In the wake of a California-based research company's decision to drop the world's first clinical trial using human embryonic stem cells, many investigators who once held to the promise of stem cell research now wonder whether the field of embryonic stem cell research has been abandoned in the U.S. completely.
The company, Geron, which pioneered the field of embryonic stem cell research, announced its decision Monday to drop its study on stem cells for spinal cord injury.
Geron cited costs as the primary reason, saying the payoff of stem cell research wouldn't come close to other more lucrative projects. The company would be better off allocating financial resources to research for cancer therapies that are near completion in development, company representatives said.
While Geron says it hasn't given up on the promise of stem cell research, many experts say the announcement signals a symbolic end to the era of embryonic stem cell research that many researchers worked so hard to launch.
Many experts say they're not convinced that financial limits are only to blame.
"This company would not walk away from this trial in the absence of an unexpected complication or safety concern, if there was any evidence that it was working," said Dr. Daniel Salomon, associate professor in the department of molecular and experimental medicine at the Scripps Research Institute in San Diego. "The assumption has to be that they designed a study with a purposeful plan to complete it to a certain benchmark of efficacy and that they had the funds for that effort in hand."
In 2009, the Obama administration lifted former president George W. Bush's restrictions on funding for stem cell research, which expanded the financial limits of the field.
Geron's trial on therapies for spinal cord injury became the first embryonic stem cell based research approved in the U.S.
"Without seeing the data, one cannot be certain that there was not a clinical reason for stopping the trial," said Dr. Robertson Parkman, professor of pediatrics at the University of Southern California.
Embryonic stem cells are considered so-called blank slates capable of transforming into any of the more than 200 distinct types of cells in the human body. Despite debates by pro-life members, embryonic cells have been considered by many scientists to hold the key to many therapies.
Sixty-two percent of Americans are in favor of conducting research that uses embryonic stem cells, according to a review of eight recent survey findings published Wednesday in the New England Journal of Medicine.
Fifty-five percent of Americans believe the federal government should fund the research, according to the findings, which was supported by the Robert Wood Johnson Foundation.
More Democrats than Republicans support the research, suggesting that the outcome of the 2012 election could affect future federal funding.
Many experts said the overhyped image of embryonic cells as the sword in the stone of scientific research has caused many to feel disillusioned.
"[Embryonic stem cells] are not ready for 'prime-time,'" said Dr. Bryon Petersen, professor in the Institute for Regenerative Medicine at Wake Forest Baptist Medical Center. "There are too many variables about these cells that we just don't know about."
In many ways, these expectations have damaged the true potential of embryonic stem cell research, he said.
"Embryonic stem cell research as a scientific endeavor is absolutely legitimate, and its contributions to our understanding of development and tissue specificity cannot be dismissed as hype now," said Salomon. "It certainly is not an indictment of a whole scientific field just because Geron failed in their first trial."
Perhaps Geron's quest to find therapies for spinal cord injuries was too ambitious for the first U.S. embryonic stem cell trial, Petersen said. He called the endeavor "like trying to run when we can't even walk."
"A lot of basic science needs to be completed before we go running off to the clinics with stem cells," said Petersen.
Although Geron has called it quits, more than a dozen other companies are holding on to their work with embryonic stem cells.
"Those that want to continue to move the field forward will want to know what Geron learned and what might be avoided to enhance the potential of success in the next trial," said Salomon.