Interruptions of biological and targeted synthetic disease-modifying antirheumatic drugs in rheumatoid arthritis: a descriptive cohort study assessing trends in patient characteristics in Switzerland.

To identify differing patient characteristics at the time of stop and restart of biological or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in rheumatoid arthritis (RA), stratified by stop reason. Explorative descriptive cohort study. Swiss Clinical Quality Management in Rheumatic Diseases (1999-2018). Patients with RA who stopped their first b/tsDMARD. We assessed patient characteristics at b/tsDMARD stop and restart, stratified by stop reason (non-response, adverse event, remission, other). Among 2526 eligible patients, most patients (38%) stopped their b/tsDMARD due to non-response. At treatment stop, most characteristics did not differ by stop reason, yet some differed significantly (p<0.0001, those stopping due to remission had lowest median Health Assessment Questionnaire measurements (0.1) and were least likely to use leflunomide combination therapy (3.9%) and to have fibromyalgia (6.7%)). The majority of patients restarted b/tsDMARDs without changes in patient characteristics at restart. However, among the 48% of patients who restarted a b/tsDMARD after having previously stopped due to remission or other reasons, disease activity measurements were significantly worse compared with treatment stop date (mean disease activity score-erythrocyte sedimentation rate score of 2.0 at b/tsDMARD restart vs 3.5 at treatment stop (p<0.0001)). Furthermore, we observed non-significant trends in several patient characteristics (eg, higher proportion of women (75% at b/tsDMARD restart vs 70% at treatment stop, p=0.38), patients with seropositivity (anti-citrullinated protein antibody positive 67% vs 58%, p=0.25), with family history of rheumatic diseases (24% vs 20%, p=0.15), osteoarthritis/arthroplasty (25% vs 20%, p=0.34) and the metabolic syndrome (11% vs 6%, p=0.15). Differences among patient characteristics across b/tsDMARD cessation strata were few. However, differences between stop and restart may have identified an RA phenotype that is challenging to treat. Further research ...