TUESDAY, Nov. 1 (HealthDay News) -- Multiple sclerosis patients
may eventually benefit from a novel treatment that takes aim at the
abnormal behavior of a specific type of immune cell, preliminary
research suggests.
The errant behavior of the cells in question -- known as "B
cells" -- is viewed as key to the development of this chronic and
disabling nervous system disease, commonly called MS.
The new therapy's potential is only in the early stages of
exploration, cautions an international study team comprised of
researchers from the United States, Canada, Switzerland and the
Netherlands, in the report published in the Nov. 1 online edition
of
The Lancet.
But initial indications suggest that the new antibody drug,
called ocrelizumab, successfully targets these renegade cells with
hopeful results: a significant reduction in disease-related
inflammatory brain lesions.
"Our findings show that ocrelizumab rapidly suppresses inflammatory activity," noted the study authors, led by Dr. Ludwig Kappos from the University Hospital, Basel, Switzerland, in a journal news release.
Describing the targeting of B cells as an "innovative
therapeutic approach," Kappos and his colleagues reported that in
testing among 218 patients, the drug's impact on lesions was "rapid
and pronounced." What's more, to date the treatment appears to be
safe.
The study authors noted that MS is a progressively debilitating
disease that attacks an individual's central nervous system,
disrupting the normal brain, spinal cord and optic nerve
function.
A classic characteristic of the disease is inflammation, which
takes the form of brain lesions.
The immune system's T cells have long been implicated in disease
progression, but the notion that B cells may also play a major role
is relatively new.
With this new potential target in mind, researchers configured
ocrelizumab to specifically focus on a protein (CD20) found on the
surface of certain B cells.
To test the drug, Kappos and his team recruited patients aged 18
to 55 seeking MS treatment in 79 centers in 20 countries.
The patients were divided into four groups, treated with: a low
dose of ocrelizumab (600 milligrams); a high dose of ocrelizumab
(2,000 mg); a well-known MS inflammation treatment known as
"intramuscular interferon beta-1a"; or a sugar pill (placebo).
After 24 weeks, some of the doses were adjusted.
The result: at week 24, all of the patients receiving either
dose of ocrelizumab fared better in terms of lesion count than
either the placebo or standard treatment groups.
The number of active lesions had dropped 89 percent more among
the 600-mg group compared with those getting a placebo. Similarly,
those in the 2,000-mg group experienced a 96 percent bigger drop in
lesions. What's more, relapse rates were much lower among those
taking the new drug, in contrast to those taking a placebo.
The investigators further noted that even eight months after
treatment launch, no serious adverse effects were directly
attributable to the new drug.
That said, Dr. Moses Rodriguez, a professor of neurology and
immunology at the Mayo Clinic in Rochester, Minn., disputed the
premise that ocrelizumab is shaping up as anything new and
innovative.
"In fact, there's nothing novel about this at all," he said. "There is another drug, called rituximab, that's been in early trials for MS for years. And all this new drug is attempting to do is replicate the same that rituximab already does. And I see no major advantage of this drug versus that older drug. It's not better or worse. It's the same," Rodriguez noted.
"So bottom-line, I would not sell this as a major breakthrough in MS," cautioned Rodriguez. "It's not."
Funding for the study was provided by F. Hoffmann-La Roche and
Biogen Idec. Inc.
More information
For more on multiple sclerosis, visit the
U.S. National Library of Medicine.