Certolizumab plus methotrexate eases
RA.
by Evans, Jeff
BARCELONA -- Treatment of rheumatoid arthritis with a combination
of certolizumab pegol and methotrexate improved symptoms in a
significantly greater proportion of patients than methotrexate alone,
according to the results of a phase III trial.
In the 52-week, multicenter, randomized, double-blind trial, about
60% of patients who received dosing regimens with either 200 mg or 400
mg of certolizumab pegol (Cimzia) and methotrexate achieved an American
College of Rheumatology (ACR) 20 level of response at 24 weeks on an
intent-to-treat basis, compared with only 14% of those who received
placebo plus methotrexate. An ACR 20 level of response is achieved when
there is 20% improvement in the number of tender and swollen joints as
well as a 20% improvement in at least three of five other parameters.
The rheumatoid arthritis patients in the trial, called RAPID 1, had
to have an inadequate response to methotrexate alone for at least 6
months prior to the study, Dr. Edward C. Keystone reported at the annual
European Congress of Rheumatology.
Certolizumab pegol is a humanized monoclonal Fab' fragment
conjugated to polyethylene glycol, which prolongs the amount of time
that the drug remains in the bloodstream. It is the first anti-tumor
necrosis factor-[alpha] drug to be constructed without the Fc fusion
protein, which may cause adverse effects in other anti-TNF-[alpha]
agents.
The drug also is produced in bacteria rather than in Chinese
hamster ovary cells, said Dr. Keystone, director of the Rebecca
MacDonald Centre for Arthritis and Autoimmune Disease at the University
of Toronto. He has received research funds from and has been a
consultant for the biopharmaceutical company Union Chimique Beige (UCB),
which funded the study.
The RAPID 1 trial tested the lyophilized formulation of the drug,
whereas the RAPID 2 trial evaluated the liquid form of the drug.
The 397 patients who were assigned to the 200-mg arm initially
received a 400-mg loading dose of certolizumab pegol at 0, 2, and 4
weeks, followed by 200 mg every 2 weeks. The 394 individuals in the
400-mg arm received 400 mg every 2 weeks. The 201 placebo-treated
patients followed the same schedule as the 400-mg group. If the patients
did not reach an ACR 20 response by 16 weeks, they entered an open-label
extension in which they received 400 mg certolizumab pegol every 2
weeks, Dr. Keystone said.
At baseline, the patients averaged 52 years of age, 6 years of RA,
13 mg/week methotrexate, 1.5 treatment failures on disease-modifying
anti-rheumatic drugs other than methotrexate, a Disease Activity Score
of 7, and about 30 tender and 20 swollen joints.
On an intent-to-treat basis, similar percentages of patients who
took the 200-mg and 400-mg certolizumab pegol dosages achieved an ACR 50
level of response (37% and 40%, respectively) or ACR 70 level of
response (21% in each). ACR 50 and 70 responses occurred in 8% and 3%,
respectively, of patients in the placebo group.
Most patients who achieved either an ACR 50 or ACR 70 level of
response did so by 16 weeks, Dr. Keystone said.
BY JEFF EVANS
Senior Writer
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