The human first trial to use embryonic stem cells for the treatment of macular degeneration has published its results,representing a milestone in the use of the controversial therapy.
An new trial published in the leading medical journal The Lancet, reports on the the use of human embryonic stem cells to treat macular degeneration in two patients. It is the first report of the use of such cells in humans for any purpose.
The study involved one elderly patient and one young patient with different forms of macular degeneration that had led to severe vision loss. The transplants appeared safe after four months, and both patients had some improvement in vision.
In an associated press release lead author Dr Robert Lanza said:
“It has been over a decade since the discovery of human embryonic stem cells. This is the first report of hESC (human embryonic stem cell) -derived cells ever transplanted into patients, and the safety and engraftment data to-date looks very encouraging. Although several new drugs are available for the treatment of the wet type of AMD, no proven treatments currently exist for either dry-AMD or Stargardt’s disease.
“Despite the progressive nature of these conditions, the vision of both patients appears to have improved after transplantation of the cells, even at the lowest dosage. This is particularly important, since the ultimate goal of this therapy will be to treat patients earlier in the course of the disease where more significant results might potentially be expected.”
There is an ongoing ethical debate surrounding whether or not embryonic stem cells should be used in treatments (on the basis that an embryo can be regarded as the earliest form of human life).
Our colleagues at the UK Science Media Centre collect the following expert comments.
Professor Daniel Brison, Co-Director of the North West Embryonic Stem Cell Centre, Manchester, said:
“This is a very exciting moment for embryonic stem cell therapies. This is the first peer-reviewed scientific report showing that cells derived from human ES cells can be transplanted safely into a patient with no sign of complications. Although the study is limited to safety considerations, very small in scope, and at a very early stage, this is nonetheless a ground breaking moment for embryonic stem cell therapies. It is also very significant for the UK that the second trial of these therapies has now begun in London, only 4 months behind the US trial. These trials have used human ES cells created at research grade and this was possible as they were transplanted into the eye which is a very localised site in the body. In order to realise the full potential of ES cell therapies in the future, it will be very important to use the new generation of clinical grade ES cells now being produced in the UK.”
Professor Chris Mason, Chair of Regenerative Medicine Bioprocessing, University College London, said:
“The preliminary data on the two US patients treated using human embryonic stem cell-based therapies in June 2011 is highly encouraging, but is only the start of gathering the necessary safety data before it is possible to test if the therapy will have an impact on patients’ vision. Overall the process of testing for safety and efficacy is likely to take a minimum of 5-10 years before the potential therapy could enter routine clinical practice.
“It is not surprising that the first European human embryonic stem cell-based therapy was carried out in London, given that the UK is a world leader in cell therapy.
“The safety of embryonic stem cell-based therapies in patients is now slowly starting to emerge with both Geron data for spinal cord injury and now ACT for retinal disease. It is still a long way to go before we will have the answer as to whether embryonic stem cell-based therapies will be safe and efficacious, but progress continues to be made towards striving for the ultimate goal of life-changing therapies for patients and their carers.”
Dr Dusko Ilic, Senior Lecturer in Stem Cell Science, Kings College London, said:
“The most important thing is that Robert Lanza and his team at the Advanced Cell Technology get across a message to the media and the public that ongoing clinical trials for dry age-related macular degeneration and Stargardt’s disease with retinal pigment epithelium (RPE) derived from hES cells are safety trials. Even though in preclinical trials, the RPE were capable of extensive photoreceptor rescue in an animal model of retinal disease, resulting in improvement in visual performance without evidence of untoward pathology, we should keep in mind that people are not rats. The number one priority of initial clinical trial is always patient safety. If everyone expects that the blind patients will see after being treated with hES cell-derived RPE, even if the treatment ends up being safe (which is what Advanced Cell Technology are trying to determine in this trial), they risk being unnecessarily disappointed.”
Professor Peter Coffey, Director of the London Project to Cure Blindness said:
“At last seeing fruits of human embryonic stem cell research entering clinical trials. This will help determine the safety of these therapies. I am immensely happy that this has happened in the eye. And will only help those patients with, until now, blinding eye diseases. Hopefully we will be able to enter our own clinical trials using embryonic stem cell therapy soon.”