents say that there are serious diseases demanding cures, and that those who would counsel caution are obstructionists who fret too much about enhanced Olympic athletes.  (Example here, but subscription required.)  But the ethical issues are several: How safe and reliable will the technique be, and how much testing should be required before trying to birth “edited” babies?  How many embryos will have to be destroyed to perfect the approach?  How can we know whether there will be unforeseen long-term effects, after several generations?  How much should we care about that?  How will discrimination be avoided?  What are the implications for control of human reproduction–no more babies from sex? And who will decide and control that?

And–where, short of the Olympics, will it all end?  Should we try to edit genes that are known to increase cancer risk, to eliminate them from the human race?

The Hastings Center recently convened journalists to discuss some of the ethical issues with gene editing.  But even then, they are more concerned about whether there is a parental duty to “edit” the next generation.  Precautionary deliberations appeared to be limited to environmental concerns from the use of “gene drive” to spread genetic modifications rapidly through entire plant or animal species.  (Fair enough, but I’d extend the precautions to humans, where “gene drive” is not an issue.)  And, helpfully, the Hastings symposium did ask, will general press coverage necessarily be biased because reporters’ sources are the very scientists who tend to be enthusiasts?  In any event, the Center should not only do more public education events, but should make much more of the detailed content from such symposia available to the public for free, online, much as the Presidential bioethics commissions do.  As it is, we are left with their brief press releases, usually.  Thin gruel, IMHO.

This entry was posted in Genetics, Health Care and tagged , , , , . Posted by Jon Holmlund. Bookmark the permalink.

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