Studies Back New RA Drug
Researchers Say Actemra May Help Treat Rheumatoid Arthritis and Juvenile Idiopathic Arthritis
March 20, 2008 -- Actemra, an experimental biologic drug, shows promise in
treating rheumatoid arthritis
and juvenile idiopathic arthritis (formerly called juvenile
rheumatoid arthritis, or JRA).
That news comes from the drug's phase III trials, which test safety and
Biologic drugs, such as Actemra, target specific parts of the immune system
that lead the inflammation that causes joint
damage in RA. Current biologic drugs used to treat RA include Enbrel,
Humira, Orencia, Remicade, and Rituxan.
Actemra is not yet available. It works on a different area of the immune
system than the other biologic drugs.
One trial covered rheumatoid
arthritis; the other focused on juvenile idiopathic arthritis. Results for
both trials appear in the March 22 edition of The Lancet.
A related editorial voices "cautious optimism" but calls for more
studies on Actemra's possible effects on cholesterol, and for head-to-head comparisons of Actemra
and other biologic arthritis drugs.
Rheumatoid Arthritis Study
The rheumatoid arthritis study included 621 patients with moderate to severe
rheumatoid arthritis who had already tried the drug methotrexate for their RA.
The patients got injections of a higher dose of Actemra, a lower dose of
Actemra, or a placebo every four weeks for six months.
At the end of the study, 59% of the patients who got the higher Actemra
dose, 48% of those taking the lower Actemra dose, and 26% of those who got the
placebo had at least a 20% improvement in their signs and symptoms of RA, which
is considered significant improvement.
Upper respiratory tract infections were the most common side effects seen in
the Actemra group. Liver enzyme levels also rose for some Actemra patients, but
those were typically one-time events and weren't linked to symptoms of liver
disease, according to the researchers.
Total cholesterol and LDL ("bad") cholesterol levels rose in the Actemra users. The reason
for that isn't clear. Major heart "events" -- such as heart attacks --
weren't more common with Actemra use, but the study only lasted for six months,
which may not have been long enough to detect cardiovascular risk.
WebMD reported on the study
last June, when researcher Josef Smolen, MD, of Austria's Medical
University of Vienna, presented the findings in Barcelona, Spain, at the
European League Against Rheumatism's annual meeting.
The study, which didn't look at the drug's long-term safety, was funded by
Hoffmann-La Roche and Japan's Chugai Pharmaceutical Co., which are developing