Biologics can be used effectively for both elderly-onset and young-onset RA patients

According to new research findings presented this week at the 2019 ACR/ARP Annual Meeting, both patients with rheumatoid arthritis whose disease onset occurred at an older age and those whose disease onset occurred earlier in life have similar improvements in clinical disease at 48 weeks after starting biologic disease-modifying antirheumatic drugs, as well as similar drug maintenance and adverse events discontinuation rates (Abstract #1345).

Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis and it is a chronic disease that causes joint pain, stiffness, swelling and decreased movement of the joints. Small joints in the hands and feet are most commonly affected. Sometimes RA can affect your organs, such as eyes, skin or lungs.

Patients with elderly-onset RA could present with higher disease activities and increased disabilities as compared to those with young-onset RA. Despite this, previous studies showed elderly patients receive biologics less frequently than younger individuals, suggesting patients with elderly-onset RA are potently undertreated. On the other hand, in our daily practice, we have seen many elderly-onset RA patients treated with biologics effectively and safely. We wanted to investigate if there are differences in efficacy and safety of biologics between the two age groups."

Sadao Jinno, MD, MSc, instructor of rheumatology at Kobe University School of Medicine and the study's lead author

Researchers in Japan conducted the study with 7,183 patients with RA who were age 18 or older and enrolled in a Japanese multicenter observational registry between September 2009 and December 2017. The patients also had to have a 3.2 or higher on the Disease Activity Score in 28 joints (DAS-28) and erythrocyte sedimentation rate measurement when they started biologics.

They assessed the relationship between age of RA onset and the clinical effectiveness of therapy at 48 weeks. The primary outcome for the study was a Clinical Disease Activity Index (CDAI) score at 48 weeks. Secondary outcomes included biologic retention at 48 weeks, achievement of a clinical disease activity index remission and low disease activity, or remission.

Among the patients on biologics, there were less in the elderly-onset RA group compared to the young-onset RA group. Of 989 patients who initiated biologics, 364 (37 percent) were elderly-onset. After adjusting for differences in baseline characteristics between the two age groups, researchers found no significant differences in the CDAI scores at 48 weeks. They did find a trend toward lower index remission rates in the elderly-onset group, but low disease activity/remission rates were similar between the two groups.

"Our findings showed there were no significant differences in Clinical Disease Activity Index scores at 48 weeks between elderly-onset and young-onset RA, suggesting biologics can be used for those with elderly-onset RA as effectively as for those with young-onset RA. We also found there was no difference of adverse event discontinuation rates between the two groups," says Dr. Jinno. "Clinicians should choose wisely which patients with elderly-onset RA are safely treated with biologics given that they are still at risk of developing adverse events, especially infections. Next, we plan to investigate if patients with elderly-onset RA respond differently to various modes of biologics."