Last week, federal regulators gave the go-ahead for the nation’s first trial of embryonic stem cells in human beings. Geron Corporation will run the trial. It is designed to assess the safety of so-called GNROPC1 oligodendrocyte stem cells in treating spinal cord injuries.
Geron plans to begin testing by year-end. It will enroll about 10 patients over 2 years and follow them for 15 years after treatment. For safety reasons, Geron will space-out each enrollee by at least 30 days.
The primary purpose of the trial will be to determine whether GRNOPC1 is safe. Geron will assess efficacy as a secondary outcome.
The treatment involves injecting the stem cells into the spinal cord of injury victims 1-2 weeks after the injury occurs.
The FDA originally accepted Geron’s study application in January, 2009. It subsequently held things up after Geron reported that mice treated with GRNOPC1 had developed tiny cysts on their spines. According to Geron, many patients with spinal cord injuries develop larger cysts as the injury heals. Geron also reported that the cysts were not observed in a second animal study.
Oligodendrocyte stem cells mature into myelin-producing oligodendrocytes. Myelin forms a sheath around nerve cells that protects them and facilitates conduction of impulses via the nerves from the brain to the muscles, skin and internal organs. The hope is that the GRNOPC1 stem cells will facilitate healing of damaged spinal cord tissue and restore normal nerve conduction.
Embryonic stem cell research is controversial because in some cases, the cells are obtained from aborted human embryos. In 1996, Congress prohibited federal funds from being used to support stem cell research. Six years later, President Bush relaxed the ban by allowing federal funds to be used for research on stem-cell lines already in existence. In March, 2009, President Obama lifted the ban altogether.