Embryonic stem cells used on patient for first time
For the first time, surgeons have injected a spinal cord injury patient with human embryonic stem cells in a federally approved experiment, a biomedical firm said Monday.
Food and Drug Administration officials approved the start of the privately funded safety trial in July, allowing a long-awaited test of the cells, which were grown from a single embryo to resemble forerunners to spinal cells. The unnamed patient received the cells at the Shepherd Center, an Atlanta hospital specializing in brain, spine and related ailments.
Human embryonic stem cells are precursors to all human tissues. Researchers first grew them from embryos in 1998. Medical researchers have since looked to the cells to study organ development, test drugs and, now in the clinical trial, grow rejection-free replacement organs.
“Many predicted that it would be a number of decades before a cell therapy would be approved for human clinical trials,” according to a statement by Thomas Okarma of the experiment’s sponsor, Geron Corp. of Menlo Park, Calif. He called the start of the trial at Shepherd and six other facilities “a milestone” for the long-contentious field of human embryonic stem cell research.
In the safety trial, patients will receive injections of about 2 million cells grown specifically to resemble precursors to spinal cord cells, within 7 to 14 days of injuries to their middle back, or thoracic vertebrae. In theory, the cells should grow into spinal tissues, helping to repair the injury. The immune system of the patients will be suppressed by drugs for months to help prevent rejection.
“I would say this is akin to an organ transplantation,” says stem cell researcher Allison Ebert of the University of Wisconsin, who was not part of the study. “This is just a study for safety to see how these cells respond to the human spinal cord. But it is a logical step, one of many in the pipeline.”
The Shepherd Center could not provide details of the patient or allow interviews with physicians out of medical privacy concerns, spokeswoman Jane Sanders said.
Geron’s Okarma has maintained that the spinal precursor cells used in the study show a broad ability not to antagonize the immune system. But the FDA held up approval of the clinical trial for months, requesting extra animal safety studies and added steps for patient protection, primarily out of fears that the injected cells would grow into tumors or trigger extra pain.
“Even if this trial turns out to be negative, these data will be useful …making it an important first step,” Ebert says.
Despite the hopes of medical advocates, research using human embryonic stem cells has been highly controversial, because the cells are grown from ones taken from the destruction of 5- to 6-day-old human embryos. Citing moral qualms in a 2001 announcement, then-president George W. Bush limited federal funding of research using human embryonic stem cells to 21 already-created stem cell colonies, or lines.
President Obama reversed that policy last year, leading to the FDA approval of the clinical trial and 76 lines receiving the go-ahead for federal research funding.