Scientists are "cautiously very excited" about their new findings.
Stem cells have been safely injected into the brains of patients with secondary progressive multiple sclerosis, and seem to have protected them from further damage – a breakthrough that could pave the way for new treatments.
“We don’t know yet whether this is the beginning of a fantastic journey or not, but the results are very strong and very consistent,” Prof Stefano Pluchino at the University of Cambridge told The Guardian.
MS is caused when a malfunctioning immune system attacks the fatty layer that protects nerve fibres in the brain and spinal cord. As a result, the signals travelling along the nerves are disrupted, causing symptoms ranging from problems with vision and balance to paralysis.
Existing drugs can reduce the severity and frequency of relapses, but two-thirds of patients still go on to develop secondary progressive MS - an increasingly debilitating form of the disease.
In the small, early-stage trial, led by scientists at the University of Cambridge, 15 patients were injected with stem cells removed from a foetal donor, in the hope that this would suppress brain inflammation. Over the next 12 months, none of the patients (all of whom had a very high level of disability) showed any worsening of their symptoms, which suggested the cell therapy had stopped or slowed the disease's advance, says a report in the journal Cell Stem Cell, and side effects were relatively mild.
Study leader Prof Stefano Pluchino described himself as "cautiously very excited" about the findings, but stressed that larger studies are needed to confirm them and, of course, the researchers are now keen to run a larger trial to confirm whether or not the injections are changing the course of the disease.