Background The goal of optimisation is the individualisation of treatments, guaranteeing the lowest effective dose and an adequate safety profile, minimising associated costs. An optimisation strategy is to extend the dosing interval.

Purpose The main objective was to evaluate the optimisation of biological therapies and their associated cost savings.

Material and methods A retrospective, observational and descriptive study of the optimisation of biological therapies used in autoimmune digestive, dermatologic and rheumatic diseases during 1 year (2016) has been done.

The standard treatment regimen of these drugs are: etanercept 50 mg/weekly, adalimumab 40 mg/fortnightly, ustekimumab 45 mg/12 weeks, infliximab 5 mg/Kg/8 weeks, except in rheumatoid arthritis (RA), 3 mg/kg/8 weeks.

The cost saving achieved was calculated by comparing the total cost of doses administered in a year to the total cost of doses which would have been administered if the drug was not optimised. Doses adjusted by weight for infliximab were calculated for each patient.

Results During the study period, 276 patients were analysed. (39% inflammatory bowel disease (IBD), 27% RA, 19% ankylosing spondylitis (AS), 5% psoriatic arthritis (PA), 5% psoriaisand 5% other autoimmune diseases (OAD)). Fifty-five patients were optimised (20%).

From all optimised patients, optimisation according to diagnosis was: RA (44%), AS (22%), IBD (15%), PA (9%), psoriasis (5%) and OAD (5%).

The treatment optimisation regimen used were:

• Etanercept (49%): 50 mg/10 days (37%); 50 mg/fortnightly (29%); 50 mg/21 days (26%); 50 mg/monthly (4%); 50 mg/8 days (4%).

• Adalimumab (35%): 40 mg/21 days (58%); 40 mg/monthly (27%); 40 mg/18 days (5%); 40 mg/45 days (5%); 40 mg/56 days (5%).

• Ustekimumab (5%): 45 mg/16 weeks (67%); 45 mg/13 weeks (33%).

• Infliximab (11%): 5 mg/kg/10 weeks (50%); 5 mg/kg/11 weeks (33%); 5 mg/kg/12 weeks (17%).

A cost saving of €6 42 637 was achieved in 2016.

Conclusion A higher optimisation rate was found in RA. Etanercept was the most optimised drug. The most commonly used optimisation treatment regimen was adalimumab 40 mg/21 days. During the study period, optimised patients had disease remission. This strategy shows many advantages from the point of view of safety, life quality of patients and the saving in healthcare costs.

No conflict of interest