A cross-sectional, non-interventional study was conducted in the Hospital General Universitario Gregorio Marañón (HGUGM) in Madrid (Spain), from October 2010 to October 2011. During the study period, patients receiving anti-TNF for a minimum period of 12 months, and attending per routine follow-up the Biological Therapy Unit at the Rheumatology Department, were subsequently included. Requirements included being diagnosed with RA, according to the American College of Rheumatology's (ACR) 1987 revised criteria,7 and treated with any of the following anti-TNF drugs: etanercept (ETN), adalimumab (ADA), or infliximab (IFX),administered either at standard or modified doses. Standard therapy was that in accordance with the approved prescribing information: ETN 25mg twice a week or 50mg weekly, ADA40mg every other week, and IFX 3mg/kg every 8 weeks. Modified therapy was either escalated (the time between doses was shorter or the doses were higher than the standard ones) or reduced (the time between doses was longer or the doses were lower than the standard ones). Dose tapering was adopted if the patient was in remission by DAS28 <2.6 or low activity <3.2 for those with very established and chronic disease for at least 1 year, based on a clinician and patient agreement, and not following any standardized protocol.

The variables studied were the percentage of patients treated with each drug (IFX, ADA, and ETN), the prescribed dosages, the distribution of patients in clinical categories according to the Disease Activity Score (DAS28):11 Remission (DAS28 <2.6); Low activity (DAS28: 2.6–3.2); Moderate activity (DAS28: 3.2–5.1); or High activity (DAS28 >5.1) in each treatment group, and the concomitant treatment with DMARDs: methotrexate (MTX), leflunomide (LF), sulfasalazine, andhydroxychloroquine.

The study was approved by the HGUGM Ethics Committee and all participants provided written informed consent.

Data was analyzed with the SPSS 17.0 statistical program. Continuous variables were described using mean and standard deviation (SD) or median and range. Categorical variables were described with frequencies and percentages. Statistical analyses including parametric and non-parametric tests in relation with variables distribution were performed comparing the 3 groups (ANOVA or Kruskal–Wallis test). Additional comparisons between IFX-ADA, IFX-ETN, and ETN-ADA groups were carried out using non-parametric or parametric tests (U Mann–Whitney, Chi square).

195 RA patients were included. Participants were predominantly women (79%) and the global mean age was 58.1 (±14.9) years. Patients were distributed into 3 groups, according to the anti-TNF drug used: 81 patients in the ETN group (41.5%), 56 in the ADA group (28.7%), and 58 in the IFX group (29.7%). Mean disease duration (years) was statistically different between groups (P=.01) although most patients (42.2%) had a mean disease duration between 10 and 20 years. In the 2–5 year range of duration, however, the percentage of patients in the ADA group was significantly higher when compared to ETN and IFX (P=.03). There were also significant differences between groups in terms of time from diagnosis to the administration of the first biological treatment. IFX was most commonly used as first-line biological treatment, whereas ETN was the option most commonly used as second-line.

Most patients in ETN (72.8%) and ADA (69.6%) groups were treated with the standard dosages. In the ETN group there were no patients in escalated doses while most patients in IFX had an escalated regimen (69%). The percentage of patients with reduced doses were 27.1% and 25% for both the ETN and ADA groups respectively, with less than 4% in the IFX group.

The distribution of patients in the ETN and ADA groups were similar, with most patients receiving the standard therapy, whereas in the IFX group there was a considerable proportion of patients with an escalated regimen. We found more than 60% of responders (DAS28 ≤3.2) in the ETN and ADA groups and less than 50% in the IFX one. Fig. 1 shows the distribution of responder and non-responder patients within the different treatment regimens (standard, escalated, and reduced) of the evaluated drugs. Both ETN (61.7%) and ADA (64.3%) groups had more responders than non-responders in any of the dosage regimens, even in the reduced one. On the other hand, the IFX group, despite having the higher number of patients in an escalated regimen, had globally less responders (48.3%), even at increased doses, where responders and non-responders were distributed at 50%. However, mean DAS28 value was similar for all anti-TNF (ETN: 2.8±1.5, ADA: 2.7±1.5,IFX: 3.3±1.5; P=.6). ETN patients, regardless of biologic line, were less likely to use concomitant DMARD than ADA or IFX patients. The drug more frequently used in association was methotrexate (MTX) followed by leflunomide (LEF).

Fig. 1.

Percentage of responders (DAS28 ≤3.2) and non-responders (DAS28 >3.2) in the different dosage regimens of anti-TNF treatments. ETN: etanercept; ADA; adalimumab; IFX: infliximab. Reduced (the time between doses was longer or the doses were lower than the standard ones). Standard (according to the approved prescribing information): ETN 25mg twice a week or 50mg weekly, ADA 40mg every other week, and IFX 3mg/kg every 8 weeks. Escalated (the time between doses was shorter or the doses were higher than the standard ones).

(0.12MB).

The authors declare that the procedures followed were in accordance with the regulations of the responsible Clinical Research Ethics Committee and in accordance with those of the World Medical Association and the Helsinki Declaration.

The authors declare that they have followed the protocols of their work centre on the publication of patient data and that all the patients included in the study have received sufficient information and have given their informed consent in writing to participate in that study.

The authors have obtained the informed consent of the patients and/or subjects mentioned in the article. The author for correspondence is in possession of this document.