Rheumatoid arthritis (AR), psoriatic arthritis (PSA) and ankylosing spondylitis (AS) are autoimmune systemic diseases characterized by inflammation, pain and joint degeneration. The objective of this study is to evaluate, under the actual conditions of use, dosing patterns of adalimumab, etanercept, golimumab and infliximab in these pathologies, and compare them with the label regimens recommended, as well as evaluating the financial implications of these regimen modifications. The study population included all adult patients diagnosed with RA, PSA or AS who had been treated with adalimumab, etanercept, golimumab and infliximab for at least 6 months between 1 January 2011 and 31 December 2013. The main variable of this study was to assess the dose dispensed for drugs administered subcutaneously and the dose prepared/administered for drugs administered intravenously, and the annual costs of the treatment. A total of 5,428 episodes were included. The mean weekly dose was lower than the standard dose in the three pathologies studied in the patients treated with adalimumab and etanercept (84.3% vs 81.2% for RA, 85.0% vs 78.0% for PSA and 87.8% vs 81.6% for AS). The drugs with highest dose optimization in RA are etanercept (46.3%) followed by adalimumab (46%); however, the highest percentage of patients with major dose optimization corresponds to etanercept (11.6%). Both in the PA and the AS group, we also observed that etanercept is the drug more optimized, corresponding to 53.9 and 43% of patients, respectively. By contrast, 48.5% of patients with RA treated with infliximab required dose intensification; however, infliximab dose intensification in PSA and AS is not so pronounced. The practice of optimization of dose regimens in patients with rheumatic diseases under treatment with anti-TNFα is spreading among professionals, resulting in annual cost reduction in the treatment of rheumatic arthropathies. However, long term follow-up will be necessary to assess the influence of this optimization on health outcomes.
Keywords: adalimumab; ankylosing spondylitis; antirheumatic agents; cost; etanercept; golimumab; infliximab; psoriatic arthritis; real-world data; rheumatoid arthritis.