WASHINGTON – Use of adalimumab in combination with another drug, usually methotrexate, seems to boost treatment response to such an extent that patients with rheumatoid arthritis can sometimes be tapered off one or both drugs over the subsequent 2 years.
Those are the findings of three separate posters that were based on data from the CORRONA (Consortium of Rheumatology Researchers of North America) registry – a multicenter, longitudinal, prospective database in the United States with more than 30,000 patients.
Dr. Daniel E. Furst
The studies were presented on Nov. 11 at the annual meeting of the American College of Rheumatology.
In the first study, led by Dr. Daniel E. Furst, Carl M. Pearson Professor of Medicine at the University of California, Los Angeles, the researchers looked at RA patients enrolled in CORRONA between March 2002 and September 2011 who initiated adalimumab treatment and had at least one follow-up visit on record.
The researchers assessed 417 patients with 2 years of follow-up, a mean age of 54.2 years, and a mean disease duration of 10.1 years; most (79.3%) were female.
Overall, 67% of patients were treated concurrently with methotrexate upon adalimumab initiation, but at 2 years, the odds ratio for concomitant methotrexate was 0.68 (95% confidence interval, 0.48-0.95; P = .05).
Patients with two or more comorbidities, including hypertension, cancer, chronic obstructive pulmonary disease, and diabetes, were even less likely to continue to need to take methotrexate (OR, 0.48; 95% CI, 0.29-0.80; P = .01).
"This suggests the clinical efficacy of adalimumab in RA disease control across a medically diverse patient population," noted Dr. Furst.
In a second, independent study from CORRONA, Dr. Allan Gibofsky, professor of medicine and public health at Cornell University and professor of law at Fordham University, both in New York, looked at 1,639 patients who initiated adalimumab therapy over the same time period and who had at least one follow-up visit on record.
Dr. Gibofsky found that 1,003 of these patients eventually discontinued adalimumab after a median of 632 days, according to a Kaplan-Meier estimate; 1,358 experienced some form of treatment change (including discontinuation, but also dosing/frequency changes or addition of another disease-modifying antirheumatic drug).
In this analysis, while use of a prior biologic was highly predictive of regimen change (hazard ratio, 1.532; CI, 1.259-1.864; P less than .0001), use of methotrexate at adalimumab initiation was associated with a significantly decreased likelihood of adalimumab treatment change (HR, 0.88; CI, 0.835-0.919; P less than .0001).
Finally, a third CORRONA-based study presented at the meeting confirmed that combination therapy with methotrexate and tumor necrosis factor–inhibitors like adalimumab is increasing.
Dr. Deborah Wenkert of Amgen Inc., based in Thousand Oaks, Calif., and her colleagues looked at the prevalence of combination therapy over two time periods: 2002-2004 and 2007-2009.
She found that the mean clinical disease activity index (CDAI) at initiation of combination therapy was significantly lower during the later time period, versus the earlier, and that "among all RA patients with 2 years of follow-up, a higher percentage of patients initiated combination therapy in 2007-2009 than 2002-2004 in each maximum CDAI category."
The trend could reflect "stricter definition and implementation of aggressive treatment goals in the later time periods," Dr. Wenkert added.
All investigators disclosed multiple relationships to pharmaceutical makers, including the makers of adalimumab.