LONDON -- Rheumatoid arthritis patients who were seropositive -- particularly for anti-cyclic citrullinated peptide (CCP) antibodies -- responded better to treatment with abatacept (Orencia) than patients without the antibodies, according to five-year registry data.
On a univariate analysis, the presence of both rheumatoid factor and anti-CCP antibodies was associated with response to abatacept therapy, according to Jacques Eric Gottenberg, MD, PhD, of University Hospital in Strasbourg, France, and colleagues.
But on multivariate analysis, after controlling for baseline disease activity scores, only anti-CCP positivity was associated with response to the drug, with an odds ratio of 2.1 (95% CI 1.2 to 3.7, P=0.006), Gottenberg reported here at the annual meeting of the European League Against Rheumatism (EULAR).
These findings emerged from analysis of data from the Orencia and Rheumatoid Arthritis (ORA) registry, which was established by the French Society of Rheumatology in 2008.
Abatacept is a selective T-cell co-stimulator that binds B7 and blocks the signal mediated by the CD28-CD80/86 pathway. It is currently recommended for use in patients with rheumatoid arthritis who have not responded to treatment with conventional disease-modifying drugs or tumor necrosis factor (TNF) inhibitors.
The registry now includes 1,031 patients taking this drug, who have been followed-up every six months for five years. Efficacy data were available for 439.
"Registries provide important information beyond what is learned in clinical trials," said Gottenberg.
"They include unselected patients, concomitant medications, and have longer follow-up, which is very important in real-life clinical practice because patients who remain on treatment in these registries reflect the balance of benefits and risks," he said.
About 80% of the patients in this analysis were women, and median disease duration was 14 years.
A total of 71.9% were positive for rheumatoid factor, as were 68.9% for anti-CCP antibodies.
Patients had previously received a median of three disease-modifying anti-rheumatic drug.