Chemotherapy is often (and only) associated with cancer, and for good reason: It’s one of the only methods of treating cancer that has been consistently useful. However, new research suggests the aggressive form of therapy may be good for something other than killing cancerous tumors.

Multiple sclerosis (MS) is a debilitating disease, in which nerve damage messes with the communication between the brain and body. More than 100,000 people in the UK suffer from the condition, which can cause symptoms including pain, fatigue, impaired coordination, and vision loss. A small number of this population underwent a trial involving chemotherapy — the results, according to The Guardian, were "remarkable."

The treatment involves the destruction of an MS patient's immune system, which is then rebuilt with stem cells previously gathered from their blood. About 20 patients have received the treatment, formally known as autologous [hematopoietic] stem cell transplant (HSCT).

"The immune system is being reset or rebooted back to a time point before it caused MS," explained professor John Snowden, consultant hematologist at Royal Hallamshire Hospital, to BBC.

This hospital, located in Sheffield, UK, is participating in an international trial involving MS patients from across the world, including the U.S., Brazil, and Sweden.

One patient who recently received the HSCT treatment, Steven Storey, was diagnosed with MS in 2013. He "went from running marathons to needing 24-hour acute care," he said, recalling the onset of his condition. "At one point, I couldn’t even hold a spoon and feed myself."

But after the transplant, Storey said he was able to move his toes. Four months later, he could stand without help. "It's been incredible. I was in a dire place, but now I can swim and cycle and I am determined to walk," he said.

Basil Sharrack, a consultant neurologist at Sheffield, said the treatment has so far generated great results.

"It is important to stress, however, that this treatment is only suitable for patients with relapsing remitting multiple sclerosis disease who have had two or more significant relapses in the past 12 months, failed to respond to standard drug treatment and who have had the illness for at least 10 years," he said.

HSCT, despite its victories, is still a risky process, according to Emma Gray, the head of clinical trials at the MS Society.

"We want people to be aware that HSCT is an aggressive treatment that comes with significant risks. It needs to be carried out ay an accredited [center] or as part of a clinical trial."

According to BBC, HSCT "has a one-time cost for patients of a little more than $40,000, which is comparable to a full year of traditional MS treatment."