Age of Onset Has Minimal Impact on Safety, Efficacy of Biologic DMARDs

Results of a new study suggest a patient’s age at on-set of rheumatoid arthritis(RA) has little impact on disease activity improvements offered by biologics.

Presented by Sadao Jinno, MD, MSc, instructor of rheumatology at Kobe University School of Medicine, at the 2019 American College of Rheumatology annual meeting in Atlanta, GA, the 7000-patient analysis revealed improvements in disease activity score in RA patients initiating biologic DMARDs was comparable between those with elderly-onset and early-onset RA.

“Essentially, patients with elderly-onset RA can be treated as effectively and safely as the young-onset RA patient… Elderly patients with RA should be treated, by and large, like the way the young-onset patients get treated,” Jinno said in a press conference at ACR 2019.

To evaluate the effect of age of RA onset and clinical effectiveness of bDMARDs at 48 weeks, investigators conducted a multicenter, observational study of 7183 patients with RA in Japan. All patients included in the analysis were 18 years of age or older, were required to have a 3.2 or higher on the DAS-28 scale, and have erythrocyte sedimentation rate measurement performed when they started biologics.

For the purpose of the study, investigators defined elderly-onset RA as RA with onset at 60 or older. Primary outcome measure of the study was Clinical Disease Activity Index (CDAI) score at 48 weeks. Secondary outcome measures for the study included biologic retention at 48 weeks, achievement of CDAI remission, and low disease activity or remission.

Investigators noted the use of a generalized estimating equation model with inverse probably of treatment weight to assess relationships between age at onset and clinical effectiveness at 48 weeks. Additionally, cox proportional hazards model was used to compare biologic retention rate.

Upon analyses, investigators observed the proportion of bDMARDs was lower in the elderly-onset group than the young-onset group(18.3% versus 28.0%, P<0.001). Of the 7183 patients included in the study, 989 were classified as bDMARD initiators—investigators pointed out the majority of these patients identified as elderly-onset RA(36.8%).

Adjusted analyses revealed no significant changes in CDAI score at 48 weeks between the two groups(1.01, 95% CI=-0.62-2.64, P=0.22). A trend of lower remission in the elderly-onset group(OR=0.52, 95% CI=0.24- 1.14, P=0.10) was noted, but investigators also pointed out the remission rate was similar between the 2 groups(OR=0.86, 95% CI=0.29-2.52, P=0.77). Additionally, drug maintenance rates and adverse event discontinuation rates were similar between both groups examined.

This study, “Biologics Offer Similar Disease Activity Improvement for Both Elderly-Onset and Young-Onset RA Patients,” was presented at ACR 2019 by Sadao Jinno, MD, MSc.