Science is always at its most exciting when it looks to the far horizons. And the unavoidably controversial yet incredibly promising area of stem cell science provides arguably one of the most apt examples. Indeed even to the most disinterested layman, the idea of using the human body’s own cellular foundations to regenerate damaged organs must surely evoke at least a flicker of excitement. Conversely, and to those patients for whom stem cell science may one day represent a potential new lease on life, this really is the science of dreams.
Earlier this week, and in what looks set to become the next potential breakthrough on the trail, British regulators made history when they gave Moorfields Eye Hospital in London approval to carry out Europe's first embryonic stem cell trial. The trial, which will take place in partnership with American bio-tech firm, Advanced Cell Technology (ACT), is also the first clinical trial based on embryonic stem cells to take place outside the United States. ACT has already begun treating patients on the other side of the Atlantic and its Chief Scientific Officer, Robert Lanza told the Guardian that the trial ‘confirms’ the UK’s position as ‘the leader in stem cell work in Europe’.
The treatment will initially be carried out on twelve patients suffering from Stargardt's disease, a genetic and incurable form of macular degeneration. Stargardt's is one of the leading causes of blindness in young people and it works by attacking the central part of the retina — the macula — progressively leaving its subject blind, or with peripheral vision at best. Specifically, the procedure will be carried out by injecting the patient’s eye with between 50,000 and 200,000 replacement cells, known as retinal pigment epithelial cells (RPE). These cells are derived from human embryonic stem cells (hESCs) and physicians hope the procedure will either slow or reverse the effects of the disease.
These initial trials, the first to take place in any country within Europe, will function primarily as a test of safety and tolerance and are due to begin in December, having just this week received the required regulatory approval from the UK's Medicines and Healthcare Products Regulatory Agency (MHRA). Any subsequent trials will be directly linked to the outcome, of which initial results are expected early next year.
In theory, the hope that surrounds human embryonic stem cells is easily comprehensible. Indeed, their ability to potentially turn into any of the 200 or so cell types in the body offers tremendous opportunities in terms of either replacing diseased tissue, or even growing replacement organs from scratch. Moreover, already proven treatments in the wider field of stem cell science, such as bone marrow stem cell transplants, have now been available for decades. One of the leading surgeons conducting the trials at Moorfields, Professor James Bainbridge, echoed this enthusiasm, commenting that "there is real potential that people with blinding disorders of the retina including Stargardt's disease and age-related macular degeneration might benefit in the future from transplantation of retinal cells."
In practice however, the trials now taking place in London — alongside those already underway in California at the hands of bio-tech firm Geron — represent only the very first step on the road to treatments utilising human embryonic stem cells. An area of science that is as controversial as it is promising.
Indeed for many of the world’s religious groups and ethical watchdogs, the potential sourcing of human embryonic stem cells presents moral quandaries aplenty. Specifically, such groups charge that the procedure inherently relies on, and indeed begins with, the destruction of a human embryo, and is as such unethical by definition. This despite the fact that at least in the case of the aforementioned trial, the stem cell line in question was created using a donated embryo of just a few cells.
Conversely, supporters of the trial argue that embryonic stem cell science has the potential to treat a multitude of life-threatening conditions, not limited to cancer, heart disease, Parkinson’s disease and diabetes. And that given scientists’ emerging ability to create pluripotent stem cells without destroying embryos — by way of induced pluripotent stem cells (iPS) —ethical objections are becoming increasingly outdated.
Yet beyond the debatable and ultimately resolvable hurdle of human ethics still lies the burden of evidence itself. By the end of next year, we may well have some answers to all the hype – be they corroborative or otherwise. And should the results emerge as positive, palpable, mass-market treatments might then sensibly be talked about.
Last updated on: 26/09/2011 11:44:23