LOS ANGELES: 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 for 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 favouring 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, a cell-therapy company in Australia and Athens, Georgia. “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.

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.—Dawn/LAT-WP News Service (c) Los Angeles Times.