http://www.forbes.com/2001/11/26/1126cloning.html
11.26.01, 10:19 AM ET
NEW YORK - The scientists who announced
yesterday that they had cloned a human embryo--a first--want to eventually
use cloning as a therapy for diseases like AIDS and Parkinson's. But one
thing evident from their research: Such therapeutic cloning could be a
very expensive treatment, more costly than even the priciest drugs.
These researchers, working at privately
held Advanced Cell Technology (ACT) in Worcester, Mass., have no intention
of creating cloned babies. Instead, they want to use somatic cell nuclear
transfer, the same process used to clone Dolly the sheep in 1997, to create
embryonic stem cells. The cloned cells would be genetically identical to
the patient's own, so they could replace part of an ailing brain or heart
without touching off a full-scale attack from the patient's immune system.
At least, that's the theory. But
creating a cloned embryo requires human egg cells, and egg cells aren't
cheap. In vitro fertilization clinics will generally pay an egg donor $3,000
to $5,000, and Advanced Cell Technology took 71 eggs from seven women.
Each of these women had to be treated
with drugs, first to stop their ovary production, then to kickstart it
into overdrive so that she could provide the scientists with about ten
eggs each. Removing the eggs requires a serious medical procedure that
can scar.
The process looks at least as inefficient
as cloning in animals. Nineteen eggs underwent nuclear transfer. Their
genetic material was removed and replaced with similar material from a
donor. They then began to divide into embryos, but none grew past the six-cell
stage. Stem cells are taken from embryos with more than 100 cells.
Researchers working with animals
don't have to worry about getting enough eggs. Cow eggs, for instance,
can be bought cheaply from slaughterhouses that would otherwise discard
them. For a recent paper on cloning in Science, Peter Mombaerts, a scientist
at Rockefeller University in New York City who clones mice, ran through
4,000 mouse oocytes--he estimates that might be $2,000 worth of mice. Doing
the same work in humans, he estimates, could cost $2 million.
Scientists will almost certainly
use fewer eggs if therapeutic cloning is used on people. But even if it
required a mere 100 eggs, taken from ten donors, the cost of simply paying
the donors could easily reach $50,000. On top of that, there would be medical
costs involved in procuring the egg. Mombaerts believes it could cost more
than $1,000 per egg when all is said and done. That means costs to treat
one patient could conceivably soar above $100,000.
That would make eggs the limiting
factor in using nuclear transfer to treat human diseases. Such high costs
are not unheard of in biotechnology--for instance, treating a patient for
a year with a rare joint disorder called Gaucher's disease with Genzyme's
(nasdaq: GENZ - news - people) Cerezyme can cost $170,000.
ACT Chief Executive Michael West
has in the past expressed a belief that if the cure works, it will be paid
for. But West was once worried enough about the problem that ACT tried
to create human stem cells using cow eggs. Geron (nadsaq: GERN - news -
people), the stem-cell company he founded before moving to ACT, has often
talked of nuclear transfer as a way of figuring out how to make stem cells.
Geron's current CEO, Thomas Okarma, believes the first uses of embryonic
stem cells as a therapy will have to make use of powerful drugs that suppress
the immune system.
Another limiting factor on cloning:
expertise. Mombaerts calls his former colleague Teru Wakayama, who is now
at ACT, "the Tiger Woods of the micropipette." The inference is that, like
golf, cloning mouse cells is a skill that involves exactly how the requisite
tool is held and used--an art as much as a science. "That's one reason
scientists think it will be a decade or two before this technology reaches
the clinic."
Nonetheless, ACT's paper, published
yesterday in the Journal of Reproductive Medicine, provides a guidebook
to groups that want to clone human embryos to make babies. The steps at
the beginning are the same. That is likely to spook lawmakers who already
voted in the House of Representatives to make all human cloning, including
the therapeutic kind, illegal. If the Senate passes a similar bill, President
George W. Bush will surely sign it.
Whatever the lawmakers decide, though,
this work will almost certainly continue--if not on U.S. soil, then elsewhere.
"They've bitten the bullet now," Mombaerts says. "We can't go back."
© 2001 Forbes.com
Matthew Herper, Forbes.com