Rheumatoid Arthritis Patients On Persistent Moderate Disease Activity On Biologics Have Adverse 5-years Outcome Compared To Persistent Low-remission Status Yet They Represent A Heterogeneous Group: Lower-moderate Has Better Functionality And Fewer Serious Adverse Events Than Higher-moderate Subgroup
Abstract Background The long-term outcome of rheumatoid arthritis (RA) patients who in clinical practice, exhibit persistent moderate disease activity (pMDA) despite treatment with biologics has not been adequately studied. Herein, we analyzed the 5-year outcome of the pMDA group and assessed for within-group heterogeneity. Methods We included longitudinally-monitored RA patients from the Hellenic Registry of Biologic Therapies with persistent (cumulative time ≥50% of a 5-year period) moderate (pMDA, 3.2<DAS28≤5.1) or remission/low (pRLDA, DAS28≤3.2) disease activity. The former was further classified into persistent lower-moderate (plMDA, DAS28<4.2) and higher-moderate (phMDA, DAS28≥4.2) subgroups. Five-year trajectories of functionality (HAQ) was the primary outcome in comparing pRLDA versus pMDA and assessing heterogeneity within the pMDA subgroups through multivariable mixed-effect regression. Results We identified 295 patients with pMDA and 90 patients with pRLDA, the former group comprising of plMDA (n=133, 45%) and phMDA (n=162, 55%). pMDA was associated with worse 5-year functionality trajectory than pRLDA (+0.27 HAQ units, CI 95% +0.22 to +0.33; p<0.0001), while the phMDA subgroup had worse 5-year functionality than plMDA (+0.26 HAQ units, CI 95% 0.18 to 0.36; p<0.0001). Importantly, higher persistent disease activity was associated with more serious adverse events (SAEs) [pRLDA: 0.2±0.48 vs pMDA: 0.5±0.96, p=0.006; plMDA: 0.32 ±0.6 vs phMDA: 0.64 ±1.16, p=0.038). Male gender (p=0.017), lower baseline DAS28 (p<0.001), HAQ improvement >0.22 (p=0.029) and lower average DAS28 during the first trimester since treatment initiation (p=0.001), independently predicted grouping into pRLDA. Conclusions In clinical practice, RA patients with pMDA while on bDMARDs have adverse long-term outcome compared to lower disease activity status, while heterogeneity exists within the pMDA group in terms of 5-year functionality and SAEs. Targeted studies to better characterize pMDA subgroups are needed, in order to assist clinicians in tailoring treatments.