In a small study published online, the chemotherapy drug cyclophosphamide was found to slow disease progression and improve physical functioning in patients with very rapidly progressing MS when given in high doses.
All but one of the nine patients in the study had been treated unsuccessfully with conventional multiple sclerosis drugs.
"These patients were the worst of the worst in terms of disease progression," researcher Douglas A. Kerr, MD, PhD, tells WebMD. "We were hoping that this treatment would stop progression, and it did. But we also saw something that we did not expect to see at all, which was recovery of function."
On average, the patients were 39% less disabled at the end of almost two years of follow-up than they were prior to treatment, Kerr says.
Treatment Targets Inflammation
There are approximately 400,000 people in the United States living with multiple sclerosis, with 200 new cases diagnosed each week, according to the National MS Society.
MS is widely believed to be an autoimmune disease, in which the body's own defense system attacks the coating that protects nerve fibers of the central nervous system known as myelin. When this coating is damaged or destroyed by inflammation, the nerves that carry signals to and from the brain and spinal cord no longer function properly.
Symptoms may be mild, such as numbness in the arms and legs, or severe, leading to complete paralysis and blindness.
The progression and severity of the disease and the response to available treatments vary greatly from patient to patient, and some patients do not respond to any of the approved treatments.
Cyclophosphamide has been used since the late 1950s to treat cancer.
Recently, the drug has been given experimentally in high doses along with bone marrow transplants to MS patients with very aggressive disease.
Though the combination has been shown to be very effective in the hardest-to-treat patients, even producing cures in some, it is also highly toxic, expensive, and risky, with about 5% of patients dying as a result of the treatment, Kerr says.
In the newly reported study, Kerr and colleagues from the Johns Hopkins University examined the effectiveness of high-dose cyclophosphamide alone, without bone marrow transplant, in six men and three women with rapidly progressing MS.
The thinking was that cyclophosphamide would slow or halt disease progression by calming the inflammation that destroys myelin.
The patients were treated intravenously over four consecutive days, then given another medication to boost new immune cell production. They were followed for an average of 23 months after treatment.
New MS Treatments Needed
Most of the patients showed significant improvement in physical abilities following treatment, although four patients showed evidence of disease reactivation over the two years of follow-up.
The study appears in the August issue of the journal Archives of Neurology.
"These patients were still much better than they were at the beginning of the study when controlled on other medicines, but the MS was not completely kicked," Kerr says.
The Johns Hopkins researchers hope to conduct larger studies that include patients with less aggressive MS.
They also want to include other drugs in the regimen that might solve the problem of disease reactivation.
National MS Society Vice President of Biomedical Research Patricia O'Looney, MD, tells WebMD that treatment options for patients with the most aggressive forms of multiple sclerosis are badly needed.
"This could prove to be an effective treatment for patients who don't respond to current drugs," she says. "But because of the small number of patients, it is still too early to draw too many conclusions about cyclophosphamide's role in the treatment of MS."