Background In the management of rheumatoid arthritis (RA) patients, the election of the drug and dosage needs to be personalized considering each particular subject conditions.
Objectives Assessclinical characteristics, disease activity and concomitant treatment in patients with RA treated with diverse anti-TNF dosage strategies. Estimate annual associated costs (2011).
Methods Cross-sectional study (2011) conducted at the Hospital Universitario Gregorio Marañόn Rheumatology Department. Inclusion criteria: patients diagnosed of RA (ACR 1987 revised criteria); attending routine follow-up visit; treated with anti-TNF: etanercept (ETN), adalimumab (ADA) or infliximab (IFX). Main variables were drug administered, dosage regimen, disease activity (DAS28) and concomitant treatment (DMARD). Anova test was using to compare groups. Doses where calculated based on percentage of dose, considering 100% the stardard dose in RA (ETN 50mg once weekly; ADA 40mg every other week; IFX 3 mg/kg/8 weeks). Escalated and reduced doses were defined as those higher and lower than standard doses respectively. Associated annual costs were estimated based on national pricing including tax.
Results The study evaluated 195 patients (79% women, mean age 58.1). The distribution by anti-TNF used was n: 81 ETN, N: 56 ADA and n: 58 IFX. There were significant differences between years to first biologic from diagnosis (IFX:7.5, ETAN: 5.7 and ADA: 5.9, p:0.03) and % of patients with previous biologic drugs (IFX:,12.7, ETN: 36.7, ADA: 29.7, p:0.04) Dose regimens and estimated costs are shown in the Table. Regarding disease activity, 61.73% and 64.29% of patients were good responders (DAS 28<3.2) in the ETN and ADA groups, versus 48.28% in the IFX but cross-sectional DAS28 value was similar between groups (ETN: 2.7±1.5, ADA: 2.6±1.5), IFX: 3.2±1.5, p=0.6). ETN patients were less likely to use concomitant DMARD (58.02% vs 66.07% in ADA vs 79.31% in IFX),
Conclusions Choosing a minimum effective dose is important to achieve the goal of effectiveness while reducing adverse events and costs. ETN seems to be associated with lower doses and less concomitant DMARDs while maintaining clinical control in RA patients.
Disclosure of Interest None Declared