Background/Purpose: Patients with Rheumatoid Arthritis (RA) who don’t respond to conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) should be treated with biologic agents(1). The objective of this analysis was to evaluate the impact of initiating a biologic agent early (after failure to 1 csDMARD) versus later (after failure to 2 csDMARDs).

Methods: RA patients starting their first biologic agent after enrollment in Corrona between May 2002 and July 2014 and with at least 1 year of follow-up in the registry were included in the analysis. Baseline characteristics of patients initiating a biologic agent after therapy with 1 vs 2 csDMARDs were compared. The second csDMARD could be added to the first csDMARD or substitute therapy with the first csDMARD. The two cohorts were matched using propensity score (PS). Disease activity and functionality outcomes were assessed at 1 year post biologic initiation among the matched groups. The rate of biologic drug changes in the first year after biologic initiation were evaluated among the matched groups. Time to initiation of biologic and time spent in moderate/high disease activity prior to biologic initiation were evaluated. Mixed logistics and mixed linear regression models were used to evaluate binary and continuous outcomes.

Results: A total of 1612 patients initiated their first biologic after therapy with 1 csDMARD (group 1) and 288 patients after therapy with 2 csDMARDs (group 2). Baseline characteristics at the time of the biologic initiation for group 1 (vs group 2) were: 75.4% females (vs 78.5%), age (mean ±SD) of 57.4±13.2 years (vs 57.5±12.3), Caucasian race 89.1% (vs 93.8%), disease duration 6.3± 8.4 (vs 6.9±7.3), baseline CDAI 19.9±14.0 (vs 19.4±13.2) seropositivity 81.8% (vs 78%).  After PS matching 288 patients remained in each group. Similar improvements in disease activity occurred in both groups after 1 year of follow up: 53.4% in group 1 vs. 49.3% in group 2 achieved LDA (p=0.4), mean (SD) CDAI change was 8.4 (13.2) in group 1 vs 7.1 (13.5) in group 2 (p=0.2) and mean (SD) HAQ change was 0.08 (0.36) in group 1 vs 0.06 (0.41) in group 2 (p=0.5). Switching to an alternate biologic occurred in 7.6% and 15.3% of patients in group 1 and 2, respectively, while 14.2% and 15.3% discontinued biologic therapy at 1 year (p=0.01). The time since initiation of the first csDMARD to initiation of the first biologic was 13.3 ±15.9 months for biologic initiators in group 1 vs 20.7±19.7 in group 2 (p<0.01). Time spent in moderate or high disease prior to initiation of the biologic agent was 8.1±10.8 months in group 1 vs 13.7±14.9 months in group 2.

Conclusion: Earlier initiation of a biologic agent was associated with a shorter period of time spent in moderate/high RA disease activity and a higher likelihood of remaining on the same biologic at 1 year after initiation.

References:

1. Singh et al. 2012. Update of the 2008 American College of Rheumatology (ACR) Recommendations for the use of Disease-Modifying Anti-Rheumatic Drugs and Biologics in the treatment of Rheumatoid Arthritis (RA). Arthritis Care Res (Hoboken). 2012 May; 64(5): 625–639

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-impact-of-biologic-agent-initiation-after-1-versus-2-prior-csdmards-in-patients-with-rheumatoid-arthritis/