I am living proof that cell therapy can work
With research into its potential to repair spinal cord damage, reverse blindness and treat currently incurable conditions such as Parkinson’s disease and multiple sclerosis, stem cell therapy could be on the brink of transforming our healthcare. Pennie Taylor investigates
Having been a fit and active child, Megan Whitehead remembers thinking it was strange when in 2002, aged 11, she suddenly found it hard to walk up the hill to her school in Tonbridge, Kent. “After 10 minutes I was out of breath and had to stop,” she says. “It was a bit weird, but everyone thought it was linked to growing and would pass.”
Eventually her mother Victoria took Whitehead to the GP, who also thought there was nothing wrong but ordered blood tests anyway. “That was on a Wednesday,” the daughter recalls. “On the Friday I was called out of class and told that my blood count was really, really low. That’s when it all began …”
Whitehead was diagnosed with aplastic anaemia, a rare autoimmune disease that causes the body to stop producing healthy blood cells. Without effective treatment the condition can be fatal. Over the next six years Whitehead underwent three courses of aggressive antibody treatment, which meant being kept in isolation for weeks on end. None of these worked.
Another treatment option was the replacement of blood stem cells, produced in the bone marrow, which in turn create the 200 specialised types of blood cells that continually regenerate the body. Stem cells may be taken from the person being treated and reimplanted, donated by a close relative, or from an unknown volunteer on the international bone marrow registers. But in Whitehead’s case no-one was a good enough match. Instead, she was maintained on autoimmune drugs in the hope that an effective treatment might one day be found in this fast-moving field of medicine.
By the time she was 17, cord blood donation had become available. Drawn from umbilical cords and placentas donated after births, this blood is a rich source of undifferentiated stem cells, which are capable of becoming cells with specific functions.
A round of chemotherapy and radiation was used to destroy Whitehead’s existing bone marrow and faulty immune system in order to accommodate the donor cells. Then Whitehead received a transfusion of cord blood taken from two donations.
Over the following six and a half weeks, once again living in isolation in hospital to avoid infection, Whitehead’s blood levels were monitored daily. But again, her blood cell levels did not rise. Instead she suffered a severe allergic reaction and then a blood infection.
“Those were very scary times,” she says. “There were moments when I did think I might die.”
In March 2009, after enduring more long spells in lonely hospital rooms, Whitehead persuaded her doctors that she needed a break. She was allowed to go home, on the proviso that she didn’t enter crowded places, where the risk of infection is high.
Despite the warnings, Whitehead was determined to return to college to continue her education, says her mother. “Megan was amazing, really tough. She wouldn’t have got through it otherwise.”
Then in April 2010 the family were told about a new experimental treatment, haploidentical stem cell transplantation (HSCT). This uses partially matched donor blood which is modified to reduce the risk of rejection by the recipient’s body.
Victoria Whitehead, a 50% blood match, jumped at the chance to help her daughter.
‘Amazing to watch’
“It was easy,” she says. “I had to give myself daily injections to stimulate the release of stem cells, and then on the sixth day I went into hospital where they connected a needle to each arm and filtered out the cells. It was amazing to watch.”
It took almost eight hours to give the donation, which was immediately transfused into her daughter, who had received more chemo and radiotherapy to prepare her for the stem cell transplant. “At the time I wasn’t emotional at all, just concerned that it might not work,” Victoria Whitehead adds. “Now, I can’t help but get tearful when I think about it. It can’t believe that it took what felt like so little to save my daughter’s life.”
Cell therapy is an extremely complex science, and it offers the potential to be a real game-changer in many areas of medicine says Professor Brendon Noble, a specialist in regenerative medicine and trustee of the UK Stem Cell Foundation (UKSCF). With a professional interest in osteoarthritis he can see the prospect of using differentiated cells to replace damaged cartilage, which would transform the experience of people whose only option so far has been drugs and surgery.
There is further work taking place to explore the use of targeted cell therapies to repair damaged livers and spinal cords; to reverse the effects of macular degeneration, glaucoma and blindness; to fix deteriorating bone and to address currently incurable conditions such as Parkinson’s disease and multiple sclerosis (MS).
