Elderly-Onset Rheumatoid Arthritis DMARD Response Similar to Non-EORA Counterparts

The Clinical Disease Activity Index (CDAI) responses to biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) and the proportion of adverse events were comparable between patients with elderly-onset rheumatoid arthritis (EORA) and non-EORA, according to a study published in The Journal of Rheumatology.¹

Patients with EORA, defined as developing RA after 60, have different, and often more severe, disease characteristics when compared with younger-onset RA (YORA). However, the comparison between EORA and non-EORA patient groups is underexplored.

“Biological factors such as serological findings, organ function, and fragility differ between elderly vs younger patients,” explained investigators. “Therefore, comparing EORA patients with the same age group of patients with RA who have had a longer disease duration is as important as comparing patients with EORA and YORA.”

Investigators utilized data the FIRST registry to study a cohort of patients aged ≥ 60 years with RA who were receiving b/tsDMARDs. Those who had developed RA over the age of 60 were included in the EORA group, and patients under the age of 60 were categorized as non-EORA. Data were collected, such as demographics, disease characteristics, disease activity, functional status, and treatment. Initial follow-ups were conducted at 2, 22, and 54 weeks, and then yearly until discontinuation of therapy.

Data from a total of 1040 patients in the EORA cohort and 710 in the non-EORA group were analyzed. At baseline, age and high disease activity (HDA; CDAI > 22.0) were higher in the EORA group. However, during follow-up visits, low disease activity (LDA; CDAI ≤ 10.0) was similar between the 2 cohorts. By week 54, 41.9% (n = 436) patients in the EORA group and 38.9% (n = 276) patients in the non-EORA group chose to discontinue the trial. Reasons included less efficacy, infection, and adverse events.

After controlling for variables, which included sex, glucocorticoid (GC) usage, methotrexate (MTX) dose, and previous use of b/tsDMARDs, investigators determined EORA was not indicative of changes in CDAI scores over time. However, there was a definite correlation between GCs and higher CDAI scores. Patients who received MTX (1-10 mg/week) had lower scores when compared with nonusers. Health Assessment Questionnaire-Disability Index (HAQ-DI) analysis showed male sex, MTX, and EORA were associated with lower scores, while patients over the age of 70 receiving GC had higher scores.

There were no significant differences in the lack of efficacy in b/tsDMARDs as a reason for discontinuation in either group.

The ratios of infection and serious adverse events were calculated to determine the drug safety. In total, 16 patients dropped out due to infection, and 88 discontinued treatment due to serious adverse events. After controlling for variables, there were no differences between the 2 groups.

Three response patterns were identified using trajectory analysis of fluctuations in CDAI responses to b/tsDMARDs through 54 weeks. Group 1 was comprised of rapid responders with lower baseline CDAI scores and LDA weeks (EORA: n = 859, 83.0%; non-EORA: n = 572, 81.6%). Group 2 included the slower responders with higher baseline CDAI scores that continued to improve over the 54-week period (EORA: n = 75, 7.2%; non-EORA: n = 62, 8.8%). Group 3 was comprised of non-responders (EORA: n = 101, 9.8%; non-EORA: n = 67, 9.6%). Investigators determined percentages of patients in each group were similar between both patients with EORA and non-EORA.

The retrospective nature of the study is intrinsically limiting, as investigators had a finite amount of access to detailed patient data. Further, a few patients were treated with several different agents and comorbidities were not included. Lastly, the number of dropouts was small, which impacted the Cox regression analysis and created uncertainty as to whether this indicated an actual lack of difference or if the sample size was too small.

“The importance of early intervention for elderly patients with RA is underscored by the observation that multiple or widespread chronic pain may lead to declined activity and onset of disability among elderly people. Thus far, low doses of GC appear to be preferred in such situations,” concluded investigators. “However, GCs increase the risk of osteoporosis and pathological fracture, so they may also contribute to comorbidities among the elderly. In addition, GC use could increase the risk of poor treatment outcomes and serious infectious diseases. Therefore, when elderly patients are refractory to conventional therapy, introduction of a b/tsDMARD would be a treatment option that can be used to minimize GC doses.”

Reference:

Ochi S, Mizoguchi F, Nakano K, Tanaka Y. Similarity of Response to Biologics Between Elderly-onset Rheumatoid Arthritis (EORA) and Non-EORA Elderly Patients: From the FIRST Registry [published online ahead of print, 2021 Feb 15]. J Rheumatol. 2021;jrheum.201135. doi:10.3899/jrheum.201135