26 January 2009
ByAppeared in BioNews 492
The US Food and Drug Administration (FDA) has allowed the biotech firm, Geron, to begin clinical trials using embryonic stem cell (ES cells) to help treat spinal cord injury sufferers who have become paralysed from the chest down. The product known as GRNOPC1 will be tested for its safety first, with further regulatory approval needed to test efficacy.
The trial will involve 8-10 patients being injected with cells derived from human embryos which have been developed into cells called oligodendrocyte progenitor cells (OPCs). It is believed that these cells, when injected into the spines of patients up to two weeks after paralysis, will generate new OPCs. Oligodendrocyte cells create a substance called myelin which covers the shafts of nerve cells in a protective film allowing impulses to travel freely between the brain and body. Injury can cause the oligodendrocyte cells to die and myelin ceases to be produced. The effect is that the nerves then stop functioning correctly leading to paralysis. 'They are the nursemaids of the nervous system', explained Thomas Okarma, chief executive of Geron. 'You cannot get OPCs from the adult body, but now we can make them in large quantities, for the first time, from embryonic stem cells'.
Geron used cell lines eligible for funding under former-President Bush's restrictive policy on ES cell research although it says it did not access federal funding. It took three years for the company to develop the treatment from the laboratory into a product suitable for human testing. It needed to ensure the cells would not continue differentiating creating tumours called teratomas and that the cells would not be rejected by the recipient's immune system, both of which were successfully overcome in animal trials.
The announcement comes as President Obama, who supports ES cell research, takes over the Presidency, although the FDA says it was not politically motivated in approving Geron's work. 'The FDA looks to the science on these types of issues, and we approve [such applications] based on a showing of safety', said Karen Riley, spokeswoman of the FDA, adding that 'political considerations have no role in this process.'
It is reported that Geron, founded in 1992, has spend over $100 million on developing ES cell therapies. Upon news of the announcement of GRNOPC1, the company saw its share price shoot up by over 36 per cent. 'This marks the beginning of what is potentially a new chapter in medical therapeutics - one that reaches beyond pills to a new level of healing: the restoration of organ and tissue function by the injection of healthy replacement cells. The ultimate goal is to achieve restoration of spinal cord function', said Mr Okarma.