Second US firm gets stem cell go-ahead
Washington, November 22, 2010
The US Food and Drug Administration has approved the second trial of human embryonic stem cells -- this one testing cells in people with a progressive form of blindness.
Massachusetts-based Advanced Cell Technology said it would start testing its stem cell-based treatment on 12 patients with Stargardt's macular dystrophy.
Last month Geron Corp enrolled the first patient in its study using the cells in people whose spinal cords have been crushed.
"It is exciting -- a vindication. All this work really came through," said Dr Robert Lanza, chief medical officer of the company, which has struggled to stay solvent as it gambled on the controversial cells.
Stem cells are the body's master cells, the source of all other cells. Proponents of using embryonic stem cells say the field could transform medicine, providing treatments for brain diseases like Parkinson's, juvenile diabetes or severe injuries.
But opponents object because to get the cells, someone has to take apart a human embryo.
Last year the Obama administration overturned the strictest of the limitations on using federal funds for the research, but this summer, two researchers challenged the policy.
A US appeals court has ruled that funding could continue while the government appeals, but grants from the National Institutes of Health have been frozen and unfrozen as various courts have weighed in.
Stargardt's disease causes progressive vision loss, usually starting in children or young adults 10 to 20 years old, as eye tissue called the retinal pigment epithelium, or RPE, degenerates. There is currently no treatment for Stargardt's disease.
ACT has coaxed human embryonic stem cells into becoming RPE cells, which will be infused into patients' eyes.
"We can generate a virtually unlimited supply of healthy RPE cells," Lanza said. The company uses a unique type of human embryonic stem cell, taken from embryos left over at fertility clinics. A single cell is removed when the embryo only has about eight cells -- a process sometimes used when clinics want to test the embryos of people with genetic diseases to ensure they are healthy.
In theory, the embryo can continue developing, but in this case ACT has not implanted the embryo. In the past, the company hoped this method of generating human embryonic stem cells would be less controversial than using an entire embryo.
Lanza said getting FDA approval for the trial was difficult. "They had us jumping through hoops," he said. This was in part because the powerful embryonic cells have the power to give rise to all cell types and can cause teratomas -- strange tumors containing a mix of cells.
Lanza said the company can find even a single cell that might do this and remove it from the treatment batch.
In addition, he said treating an eye disease offers the opportunity to watch the treatment. "We can look into the eye in real time and see what is going on," he said.
Research centers at the University of Oregon and University of Massachusetts will begin enrolling patients after their internal Institutional Review Boards approve the trial. "My guess is that we could start in as soon as two to three months," Lanza said. - Reuters