Clone Profit? Unlikely
Forty Nobel laureates and patient-advocacy groups have lobbied senators to allow human cloning for medical research.
Thomas Okarma, too, has met with senators to advocate cloning, but not because he sees any business potential in it. As chief executive of Geron Corp., a cell therapy company, he has no interest in using cloned embryos to produce customized treatments for disease. The odds favoring success “are vanishingly small,” he said, and the costs are daunting.
Okarma said it would take “thousands of [human] eggs on an assembly line” to produce a custom therapy for a single person. “The process is a nonstarter, commercially,” he said.
The battle over a government ban on human cloning soon will reach the Senate floor. Advocates of a limited ban argue cloning research is needed to develop tailored stem cell treatments for Parkinson’s, diabetes and other debilitating diseases.
Lost in the debate is the limited commercial promise of therapeutic cloning. Few companies believe it will produce affordable medications. The economic and regulatory hurdles are high, and the likely fallout is even more controversy.
“Where do you source that many eggs? Sourcing human eggs is a contentious issue in itself,” said Alan Robins, chief scientific officer of BresaGen Ltd., a cell therapy company in Australia and Athens, Ga. “It is not something we want to get involved in.”
Cloning involves stripping DNA from an egg cell and replacing it with genetic material from a patient’s cell, such as a skin cell. The result is an embryo with the same genetic profile as the patient.
In theory, this embryo could be implanted in a woman’s womb and become a child. But some scientists want to use cloned embryos as a source for stem cells. These stem cells could be grown into replacement tissues, such as nerve cells and heart cells. Because they would have the same genetic makeup as the patient, the cells might be accepted by the patient’s body and avoid problems with immune rejection.
But the method is controversial because it involves the creation and destruction of embryos, or what some people consider the earliest stage of human life.
Geron and BresaGen study stem cells derived from embryos donated by fertility clinics, which is also controversial. Executives at those companies are not opposed to therapeutic cloning on ethical grounds. They believe there are more-efficient ways to deal with immune rejection, which is a drawback of embryonic stem cells, valued by scientists because they can turn into any of the 300 cell types in the body.
One alternative is immunosuppressant drugs, which are now administered to organ transplant recipients. Another possibility is a two-step therapy under development at Geron that involves pre-treating patients with stem cells to build their immune tolerance. The technique would allow Geron, based in Menlo Park, to treat large numbers of patients with its cells.
Therapeutic cloning, on the other hand, is a form of individualized medicine.
“We don’t think it makes sense as a business model, producing cell therapies for a patient population of one,” BresaGen’s Robins said of therapeutic cloning. “But we don’t support a ban on it.”
Biotechnology Industry Organization, a trade group that represents the industry, favors a partial cloning ban. The group supports a bill by Sens. Dianne Feinstein (D-Calif.) and Edward M. Kennedy (D-Mass.) that would permit human cloning to develop new medicines but would outlaw reproductive cloning to produce children.
The bill competes with one sponsored by Sens. Sam Brownback (R-Kan.) and Mary Landrieu (D-La.) that would ban cloning for any purpose. The House has passed a similar anti-cloning measure.
Carl B. Feldman, president of the trade group, said in a statement last week that therapeutic cloning was “key to ... responsible development” of embryonic stem cell research. He said human cloning could spur development of treatments for Alzheimer’s, spinal cord injuries and other degenerative diseases.
The trade group represents academic institutions as well as about 1,000 biotechnology companies.
The cloning furor picked up steam in November, when Advanced Cell Technology Inc. claimed to have cloned seven embryos from donated eggs. All died and none grew beyond six cells--too small to produce stem cells.
The Worcester, Mass., company advocates therapeutic cloning, which is a critical part of its strategy for entering the pharmaceutical business. Most of its operating revenue comes from cloning farm animals. Advanced Cell’s Web site urges visitors to lobby President Bush, his Cabinet and members of Congress.
Robert Lanza, vice president for medical and scientific research at Advanced Cell, acknowledged that cloning is in the “experimental stage.”
But he predicted that it would produce affordable therapies, at least when compared with organ transplants. A heart transplant, for example, costs upward of $100,000.
Lanza said the company would not be in the business of procuring eggs. Rather, he said, an egg cell would be donated by a relative of the patient--the mother of a diabetic child, for example. The egg would be stripped of its genetic material and merged with DNA extracted from one of the child’s cells. Stem cells from the resulting embryo would then be transformed into insulin-producing islet cells, he said.
Advanced Cell is not close to offering such a treatment. But Lanza said such therapies, now theoretical, could cost $10,000 or less, becoming profitable to the company and sparing patients “a lifetime of going blind and kidney failure.”
However, Advanced Cell would have to spend millions of dollars to develop its cloning technology to the point at which it can be marketed, competitors said. Geron’s Okarma said that with today’s technology, it takes “100 eggs if you’re lucky” to produce an embryo large enough from which to extract stem cells.
Okarma said the process of extracting stem cells also is inefficient. One “very prominent researcher” in Britain went through 1,000 embryos before obtaining useful cells, he said. (The embryos were donated by fertility clinics.)
Any resulting stem cell therapy can’t be compared with an organ transplant in terms of price or effectiveness, said BresaGen’s Robins. Cells would be placed in the body to generate repair tissue, such as patching damaged heart muscle, he said.
“We are not talking about growing new hearts here,” Robins said. “We are using cells for repair, and I don’t think they will be able to repair all damaged hearts, and therefore it is not an alternative to an organ.”
Robins said cell therapies would be useful in “a small fraction of organ failures.”
Quality control presents another hurdle, said Lutz Giebel, CEO of CyThera, a cell therapy company in San Diego. The Food and Drug Administration is set up to sample drugs produced in large commercial lots, not individual cell therapies, he said.
“It is not commercially viable,” Giebel said. “Quality control is difficult; the FDA can’t regulate it, [and] no one can afford the treatment.”
Giebel called therapeutic cloning a “research tool only.” A complete ban on human cloning would have “a limited impact on corporate product development,” he said.
Cloning might make sense as a tool for developing ethnically diverse stem cell lines, Robins said. Because most cell lines were derived from embryos donated by fertility clinics, the cells have the genetic characteristics of white middle-class Americans--the typical clinic client, said Robins.
Through cloning, Robins said, companies could create additional stem cell lines that reflect a more diverse population. It would then be possible to “match” cells to patients based on genetics--just as donated organs and bone marrows are matched to patients. The process would reduce problems with immune rejection.
But such an undertaking would require many egg cells and probably would reopen further controversy.
“We’ve done some theoretical calculations,” Robins said. To provide matches for the world’s population, he said, “it would take 500 to 600 cell lines.” That is 10 times the number of existing cell lines approved for government research.