“There’s a great deal yet to be done to understand it fully, but cell therapies could be applicable to any condition,” says Prof Noble. “In medicine there are long periods when nothing much happens, then along come developments such as antibiotics and organ transplantation that revolutionise things. I honestly believe we are on the cusp of the next big breakthrough with cell therapies. But we have to be patient to ensure that we get it right.”
In the UK, access to research trials that are developing new cell treatments is limited. And there is anecdotal evidence that people with diseases such as Parkinson’s and MS may be attracted to go overseas to try clinically unproven cell therapies. That causes patient representatives in the UK deep concern. “Understandably, people are looking for any kind of hope and we know that some are taking huge risks – both physically and financially – to pursue treatments abroad,” says Pam Macfarlane, chief executive of the MS Trust.
“We hear from people who are prepared to remortgage their homes to go to Russia or Mexico looking for a stem cell cure, but as yet the research is not there. We need more clinical trials to understand who is most likely to benefit.”
Dr Arthur Roach, director of research at the charity Parkinson’s UK, agrees. “Cell treatments for Parkinson’s disease would need to be transplanted deep into the brain, a major undertaking carrying its own risks,” he says. “There are many exciting treatments coming up the track, and cell therapy is just one of them. This is a field that attracts a lot of bad science, and there are unscrupulous clinics out there trying to make a fast buck. People have to be aware of that.”
That is why the UKSCF is preparing a fact sheet, with questions that anyone considering treatment abroad is encouraged to ask. “I would never entirely exclude going abroad, but where is the follow-up if things go wrong once they return home?” says Prof Noble. “And where is the regulation to protect against bad practice? It is vital to be properly informed.”
It may take time, but laboratory-based scientists and the pharmaceutical industry are working to bring cell research to fruition for the benefit of patients. “It is a global effort, and I am utterly confident that it will happen,” Prof Noble adds. “When it does, it will change the way medicine is practised immeasurably.”
The development of cell therapies will undoubtedly be expensive: any new treatment takes years to pass the rigorous tests required before licensing, and the investment is considerable. But although the short-term cost issues will be challenging, the long-term potential savings to the NHS of effective cell treatments for increasingly common conditions such as diabetes, dementia and arthritis are staggering.
No respectable clinician uses the word ‘cure’ lightly, but that is precisely what has happened to Megan Whitehead thanks to cell therapy. “It was amazing to receive the letter from my specialist in summer 2012 telling me that to all intents and purposes I am cured,” she says. “I’m down to yearly check-ups, and life is very good.”
Now aged 25, Whitehead is training to be a doctor and hopes to specialise in cancer care when she graduates next year. “I think it helps that I know what people are going through, and that there is light at the end of the tunnel,” she says. “I am living proof that cell therapy can work.”
The stem cell breakthrough
Transplantation of stem cells has proved a breakthrough in the treatment of blood cancers and blood disorders. “It offers the chance of survival to people who have exhausted all other treatments for diseases such as leukaemia,” says Dr Neema Mayor, left, senior research scientist with the Anthony Nolan Research Institute, an arm of the charity that develops stem cell treatment and co-ordinates the UK stem cell donor register. “Blood disorders have led the way in this field.”
Much has been achieved since 1974 when Shirley Nolan, mother of three-year-old Anthony, set up the first bone marrow register to match potential donors with people in need. No donor was found to save her son, but so far more than 15,000 transplants have been facilitated thanks to the Anthony Nolan register. Success rates range from 30% to 70% depending on factors including compatibility of tissue types.
There are now more than one million donors on the combined UK stem cell registers, which include the Anthony Nolan register. These operate in partnership with others worldwide to offer the widest possible cell pool for recipients.
Ninety per cent of donations are made using peripheral blood cell donation, which means taking blood from an arm in a similar way to regular blood donation. Only 10% of donor cells come from bone marrow, collected under anaesthetic from the pelvis. “These days, the effects on the donor are minimal,” says Dr Mayor. “The stem cells they give are replaced within weeks. But the pride stays with people forever.”
Embryonic cells (perhaps the by-product of IVF treatment) and foetal tissue are rich sources of stem cells described as ‘immortal’, as they can be turned into any cell type. Anthony Nolan does not work with embryonic or foetal tissue, and their use in biomedical research is hotly debated.
For more details
UK stem cell foundation www.ukscf.org
Anthony Nolan www.anthonynolan.org