Background Biological therapy has changed the management of patients with inflammatory disease, but with a great increase of pharmaceutical costs and emergence of potential adverse effects. At the end of 2011 we established an internal protocol in management and dose optimization of the patients with biological treatment. Those patients with inflammatory disease who achieve remission by clinical and laboratory parameters and show no ecographic activity (arthritis, enthesitis), receive a reduction of dose. Patients with etanercept 50 mg sc. weekly reduce dose to 25 mg, and patients with adalimumab at a dose of 40 mg/2 weeks increase injection interval to 3 weeks. Thus we have achieved optimization of 20% in 2012, which is close to 40% at the end of 2013. Objectives To show that there is not a significant clinical or analytical worsening in our optimized patients, considering basal data at the time of optimization and six months later. Methods Retrospective analysis of data from clinical records and our database of 105 patients treated with etanercept and adalimumab, optimized from 2011, considering lab tests results (ESR, RCP), disease activity (DAS 28, BASDAI), functional capacity indexes (HAQ, BASFI), and GP E (global patient evaluation of the disease). We used SPSS 21.0 for statistical analysis. Results 105 patients (53 female and 52 male), 31% with rheumatoid arthritis (RA), 27,5% with ankylosing spondylitis (AS), 37,7% wiyh psoriatic arthritis (PA), and 3,8% juvenile idiopatic arthritis (JIA), most of them with a longstanding disease, with a mean of 152,47 months of evolution (18-638). Table 1 shows both, the basal findings and the results from six months later. Parameter Basal 6 Months later ESR 12,5 (1–64) 16,3 (1–52) RCP 0,23 (0,02–1,3) 0,43 (0,1–1,4) DAS28 2,04 (0,11–4,03) 2,51 (1,13–4,88) HAQ 0,5 (0–2) 0,5 (0–2) BASDAI 1,45 (0–9,2) 2,38 (0–7) BASFI 1,85 (0–9) 2,9 (0–9,5) EGP 21,03 (0–100) 27,07 (0–100) Furthermore, 32,4% of patients had a DAS 28 increase over 0,6, but in only 14,7% DAS 28 increase resulted over 1,2. BASDAI an BASFI increases >2 from basal occurred in 4,4% of patients. EGP increases >20 from baseline occurred in 15% of patients. Conclusions Our patients optimized with etanercept and adalimumab maintain remission criteria based on clinical and laboratory parameters at six months. So, optimization seems to be safe and cost effective in an important amount of patients with longstanding disease. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5931