Effectiveness and safety of treat-to-target strategy for methotrexate-naïve rheumatoid arthritis patients >75 years of age

Abstract

Objectives: To identify differences in effectiveness and safety of a treat-to-target (T2T) strategy comparing late-onset MTX-naïve RA patients (LORA) ≥75 or <75 years of age. Methods: Treatment was adjusted to target low disease activity with conventional synthetic DMARDs followed by biologic DMARDs (bDMARDs) in LORA ≥75 years (n ¼ 98, mean age 80.0 years) and LORA <75 years (n ¼ 99) with moderate–high disease activity. Achievement of Simplified Disease Activity Index (SDAI) remission at week 156 by non-responder imputation analysis was evaluated as a primary outcome. Results: LORA ≥75 years had more comorbidities than LORA <75 years, but SDAI and ACPA positivity were similar at baseline. Of the LORA ≥75 years, 70.4% started MTX and 34.1% and 37.1% received a bDMARD at week 52 and 156, respectively (very similar to the LORA <75 years). Glucocorticoid use was more frequent in the LORA ≥75 years than in the LORA <75 years. Comorbidities/adverse events more frequently contributed to the reasons for non-adherence to T2T in the LORA ≥75 than in the LORA <75. At week 156, 32.7% of the LORA ≥75 and 66.7% of the LORA <75 achieved SDAI remission (P < 0.001). The cumulative incidence of serious adverse events (SAEs) over 156 weeks was 42.8% in the LORA ≥75 and 22.1% in the LORA <75. Multivariable analysis indicated an increased risk of SDAI non-remission at week 156 in the LORA ≥75 [odds ratio 2.82 (95% CI 1.29. 6.14)] after adjusting for comorbidities at baseline, non-adherence to T2T and SAEs. Conclusions: It was more difficult to achieve remission in the LORA ≥75 patients than in the LORA <75 patients due to both poor treatment response and safety issues. Lay Summary What does this mean for patients? The proportion of patients ≥75 years of age with rheumatoid arthritis (RA) is increasing. However, it is not known whether a standard treatment strategy with the goal of low disease activity (i.e. where your symptoms are under control) would be beneficial in people with late-onset RA. Late-onset RA is where people develop RA at >60 years of age. Our study investigated the effectiveness and safety of treatment in people ≥75 years of age with late-onset RA. We found that this age group had more comorbidities (i.e. where a person has more than one disease at the same time) than people ages 60–74 years. Comorbidities and other medical problems prevented optimal treatment in the ≥75 group more so than in the 60- to 74-year group. Despite similar disease activity when starting treatment, only 32.7% of the ≥75 group were in remission (i.e. had very few or no RA symptoms) after 3 years of treatment, compared with 66.7% of the 60- to 74-year age group. Serious medical problems were more common in the ≥75 group. Our findings suggest that a poorer response to treatment and a higher rate of serious medical problems make it more challenging for people ≥75 years of age to reach remission. We need to consider and address optimal treatment strategies for this group of people in the near future.