London: Promising results from a trial of a new stem-cell based therapy
for a rare and debilitating skin condition have been published in the Journal of Investigative Dermatology.
The therapy, involving infusions of stem cells, was found to provide
pain relief and to reduce the severity of this skin condition for which
no cure currently exists. RDEB (recessive dystrophic epidermolysis bullosa) is a painful skin disease in which very minor skin injury
leads to blisters and poorly healing wounds. About 1,000 people in the
UK live with RDEB.
The fragile skin in RDEB also scars, develops
contractures and is prone to life-shortening skin cancers. There is
currently no cure for RDEB.
The Phase I/II EBSTEM trial, funded by the Sohana Research Fund
with donations from Goldman Sachs Gives, tested the safety of the
treatment and also sought to establish whether it could help to reduce
the severity of the disease and improve quality of life for these
patients.
During the first six months of the trial, participants were given
three infusions of mesenchymal stromal cells (stem cells) grown from the
bone marrow of unrelated donors. Mesenchymal stem cells (MSCs) have
been shown to home to wounded tissue and mediate wound healing in
previous studies. Although the cells do not survive permanently, they
may still deliver clinical benefits.
The children were then monitored for a year after the cell
infusions. A range of monitoring tests showed no serious adverse effects
in patients who received the therapy. The pain score (level of pain)
reported was on average lower than before treatment, and the severity of
the condition was also reported to have lessened following the
infusions. Parents also reported better wound healing, less skin redness
and fewer blisters.
Overall, the paper concludes that the outcomes of the trial are
promising, although this is an unblinded study of participants which may
introduce a positive bias in the information reported. In interviews
families reported a range of benefits from having better sleep, a parent
being able to return to work part-time because of reduced caring needs,
and a family being able to plan their first vacation together.
However, further work is needed to better understand the
mechanisms involved – for example, whether the stem cells trigger the
production of a variety of growth factors and cytokines – immune system
regulators - to stimulate wound healing and reduce inflammation in the
skin. Further studies are also needed to confirm the efficacy of the
treatment and establish the optimal dose of cells to give RDEB
patients.
Dr Gabriela Petrof, lead author from St John's Institute of
Dermatology at King’s College London, said: ‘We found that wound healing
improved in all 10 children and the skin was less inflamed. Many of the
kids also mentioned their skin was less painful and itchy, and their
parents noted how much more energetic they were.’
Professor John McGrath, senior author from St John's Institute of
Dermatology at King’s College London and honorary consultant
dermatologist at Guy’s and St Thomas’ NHS Foundation Trust, added: ‘In
25 years of my research on RDEB, this is the only time I have seen any
treatment change the nature of the condition. The outcomes are truly
impressive and injecting the MSCs raised no safety concerns. At the same
time, it’s important to note that this is not a cure and that the
benefits wear off after about six months.’
‘Moving forward, we are now starting to introduce repeated
infusions of MSCs into routine NHS clinical care. But we are also
starting new clinical trials – combining cell and gene therapy to give
patients with RDEB, children and adults, even better treatments as we
search for a cure for this devastating inherited skin condition.’
Dr Anna Martinez, principal investigator from Great Ormond Street
Hospital, said: ‘Giving the cells is straightforward, but we now have to
fine tune the optimal dose and interval between infusions whilst work
continues on more long term-therapies.’
The study was also supported by the UK National Institute for
Health Research (NIHR) Biomedical Research Centre based at Guy's and St
Thomas' NHS Foundation Trust and King's College London.