Friday January 30 2009
MS is a condition of the central nervous system
“Stem cell transplants could provide a cure for multiple sclerosis”, The Sun reported. It said that in a recent trial of 21 patients with MS, 17 had shown improvement three years after being injected with cells from their own bone marrow. The newspaper said the stem cells appear to reduce the inflammation that can worsen the disease. The study leader was quoted as saying: “It seems to prevent neurological progression and reverse disability.”
The news story is based on an early phase trial, which found that stem cell transplants reversed neurological deficits in people with relapsing-remitting MS, the most common form of the disease. It did not look at other forms of the condition, such as secondary progressive MS. Patients were compared before and after the transplant, and the results were promising, with sustained improvements in disability in 81% of patients.
As is usual when testing treatments, the intervention will go on to be tested in larger, controlled trials, probably randomised controlled trials across different centres. Until then, the researchers emphasize that it’s not possible to determine whether this treatment is better than existing treatments for relapsing-remitting MS.
Where did the story come from?
The research was carried out by Dr Richard K. Burt and colleagues from the Northwestern University Feinberg School of Medicine and Department of Neurological Sciences, Rush University Medical Centre in Chicago, Imperial College London, the University of Utah and other international academic and medical institutions. The study was published in the (peer-reviewed) medical journal: the Lancet.
What kind of scientific study was this?
The researchers say that when most people are first diagnosed with MS, they have only intermittent symptoms; a form of the disease called relapsing-remitting MS. Although many go on to develop irreversible progressive MS, which results in gradual reduction in neurological function, MS may be at least partially reversible while in this initial phase.
During its early stages, the immune system limits the damage that MS has on nerve cells. Treatments at this time include immune therapies aimed at improving this response. This early phase I/II study investigated if the transplantation of certain blood stem cells during the relapsing-remitting phase of MS could reverse neurological disability. The process of transplanting blood stem cells back into bone marrow is known as haemopoietic stem cell transplation.
The study involved 21 MS patients aged between 18 and 55 years who had not responded to at least six months of therapy with interferon alpha (an immune therapy). All patients had a minimal to severe disability (according to a well-known disability scale) and had normal lung, kidney, heart and liver function and no history of cancer (except skin cancer).
Before their stem cell transplantations, the patients’ immune systems were prepared for the donor cells by a non-myeloablative pre-treatment. This means that their body’s ability to make blood cells was only weakened rather than destroyed. The patients’ physical and neurological abilities were tested by several assessments including a timed 25ft walk and a nine-hole peg test. These were repeated six and 12 months after the transplantation, and annually after that. The patients were also asked to report any new symptoms or worsening between visits, at which point they would be immediately reassessed.
Disability and function was assessed using the expanded disability status scale (EDSS), the neurological rating scale (NRS) and the paced auditory serial addition test (PASAT). Blood transfusions and antifungal and antiviral treatment were given as necessary during the procedure, and adverse events were dealt with.
The patients were followed up for an average of 37 months and their neurological functioning, progression free survival (the length of time that symptoms do not worsen) and performance on different tests were compared with measures taken before treatment.
What were the results of the study?
The study found that the patients’ average score on the EDSS had significantly improved by 0.8 points six months after the stem cells were transplanted, and had improved by 1.7 points by the fourth year of follow-up. Other measures of neurological function also significantly improved after the transplant for the majority of patients, including assessments on the NRS, the timed 25ft walk and the PASAT. Although there was an improvement in scores on the nine-hole peg tests, these were not significantly different between the time before and after transplantation. The patients also reported that their general health status improved.
Despite showing early neurological improvements, five patients relapsed an average of 11 months after transplantation.
What interpretations did the researchers draw from these results?
The researchers conclude that 81% of patients showed a reversal of neurological disability. They also had sustained improvements in function as demonstrated by improvements of one point or more in EDSS scores. They say that stem cell transplantation reverses neurological deficits in people with relapsing-remitting MS, but caution that these results need to be confirmed in a randomised trial.
What does the NHS Knowledge Service make of this study?
This study focuses on relapsing-remitting MS, which is the most common of the four types of multiple sclerosis. Many people with this type go on to develop secondary progressive MS (a steady worsening in symptoms and disability). It is important to highlight that the findings only apply to people who have relapsing-remitting MS. The researchers state that studies have found no improvement in neurological disability with transplantation in secondary progressive MS.
When new treatments are being tested, they usually go through a three-stage study process before being licensed for use. Early studies – phase I and II trials such as this one – are smaller and often do not have a comparison group with which to compare an intervention. If efficacy (the power to produce an effect) and safety are demonstrated in such studies, the intervention is then assessed in larger studies; the largest being phase III trials which are randomised, controlled studies which can have thousands of patients. Given the promising results in this preliminary study, stem cell transplantation for relapsing-remitting MS patients will probably be studied further in larger trials.
The researchers draw attention to the fact that this study does not compare stem cell treatment with current management of relapsing-remitting MS. Only a randomised controlled trial will provide this answer.