VICTORIA, B.C. – Patients with rheumatoid arthritis who achieve remission on an agent targeting tumor necrosis factor have improvements in a variety of measures of resource use, activities of daily living, and employment, data have shown.
Investigators led by Dr. Cheryl Barnabe, a rheumatologist at the University of Calgary (Alta.), analyzed data from the Alberta Biologics Pharmacosurveillance Program for 1,315 patients with rheumatoid arthritis (RA) treated with a monoclonal antibody to tumor necrosis factor (TNF).
Dr, Cheryl Barnabe
"Even in this patient group with severe disease and long disease duration, 34% were able to achieve remission in their first year of anti-TNF therapy, and an additional 25% were able to achieve minimal disease activity," she reported at the annual meeting of the Canadian Rheumatology Association.
Compared with their counterparts who had continued moderate or high disease activity, these patients had roughly one-third to three-fourths reductions in rates of limitations of daily activities, hospitalization, and curtailed work hours, and in over-the-counter drug costs.
The group who improved to the point of having minimal disease activity on therapy also had comparatively better outcomes, although the differences were generally smaller.
"The patients who achieved remission had benefits over those who had only attained minimal disease activity, implicating that our treatment goal should be remission and not just minimal disease activity," Dr. Barnabe said.
The Alberta Biologics Pharmacosurveillance Program prospectively collected data on safety, efficacy, function, quality of life, and resource use among patients with RA treated with anti-TNF biologics between April 2004 and March 2011. Costs to the health care system were ascertained by linking to the provincial health care utilization database.
Patients’ clinical response was defined as remission, minimal disease activity, or moderate-to-high disease activity using established assessment tools. The investigators compared outcomes for patients in their first year of a first anti-TNF therapy.
On average, the patients were 42 years old at diagnosis and had had RA for 14 years, Dr. Barnabe reported. The median number of disease-modifying antirheumatic drugs they had received was three. Their mean 28-joint Disease Activity Score at treatment start was 5.93.
The anti-TNF agent administered was etanercept (Enbrel) in 55% of patients, infliximab (Remicade) in 22%, adalimumab (Humira) in 18%, golimumab (Simponi) in 4%, and certolizumab (Cimzia) in 1%.
Compared with other patients, those who achieved remission in the first year of therapy had lower measures of inflammation, disease activity, and pain at baseline, according to Dr. Barnabe. However, they were similar with respect to measures of resource use, activities of daily living, and employment.
The main results showed that relative to their counterparts who had continued moderate-to-high disease activity, patients achieving remission were significantly less likely to have had a recent hospitalization (5% vs. 8%), had lower monthly costs for over-the-counter drugs ($15 vs. $59), and were less likely to have been unable to do usual activities in the past month (28% vs. 52%), to have needed help from others with activities of daily living in the past month (18% vs. 39%), and to have had to reduce their work hours in the past 6 months because of poor health (2% vs. 7%).
Patients achieving minimal disease activity also fared better than those with continued moderate-to-high disease activity, although benefits were smaller, according to Dr. Barnabe.
The disease response groups were statistically indistinguishable with respect to some other outcomes, such as outpatient visits, diagnostic tests, the use of community services, missed days of work, and the need to stop work or retire early because of arthritis.
Dr. Barnabe disclosed financial relationships with Abbott, Amgen/Pfizer, Bristol-Myers Squibb, and UCB. The program had independent multisource industry funding between 2009 and 2012.