New Oral MS Drugs May Be on the Horizon
Studies Show Cladribine and Fingolimod Are Effective Treatments for Multiple Sclerosis
Cladribine for MS
In a third study, Gavin Giovannoni, MB, PhD, of Barts and the London
School of Medicine and Dentistry at Queen Mary University of London and his
colleagues evaluated more than 1,300 MS patients who were randomly assigned
either two or four short courses of oral cladribine or a placebo. The treatment
course included one or two pills a day for four or five days, totaling 8 to 20
days of treatment annually.
Over the nearly two-year study period, nearly 80% of those on the low-dose
cladribine were relapse-free, nearly 79% of those on the higher dose were
relapse-free, but just 61% of those on placebo were relapse-free.
Giovannoni calls the results excellent. "This means that four out of five
people are disease-free in terms of relapses," he tells WebMD.
Cladribine by injection is already approved for treating leukemia under the
brand name Leustatin. Shingles occurred in 20 of the patients taking cladribine
vs. none in the placebo group.
''This is really big news," says John Richert, MD, executive vice president
for research and clinical programs at the National Multiple Sclerosis Society,
New York. MS patients often grow tired of having to have drugs injected, he
says, and so stop taking them. "Having oral therapies available increases the
likelihood that people will be willing to start the drug early in the course of
their disease and continue on the drugs with good compliance long term."
But Richert expressed some caveats about side effects. One side effect of
cladribine involves cancer cases. Three cancers occurred in patients in one
study getting the low-dose cladribine. "This has to be followed up long term,
as the authors note," Richert says.
And, he says, the data on the drugs are confined to the form of MS known as
relapsing-remitting. Eventually, some patients with relapsing-remitting make a
transition into secondary-progressive MS, in which the disease worsens more
steadily. Others have progressive disease from the beginning known as
primary-progressive MS, while others have progressive-relapsing MS.
In an accompanying editorial, William Carroll, MD, of Sir Charles Gairdner
Hospital in Perth, Australia, calls the new drugs a welcome addition to
treatment options but also notes that the existing therapies remain ''very
effective, particularly when they are administered early."
He points out that side effects of the new drugs -- including infections,
cancers, and low white blood cell counts -- must be weighed against their
benefits. Other side effects included herpes zoster (shingles) infections and
herpes virus infections; in some cases they were more frequent in those getting
the new drugs and in some cases not.
Both drugs work by reducing the number of potentially aggressive
lymphocytes, a type of white blood cell, available to enter the central nervous
system, although they do so in different ways.
Merck-Serono supported the cladribine study; Novartis Pharma supported the
fingolimod studies. Carroll, the editorial author, reports receiving honoraria
from Merck-Serono and fees from other pharmaceutical companies. Cohen, who led
one fingolimod study, reports receiving consulting fees form Novartis, and
Ludwig Kappos, MD, who led the other fingolimod study, has gotten consulting or
advisory fees from Novartis and Merck Serono and others. Giovannoni, who led
the cladribine study, reports receiving consulting fees from Merck Serono,
Novartis, and others.