Doctors in Bristol are to carry out a trial using stem cells on 80 multiple sclerosis (MS) patients following a $1m (£610k) donation.
People selected will have their bone marrow harvested which is then filtered before being injected into their blood.
Trials on a smaller group of people last year found it increased nerve function by up to 20%.
The research is taking place at the Burden Neurological Institute based at Bristol's Frenchay Hospital.
MS is a nervous system disorder which affects an estimated 100,000 people in the UK.
It can lead to a variety of symptoms, including muscle weakness, extreme fatigue, loss of co-ordination and visual and speech difficulties.
As the cells come from the patients' own bodies there are no ethical issues surrounding their use.
Professor Neil Scolding, who leads the team, has described the donation from the Silverman Family foundation in American as a "godsend".
He said: "When you inject these cells in to the bloodstream they do find their way into the brain and spinal chord.
"We know once they get there they are capable of encouraging repair of damage in a variety of ways."
'Great to see'
Half of the group will have the injection immediately and the two groups will be compared after a year.
The second group will have their treatment a year later as it is thought unethical to deny them the potential benefits.
One of the patients who had the treatment last May is David Franks.
Mr Franks had to retire from his job as a children's surgeon early because of his MS.
He said: "I am not any worse. I may be a bit better.
"But I am certainly not going down hill as fast as I was before the treatment".
Commenting on the trial, Dr Susan Kohlhaas from the MS Society said: "Stem cells hold promise as a potential treatment for MS so it's great to see research is at the stage where these treatments can be tested in people with the condition.
"It's exciting to see this work moving forward."