A patient paralysed through spinal cord injury has become the first person to receive human embryonic stem cell (ES cell) treatment in a clinical trial being conducted in the United States. The anonymous patient was injected with stem cells at the site of injury in the hope that the cells will repair the damaged nerve tissue to restore some movement.
The clinical trial, which involved cells derived from embryos under 14 days old, is being run by the Californian biotechnology company, Geron Corporation. Stem cells have already been used for therapeutic purposes, but this is the first time embryonic stem cells, rather than adult cells, have been used in humans as part of a regulated clinical trial.
'Initiating the GRNOPC1 clinical trial is a milestone for the field of human embryonic stem cell-based therapies', said Dr Thomas Okarma, chief executive of Geron. 'When we started working with human ES cells in 1999, many predicted that it would be a number of decades before a cell therapy would be approved for human clinical trials'.
The clinical trial involves isolating ES cells before growing them into oligodendrocyte progenitor cells (OPCs). Whilst ES cells have the potential to develop into any cell type in the human body, known as pluripotency, OPCs have developed beyond this stage and will turn only into nervous system cells, including oligodendrocytex. Previous studies have shown this reduces the risk of excessive cell growth, which can develop into tumours. By injecting OPCs at the site of injury, it is believed the cells will develop into new oligodendrocytes, restoring function to the damaged nerve cells.
'This is indeed a significant milestone in our journey towards the promise of stem cell-based medicines', said Dr Ben Sykes, executive director of the UK National Stem Cell Network. 'Geron's commitment to reaching this first stage of phased clinical trials has been rewarded with the first full regulatory approval - at least in the Western world - to proceed with a human embryonic stem cell-based therapy in a human patient'.
Four people each day in the UK sustain spinal cord injuries leading to paralysis. Spinal cord injury is often due to bruising rather than severing of the spinal cord. Bruising results in inflammation, which is responsible for the loss of oligodendrocytes. These cells protect and insulate the nerve cells of the spinal cord and - if lost - cause the nerve cells to stop functioning, leading to paralysis.
The patient was treated at the Shepherd Centre, Atlanta, one of seven American centres taking part in the clinical trial. Professor Sir Ian Wilmut, Director of the Medical Research Council Centre for Regenerative Medicine at the University of Edinburgh said: 'This is very exciting news, however, it is very important to appreciate that the objective of trials at this stage is to confirm first of all that no harm is done to patients, rather than to look for benefits. Once that has been confirmed then the focus moves on to development and assessment of the new treatment'.
Professor Chris Mason, a regenerative biologist at University College London said: 'This pivotal clinical trial is a major morale boost for scientists, clinicians and most of all patients by finally commencing the transformation of stem cells from a scientific curiosity into advanced healthcare'.