Characteristics at start of originator etanercept (ETN) or biosimilar SB4 according to biological treatment history
| ETN, n=2724 | SB4, n=2985 | ||||
| Bio-naïve | bDMARD experienced | Bio-naïve | Non-medical switch from ETN | bDMARD experienced | |
| No | 1124 | 1600 | 567 | 1537 | 880 |
| Baseline characteristics | |||||
| Female | 64.5% | 67.9% | 64.9% | 58.8% | 69.7% |
| Age, years | 53 (41–62) | 53 (42–62) | 53 (39–63) | 58 (47–68) | 55 (43–64) |
| Diagnosis | |||||
| RA | 53.6% | 51.2% | 60.9% | 55.5% | 58.2% |
| PsA | 27.3% | 20.8% | 15.3% | 22.3% | 14.8% |
| AxSpA | 19.0% | 28.1% | 23.8% | 22.2% | 27.1% |
| Treatment start year, % | |||||
| 2010–2013 | 92.7% | 77.9% | 0% | 0% | 0% |
| 2014–March 2016 | 7.3% | 22.1% | 0% | 0% | 0% |
| April 2016–February 2018 | 0% | 0% | 100% | 100% | 100% |
| Disease duration, years | 3 (1–9) | 7 (2–14) | 3 (1–9) | 12 (8–20) | 6 (3–13) |
| Concomitant medication use | |||||
| Concomitant MT (oral or s.c.)* | 49.5% | 45.8% | 42.3% | 48.9% | 43.4% |
| Recent NSAID prescription† | 38.9% | 43.8% | 42.2% | 37.9% | 47.2% |
| Recent paracetamol prescription† | 35.2% | 41.9% | 35.3% | 48.4% | 32.4% |
| Recent corticosteroid prescription† | 36.9% | 32.4% | 39.0% | 13.8% | 35.2% |
| Prior hepatobiliary comorbidity | |||||
| Hospitalisations, 0–5 years‡ | 2.9% | 3.0% | 2.3% | 3.6% | 4.0% |
| Other prior comorbidities | |||||
| Hypertension | 27.1% | 27.5% | 25.8% | 31.8% | 28.1% |
| Diabetes | 6.9% | 5.2% | 6.0% | 8.1% | 6.5% |
| Dyslipidaemia | 13.8% | 15.2% | 13.2% | 18.1% | 16.2% |
| Coronary artery disease | 5.7% | 6.1% | 4.9% | 8.5% | 6.4% |
| Hypothyreodism | 9.7% | 11.2% | 9.2% | 12.4% | 12.6% |
| Alcohol abuse | 0.4% | 0.4% | 0.5% | 0.3% | 0.2% |
| Hepatobiliary events during 6 months of follow-up | |||||
| Person-years (PYs) of follow-up | 484.0 | 645.0 | 249.1 | 713.3 | 370.7 |
| Hospitalised or outpatient | |||||
| No of events | 9 | 17 | 6 | 4 | 11 |
| No of events, RA/PsA/AxSpA | 5/1/3 | 6/4/7 | 4/0/2 | 3/0/1 | 7/1/3 |
| Crude IR/100 PY (95% CI) | 1.86 (0.64 to 3.07) | 2.64 (1.38 to 3.89) | 2.41 (0.48 to 4.34) | 0.56 (0.01 to 1.11) | 2.97 (1.21 to 4.72) |
| Adjusted IR§ (95% CI) | 1.90 (0.66 to 3.13) | 2.61 (1.37 to 3.84) | 2.42 (0.48 to 4.36) | 0.56 (0.01 to 1.11) | 3.01 (1.23 to 4.79) |
| Hospitalised | |||||
| No of events | 3 | 9 | 4 | 2 | 3 |
| No of events, RA/PsA/AxSpA | 1/0/2 | 4/2/3 | 2/0/2 | 1/0/1 | 2/0/1 |
| Crude IR/100 PY (95% CI) | 0.62 (0 to 1.32) | 1.40 (0.48 to 2.31) | 1.61 (0.03 to 3.18) | 0.28 (0 to 0.67) | 0.81 (0 to 1.73) |
| Adjusted IR§ (95% CI) | 0.62 (0 to 1.32) | 1.37 (0.48 to 2.27) | 1.63 (0.03 to 3.22) | 0.28 (0 to 0.67) | 0.81 (0 to 1.72) |
Patient subcohorts according to current (prior) bDMARD treatment: ETN (bDMARD-naive, bDMARD-experienced) and SB4 (bDMARD-naive, non-medical switch from ETN, bDMARD-experienced). Non-medical switchers were defined as the subcohort of SB4 treated bDMARD experienced patients with immediate prior ETN (0–90 days previously).
Numbers are medians (IQR) unless otherwise stated. Individual patients could contribute to more than one treatment group. For ETN and SB4, only the first treatment course was included if a patient had >1 treatment course with the same drug. Treatment start until 1 February 2018 was allowed, all data were censored 10 August 2018. Data were complete for all variables. £30 days before until 6 days after treatment start.
Hospital contacts (hospitalised, out-patient) due to hepatobiliary events during 6 months’ follow-up are also shown.
*Current use at baseline date according to DANBIO.
†≥1 prescription in NPDR 0–1 years prior to baseline.
‡Hospitalisation in DNPR 0–5 years prior to baseline.
§Standardised for gender and age (age categories 18–45/46–60/61–95 years).
AxSpA, axial spondyloarthritis; bDMARD, biological disease-modifying antirheumatic drug; DNPR, Danish National Patient Registry; ETN, originator etanercept; IR, incidence rate; MTX, methotrexate; NPDR, National Prescription Drug Registry; NSAID, non-steroid anti-inflammatory drug; PsA, psoriatic arthritis; RA, rheumatoid arthritis; SB4, biosimilar etanercept.