RESUMEN
The aim of the study was to identify and describe the patterns of use of tocilizumab in clinical practice to ensure safety and optimal management of rheumatoid arthritis (RA). This is a 12-month prospective observational study in patients with moderate or severe RA of ≥6 months' duration who have started tocilizumab after failure of at least one previous disease-modifying antirheumatic drug (DMARD) including TNF inhibitors. For some analyses, patients were categorized by the use of tocilizumab as monotherapy or in combination, and by previous use of biological therapy. Overall, 379 were evaluable (84.4 % received tocilizumab after prior biologics and 78.4 % in combination with classic DMARDs). Tocilizumab was discontinued in 68/379 (17.9 %) patients after a median of 6.7 (3.7-10.4) months, mainly due to a lack of efficacy (24/379, 6.3 %) and adverse events (23/379, 6.1 %). Of 131 temporary interruptions of tocilizumab required in 101/379 (26.6 %) patients, 81/131 (61.8 %) were related to adverse events, and in 120/131 (91.6 %) cases, tocilizumab was reintroduced at 8 mg/kg. Thirty-six tocilizumab dose reductions occurred in 34/379 (9 %) patients due to abnormal laboratory values in 20/34 (55.6 %) cases. DAS28-ESR scores decreased from baseline (5.6 ± 1.0) to week 24 (3.0 ± 1.4) and week 52 (2.7 ± 1.3). DAS28 response differed between biologics-naive and biologics-experienced patients, both at weeks 24 and 52. In clinical practice, tocilizumab is effective in RA while retaining the expected safety and tolerability profile. Tocilizumab seems to be more effective for biologics-naive patients than for biologics-experienced patients, while it proves to be similarly effective when used in combination or monotherapy.