In 802 arthritis patients treated with INX for median >6 years, a nationwide non-medical switch to CT-P13 had no negative impact on disease activity. Adjusted 1-year CT-P13 retention rate was slightly lower than for INX in a historic cohort.

Objective. To investigate disease activity, treatment response, and drug survival, and predictors thereof, among Danish patients with psoriatic arthritis (PsA) receiving their first treatment series with a tumor necrosis factor ␣ (TNF␣) inhibitor. Results. Of 764 patients with PsA, 320 received adalimumab, 260 infliximab, and 184 etanercept. Median drug survival was 2.9 years, and 1-year and 2-year drug survival rates were 70% and 57%, respectively. Clinical parameters that showed improvement over 6 months were the C-reactive protein (CRP) level, Health Assessment Questionnaire score, and 28-joint Disease Activity Score. Male sex, CRP level >10 mg/liter, concomitant methotrexate use, and low patient health visual analog scale score at baseline were associated with longer drug survival. Improvement was achieved by 59%, 45%, 24%, and 54% of patients according to the ACR20, ACR50, ACR70 response criteria and EULAR good response, respectively. A CRP level >10 mg/liter was predictive of the improvement responses (odds ratio [OR] 2.6 for ACR20, OR 3.0 for ACR50, OR 3.6 for ACR70, and OR 2.2 for EULAR good response).Conclusion. In these patients with PsA treated with their first TNF␣ inhibitor in clinical practice, high drug adherence and responder rates were observed. Moreover, increased levels of CRP at baseline were associated with both good treatment responses and continued treatment, which may be of clinical value in selecting the patients most likely to benefit from treatment with TNF␣ inhibitors.

TNFα inhibitors provide a rapid and sustained decrease of disease activity among patients with AS in clinical practice. Factors associated with continued treatment, clinical response and achievement of a BASDAI <40 mm were identified.

AimsThe EuroMyositis Registry facilitates collaboration across the idiopathic inflammatory myopathy (IIM) research community. This inaugural report examines pooled Registry data.MethodsCross-sectional analysis of IIM cases from 11 countries was performed. Associations between clinical subtypes, extramuscular involvement, environmental exposures and medications were investigated.ResultsOf 3067 IIM cases, 69% were female. The most common IIM subtype was dermatomyositis (DM) (31%). Smoking was more frequent in connective tissue disease overlap cases (45%, OR 1.44, 95% CI 1.09 to 1.90, p=0.012). Smoking was associated with interstitial lung disease (ILD) (OR 1.32, 95% CI 1.06 to 1.65, p=0.013), dysphagia (OR 1.43, 95% CI 1.16 to 1.77, p=0.001), malignancy ever (OR 1.78, 95% CI 1.36 to 2.33, p<0.001) and cardiac involvement (OR 2.40, 95% CI 1.60 to 3.60, p<0.001).Dysphagia occurred in 39% and cardiac involvement in 9%; either occurrence was associated with higher Health Assessment Questionnaire (HAQ) scores (adjusted OR 1.79, 95% CI 1.43 to 2.23, p<0.001). HAQ scores were also higher in inclusion body myositis cases (adjusted OR 3.85, 95% CI 2.52 to 5.90, p<0.001). Malignancy (ever) occurred in 13%, most commonly in DM (20%, OR 2.06, 95% CI 1.65 to 2.57, p<0.001).ILD occurred in 30%, most frequently in antisynthetase syndrome (71%, OR 10.7, 95% CI 8.6 to 13.4, p<0.001). Rash characteristics differed between adult-onset and juvenile-onset DM cases (‘V’ sign: 56% DM vs 16% juvenile-DM, OR 0.16, 95% CI 0.07 to 0.36, p<0.001). Glucocorticoids were used in 98% of cases, methotrexate in 71% and azathioprine in 51%.ConclusionThis large multicentre cohort demonstrates the importance of extramuscular involvement in patients with IIM, its association with smoking and its influence on disease severity. Our findings emphasise that IIM is a multisystem inflammatory disease and will help inform prognosis and clinical management of patients.

ObjectivesReal-world evidence on effectiveness of switching to biosimila r etanercept is scarce. In Denmark, a nationwide guideline of mandatory switch from 50 mg originator (ETA) to biosimilar (SB4) etanercept was issued for patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (AxSpA) in 2016. Clinical characteristics and treatment outcomes were studied in ETA-treated patients, who switched to SB4 (switchers) or maintained ETA (non-switchers). Retention rates were compared with that of a historic cohort of ETA-treated patients. Switchers who resumed ETA treatment (back-switchers) were characterised.MethodsObservational cohort study based on the DANBIO registry. Treatment retention was explored by Kaplan-Meier plots and Cox regression (crude, adjusted).Results1621 (79%) of 2061 ETA-treated patients switched to SB4. Disease activity was unchanged 3 months’ preswitch/postswitch. Non-switchers often received 25 mg ETA (ETA 25 mg pens/syringes and powder solution were still available). One-year adjusted retention rates were: non-switchers: 77% (95% CI: 72% to 82%)/switchers: 83% (79% to 87%)/historic cohort: 90% (88% to 92%). Patients not in remission had lower retention rates than patients in remission, both in switchers (crude HR 1.7 (1.3 to 2.2)) and non-switchers (2.4 (1.7 to 3.6)). During follow-up, 120 patients (7% of switchers) back-switched to ETA. Back-switchers’ clinical characteristics were similar to switchers, and reasons for SB4 withdrawal were mainly subjective.ConclusionSeventy-nine per cent of patients switched from ETA to SB4. After 1 year, adjusted treatment retention rates were lower in switchers versus the historic ETA cohort, but higher than in non-switchers. Withdrawal was more common in patients not in remission. The results suggest that switch outcomes in routine care are affected by patient-related factors and non-specific drug effects.